#emc | Logs for 2009-04-17

[00:01:11] <SkinnYPuP> http://www.metalsontheweb.co.uk/ ?
[00:01:33] <eric_unterhausen> now we're talking
[00:07:33] <SkinnYPuP> eric_unterhausen, http://business.shop.ebay.co.uk/items/Metalworking-Milling-Welding__stainless-steel_W0QQ_catrefZ1QQ_flnZ1QQ_npmvZ3QQ_sacatZ11804QQ_trksidZp3286Q2ec0Q2em282
[00:08:14] <eric_unterhausen> I never think of ebay for metals
[00:08:35] <SkinnYPuP> I get some boxes of 12l14 sometimes
[00:08:54] <SkinnYPuP> brass "weights" sometimes sell dirt cheap
[00:23:55] <willburrrr2003> Thanks to all the input I have gotten from you fine folks on here, I finished drawing up the schematics for the control panel on my minilathe cnc conversion and can start building it tomorrow ....wooohooo
[00:27:53] <willburrrr2003> I have realtime monitoring for my limit and home switches, and plc control through the modbus connection to provide (spindle start/stop, vacuum, worklight,oil for cutting,cooling fan control for controller card)
[00:29:08] <willburrrr2003> Does EMC2 still let you design your own interface layouts for your machine?
[00:29:40] <eric_unterhausen> I don't think it ever did in the way I think you mean
[00:30:17] <willburrrr2003> There was an editor, for adding indicator lights, and readouts, and push buttons to click on and such
[00:30:35] <willburrrr2003> Designing your on screen for your controller kinda stuff
[00:30:47] <willburrrr2003> Own* not on
[00:30:48] <eric_unterhausen> that sounds mach-ish
[00:31:01] <eric_unterhausen> there is pyvcp
[00:33:35] <willburrrr2003> yes it was VCP that I had read about , and pyvcp is what is recommended to use but not until v 2.2 released and 2.1 is only one available just found it in docs
[00:34:56] <willburrrr2003> With it I can add on screen controls to operate all the items being controlled through modbus connection to my PLC
[00:35:16] <willburrrr2003> and then tie all the logic together in hal and classicladder
[00:35:45] <willburrrr2003> I just couldn't remember what it was called , thanks for jogging the old memory hehe
[00:36:10] <eric_unterhausen> good thing I didn't mention vi then :)
[00:36:29] <willburrrr2003> I though vi was just a test editor?
[00:36:36] <willburrrr2003> er... text
[00:36:44] <eric_unterhausen> yeah, you can use it to change anything in emc :)
[00:37:04] <willburrrr2003> including buttons and readouts and such on scren?
[00:37:10] <eric_unterhausen> yup
[00:37:18] <willburrrr2003> wow good to know
[00:37:19] <eric_unterhausen> just have to know what you are doing ...
[00:37:32] <willburrrr2003> I have been learning loads on this project
[00:37:40] <willburrrr2003> and lots left to learn
[00:39:47] <willburrrr2003> I just found out a few weeks ago that I could get modbus support in classicladder, and just learned how do do modbus with a PLC...and was given one from going to the class.... so I decided to add it to my cnc project
[01:26:11] <|dareposte|> hi all
[01:27:40] <toastyde1th> srs
[01:39:27] <LawrenceG> hmmm... internet went black for a couple of hours....
[01:40:50] <LawrenceG> probably one of those terrorist Canadian Geese nesting on the microwave tower
[01:41:46] <jmkasunich> LawrenceG: http://www.ohiogeesecontrol.com/
[01:42:55] <LawrenceG> hey, too bad the coastal ones taste like mud!
[01:43:43] <LawrenceG> the grain feed ones from the prairies are quite tasty
[01:48:26] <toastyde1th> somebody needs to install a CIWS near those microwave towers
[01:48:28] <LawrenceG> jmkasunich, do you have a lot down by you?.... they take over the golf courses here... you need cleats (not because of the wet gras)
[01:49:38] <LawrenceG> http://www.youtube.com/watch?v=cP6GpAnmAPU like these?
[01:50:57] <LawrenceG> my Dad used to shot scotch mints at them with a sling shot from his deck!
[01:51:45] <toastyde1th> yes, exactly those
[01:51:50] <toastyde1th> also apparently they're fully autonomous
[01:51:56] <toastyde1th> nobody has to clear them to open fire, they just do
[01:52:04] <toastyde1th> and sometimes, they mistake other ships for things like missiles
[01:52:50] <LawrenceG> if they modify the software for slower moving targets it might fix the pirate problem off Somalia
[01:53:08] <toastyde1th> that IS adjustable
[01:53:14] <toastyde1th> the minimum inbound velocity
[01:53:59] <LawrenceG> nothing like 1000 rounds through the hull to let you know you are not welcome
[01:54:39] <toastyde1th> "hey that thing is shooting at us"
[01:54:44] <toastyde1th> "we must be hauling ass"
[01:55:08] <|dareposte|> i wonder if they make one for garbage cans too
[01:55:18] <|dareposte|> raccoons or possums are always getting in them
[01:55:53] <LawrenceG> could be useful for preventing red light runners
[01:56:16] <|dareposte|> permanently..
[01:57:10] <LawrenceG> the funniest thing I saw was a skunk raiding a garbage can..... I so wanted to sneak out and slam the lid back on
[01:57:14] <toastyde1th> it might fire at the light itself
[01:57:44] <toastyde1th> i do like the racoon idea though.
[01:58:03] <|dareposte|> i have my eye one one of these for the problem: http://www.airgundepot.com/gamo-whisper.html
[01:58:27] <toastyde1th> lol
[01:58:35] <|dareposte|> i shot a possum with my bow and arrow out of the 2nd story window last year, but wound up putting a hole in the trash can and garage door as well
[01:58:41] <toastyde1th> then motion tracking and a little platform
[01:58:45] <toastyde1th> and pew pew pew
[01:58:47] <toastyde1th> lasers
[01:58:51] <|dareposte|> where's optic
[01:59:11] <|dareposte|> they have a laser that would work great
[02:02:32] <|dareposte|> i wonder how many watts are required to fry through a thick skinned o'possum
[02:03:19] <|dareposte|> more importantly, i wonder if the co2 tank i got for tapping my keg can also be used for cooling a laser??
[02:03:23] <toastyde1th> i propose we don't need to know how many watts are required, because any respectable death ray constructor will rather as, "how irresponsibly powered can i make this" instead
[02:03:27] <toastyde1th> *ask
[02:03:51] <|dareposte|> i have a 400A feed to my garage, is that enough??
[02:03:56] <toastyde1th> no
[02:04:00] <toastyde1th> run extension cables
[02:04:01] <|dareposte|> dang
[02:04:04] <toastyde1th> to your neighbors
[02:04:08] <toastyde1th> or i guess a chemical laser
[02:04:10] <toastyde1th> pew pew pew
[02:04:18] <|dareposte|> maybe just run a 6-0 cable back from the pole pig
[02:04:37] <toastyde1th> there you go
[02:04:44] <toastyde1th> they have 4-0 for like 1.50 a foot
[02:04:46] <toastyde1th> at home depot
[02:07:08] <|dareposte|> hm according to my reference, 4-0 is only good for 475 amps.
[02:07:18] <|dareposte|> for an air-cooled cable
[02:08:48] <toastyde1th> well i mean at 1.50 a foot we can afford a lot of it
[02:09:06] <toastyde1th> compared to some of the smaller gauges which cost even more
[02:09:34] <|dareposte|> yeah run one per phase i guess
[02:09:58] <|dareposte|> 100kw is a big laser
[02:11:30] <|dareposte|> i bet it would take a big chiller to keep it from melting, too
[02:11:40] <|dareposte|> 1.50 a foot's not bad for that size cable I guess
[02:12:51] <|dareposte|> the most powerful laser known to civillians right now is 25kw, made by boeing
[02:13:22] <|dareposte|> according to this completely unchecked internet fly-by-night source
[02:13:39] <|dareposte|> As the press release says, it "will damage, disable or destroy targets at the speed of light, with little to no collateral damage, supporting missions on the battlefield and in urban operations." Hit the jump for the full release.
[02:13:42] <toastyde1th> nif
[02:13:59] <toastyde1th> no, there's a 80kw laser for combat
[02:14:01] <toastyde1th> but it's hard mounted
[02:14:04] <toastyde1th> it's not mobile
[02:14:17] <toastyde1th> and i don't think they fire it anymore because it costs so much
[02:14:30] <toastyde1th> prototype etc
[02:14:33] <|dareposte|> yeah
[02:15:23] <|dareposte|> i guess the power density's just not there
[02:15:33] <toastyde1th> it was there, it was just too damn big
[02:15:37] <|dareposte|> to make it really practical, i mean
[02:15:43] <toastyde1th> "cool, we can burn a damn hole in damn anything"
[02:15:45] <|dareposte|> 100kw is hard to come by on a battlefield
[02:15:47] <toastyde1th> "great, how do we get it there"
[02:15:49] <toastyde1th> "i dunno"
[02:16:37] <toastyde1th> big lasers are so cool
[02:16:45] <toastyde1th> i'm a little disappointed they don't make bright flashes and stuff
[02:16:49] <toastyde1th> like you see in Freespace 2
[02:17:13] <|dareposte|> speed of light and all
[02:17:22] <toastyde1th> yeah
[02:17:29] <toastyde1th> what's up with that, raining on all our collective parades
[02:17:47] <fenn> no scattering atmosphere in space
[02:17:48] <|dareposte|> if they had big lasers, we would probably have to chrome plate our tanks
[02:17:58] <fenn> you dont shoot a tank with a laser
[02:19:03] <fenn> toastyde1th: plasma cannons would create the sort of fancy effect you're thinking of
[02:19:12] <SWPadnos> A big enough laser could disable a tank, but you'd probably have to aim at the tracks
[02:19:13] <toastyde1th> yeah, we need to get on that
[02:19:19] <fenn> er, plasmak i mean
[02:20:14] <toastyde1th> i wonder how far that guy with the open source cruise missle got
[02:21:01] <|dareposte|> i think he got shut down or scared underground
[02:21:18] <|dareposte|> i think he underestimated the complexities of guided flight somewhat though
[02:21:30] <toastyde1th> awww
[02:21:48] <|dareposte|> can you build a missile-like object that flies in the direction you want? yah that's cake
[02:21:52] <|dareposte|> given time and money
[02:22:30] <toastyde1th> i can supply the bearings for the gyro!
[02:22:46] <|dareposte|> those mems gyros would probably be sufficient
[02:23:18] <toastyde1th> actually in a twist of irony I have built bearings for a replacement guidence system for an ICBM
[02:23:32] <toastyde1th> only once though
[02:23:39] <SWPadnos> http://www.popsci.com/bacon
[02:23:53] <fenn> chunky bacon?
[02:24:41] <fenn> I used prosciutto (Italian for "expensive bacon") because it is a superior engineering grade of meat.
[02:24:54] <fenn> obviously this guy is just a dilettante
[02:25:00] <SWPadnos> heh
[02:25:09] <SWPadnos> but he did cut a pan in half with bacon and oxygen
[02:27:12] <|dareposte|> what a great word
[02:28:07] <|dareposte|> toasty: how big is the gyro in an icbm?
[02:31:49] <toastyde1th> this was a friggin large gyro
[02:32:03] <toastyde1th> i've seen two, one was tiny, a 3" sphere in the peacekeeper
[02:32:13] <toastyde1th> this was a 15" sphere with 32 bearings
[02:32:32] <toastyde1th> i have also made bearings for 3" spheres, that came out much better
[02:32:49] <fenn> at that point you might as well just use a laser gyro, (or even better an acoustic gyro)
[02:32:50] <toastyde1th> nobody would let me do the 15" bearings properly, and we didn't get the contract because they couldn't handle the weight
[02:33:16] <fenn> http://www.abominablefirebug.com/AcousticGyro.html
[02:33:22] <toastyde1th> fenn: they wouldn't tell us why they were using this
[02:33:36] <toastyde1th> but the bearing had to have a specific surface capacetence, the real gyro had instrumentation IN it
[02:33:37] <eric_unterhausen> because they didn't want to pay to redesign
[02:33:38] <fenn> "because it looks cool" isnt good enough?
[02:34:04] <toastyde1th> so i assume they couldn't use a laser ring gyro because there's some other system that goes inside the gyro that has to remain static
[02:34:21] <toastyde1th> 15" hollow sphere, weighs about 150 lbs
[02:34:37] <eric_unterhausen> you may be assuming too much intelligence in the decisionmaking
[02:34:44] <toastyde1th> that is entirely plausable
[02:35:17] <eric_unterhausen> I probably met some of the people involved now that I think of it
[02:37:31] <toastyde1th> it was really cool
[02:37:39] <toastyde1th> i was very upset that nobody wanted to do it right
[02:37:45] <toastyde1th> we'd have made a TON of money on those things
[02:37:59] <toastyde1th> and there's a lot of astrophysics applications for that style bearing, and very few people make them
[02:38:24] <eric_unterhausen> probably fewer right now
[02:38:33] <toastyde1th> definately
[02:39:02] <toastyde1th> i met a couple guys who used to make gyros like that, they're all retired/in nursing homes
[02:39:05] <eric_unterhausen> good news is my friend that got laid off got a new job, bad news is not making bearings
[02:39:17] <toastyde1th> what's he doing now?
[02:39:35] <eric_unterhausen> something to do with ocean measurements
[02:44:01] <|dareposte|> what type of bearing did the gyro use? ball bearings??
[02:46:33] <toastyde1th> |dareposte|: air bearings
[02:46:41] <toastyde1th> spherical air bearings
[02:46:58] <|dareposte|> oh neat
[02:47:08] <|dareposte|> i want to see one..
[02:47:09] <toastyde1th> i wish i had taken pictures
[02:47:45] <toastyde1th> Zygo bought some to calibrate white light interferometers
[02:47:51] <toastyde1th> Lockheed Martin bought some for... god knows what
[02:48:07] <toastyde1th> and then there was that set of 32 for the guidence gyro
[02:48:15] <toastyde1th> if they ever come up again i will
[02:50:29] <|dareposte|> spherical air bearings... i have a hard time picturing that
[02:50:40] <toastyde1th> it's just a cup
[02:50:45] <toastyde1th> hemispherical cup
[02:51:23] <toastyde1th> we use porous media, so there's nothing to look at, just a polished surface
[02:52:15] <|dareposte|> how does it constrain the bearing?
[02:52:29] <toastyde1th> http://www.youtube.com/watch?v=0ELZcDLtlLI
[02:52:31] <toastyde1th> it doesn't
[02:52:34] <toastyde1th> the ball just floats
[02:53:04] <toastyde1th> that thingy is supported on the spherical bearing in the center of the rig, obviously
[02:54:19] <toastyde1th> but that's all it is, it's just a cup, there's no constraint
[02:54:19] <|dareposte|> so if this was used in a fighter jet that did all kinds of weird maneuvers, it wouldn't really hold it so well
[02:54:22] <toastyde1th> unless the bearing is preloaded with another opposing bearing, or with vacuum
[02:54:45] <toastyde1th> well in missles and stuff you have a set of these bearings, all opposed
[02:54:55] <|dareposte|> oh
[02:55:00] <|dareposte|> that makes sense
[02:55:09] <toastyde1th> or under vacuum, which is freaky
[02:55:15] <toastyde1th> because you can put the test ball in the bearing and turn it on
[02:55:19] <toastyde1th> and move it any way you please
[02:55:22] <toastyde1th> and it maintains orientation
[02:55:33] <toastyde1th> even upside down
[02:56:38] <toastyde1th> and when you spin it, it just goes and goes and goes
[02:56:48] <toastyde1th> when the bearing is clean there's only a little bit of drag
[02:56:58] <toastyde1th> and with a good push it'll go for about 20 minutes
[02:58:01] <eric_unterhausen> I'm tearing apart a dover air bearing for fun
[02:58:01] <Valen> I believe they dont use the FOG's because they weren't around when most of the ICBM stuff was made
[02:58:04] <toastyde1th> and here is a big damn bearing that is at our shop right now
[02:58:10] <toastyde1th> http://www.youtube.com/watch?v=jSMMiy41jSw
[02:58:23] <Valen> also for long term integration mechanical have fewer integration and quantisation issues
[02:58:24] <toastyde1th> this goes in a siemens CT scanner, at 400 rpm with a 1/2 ton ring
[02:58:53] <Valen> the MEMS gyros are only OK for about 10 minutes of integration, at the end of that they will be out by a few degrees
[02:59:39] <Valen> mix MEMS with GPS updates and your set though
[03:00:25] <|dareposte|> i wondered about those mems
[03:00:52] <Valen> they are great but suffer from a fair bit of drift
[03:01:21] <Valen> ROFL that bearing is insane
[03:01:31] <toastyde1th> it goes SO FAST
[03:01:37] <toastyde1th> like, holy crap
[03:06:21] <|dareposte|> whats the air consumption like on one of those?
[03:06:46] <toastyde1th> the really big ring i don't know
[03:07:17] <toastyde1th> but more reasonable bearings are 5-15 cubic feet per hour
[03:07:20] <toastyde1th> at 60 psi
[03:07:56] <|dareposte|> not too bad
[03:08:08] <|dareposte|> i guess there is some sort of seal on it then?
[03:08:12] <toastyde1th> ?
[03:08:17] <toastyde1th> no?
[03:08:22] <toastyde1th> that's the no-load, open air flow
[03:09:11] <Valen> whats the $ like?
[03:10:08] <toastyde1th> the cheapest bearings we have are like 25mm diameter plane bearings, 160 bucks or so
[03:10:27] <toastyde1th> most customers buy something in the 300-700 range
[03:10:32] <Valen> they an air bearing still?
[03:10:38] <toastyde1th> yeah
[03:10:40] <toastyde1th> that's all we make
[03:10:47] <Valen> whats the application for them?
[03:10:49] <Valen> typically
[03:11:27] <toastyde1th> depends on the type of bearing, we have no idea what people use our plane bearings for
[03:11:32] <toastyde1th> CMMs and other such
[03:11:41] <Valen> CMMs?
[03:11:46] <toastyde1th> coordinate measuring machines?
[03:11:52] <Valen> funky
[03:12:00] <toastyde1th> high precision robots for semiconductor handling
[03:12:07] <toastyde1th> semicon is a lot of our customer base
[03:12:19] <toastyde1th> we used to make a ring bearing for a company that made wafer inspection machines
[03:12:54] <Valen> funky stuff
[03:13:09] <toastyde1th> yeh
[03:13:17] <toastyde1th> we also make full slide assemblies for machine tools
[03:13:23] <toastyde1th> diamond turning lathes primarily
[03:13:28] <Valen> what sort of load and sizes
[03:13:36] <Valen> mega mega $ i assume though
[03:14:00] <toastyde1th> a full assembly for a 21" slide is like 20k
[03:14:14] <toastyde1th> we made a pair of 4 foot slides once, they were 125k each
[03:14:29] <Valen> ok lol a bit out of my price range ;->
[03:14:37] <toastyde1th> well that's because we make the stuff?
[03:14:42] <toastyde1th> we'd RATHER customers make their own slides
[03:14:45] <toastyde1th> and just buy the 500 dollar bearings
[03:14:53] <toastyde1th> to put in it
[03:14:56] <Valen> thats more plausable
[03:15:15] <Valen> Hard to make precision slides though
[03:15:19] <toastyde1th> exactly
[03:15:26] <toastyde1th> it's annoying as balls
[03:15:32] <Valen> lol
[03:15:34] <toastyde1th> so much grinding
[03:15:57] <toastyde1th> but they do work on scraped ways
[03:16:12] <toastyde1th> so if someone wanted to, they could scrape a slideway and drop air bearings on top of it
[03:16:33] <|dareposte|> how do the air bearings perform under load, as far as accuracy
[03:16:49] <toastyde1th> pretty well, the gap does close down
[03:16:51] <|dareposte|> CMM's don't see much load variation
[03:17:04] <|dareposte|> what's a typical gap though?
[03:17:06] <toastyde1th> but the variance in gap is insigifigant compared to the bending of the machine frame
[03:17:07] <Valen> I think what we are asking is, would they work on a mill ;->
[03:17:10] <toastyde1th> .0002"
[03:17:14] <toastyde1th> oh, of course they'd work on a mill
[03:17:18] <toastyde1th> the gap changes by millionths
[03:17:42] <|dareposte|> so then i presume the slide has to be accurate to that level too?
[03:17:49] <toastyde1th> nope, that's just what the gap is
[03:17:58] <toastyde1th> the bearing will follow the average height of the slide
[03:18:10] <Valen> mmm hover craft
[03:18:14] <toastyde1th> they work on glass panels and stuff
[03:18:28] <|dareposte|> so could you throw down some cheap extruded i-beam accurate to 0.002, and set a bearing on it and get it to function well?
[03:18:41] <SWPadnos> .0002
[03:18:47] <toastyde1th> if the beam really was flat to .002 all over it, it would work
[03:19:06] <toastyde1th> it's stuff like sharp edges, blending problems, etc that will cause problems
[03:19:12] <toastyde1th> a slow undulation in the surface is not a problem
[03:19:13] <Valen> It'd have to be aligned in all the other dimensions as well
[03:19:35] <Valen> hmm I wonder about making a "way grinder"
[03:19:42] <Valen> laser guided
[03:19:46] <|dareposte|> so why not make the slides out of super easy to machine material then, since there is probably very little wear
[03:20:02] <toastyde1th> that's why we make out slides mostly out of aluminum.
[03:20:14] <toastyde1th> downside: very thermally sensitive.
[03:20:23] <toastyde1th> so we also have to offer steel slides.
[03:20:50] <toastyde1th> and when you consider that most of the cost is in grinding, and that aluminum is harder to grind than steel
[03:20:55] <toastyde1th> the price difference is not so great
[03:21:20] <Valen> I wonder if you could machine it rather than grind
[03:21:35] <toastyde1th> not without a very expensive planer
[03:22:03] <Valen> well you don't need hardned bedways ;->
[03:22:12] <toastyde1th> the issue isn't hardness
[03:22:26] <Valen> so you should be able to machine it to at least as good an accuracy as you can mill stuff?
[03:22:42] <Valen> It'd be a B grade slide but you could do it cheap cheap
[03:22:46] <toastyde1th> it's ensuring that five different surfaces are all within .0002 parallelism and .00005 flatness
[03:23:01] <toastyde1th> who is going to buy a cheap air bearing slide?
[03:23:09] <toastyde1th> "cheap" is still going to be 10-15k
[03:23:22] <Valen> I was thinking of just making a cutter with all 5 surfaces driven
[03:23:30] <Valen> so 5 cutters
[03:23:44] <Valen> all inside one big cast iron "doovey"
[03:24:12] <toastyde1th> where are you going to hold the part from?
[03:24:22] <Valen> mount it on the slide its making
[03:24:23] <toastyde1th> the only surface that isn't getting ground are the ends
[03:24:41] <Valen> articulate the head and laser guide it
[03:24:51] <toastyde1th> what's the slide mounted to?
[03:25:21] <Valen> Hadn't got that far
[03:25:43] <toastyde1th> by doing one side at at time we can make adjustments in angle and taper
[03:25:51] <Valen> I presume some kind of table, It isn't that important
[03:25:59] <Valen> what adjustments do you need to make?
[03:26:09] <toastyde1th> say one end of the machine is hotter than the other.
[03:26:11] <toastyde1th> for whatever reason
[03:26:17] <toastyde1th> maybe the sun was beating on it
[03:26:27] <toastyde1th> that side is now going to be .0003-.0004 bigger than the other end of the machine
[03:26:33] <toastyde1th> and will put a taper in the part in that direction.
[03:26:49] <toastyde1th> so the part has to be taken out of alignment by .0003-.0004 to compensate.
[03:27:08] <toastyde1th> then the day progresses and the ambient temperature changes, and the edges of the machine start to shrink but the center has enough thermal mass to lag
[03:27:12] <toastyde1th> so now it's barreled
[03:27:19] <Valen> you would have to know that before doing it though
[03:27:34] <toastyde1th> right, and that's why the machines that could do that cost a couple million dollars
[03:27:48] <Valen> ahh I see what your saying, you are adjusting to take out variances in the machine
[03:27:53] <Valen> not in the part
[03:27:56] <toastyde1th> right
[03:28:05] <toastyde1th> but also in the part!
[03:28:08] <toastyde1th> because we have to handle the part
[03:28:10] <Valen> so if the part is hot when you cut it you still have a problem
[03:28:25] <toastyde1th> well the part tends to settle thermally faster than the machine does
[03:28:34] <toastyde1th> but you still have to dust it and see where it is
[03:28:35] <toastyde1th> then adjust
[03:28:36] <toastyde1th> then dust
[03:28:38] <toastyde1th> then adjust
[03:28:44] <toastyde1th> and on ad nauseum
[03:28:52] <toastyde1th> four hours later, you have one surface done.
[03:28:55] <Valen> What if you just grabbed the end of the slide
[03:29:05] <Valen> then pushed the laser guided cutter down it
[03:29:13] <Valen> doing all surfaces in one pass?
[03:29:27] <toastyde1th> what happens when one end of the interferometer heats up, and bends?
[03:29:39] <toastyde1th> and now there's a bow in the part we can't take out because the interferometer thinks it's straight?
[03:29:52] <Valen> I wasn't using an interferomiter sideways
[03:30:05] <Valen> run your laser from the end along the path
[03:30:24] <toastyde1th> but that's no better than just having a blind machine?
[03:30:25] <Valen> use a CCD sensor and some fancy maths to determine the position
[03:30:50] <Valen> so you can measure the deviation from the beam and correct for it
[03:30:52] <toastyde1th> i'm not aware of any scanner of that type that will get the accuracy we need, but even if there was - the ccd and laser still have to mount in some way
[03:31:19] <toastyde1th> so even if you have a laser scanner that can measure ten millionths of an inch
[03:31:40] <toastyde1th> it's just resolution, not necessarily accuracy
[03:31:52] <Valen> If you wanted to you could mount the sensor itself onto the same bearing block as the cutter
[03:32:18] <toastyde1th> where's the external reference?
[03:32:26] <Valen> I came up with the idea for our gantry mill to line up the ways
[03:32:38] <Valen> this is the "budget" version
[03:32:50] <Valen> get a laser pointer, shine it down the way
[03:33:05] <Valen> get a web cam and take the lens off
[03:33:13] <Valen> mount the web cam to the slide
[03:33:21] <Valen> shine the laser at the bare CCD chip
[03:34:10] <Valen> as the slide moves down the way look at where the laser is striking the chip, because its going to be going over lots of edges you will be able to do maths on it and very accuratly determine the center of the beam
[03:34:40] <Valen> adjust the mounts for the slide such that the laser strikes the same part of the CCD at each point
[03:34:53] <Valen> when your done you have a slide thats as straight as a laser
[03:35:33] <toastyde1th> i like your optimism, but i assure you the slides are not going to be as straight as you think they are
[03:35:55] <Valen> what are the error sources?
[03:36:23] <toastyde1th> the air, vibration, misalignment in device, the resolution of the device
[03:36:55] <Valen> air motion is canceled out through integration same for vibration
[03:37:08] <toastyde1th> uh, air defocuses the laser
[03:37:27] <toastyde1th> which is the limit when you're using an autocollomater or a tilt interferometer
[03:38:00] <Valen> not a problem because the laser is going to hit a whole bunch of cells in the CCD, then the magic software looks for the center of that hit point
[03:38:05] <toastyde1th> i'm sure you can get a decent alignment using your method, but I'd really suggest you try it and get someone to verify your result
[03:38:24] <toastyde1th> i've seen a lot of people's ideas of "high precision" in diy stuff, and it's almost always crap
[03:38:29] <toastyde1th> hence my apprehension to the idea.
[03:38:34] <Valen> provided the laser spot is all inside the CCD face you should be able to get an accurate center
[03:38:41] <toastyde1th> "should be"
[03:38:59] <Valen> well It seems to work with astronomy stuff ;->
[03:39:04] <SWPadnos> um. is the laser supposed to mounted on the slide as well?
[03:39:33] <toastyde1th> what in astronomy uses that system?
[03:39:34] <Valen> SWPadnos, could be, like i said its just something i have been thinking about
[03:39:44] <SWPadnos> oh, I see. you attempt to align the laser beam with the way, and move the sensor along the way
[03:40:00] <Valen> not the system but integrating noisy signals to get decent photos
[03:41:00] <toastyde1th> photography and trying to align a bedway to .0002" are very different things, i might point out
[03:41:29] <SWPadnos> .0002" is many pixels on an image sensor
[03:41:58] <toastyde1th> sure, but even tilt interferometers, which measure angular displacement to tenths of a second of arc
[03:42:01] <toastyde1th> have problems doing it
[03:42:26] <Valen> they are using a different method though
[03:42:30] <toastyde1th> yes, they are
[03:42:48] <toastyde1th> but you see the accuracy they can get
[03:42:50] <Valen> they are sensitive to loosing phase lock due to vibration etc
[03:43:01] <toastyde1th> okay, but they're getting that accuracy
[03:43:11] <toastyde1th> and it's STILL wrong
[03:43:25] <toastyde1th> versus a method of unknown accuracy
[03:43:32] <Valen> how do they come up with the accuracy in the first place?
[03:43:42] <toastyde1th> of which
[03:43:46] <toastyde1th> the interferometer?
[03:43:57] <toastyde1th> or the way, or what
[03:44:00] <Valen> of the reference beam
[03:44:37] <Valen> how do you make a "straight beam" from first principles?
[03:44:37] <toastyde1th> the laser wavelength is stabalized in a very narrow band of frequencies
[03:44:53] <toastyde1th> there's no reference beam in an interferometer?
[03:45:00] <toastyde1th> or are we talking about the bedway
[03:45:06] <SWPadnos> on earth, a beam of light is probably straight enough for anyone but CERN and the like
[03:45:06] <Valen> bedway sorry
[03:45:23] <SWPadnos> oh, that kind of beam :)
[03:45:38] <toastyde1th> without any external references, then you're going to have to make a set of straightedges
[03:45:41] <SWPadnos> you grind them, three at a time
[03:45:41] <toastyde1th> from autogeneration
[03:46:15] <Valen> See that just seemed like a pain in the ass to me in this day of $5 laser pointers ;->
[03:46:18] <SWPadnos> label them A B and C, you test A:B, B:C, and C:A with prussian blue or similar
[03:46:43] <SWPadnos> you'll get flatness to the resolution of your marking solution
[03:46:45] <toastyde1th> i'm not saying it doesn't or won't work
[03:46:46] <Valen> It also seems like a very difficult thing to do for large beams
[03:46:59] <SWPadnos> yes, it's difficult
[03:47:01] <toastyde1th> well they don't do that for large beams, they only use the surface to provide spotting
[03:47:22] <toastyde1th> not as a flatness reference
[03:47:33] <SWPadnos> thinking about the webcam idea, I think I wouldn't remove the lens
[03:47:53] <SWPadnos> I might zoom it as far toward telephoto as possible though
[03:48:16] <Valen> The thing with the lens though is its going to make the spot size smaller
[03:48:23] <SWPadnos> yes, it will
[03:48:24] <toastyde1th> at that point you are three steps and a jump away from an autocollomator
[03:48:38] <Valen> which is a bad thing,
[03:49:00] <Valen> you find the center of the beam by looking at pixels it crosses and the ratio between them
[03:49:01] <SWPadnos> yes and no. you're actually testing several things when you move the slide around
[03:49:13] <SWPadnos> height and two rotations come to mind
[03:49:22] <SWPadnos> also skew (tilt)
[03:49:27] <SWPadnos> actually two tilts
[03:49:32] <Valen> I was planning on using multiple sensors to check those things
[03:49:35] <SWPadnos> err, I guess those are the rotations :)
[03:50:31] <SWPadnos> one sensor is multiple sensors, that's why you use a webcam instead of a photodiode
[03:50:55] <Valen> The objective is for a 5mm x 5mm sensor with 300K CCD pixels in it is to have the laser occupy about a 4mm circle
[03:51:24] <Valen> so you then have about 1000 or so pixels that are "half covered" by the beam
[03:51:30] <Valen> IE not saturated
[03:51:47] <Valen> you they give you accuracy to about .1 of a pixel size
[03:52:20] <Valen> integrate that over 30 frames or so to null out random noise and you get a position
[03:52:35] <SWPadnos> sort of
[03:52:58] <SWPadnos> what removing the lens does is make it so the beam can come from more or less any angle and still illuminate the same pixels
[03:52:59] <Valen> your going to get a better position than looking at 20 or 30 pixels in an image
[03:53:15] <SWPadnos> leaving the lens on will give you better localization of where the beam came from
[03:53:27] <Valen> hence using multiple sensors to measure that rotation
[03:54:27] <SWPadnos> uh. the laser beam hits exactly one of the sensors (most likely), how would you plan to use more than one?
[03:54:36] <Valen> multiple lasers
[03:54:39] <SWPadnos> ah
[03:55:03] <Valen> at $5 a pop its not a big investment ;->
[03:55:15] <Valen> probably need some better optics in front of them though
[03:55:23] <Valen> or better software to ignore the noise
[03:55:26] <SWPadnos> so you'd need more edge space around the expected beam area, since you need to measure relative displacement
[03:55:39] <Valen> 1MM should suffice i'd imagine
[03:55:51] <SWPadnos> could be
[03:56:15] <Valen> assuming you start off with all your lasers lined up
[03:56:27] <toastyde1th> how does it reference the other way
[03:56:30] <SWPadnos> yeah. that's a trick too :)
[03:56:32] <Valen> I hereby patent this method as "the Anderson method" ;->
[03:56:47] <Valen> toastyde1th: how do you mean?
[03:57:04] <SWPadnos> if you have two ways, this only makes each straight. it doesn't make them parallel
[03:57:10] <toastyde1th> ^^^ this.
[03:57:14] <ds3> how bad of a flat is a frozen pool of soapy water?
[03:57:17] <Valen> Ahh that is also taken care of
[03:57:37] <Valen> off your now perfect slide (see how easy that was)
[03:57:42] <toastyde1th> ds3: pretty bad, there's a way to level a whole machine using a trough of water
[03:57:47] <toastyde1th> but it's from like, 1930
[03:57:54] <toastyde1th> so unfreeze the water
[03:57:57] <toastyde1th> and you're set =)
[03:58:00] <ds3> toastyde1th: what makes it so bad?
[03:58:13] <toastyde1th> measure it
[03:58:18] <ds3> I was hoping the soap would reduce the surface tension
[03:58:18] <toastyde1th> you've got an unknown reference.
[03:58:23] <Valen> you shine a laser (or set thereof) across the bed, bounce it off mirrors on the other slide and back to sensors on the origional way
[03:58:29] <toastyde1th> it doesn't freeze all at once
[03:58:34] <ds3> ah
[03:58:42] <toastyde1th> valen: how are you aligning the mirrors
[03:58:48] <Valen> you dont need to
[03:58:59] <ds3> people have been saying to use float glass as a poor man's surface table
[03:59:14] <Valen> you have your lasers such that they bounce at angles off the other side
[03:59:29] <toastyde1th> any arbitrary angel?
[03:59:57] <toastyde1th> *angle
[03:59:57] <Valen> yep
[03:59:57] <Valen> you just put the sensor where it hits
[04:00:04] <Valen> or more likley adjust the mirror so it hits the sensor
[04:01:02] <Valen> you don't have to use the mirrors, you can just laser straight across to sensors, its just the mirror will double the error you measure so its a somewhat free accuracy gain
[04:01:23] <toastyde1th> i'm not seeing this at all
[04:01:30] <toastyde1th> but that's okay.
[04:01:43] <toastyde1th> go do it, check it for accuracy using an accepted (and cheap) method, and if it works, sell it.
[04:02:01] <Valen> ok constrain the error you wish to measure to make it simple
[04:02:20] <Valen> lets say we want to make the 2 slides the same distance apart
[04:02:30] <toastyde1th> sure.
[04:02:40] <Valen> the slides a ~1m apart and running from left to right
[04:02:46] <toastyde1th> sure.
[04:03:52] <slick-> hola
[04:03:52] <Valen> from the left hand end of the carrage on the reference slide you shine a laser across to the unknown and bounce it back such that it hits the right hand end of the carrage
[04:04:08] <Valen> your sensor is at the point where its hitting the right hand end of the carrage
[04:04:12] <toastyde1th> kay
[04:04:46] <Valen> as the carrage on the other side moves closer to the reference carrage the spot will move towards the left hand end of the sensor
[04:04:49] <Valen> and vice versa
[04:05:03] <toastyde1th> what?
[04:05:18] <toastyde1th> i don't get it man, don't worry about it
[04:05:25] <Valen> ok you have a laser beam going like /\ that
[04:06:03] <toastyde1th> hokay
[04:06:11] <Valen> as the from one carrage to the other, as the carrages get closer you see how the distance between where the laser leaves on one side and where it comes back gets closer
[04:06:12] <toastyde1th> but where are these carriages
[04:06:23] <Valen> one is on the "reference" slide
[04:06:28] <Valen> the other is the unknown slide
[04:06:32] <toastyde1th> what reference?
[04:06:42] <toastyde1th> oh, the one you're trying to match
[04:06:43] <toastyde1th> okay
[04:06:44] <Valen> the one we made with our first laser system,
[04:07:04] <toastyde1th> how are you moving these in sync
[04:07:37] <Valen> I came up with this for a gantry style mill so you just drive the gantry down the way
[04:07:45] <Valen> or you drive both sides independantly
[04:07:51] <Valen> doesn't really matter
[04:08:08] <toastyde1th> and how is this isolating the one error you want from all the other errors
[04:08:20] <Valen> in the "real" one you use other lasers to measure all 6 degrees of freedom
[04:08:43] <Valen> basically the same system in other axes
[04:11:21] <Valen> I'm interested to hear if anybody can see where errors will be introduced?
[04:11:35] <Valen> I can see heating of the carrage moving the sensors causing a problem
[04:11:41] <SWPadnos> any time you move anything, you have the potential to introduce errors
[04:11:45] <toastyde1th> i think you are being overoptimistic about the resolution of your sensor
[04:11:45] <Valen> but its a pretty dense lump of iron
[04:11:53] <toastyde1th> the initial alignment
[04:11:59] <toastyde1th> seperation of different errors
[04:12:12] <SWPadnos> I don't see how reflecting a beam off one spot on one beam will hemp you align another beam
[04:12:20] <SWPadnos> help
[04:12:30] <toastyde1th> for instance, when i put a level on a bedway, i know exactly what it is measuring and i only get one component of error
[04:12:49] <toastyde1th> your system is measuring multiple errors simultaniously, which is usually considered A Bad Thing (tm) in the ultraprecision community
[04:13:06] <toastyde1th> when i put an autocollomator on a bedway, it measures just one thing
[04:13:13] <toastyde1th> a kingway alignment rig, just one thing
[04:13:22] <toastyde1th> a refrence flat - just one thing.
[04:13:23] <ds3> what is an autocollomatar?
[04:13:37] <Valen> yes but all those things are running off an external reference
[04:14:02] <toastyde1th> autocollomators are defocusing telescopes that watch a collomated beam of light
[04:14:07] <toastyde1th> as it reflects off a mirror
[04:14:09] <toastyde1th> it measures tilt
[04:14:24] <Valen> I am trying to use light as the reference
[04:14:38] <Valen> it being considered generally "straight" ;->
[04:14:49] <toastyde1th> right, autocollomators don't rely on ANY reference
[04:15:04] <toastyde1th> they're gauges, they don't have an absolute reference
[04:15:18] <Valen> true
[04:15:27] <toastyde1th> and they only measure ONE thing
[04:15:36] <SWPadnos> the beam of light will be straight enough, but the relationship of the sensor to the beam of light is dependent on several things
[04:15:49] <Valen> well actually when you get right down to it they are using light as the reference still
[04:15:54] <toastyde1th> valen: they'ren ot
[04:15:55] <toastyde1th> *not
[04:16:04] <SWPadnos> wheels/balls may introduce a cyclic error
[04:16:27] <Valen> they are measuring the distance between one side and another of the mirror surface?
[04:16:31] <SWPadnos> if there's a bump on the otherwise flat way, the carriage will tilt
[04:16:34] <toastyde1th> valen: no
[04:16:41] <Valen> so how do they work?
[04:16:59] <toastyde1th> they watch the change in angle of the reflected light
[04:17:28] <toastyde1th> you set it up, call one spot "zero" arbitrarily, and then as you move the mirror around and sight it with the scope, you get different tilts with repsect to your initial spot
[04:17:51] <Valen> ahh so basially the same as my "alignment" rig
[04:18:14] <toastyde1th> what happens if i move your rig straight up?
[04:18:17] <toastyde1th> no tolt
[04:18:19] <toastyde1th> *tilt
[04:18:33] <toastyde1th> with an autocollomator, nothing happens
[04:18:38] <Valen> the other sensor/laser combo picks it up
[04:18:40] <toastyde1th> which is what you want
[04:18:48] <toastyde1th> because you're not measuring vertical displacement
[04:19:01] <Valen> nothing will happen with the straight across distance meter
[04:19:16] <Valen> unless you make it such that it does
[04:19:17] <toastyde1th> you wouldn't use an autocollomator for that application
[04:19:26] <toastyde1th> it's for making individual ways or surfaces flat
[04:19:31] <Valen> you can though
[04:19:47] <toastyde1th> no, you can't, because autocollmators don't measure distances
[04:19:49] <toastyde1th> only tilt
[04:20:25] <toastyde1th> no displacement, no distance, only angle
[04:20:47] <Valen> what happens with your Autocollimator as you move it closer or further from the target surface?
[04:20:51] <toastyde1th> nothing.
[04:21:01] <toastyde1th> (given a flat surface)
[04:22:36] <Valen> I'm trying to find out how they work now
[04:22:39] <toastyde1th> it's a telescope with an internal, collimated light source that bounces off a mirror at some distance, and reflects back
[04:22:51] <toastyde1th> so you get this dot at zero on your crosshairs
[04:23:02] <toastyde1th> that's the beam the collimator is making
[04:23:12] <toastyde1th> it bounces off a reference mirror that you're free to move around
[04:23:39] <fenn> Valen: we were going to do more or less the same laser beam method to check for straightness and coplanarity of ways on a CNC router
[04:23:57] <toastyde1th> when the beam comes back, it makes a second dot on the telescope crosshairs
[04:24:09] <toastyde1th> the vertical displacement of that second dot relative to the first is your angluar error
[04:24:32] <toastyde1th> horizontal displacement is just error in how accurately the mirror is aligned back up with the scope
[04:24:40] <Valen> Yeah i think i see how it works, its beacuse its using a lens that the distance error is cancled out
[04:24:57] <toastyde1th> the lens is a collomating lens, it's not a lens for optics.
[04:25:08] <Valen> you look through it dont you?
[04:25:15] <toastyde1th> you do, but yout don't get an image
[04:25:22] <toastyde1th> because the light is focused at infinity
[04:25:31] <toastyde1th> you just get the two dots
[04:26:44] <toastyde1th> so it is completely unresponsive to distance
[04:26:49] <toastyde1th> because there's no focal point
[04:26:58] <toastyde1th> the only problem that comes in is air currents
[04:27:07] <toastyde1th> which are the major source of error.
[04:28:12] <Valen> If you had a camera hooked up to it though you could see it averaging out the position over time no?
[04:28:23] <Valen> fenn got any more info on your app?
[04:29:11] <toastyde1th> valen: that's the "auto" part, yeah
[04:29:30] <toastyde1th> uses a photodiode to give you a readout on a gauge
[04:29:47] <fenn> Valen: no, not really
[04:30:07] <Valen> it a commercial or hobby thing?
[04:30:15] <fenn> uh, does it matter?
[04:30:23] <fenn> it's a DIY thing
[04:30:38] <fenn> not super duper precision like toasty is after
[04:31:27] <toastyde1th> pew pew pew laser accuracy
[04:32:55] <Valen> must use green lasers
[04:33:03] <Valen> they are 4x cooler than red ones
[04:34:27] <toastyde1th> agreed
[04:34:42] <Valen> oh yeah toastyde1th you mentioned getting it checked somehow by a "cheap" method?
[04:34:46] <Valen> what was that?
[04:35:05] <toastyde1th> gotta find a machine level and build a kingway alignment tool
[04:35:38] <toastyde1th> the level will tell you the height errors of the ways, and also the relative height differences between the two ways
[04:35:52] <toastyde1th> then the kingway alignment thing tells you the distance between the two ways.
[04:36:10] <Valen> I meant the cheap way to see if you had made a straight way
[04:36:17] <toastyde1th> that is how you do it?
[04:36:27] <toastyde1th> a level and a homemade rig + indicator
[04:36:36] <toastyde1th> that is as cheaply a way i know how to align ways
[04:36:58] <Valen> i meant to make one "straight" in the first place?
[04:37:01] <tomp> beware that iron surface plate, is it really a lapping plate ? lotsa grooves in rectangular grid ( handy to have but not suited to inspection )
[04:37:03] <toastyde1th> a level!
[04:37:17] <toastyde1th> and scraper and straightedge, if you plan on modifying how straight it is
[04:37:25] <Valen> level tells you straight from side to side?
[04:37:44] <tomp> straight is not level, straight is not bendy
[04:38:12] <tomp> use a reference to see straight, like a scrapers edge and 2 dowel pins
[04:38:20] <toastyde1th> tomp: that doesn't work over long distances
[04:38:26] <toastyde1th> which is why they use levels and shorter straightedges
[04:38:27] <tomp> lay laser if long
[04:38:44] <toastyde1th> sorry, my boss does large machine tool alignment, and he uses levels for long machine ways
[04:38:50] <tomp> hmm, mechanically? how long
[04:38:50] <toastyde1th> long as in 200-600" boring mills
[04:39:26] <tomp> ok, a few meters, my 5meter ways
[04:40:03] <toastyde1th> all you have to do to measure the height error is just note the starting position of the level
[04:40:06] <toastyde1th> move it 8"
[04:40:10] <tomp> still id use a laser and retroreflector mounted on a bearing tractor
[04:40:11] <toastyde1th> note again
[04:40:13] <toastyde1th> move it, 8"
[04:40:16] <toastyde1th> move it again, 8"
[04:40:21] <toastyde1th> until it's down the whole way
[04:40:52] <toastyde1th> if the level read the same inclination the whole way down, you've got a straight way
[04:41:08] <toastyde1th> if it changed inclination with reference to the initial position, the way has errors in it
[04:41:16] <Valen> how do you correct for errors perpindicular to gravity though?
[04:41:30] <toastyde1th> valen: like Z?
[04:41:32] <tomp> use ways shorter than kilometers ;)
[04:41:42] <toastyde1th> you're talking about Z axis alignment?
[04:41:46] <Valen> perpindicular means at right angles
[04:42:06] <toastyde1th> right which had me confused because the ways are perpindicular to gravity
[04:42:14] <toastyde1th> which is inherently what a level is measuring?
[04:42:25] <fenn> i think he means the sides of the way (if it's horizontal)
[04:42:40] <Valen> right, how do you measure the error in the non up and down axis
[04:42:50] <tomp> 'down is where your feet are " ( skateboarder truism)
[04:42:56] <Valen> lol
[04:43:24] <tomp> Valen: the 'wiggly' ?
[04:43:29] <Valen> yes
[04:43:34] <toastyde1th> valen: i have no idea what error you're referencing
[04:43:35] <Valen> the technical term for it
[04:43:45] <fenn> toastyde1th: say you have a box way
[04:43:49] <toastyde1th> sure
[04:43:51] <fenn> there's a top and two sides
[04:43:55] <toastyde1th> yep
[04:44:02] <fenn> how to check the straightness of the sides
[04:44:06] <toastyde1th> you don't
[04:44:09] <toastyde1th> they're never straight
[04:44:11] <tomp> need a reference ( a laser or a straight edge) its comarative ( there is no difference between a duck , you need 2 )
[04:44:18] <fenn> that's dumb, the whole point is for them to be straight
[04:44:20] <toastyde1th> they're fitted to the carriage
[04:44:30] <Valen> so how do you make a straight cut?
[04:44:31] <toastyde1th> oh, you meant all the way down
[04:44:39] <fenn> i mean along the axis
[04:44:39] <toastyde1th> that's where the kingway thing i mentioned earlier comes in
[04:44:56] <fenn> and what is a kingway
[04:45:02] <toastyde1th> so like, you've checked the differential level down the axis, and across
[04:45:11] <Valen> that just makes sure they are aligned to each other no?
[04:45:12] <toastyde1th> so you know both ways are straight, and the same height
[04:45:28] <fenn> you know the top surface is flat
[04:45:32] <toastyde1th> the kingway alignment tool is a 3-point gantry
[04:46:23] <toastyde1th> two points sit on one of the ways, and the other is on a hinge sitting on the other way surface.
[04:46:44] <toastyde1th> there's an indicator measuring the hinge's position, just a normal DTI
[04:47:11] <toastyde1th> as you push the 2 point side down the way, the hinge follows the other way surface and the variation shows up on your indicator.
[04:47:12] <Valen> yeah thats still only making the ways parallel not nesicarily straight?
[04:47:36] <tomp> top parallel,motion along it not necc straight
[04:48:13] <toastyde1th> hmm, you're right
[04:48:15] <tomp> i can drive down trhe street with my head travelling parallel to the ground, but weaving like a sob
[04:48:25] <toastyde1th> i'm forgetting one of the measurements
[04:48:42] <tomp> the order... flat straight othagonal
[04:48:54] <Valen> I spose you could perhaps do something where it looks at its own way
[04:49:14] <Valen> and if it measures a diflection from infront to behind itself then its wonky
[04:49:17] <fenn> * fenn mumbles something about magnetic fields and compasses
[04:49:27] <tomp> the suspected thing is not a good reference
[04:49:38] <toastyde1th> i've got machine tool reconditioning out, give me a second to see if i can find the part about that
[04:50:05] <Valen> It seems ok if you are adjusting it to match a null
[04:50:19] <Valen> you use the tool to give you zero error
[04:51:10] <fenn> stretched wire + capacitive probe :)
[04:51:16] <Valen> lol
[04:51:24] <Valen> I like my laser system better ;-P
[04:51:28] <fenn> ok
[04:51:42] <fenn> i like checking with multiple systems
[04:51:47] <toastyde1th> connelly's saying to just use the straight edges
[04:51:50] <tomp> look at it with a reference, hold a stright edge up along side and look for daylight, thats how you were taught to check straight, now expand that to a long problem
[04:51:58] <fenn> toastyde1th: that'd be a long straight edge
[04:52:08] <fenn> for a 5m boring mill
[04:52:13] <tomp> they call it a laser
[04:52:17] <toastyde1th> they use 4 and 8 foot straight edges
[04:52:51] <fenn> 16ft straight edge would weigh 8 times what an 8 foot straightedge would
[04:53:00] <toastyde1th> it's relying on locally straight segments
[04:53:14] <toastyde1th> to give the other indication methods that work at long distances a reference
[04:53:17] <Valen> seems pretty labour intensive
[04:53:26] <toastyde1th> reconditioning a machine is very labor intensive
[04:53:33] <toastyde1th> no matter what tools you use
[04:53:36] <fenn> if you do it the hard way
[04:53:56] <toastyde1th> fenn: strange how the only people who think it's the hard way are people who have never reconditioned a machine.
[04:54:03] <fenn> meh
[04:54:10] <tomp> buy new machines! ( and dont bring me any of that old wine !)
[04:54:37] <fenn> i refuse to believe that "the hard way is the only way"
[04:54:40] <toastyde1th> you'd think with a 25,000 dollar spindle analyzer, differential electronic levels, autcollomators, 8 foot straightedges and the appropriate scraping gear to maintain them, portable grinders, and interferometers
[04:54:40] <Valen> If you leave the "Anderson laser system" in place you could actually use it while you were running the machine, to correct it back to accuracy continiously
[04:54:50] <toastyde1th> they'd be willing to spend money on a better system
[04:54:53] <toastyde1th> if one existed
[04:55:13] <fenn> people do lots of difficult things, either from ignorance or stubbornness
[04:55:39] <Valen> I think they probably are happy with how their stuff works and are willing to pay for what they know when their business is at risk
[04:55:50] <toastyde1th> and many completely inexperienced people think they know better than someone with 40 years of experience
[04:56:14] <toastyde1th> new, better things do come along all the time, and many people with 40 years plus of experience refuse to adapt
[04:56:23] <tomp> the laser could actually watch where the tool was instead of extrapolating "it oughta be there" from the scales which aint near the tool
[04:56:41] <Valen> tomp I thaught about that, its really really hard to do
[04:56:49] <toastyde1th> LODTM does it
[04:56:54] <Valen> too much crap floating about
[04:56:55] <tomp> yes
[04:57:31] <tomp> large object diamond turning machine?
[04:57:37] <toastyde1th> optic
[04:57:51] <tomp> oh, optic, cool beans
[04:58:05] <toastyde1th> actually the interesting thing with that problem is the control
[04:58:30] <toastyde1th> since emc has kins, i imagine you'd be able to adapt kins to a metrology frame like the lodtm has
[04:58:49] <tomp> http://books.google.com/books?id=1CmQgcT72awC&pg=PA545&lpg=PA545&dq=LODTM&source=bl&ots=YKUn8lMAf8&sig=8j7RqChJIkNirKJmy_rKwRY9m0s&hl=en&ei=JgzoSZXyGIuZkQWunfmKBw&sa=X&oi=book_result&ct=result&resnum=8
[04:58:54] <tomp> lodtm ref
[04:59:10] <Valen> https://www.llnl.gov/str/April01/Klingmann.html
[04:59:40] <toastyde1th> we almost got that machine, by the way.
[04:59:51] <tomp> wow, thats a weldment too
[04:59:55] <Valen> After the tool is set up, machining does not begin for at least 12 hours to allow the effect of the machinist's body heat to dissipate
[05:00:33] <toastyde1th> but it needs a new control
[05:00:39] <toastyde1th> and since it's custom, the work estimate is about 5 million
[05:00:44] <tomp> haha, the old inspector would make us wait while had a coffee and and another stub of cigar, letting the grindings sit on the surface plate
[05:00:45] <Valen> EMC4?
[05:01:34] <tomp> you guys work on some cool stuff, gotta go
[05:01:35] <toastyde1th> valen: it's actually a cluster of 4-5 controls
[05:02:54] <toastyde1th> it would be cool to have the stuff in emc, that would probably be very useful to some of the emc users
[05:04:30] <tomp> b4 i go, let emc talk to other emc's :)
[05:04:48] <tomp> k, back to orcad
[05:04:51] <toastyde1th> lol
[05:05:01] <Valen> and back down again ;-P
[05:31:56] <tomp> is there a difference between an ac and a dc relay coil? i see the parts bins here are labled 'ac/dc' for small 'ice-cube' relays
[05:35:18] <tomp> ooh. looks like i'll pass on these interchangable relays, they are not the same
[06:16:50] <JustinXJS2_> JustinXJS2_ is now known as JustinXJS2
[06:27:37] <toastyde1th> toastyde1th is now known as toastydeath
[07:21:07] <MrSunshine_> wont AC change the magnetic field each time it changes? :)
[07:21:15] <MrSunshine_> so at one time it will pull the pin the next it will push it ?
[07:41:37] <tomp> its not a short answer , sometimes you can make it work, but its not a good idea http://www.google.com/url?sa=t&source=web&ct=res&cd=3&url=http%3A%2F%2Fcr4.globalspec.com%2Fthread%2F8100%2FAC-relays-versus-DC-relays&ei=hjLoScy1Hpnu6wP4i4zFAw&usg=AFQjCNHGK8jru93ZChhOEn73fWojGmJflw
[07:42:07] <tomp> sorry, http://cr4.globalspec.com/thread/8100/AC-relays-versus-DC-relays
[07:43:07] <tomp> and an ac relay doesnt buzz like you tendered
[07:44:03] <JymmmEMC> AN AC contact will have a MUCH longer life than a DC one
[07:46:21] <JymmmEMC> add a diode to a relay to prevent bemf iirc
[07:50:57] <tomp> diode across coil of dc relay, yes, to shunt the discharge when the coil field collapses ( just like old timey car ignition), but you suggest across contact that handles ac?
[07:51:55] <JymmmEMC> no, just coil like you mentioned
[07:52:30] <tomp> gotcha, thx
[07:57:40] <tomp> new pcbs arein, the guys soldered in the dip swxs. the dip swxs are crap!, the print sez " dont put in switches, use jumper wires on component side", doh, assembler is chinese
[07:58:00] <tomp> bu dui bu dui!
[09:14:45] <piasdom> g'mornin all
[09:15:35] <alex_joni> hi
[09:22:30] <micges> good morning
[09:48:59] <alex_joni> hi
[10:28:49] <tomp> gnite
[11:15:09] <alex_joni> ROFL: http://www.zazzle.com/css_is_awesome_mug-168716435071981928
[11:16:26] <archivist> as one who has played with CSS, thats a good one
[12:09:05] <jensor> Is the msg "/dev/hda1 has been mounted 30 times without being checked, check forced" that appears occassionly when booting, normal?
[12:09:16] <pjm__> yes
[12:09:20] <jensor> ok
[12:09:27] <pjm__> u can change it so it never checks
[12:09:38] <pjm__> but its better to let it check the state of the disk now and then
[12:09:39] <jensor> is that a good idea?
[12:10:05] <jensor> Yep you're right
[12:11:07] <pjm__> http://ubuntuforums.org/showthread.php?t=300477 that explains how to do it just for info
[12:11:55] <jensor> Do you know where I can find a good treatise on the use of the sub and call functions for program control in g-code?
[12:12:14] <jensor> Iv'e had problems understanding their usage
[12:12:50] <jensor> I've researched the wiki
[12:12:55] <pjm__> ah i personally dont know, i can do g-code basics, someone here will know the answer tho!
[12:15:19] <archivist> I have never seen sensible docs, just struggled till it worked
[12:15:53] <archivist> the sub and calls were not designed by a real programmer
[12:17:10] <archivist> hmm quarter past dinner time!
[12:21:34] <archivist> Im about to g code a brocott excape wheel
[12:23:44] <archivist> http://www.orologeria.com/webart/foto/pendoleria/brocotruota.jpg
[12:25:26] <pjm__> archivist http://pjm.dyndns.org/DSC02432.jpg
[12:26:06] <tomp> http://www.geocities.com/CapeCanaveral/Hall/3934/beb112.html cool some of the math for the brocot
[12:26:31] <jensor> archivist, I've also had to struggle untill it worked!
[12:27:20] <tomp> looks awfully delicate, what diameter might that be?
[12:27:41] <archivist> tomp I dont think I shall be toooo fussy bout the real maths, I saw that page when looking for a link to a pic
[12:27:56] <archivist> 23.3 mm dia
[12:27:56] <tomp> delicate, hah, i suppose the missing teeth arent part of the design
[12:28:19] <archivist> this one here has missing hence the job
[12:29:00] <archivist> .8mm thick brass to make it out of
[12:29:49] <tomp> pretty smalll at 23.3, that scales those teeth down to 'skinny', you need a small wedm . no force on the part during machining
[12:29:54] <archivist> pjm__, that made on your machine?
[12:30:34] <archivist> tomp Im going to profile cut with a slitting saw
[12:35:30] <archivist> I get used to backing a sheet for support during the cut
[12:37:18] <Optic> poooo!
[12:52:14] <tomp> i dont see how you can use a slitting saw to cut the profile, nless you got <1mm dia slitting saw, even then, a helluva kerf (not familiar with profile cut, is that 'contour'?)
[12:55:44] <archivist> tomp http://www.youtube.com/watch?v=adT8Dr5JZ4c
[12:56:26] <tomp> oh!
[12:56:44] <tomp> i had no idea it was on edge of a short cylinder
[12:58:19] <tomp> are there any details on your a axis? looks about 4 to 8" dia?
[12:58:22] <archivist> well that one was but the brocot is on sheet / disk
[12:58:39] <tomp> ok, even flat i can see it
[12:59:04] <archivist> a axis is just a hacket Vertex 4 inch rotary
[12:59:14] <tomp> nice work!
[12:59:37] <archivist> there is a nother vid showing the flat version
[13:07:08] <Servos4ever> Hmmm That xfer didn't work anything like I hoped it would. Guess I need to read the FAQ.
[13:15:48] <tomp> the vertex tilt rotary looks interesting, abot 330$us
[13:17:45] <archivist> really needs another proper cnc axis, the setting up of fixed angles is a pain
[13:30:39] <BJT-Work> what a lovely morning to ride the bike to work :)
[13:31:01] <skunkworks> I bet - it has been 60deg and sunny here this week
[13:32:15] <BJT-Work> 55 and sunny here going up to 65 I think
[13:48:12] <skunkworks> http://imagebin.org/index.php?mode=image&id=45896
[13:48:35] <pjm__> archivist - no not made on my machine, it was something me dad made last week on their 5 axis m/c
[13:50:33] <skunkworks> I did find local ups batteries about 1/2 the cost of apc or digikey.
[13:50:41] <skunkworks> which supprised me.
[13:52:36] <Jon_geo01005> skunkworks: What is the plan for the new computer?
[13:53:37] <archivist> pjm__, I thought it was a bit big for yours!
[13:53:49] <skunkworks> none. Just playing. I have a goal3 board that I am running the gantry with.
[13:54:38] <pjm__> archivist it is 316 stainless, all out of a solid billet
[13:54:58] <pjm__> its part of a sonar apparently
[13:55:56] <eric_unterhausen> skunkworks, is that an atom?
[13:56:01] <skunkworks> yes
[13:56:08] <skunkworks> atom 330
[13:56:14] <eric_unterhausen> have you run emc on it?
[13:56:16] <skunkworks> dual core
[13:56:37] <skunkworks> I have not run emc yet. But the latency test is running while it is downloading the updates
[13:56:56] <eric_unterhausen> what kind of numbers are you getting?
[13:56:58] <skunkworks> 17162 atm
[13:57:19] <skunkworks> Highest I saw yesterday was about 18000
[13:57:27] <skunkworks> not stellar but not bad
[13:57:54] <eric_unterhausen> I haven't tried all of my candidate computers, but that's better than the one I have in there now
[13:57:54] <skunkworks> I think that is pretty close to the numbers jmkasunich was seeing
[13:58:54] <eric_unterhausen> are you going to rebuild the computer for SMP?
[13:59:00] <skunkworks> no
[13:59:15] <eric_unterhausen> could have saved $15 then :)
[13:59:26] <skunkworks> heh - yes.
[13:59:38] <skunkworks> These are acutally going to run xp at some point.
[13:59:43] <skunkworks> work related
[13:59:58] <eric_unterhausen> I'd like to get some for our robots
[14:00:05] <eric_unterhausen> now running around with laptops
[14:00:27] <archivist> hmm 6 tons for retrofit fleabay 170321680609
[14:01:49] <eric_unterhausen> that looks a lot like the old cnc we have at work
[14:02:08] <skunkworks> retrofit! nice jog wheel atleast.
[14:03:12] <archivist> I can dream cant I?
[14:03:29] <Optic> how much does a jog wheel cost?
[14:03:37] <eric_unterhausen> HNC is the toy of the moment :)
[14:03:42] <eric_unterhausen> $100
[14:03:52] <Optic> hmm :)
[14:03:54] <eric_unterhausen> from CNC4PC
[14:04:16] <Optic> and it just makes encoder-style pulses?
[14:04:16] <alSMT_> how about pyvcp jog wheel anyone us that
[14:04:31] <eric_unterhausen> yes, it's just an encoder
[14:05:05] <Optic> very nice
[14:05:52] <eric_unterhausen> wow, they have two models now
[14:07:08] <Optic> do usb parallel ports work with emc?
[14:07:14] <eric_unterhausen> no
[14:07:23] <Optic> that's the answer I was expecting :)
[14:07:30] <Optic> probably not realtime enough
[14:07:36] <eric_unterhausen> correct
[14:08:09] <SWPadnos> they're "bursty"
[14:08:14] <SWPadnos> ie, useless
[14:08:15] <Optic> yeah
[14:08:36] <skunkworks> SWPadnos: did you see the cnczone linke I posted yesterday?
[14:08:52] <archivist> till someone gets their head around the synchronous mode
[14:08:59] <skunkworks> http://www.cnczone.com/forums/showthread.php?t=78514
[14:09:03] <alSMT_> would you have to run the pyvcp jog wheel through the sim_encoder?
[14:09:22] <eric_unterhausen> what pyvcp jog wheel?
[14:09:51] <Valen> skunkworks does that have the compiz desktop/3d stuff turned on?
[14:10:23] <skunkworks> http://linuxcnc.org/docs/2.2/html/hal_pyvcp.html#r1_5_10
[14:10:31] <alSMT_> pyvcp you can create a jog wheel and it outputs a float
[14:10:58] <skunkworks> Valen: no - it is installed from the livecd which has the effects turned off.
[14:12:07] <Valen> ahh thats a shame (i was hoping it could nerf some latency ;->)
[14:12:51] <skunkworks> it runs opengl very good. (compared to other video cards I have used) it will do glxgears full screen pretty smooth
[14:12:51] <eric_unterhausen> that don't look like a jogwheel :)
[14:13:07] <Valen> skunkworks, yeah i have the same board
[14:13:15] <Valen> can't rember if its single or dual core though
[14:13:26] <Valen> using it for a digital sinage thing
[14:13:30] <eric_unterhausen> you don't want to run compiz :(
[14:13:34] <alSMT_> less than $100 though :)
[14:14:06] <eric_unterhausen> cheapest jog wheel on cnc4pc is $70
[14:14:28] <Valen> my only concern was the single PCI slot
[14:14:38] <skunkworks> glxgears does about 80fps full screen.
[14:14:47] <eric_unterhausen> too bad the pci slot isn't right angle
[14:14:48] <Valen> don't know what i'd want another one for just yet but its always a real pain when you find you want it
[14:15:08] <Valen> you can get right angle adaptors for PCI if you want it
[14:15:26] <eric_unterhausen> any good sources?
[14:15:40] <Valen> I believe they come with cases that can use them
[14:16:02] <eric_unterhausen> that means the case costs x times the mobo
[14:16:15] <Valen> something like that
[14:16:30] <Valen> If you aren't after super small just stick it in a regular case
[14:16:43] <eric_unterhausen> where x is an integer between 2 and 5
[14:16:44] <tomp> is there some ngc files for 5 axis? ( to run with the cvs versions of emc with max5kins? )
[14:16:45] <Valen> or use low profile cards in a low profile case
[14:17:09] <eric_unterhausen> m5i20 not low profile
[14:17:18] <Valen> bandsaw
[14:17:33] <eric_unterhausen> bandsaw == sparks
[14:17:46] <Valen> your thinking grinder
[14:18:18] <eric_unterhausen> ok, I found a riser card on ebay that is not right angle
[14:18:36] <tomp> 2 slot pci mobo with pci cpu card and m5i20 = small
[14:18:39] <eric_unterhausen> that's just about the most useless thing I can think of
[14:18:42] <BJT-Work> if bandsaw = sparks then blade = junk
[14:19:13] <eric_unterhausen> if you cut your pci card in half
[14:19:31] <eric_unterhausen> or is that not the purpose of the bandsaw :)
[14:20:07] <Valen> if you want small do PC104 stack
[14:20:22] <eric_unterhausen> PC104 would be great if it worked
[14:20:30] <Valen> mesa have PC104 cards
[14:20:35] <Valen> why would it not work?
[14:20:46] <eric_unterhausen> have you used it?
[14:20:57] <eric_unterhausen> I've wasted months of my life getting things to work
[14:21:00] <Valen> no but it seems fairly prevalant
[14:21:05] <eric_unterhausen> somethings simply don't work
[14:21:07] <Valen> why do they not work?
[14:21:19] <skunkworks> http://cgi.ebay.com/Rightward-Right-Angle-32-Bit-32Bit-1U-PCI-Riser-Card_W0QQitemZ310136061136QQcmdZViewItemQQptZUK_Computing_ComputerComponents_InterfaceCards?hash=item310136061136&_trksid=p3286.c0.m14&_trkparms=72%3A1205%7C66%3A2%7C65%3A12%7C39%3A1%7C240%3A1318%7C301%3A1%7C293%3A1%7C294%3A50
[14:21:28] <Valen> anybody know some good suppliers of ballscrews
[14:21:57] <Valen> both screw and nut?
[14:22:04] <Valen> where good is ~= cheap
[14:22:12] <eric_unterhausen> skunkworks, I'll just import directly from hong kong and save a buck
[14:22:47] <eric_unterhausen> somebody sells a ribbon cable riser card
[14:22:50] <skunkworks> http://cgi.ebay.com/PCI-Right-Angle-Riser-Card_W0QQitemZ360009325440QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item360009325440&_trksid=p3286.m20.l1116
[14:22:50] <Valen> I must use a wireless xbox controller for the jog control when we get the mill going
[14:23:10] <Valen> skunkworks, the only problem is finding cases to put them in
[14:23:27] <eric_unterhausen> that's not a problem if you have a bandsaw
[14:23:54] <skunkworks> http://www.youtube.com/watch?v=IgGxaNq46Pk
[14:23:56] <Valen> tis, because they need to have the card slot in the right position, a few mm out and it just wont fit
[14:24:24] <Valen> heh that the xbox controller?
[14:24:44] <eric_unterhausen> for me it's going in a big cabinet
[14:25:06] <eric_unterhausen> but a computer case takes up too much space
[14:25:21] <Valen> what is he using for motors on that?
[14:25:48] <skunkworks> http://www.electronicsam.com/images/KandT/cncworkshop/mazake2.JPG
[14:27:03] <tomp> where can i find the the ngc file behind this http://www.youtube.com/watch?v=fWKYQUj5AOs
[14:27:26] <eric_unterhausen> you ping chris radek
[14:27:44] <tomp> thx ;) and i remmeber that panel
[14:28:06] <skunkworks> who needs a case ;)
[14:28:26] <eric_unterhausen> skunkworks, is that a full sized power supply?
[14:28:26] <skunkworks> 18299
[14:28:38] <skunkworks> which? in the mazak?
[14:28:50] <skunkworks> Looks like it to me..
[14:28:52] <eric_unterhausen> your last link
[14:29:01] <eric_unterhausen> looks flatter than that
[14:29:03] <Valen> skunkworks is there any more info on the machine at http://www.youtube.com/watch?v=IgGxaNq46Pk&feature=channel_page
[14:29:38] <eric_unterhausen> the video makes it look about 2x normal size
[14:29:42] <skunkworks> valen - That is 'theball' when he is on here.. I don't have any specs
[14:29:58] <skunkworks> The_ball_
[14:29:59] <Valen> dang :-<
[14:31:18] <Valen> looks like NMEA 34 mount motors at least though
[14:31:51] <eric_unterhausen> I'm guessing not that big
[14:32:19] <Valen> some pretty big box section
[14:32:34] <Valen> mounting the motors
[14:34:02] <skunkworks> http://www.electronicsam.com/video/MVC-341W.MPG ;)
[14:34:48] <skunkworks> http://www.electronicsam.com/video/VIDEO1.mpeg
[14:34:58] <alSMT_> when I run the pyvcp float into sim_encoder and move the jog wheel one increment off zero it acts like a button sim_encoder keeps making pulses "net velX Index_pyvcp.x-jog-wheel => sim-encoder.0.speed
[14:36:03] <skunkworks> Do you have to run it into the sim encoder? If it outputs a float - can you just hook it into the jog inputs?
[14:36:10] <tomp> found the 5axis demo file, its intuitively named 'cone'
[14:36:24] <eric_unterhausen> tomp: nice
[14:36:47] <skunkworks> * skunkworks has not done that before so I may be wrong.
[14:36:57] <eric_unterhausen> I'd like at least 4 axis, but 3 axis would be a good start :(
[14:37:03] <alSMT_> me either
[14:37:36] <alSMT_> i'll give that a shot
[14:40:16] <tomp> is the re-curring output desired? ( did you want the output to continue stepping due the the 'error' dialed in ?)
[14:40:59] <SWPadnos> skunkworks, no, I hadn't looked. I'll reply now (if I can remember my password)
[14:41:53] <SWPadnos> oh yay. Firefox remembers my password
[14:42:13] <tomp> the 5 axis demo is nice but i had to choke the speeds and overrides way down to stop 'joint 0 following error' (>way< down)
[14:42:15] <Valen> always handy
[14:42:18] <eric_unterhausen> somebody showed me it's saved in plain text
[14:46:56] <tomp> SWPadnos: the thumb drive is partially persistant.. it remembered i had 4 desktops, but didnt remember the tcpip setup ( tho i saved it ). i moved stuff on desktop, and made bookmarks in ffox. only the 4 desktops persisted
[14:47:16] <SWPadnos> I think the persistence only applies to personal settings
[14:47:28] <SWPadnos> the casper filesystem may get mounted over the /home directory or something
[14:47:47] <SWPadnos> hmmm. actually, the ff history should persist also
[14:48:38] <alSMT_> sorry
[14:49:27] <alSMT_> tomp: no not the desired stepping
[14:50:49] <tomp> does it seem like, emc sees the dialed in value as an error, moves to get rid of it, and sees it again and again? ( and how fast does it occurr ?)
[14:52:15] <alSMT_> when I move the dial one poss it jogs as a button would one poss opposite way moves in op dir
[14:53:36] <tomp> im still getting the idea..., and what did you want to happen? ( move one unit in the direction expected )?
[14:53:52] <alSMT_> yes
[14:54:17] <alSMT_> like a jog wheel
[14:55:45] <alSMT_> pyvcp.jog wheel outputs a float and not a quad signal like a real jog wheel
[14:57:12] <tomp> ok, but sending the value to 'speed' will cause and endless motion. setting a new position would be finite.
[14:57:38] <tomp> speed != 0 = motion forever
[14:59:27] <tomp> and the 'event' wont retrigger cuz the data would be the same
[14:59:30] <tomp> i think
[14:59:40] <dave_1> hi tomp
[14:59:52] <tomp> dave hello how are you
[15:00:22] <tomp> goint to the workshop?
[15:00:25] <dave_1> doing rather well, but not getting enough done ;-)
[15:00:34] <tomp> haha
[15:01:29] <dave_1> no I'm not but wish I was. Will pour equivalent $$ into my shop this year. Last years trip approached $2K... ouch!
[15:02:23] <alSMT_> can I i take the float and conv_float_s32 and send it to axis.0.jog-counts and bypass sim and encoder all together
[15:02:48] <dave_1> tomp you home now or still in asia?
[15:03:10] <tomp> oh, in taichung, leaving on 30th
[15:03:44] <dave_1> sometime when you get back email me with your address and I'll try to send that servo amp
[15:04:02] <tomp> alSMT_: i dont know but i'd try, it really seems like speed is not what you wanna tickle
[15:04:24] <tomp> dave, dont worry about it, can you use it?
[15:04:28] <alSMT_> ok
[15:05:03] <dave_1> probably not. but appreciate the offer
[15:05:18] <tomp> alSMT_: does that make any sense?
[15:05:59] <tomp> dave_1: ok, when i get back, but send cheapo, no hurry, put in a pc of paper and label it books ;)
[15:06:38] <dave_1> probably use one of the PO single price boxes
[15:06:46] <alSMT_> witch part?
[15:07:53] <tomp> alSMT_: that sending a value to speed will move forever
[15:08:26] <dave_1> help! I'm having trouble with ssh. To one emc machne it works and to the other I get a 'connection refused' .. ideas to fix?
[15:08:43] <dave_1> ps ping works to both machines
[15:08:52] <SWPadnos> trying to connect to the same machine, or to each other?
[15:09:06] <SWPadnos> oh, to the other ...
[15:09:15] <SWPadnos> * SWPadnos had to share his coffee this morning
[15:09:30] <SWPadnos> do you have ssh installed on the second emc machine?
[15:09:46] <SWPadnos> ssh server, that is
[15:10:00] <alSMT_> tomp: yes
[15:10:06] <dave_1> don't know ... standard 8.04 emc Ubuntu
[15:10:19] <SWPadnos> it's not installed by default
[15:10:25] <dave_1> ah!
[15:10:34] <dave_1> guess that is the first task.
[15:10:50] <dave_1> will try that and get back to you. tnx
[15:10:53] <tomp> alSMT_: then experiment with sending offsets, or setting the jog counts like you said
[15:11:03] <SWPadnos> dave_1, it's called openssh-server
[15:11:11] <dave_1> tnx
[15:11:18] <SWPadnos> sure
[15:11:49] <tomp> isnt there a permitted machine list for ssh? (some /etc/blah file)?
[15:11:55] <alSMT_> tomp: rodger that
[15:11:58] <SWPadnos> ./ssh/known_hosts
[15:12:22] <SWPadnos> there are probably ways of restricting which machines you can connect to as well, but I've never messed with that
[15:12:34] <tomp> alSMT_: let us know the progress, sounds cool
[15:13:00] <dave_1> usually I'm just happy to get it to work.
[15:13:33] <SWPadnos> it is a little surprising that openssh-server and openssh-client aren't installed by default (client may be)
[15:13:49] <tomp> wow i had a skype to land line call here from USA, really good quality
[15:14:04] <alSMT_> ok
[15:14:19] <dave_1> bbl
[15:14:19] <tomp> i remember that FISH used it inside Midnight Commander, very handy
[15:14:25] <tomp> bye dave
[15:19:00] <Jon_geo01005> Any of you used SolveSpace before?
[15:19:09] <Jon_geo01005> It's a little CAD package.
[15:19:21] <Jon_geo01005> http://solvespace.com/index.pl
[15:24:40] <dave_1> SWP fixed that problem. ssh now works. tnx
[15:27:36] <tomp> Jon_geo01005: perl plugin? whats required?
[15:28:30] <Jon_geo01005> No, it's a standalone application.
[15:29:19] <Jon_geo01005> does parametric sketching, my favorite part of NX and solidworks.
[15:32:20] <tomp> Jon_geo01005: this group is about linux based cnc control, dont worry, but most would need to reboot to try a windows app.
[15:32:55] <tomp> i'll dload it and try out the demo
[15:33:27] <Jon_geo01005> Well I don't mean to be tool pessimistic, but you may have to reboot to use any worthwhile CAD....
[15:33:55] <archivist> people are now developing linux capable cad
[15:34:16] <eric_unterhausen> heekscad looks good
[15:34:17] <Jon_geo01005> Don't bother rebooting though, the video demos on their website show all you can do.
[15:34:27] <eric_unterhausen> video doesnt work here
[15:34:37] <archivist> a way do go to beat solidworks though but getting there
[15:34:38] <tomp> sorry jon, the vids say they require m$ codes
[15:34:57] <tomp> hese videos are encoded with the Windows Media Video 9 Screen codec. If you are unable to view them, then ensure that you are using a recent version of Windows Media Player.
[15:35:08] <Jon_geo01005> I like linux, and I have used NX on linux and it's great. Sorry the videos don't work.
[15:35:10] <archivist> heh!
[15:35:25] <tomp> np, we can look after reboot
[15:35:47] <tomp> thx for the link
[15:36:26] <archivist> Im also waiting on the slamdunk gui on top of brlcad
[15:37:03] <archivist> but grass grows faster
[15:37:25] <tomp> i'd like to learn more of apt, tho its not cad as much as cutter path
[15:38:09] <archivist> a couple in #cam know apt
[15:38:33] <tomp> and im still putzing with the 5 aqxis vismach demo, lotsa joint erros till i uped the accel, now i'm stuck with axis 2 on a limit
[15:38:46] <tomp> archivist: yep, cluey people
[15:39:11] <dave_1> apt would be a lot easier to use if the error messages were text and not just a number.
[15:40:20] <Jon_geo01005> Heekscad would be much much better in my eyes if it had a sketcher that used a solver to enforce constraints.
[15:40:40] <Jon_geo01005> Like solidworks, NX, ect.
[15:41:07] <dave_1> since Stuart is an apt expert or has experts in his shop then emc workshop could be a good time to pick his brains :-)
[15:42:00] <tomp> joint 2 on limit swithc error
[15:42:06] <archivist> Jon_geo01005, add an issue to heekscad or comments to issue 49
[15:42:30] <tomp> dave_1: didnt know stuart used apt
[15:42:54] <archivist> Jon_geo01005, I was discussing with the writer yesterday
[15:44:21] <Jon_geo01005> I'm looking around the web to see if there is an opensource constraints solver that could be more or less plugged in.
[15:44:37] <dave_1> whole shop is a commercial version of apt
[15:45:27] <tomp> !
[15:45:38] <archivist> Jon_geo01005, by the way we lurk in #cam
[15:46:35] <Jon_geo01005> Thanks for the note.
[15:57:02] <BigJohnT> this is odd... if I drive my van from shop to shop it is 8 miles... if I drive the bike it is 36 miles
[15:57:26] <SWPadnos> good thing you get 4.5x the fuel economy on the bike
[15:58:33] <BigJohnT> only twice as much
[15:58:40] <BigJohnT> :)
[16:19:05] <skunkworks> huh - I just fdisked my keychain drive.
[16:19:06] <skunkworks> oops
[16:26:17] <skunkworks> i bought GetDataBack a long time ago - looks like my activation key still works for the latest version. (looks like I recovered everything)
[17:14:25] <skunkworks> damn - jmkasunich sure knows how to explain things.
[17:34:20] <skunkworks> LawrenceG: how did it go last night?
[17:35:29] <LawrenceG> got distracted.... no progress
[17:36:00] <skunkworks> heh
[18:15:06] <skunkworks> eric_unterhausen: if I am reading that right - looks like maybe 30000 period is pushing it.. http://imagebin.org/45923
[18:17:27] <SWPadnos> interesting. that makes me think that the base thread is getting interrupted by something
[18:17:32] <SWPadnos> which is supposed to be impossible
[18:18:25] <alex_joni> impossible he says
[18:18:47] <SWPadnos> I'd reset tmax to 0 and let it run another day or two, see if it happens again
[18:18:49] <alex_joni> if it were impossible, the machine wouldn't have latency :P
[18:18:53] <SWPadnos> well, supposed to be impossible ;)
[18:18:57] <SWPadnos> yes, it still would
[18:19:11] <SWPadnos> there's a difference between interrupt response and re-interrupting the interrupt
[18:19:30] <alex_joni> also .. the Time and Max-Time are in machine counts.. right? not usec like the Period
[18:19:49] <alex_joni> CPU cycles I mean
[18:21:31] <alex_joni> hal_lib.c: /* capture execution time */
[18:21:32] <alex_joni> end_time = rtapi_get_clocks();
[18:21:34] <skunkworks> It seems to happen right at startup.
[18:22:01] <alex_joni> skunkworks: what kind of CPU?
[18:22:15] <skunkworks> (as fast as I can get into hal config - the tmax is alread > 20000
[18:22:22] <skunkworks> it is that atom 330
[18:24:19] <alex_joni> how many MHz I mean
[18:24:36] <alex_joni> skunkworks: if the numbers are in CPU cycles, then it's not really a lot
[18:25:21] <SWPadnos> that's the Atom board?
[18:25:37] <SWPadnos> if so, it's a 1.6GHz CPU I think, so still 20 uS max time
[18:25:46] <skunkworks> yes
[18:25:51] <skunkworks> atom board
[18:25:52] <SWPadnos> well, maybe 18 uS
[18:26:05] <SWPadnos> still a lot more than I'd expect for a parport read/write/make-pulses
[18:26:31] <skunkworks> I think that is ns.
[18:26:42] <SWPadnos> no, tmax and time are in CPU cycles
[18:26:58] <SWPadnos> As posted by Alex:
[18:27:00] <SWPadnos> [14:21:48]hal_lib.c: /* capture execution time */
[18:27:01] <SWPadnos> [14:21:49]end_time = rtapi_get_clocks();
[18:27:14] <skunkworks> it shows you the base thread of 30000 - and if I set the base thread to 20000 - I instantly get a realtime error
[18:27:27] <skunkworks> hmm
[18:27:37] <SWPadnos> 28000 / 1.6 is pretty close to 20000
[18:27:42] <skunkworks> ah - ok
[18:27:52] <alex_joni> it's around 16 usec
[18:27:57] <SWPadnos> so you should get some realtime erros, I'd think
[18:28:27] <alex_joni> 1/1.6Ghz * 26952 = 0.000016845
[18:28:52] <skunkworks> that makes sense.
[18:28:52] <alex_joni> SWPadnos: realtime errors are calculated in the servo-thread
[18:28:56] <SWPadnos> heh - I was reading that as 28000-29000 for some reason :)
[18:29:07] <SWPadnos> aren't there two different possible errors?
[18:29:11] <alex_joni> yes
[18:29:16] <SWPadnos> one is missed deadline or something
[18:29:17] <alex_joni> one is an error reported by RTAI
[18:29:20] <alex_joni> yup
[18:29:23] <SWPadnos> right
[18:29:27] <alex_joni> but it happens in dubious cases :D
[18:29:57] <alex_joni> skunkworks: you should be able to see each of those functions
[18:30:10] <alex_joni> how long they took
[18:33:51] <alSMT_> is this the correct way to convert float to s32 "net conv_float_s32.0.in <= Index_pyvcp.x-jog-wheel"?
[18:34:26] <alex_joni> you need a name for the net
[18:34:40] <alex_joni> net mysig conv_float_s32.0.in <= ....
[18:35:29] <alSMT_> do I need to addf to conv_float_s32 also
[18:36:23] <skunkworks> pastebin.ca
[18:36:28] <skunkworks> oops
[18:38:06] <skunkworks> http://pastebin.ca/1395161
[18:41:29] <alSMT_> I get this "ndex_pyvcp.hal:3: pin 'conv_float_s32.0.in' does not exist" when I use this "net mysigxf conv_float_s32.0.in <= Index_pyvcp.x-jog-wheel
[18:43:40] <SWPadnos> you also need a signal name
[18:43:54] <SWPadnos> err, nevermind me
[18:46:03] <alex_joni> alSMT_: I assumed you looked up the pin name
[18:46:25] <SWPadnos> try using - instead of _
[18:46:27] <alex_joni> for a pin called conv_float_s32.* to exist you probably need to loadrt such a component first
[18:46:29] <alSMT_> it doesn't complain with out the name but it doesn't update the float either
[18:46:32] <alex_joni> and check the man page
[18:46:55] <SWPadnos> also, you do need to add the function to a thread, or the output will never update
[18:47:13] <alex_joni> skunkworks: crap, I thought each function has a t-max
[18:47:58] <skunkworks> heh
[18:48:14] <SWPadnos> they do
[18:48:35] <SWPadnos> 275. 4 s32 RW 49392 motion-command-handler.tmax
[18:48:40] <SWPadnos> (for example)
[18:48:43] <alSMT_> i load the component and it complains when I addf failed
[18:49:14] <SWPadnos> alSMT_, are you editing a hal file and reloading emc every time, or doing this at a halcmd prompt?
[18:49:19] <alSMT_> addf conv_float_s32.0 servo-thread
[18:49:23] <alSMT_> yes
[18:49:39] <SWPadnos> yes which?
[18:50:06] <alSMT_> edit and save reload
[18:50:15] <SWPadnos> I think you'll find that all the names have "-" instead of "_" in them
[18:50:35] <SWPadnos> you can easily see this if you use halcmd to load and then inspect the names
[18:52:33] <alex_joni> skunkworks: seems the parport access is the one that takes a long time
[18:53:42] <skunkworks> everyone says the onboard printer ports suck usually.
[18:53:56] <SWPadnos> that chipset is a dog, in my experience
[18:54:05] <SWPadnos> even for PCI
[18:54:13] <SWPadnos> (much faster than a parport, but very slow for PCI)
[19:00:55] <alSMT_> SWPadnos: yep the name game it works
[19:04:03] <alSMT_> why the naming diff ?
[19:04:23] <alSMT_> SWPadnos: thanks you to Alex
[19:07:55] <SWPadnos> alSMT_, is it spelled with underscores somewhere?
[19:17:51] <jepler> more specifically, if anything in the manpage is wrong http://linuxcnc.org/docs/2.3/html/man/man9/conv_float_s32.9.html please point it out so it can be corrected
[19:21:34] <alSMT_> jepler: no I just didn't get it right the docs show the right thing "_' "-" I just didn't notice the diff in the naming
[19:23:04] <Optic> hi
[20:55:16] <skunkworks> http://www.onel.se/all_files/gecko_g540.html
[21:00:12] <SWPadnos> hmmm. that's unlikely to work right
[21:00:38] <SWPadnos> the step outputs should be inverted
[21:01:17] <SWPadnos> also the timings are wrong (that "gecko" selection is for the G20x/G21x drives I think)
[21:01:58] <skunkworks> http://www.cnczone.com/forums/showthread.php?t=78514
[21:02:21] <SWPadnos> ok, thanks
[21:03:06] <skunkworks> didn't you get the email ? ;)
[21:03:12] <SWPadnos> :P
[21:05:11] <skunkworks> no latency errors running emc/axis all day with 30us base period
[21:05:15] <skunkworks> on the atom
[21:05:25] <SWPadnos> cool
[21:05:35] <SWPadnos> hmmm. is that a DoubleStep config?
[21:05:55] <skunkworks> hmm - I don't know. It is the stepper_inc
[21:05:56] <SWPadnos> I don't remember seeing parport.0.reset in there
[21:05:56] <skunkworks> inch
[21:06:02] <SWPadnos> ok, probably not then
[21:06:15] <skunkworks> would that help or hurt?
[21:06:52] <SWPadnos> it could explain some of the thread max time
[21:07:29] <SWPadnos> but the explanation was there anyway, the read and write functions both had numbers >20000, and even make-pulses had >11000 IIRC
[21:38:10] <fenn> good thing we have screenshot software otherwise we'd be forced to share .ini files
[21:38:55] <toastydeath> and you know what happens when you share unprotected .ini files
[22:28:44] <alex_joni> good night all
[22:56:25] <justa> justa is now known as _justa_
[23:16:55] <invite> I'm willing to use emc2 with TI UC3717 stepper drivers
[23:17:13] <invite> In half step mode I need to feed the integrated chopper circuit
[23:17:37] <invite> limiting current pins (2) with a High/low sequence.
[23:17:52] <invite> Do I need to write a new hal component for that or
[23:18:01] <invite> does something like that already exists?
[23:19:51] <jepler> the types of output available in stepgen are listed in the manual. I am not familiar with UC3137 (googling datasheet), but this doesn't sound like one of the standard sequences to me.
[23:20:31] <jepler> step types are documented in the following places: "man 9 stepgen" or http://linuxcnc.org/docs/html/hal_rtcomps.html#sub:Stepgen-Step-Types
[23:24:07] <jepler> if this requires 5 or fewer outputs per axis, then you can just change one of the "master_lut" tables in stepgen.c and recompile. If it requires 6 or more (from the datasheet it looks like 6 are required), then you will have to modify stepgen to accomodate a 6-phase output type.
[23:25:13] <jepler> if 6 outputs are required per motor, I don't think you can control 3 axes with a single parport; there are only 12 outputs and you'd need 18.
[23:25:49] <jepler> you might also consider adding a microcontroller which reads emc's step&direction or quadrature outputs and drives the 6 inputs of the UC3137 chips..
[23:27:50] <invite> yes it's a 6 wires per axis
[23:28:16] <invite> hmm...
[23:28:19] <archivist> url for the data sheet
[23:28:22] <jepler> ah, there's a 4 I/O solution shown on figure 12
[23:28:47] <invite> http://focus.ti.com/docs/prod/folders/print/uc3717.html
[23:28:47] <jepler> http://focus.ti.com/docs/prod/folders/print/uc3717.html
[23:29:43] <jepler> that doesn't look like any of the stepgen tables, but you should be able to modify one of the 4-phase step types to give that waveform
[23:30:18] <jepler> to do this you'd have to install from source. there are full instructions for this on our wiki: http://wiki.linuxcnc.org/cgi-bin/emcinfo.pl?Installing_EMC2#On_Ubuntu_6_06_or_8_04_from_source
[23:31:04] <invite> so I'll have to implement the waveform shown in figure 14
[23:31:37] <jepler> stepgen.c is in src/hal/components/stepgen.c, and for each step type there's a master_lut entry which defines which outputs are active for each step in the stepping sequence. You could modify the one for step type 9 or 10 (half-step, 4-phase configurations) to match the one in the datasheet
[23:32:08] <jepler> or you could add a new step type which would be type 15
[23:32:16] <invite> :)
[23:32:26] <jepler> bbl
[23:33:07] <invite> will see what my if c skills will fit the needs :)
[23:33:09] <invite> thanks jeff
[23:33:35] <archivist> or use a more modern chip :)
[23:34:08] <invite> like what ? (I'm not looking for a whole board)
[23:37:06] <invite> and isn't the duo L297/298 more oldish ?
[23:43:01] <Goslowjimbo> Can you ever connect a pin directly to a pin in HAL?
[23:45:14] <Goslowjimbo> I want to use the and2 to and 3 different pins to get essentially a 3 input and gate, then output pin to an output pin.
[23:46:53] <Goslowjimbo> I got this working after looking at it for 3 evenings, but just by using dummy signals. (Actually, I never got the final output pin routed to another pin.
[23:47:12] <Goslowjimbo> )
[23:48:47] <_Poincare> _Poincare is now known as Poincare