#emc | Logs for 2007-08-09

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[00:09:46] <toastydeath> i'm thinking about buying a used electronic indicator setup
[00:09:56] <toastydeath> ebay always freaks me out a little
[00:10:09] <toastydeath> i should just do it and stop whining
[00:23:58] <Guest272> join emc-devel
[00:24:02] <Guest272> oops
[00:24:31] <Guest272> Guest272 is now known as skunkworks_
[00:26:10] <fenn> skunkworks_: emc2/share/axis/images/axis.ngc
[00:27:27] <fenn> easy enuf to make a new one with ttt
[00:28:05] <skunkworks_> crap - thanks. I think I failed gnome file serching.
[00:28:23] <fenn> find ./ -name axis.ngc
[00:29:10] <fenn> actually locate works best for most things
[00:29:45] <fenn> you can even do regexp's and stuff
[00:29:56] <skunkworks_> I was trying to use the file browser.. as I am a windows person :(
[00:31:57] <skunkworks_> skunkworks_ is now known as skunkworks
[00:34:44] <skunkworks> http://www.youtube.com/watch?v=dKz81fY1OjY
[00:36:46] <cradek> skunkworks: cool!
[00:37:05] <skunkworks> :)
[00:37:41] <cradek> even though I've seen it 1000 times, it's fun to see the machine and the cone doing the same thing - your video shows that nicely
[00:38:08] <jepler> doesn't the comment right at the top say "not for milling"?
[00:38:19] <jepler> sheesh ,some people can't follow directions
[00:39:03] <cradek> yeah but it seems to be the first thing a lot of people cut
[00:39:57] <skunkworks> * skunkworks never notice the comment
[00:40:04] <skunkworks> noticed
[00:41:17] <skunkworks> the begining of the video chunks - oh well. people will probably think it is the machine doing it ;)
[00:46:02] <cradek> only for about one second here
[00:46:17] <skunkworks> right
[00:47:06] <skunkworks> my minidv worked pretty well - I think this is the first time I have used the firewire port to download the video
[01:38:24] <Ziegler> Realtime : http://linux.slashdot.org/article.pl?sid=07/08/08/1810243
[01:49:31] <fish> hello
[01:49:41] <skunkworks> Hi
[01:49:54] <fish> hows everyone doing tonight
[01:50:04] <fenn> content
[01:50:18] <toastydeath> full of rage and bile
[01:50:23] <fish> haha uh oh
[01:50:35] <fenn> he's always like that
[01:50:44] <fish> his name gives it away
[01:50:55] <toastydeath> it's so true.
[01:51:13] <fish> anyway, I have a question about linuxcnc
[01:51:21] <fish> on the site, it talks about "path deviation limited to a specified tolerance"
[01:51:26] <Ziegler> anyone read this: http://linux.slashdot.org/article.pl?sid=07/08/08/1810243 ?
[01:51:28] <fish> does that have anything to do with backlash?
[01:51:52] <fenn> no, it doesnt have much to do with emc at all really
[01:52:30] <skunkworks> backlash is a separate setting.
[01:52:41] <fish> ok, but there is a setting for backlash right?
[01:52:44] <skunkworks> yes
[01:52:50] <fenn> it's called "backlash" i believe
[01:53:06] <fish> because I'm planning to go with ACME leadscrews instead of ballscrews
[01:53:16] <fish> to save some money
[01:53:31] <fish> and I'm concerned about backlash
[01:53:41] <fenn> you should make an anti-backlash nut
[01:53:54] <fish> like a split nut design eh
[01:54:07] <fish> adjustable
[01:54:10] <fish> etc
[01:54:14] <skunkworks> backlash comp is a bad solution. Like fenn said - try to remove it. split nut - spring loaded nut..
[01:54:19] <toastydeath> weights
[01:54:42] <fish> what's the least backlash I can get with leadscrew?
[01:54:42] <toastydeath> doesn't work for large forces, though.
[01:54:46] <toastydeath> 0
[01:54:53] <toastydeath> but it involves a tremendous amount of work
[01:54:58] <fish> what's a realistic number?
[01:55:02] <fish> 4 thou?
[01:55:08] <toastydeath> couple thousandths
[01:55:21] <fish> that's pretty good
[01:55:23] <toastydeath> if you keep a split nut adjusted, it will stay pretty low
[01:55:38] <fenn> here is an interesting design (the white ones) http://www.aanrip.nl/abacklash2.jpg
[01:55:45] <fish> thanks
[01:55:54] <fenn> http://www.aanrip.nl/backlashmoer2.jpg
[01:55:56] <fish> how does backlash comp work exactly?
[01:56:09] <toastydeath> it knows it needs to move the screw X amount before the axis will move
[01:56:20] <fenn> when you change direction it advances the screw that amount
[01:56:45] <fenn> however consider what happens if you're doing climb milling
[01:57:15] <toastydeath> bad things!
[01:57:14] <fenn> the cutting forces will take up the backlash, and then you advance the screw suddenly, making a very high chip load for a brief period
[01:58:05] <fish> oh I see
[01:58:38] <fish> but the cutting forces don't take up the backlash consistently?
[01:58:54] <toastydeath> in climb milling the forces reverse
[01:59:05] <toastydeath> instead of pushing the axis, the machine pulls it along
[01:59:11] <toastydeath> and the screw holds it back
[01:59:24] <Skullworks-PGAB> well - maybe
[01:59:45] <fish> I see
[02:00:03] <fenn> also you can do the same sort of thing in the z axis with spiral cutters
[02:00:11] <Skullworks-PGAB> an 1/8" endmill isn't going to pull the table out of backlash
[02:00:50] <Skullworks-PGAB> having more than 50% cutter engagement cancels the climb pull too
[02:00:58] <toastydeath> it can
[02:00:59] <fenn> thats not really climb milling though
[02:01:04] <Skullworks-PGAB> except at breakout
[02:01:15] <Skullworks-PGAB> sure it is
[02:01:37] <fenn> what if you're 80% cutter engagement? 99%? 100%? what's the cuttoff point?
[02:02:13] <Skullworks-PGAB> direction of cut is by is the clip thicker or thinner at the end of the cut
[02:02:19] <fish> this is all over my head
[02:02:27] <fenn> its irrelevant
[02:02:37] <fenn> isnt irc great?
[02:02:39] <fish> does the sieg x3 actually weight 700 lbs?
[02:02:45] <toastydeath> Skullworks-PGAB: we're talking about the cases where backlash is a problem
[02:02:59] <Skullworks-PGAB> climb milling always has the thinnist clip as cutting edge departs the work
[02:03:13] <Skullworks-PGAB> yes
[02:03:15] <toastydeath> climb milling is just an example of the problem being detailed
[02:03:52] <fenn> fish i can imagine it weight 700 lbs
[02:04:05] <fish> but x2 is only 160 lbs
[02:04:13] <fish> from the pictures, it doesn't seem like the x3 is that much bigger
[02:04:21] <Skullworks-PGAB> X3 wighes about 390 lbs
[02:04:40] <Skullworks-PGAB> shipping wieght it under 450
[02:05:36] <fish> ah
[02:05:39] <skunkworks> * skunkworks would love a x1/x2 for my office..
[02:06:01] <fish> well looks like I will be getting the x2
[02:06:04] <fenn> skunkworks: why not go for an x3? seems a more useful size
[02:06:06] <fish> x3 is too big to fit in my apartment
[02:06:12] <skunkworks> I have stuff that big
[02:06:19] <skunkworks> or access to it anyways
[02:06:29] <fenn> ah but what if you don't!
[02:06:31] <Skullworks-PGAB> Approximate shipping weight: 372 lbs. ( from the Grizzly web sight
[02:06:47] <Skullworks-PGAB> it is big
[02:07:00] <skunkworks> then I would have a bridgeport sized mill in the garage :)
[02:07:14] <Skullworks-PGAB> mine is all over the house
[02:07:23] <fenn> bridgeport sized stuff takes.. infrastructure
[02:07:31] <toastydeath> infrastructure == garage
[02:07:34] <fenn> cant just put it in a car
[02:07:42] <toastydeath> rent a wrecker
[02:07:47] <toastydeath> get some tubes
[02:07:49] <toastydeath> and a toe jack
[02:07:52] <fenn> yeah yeah
[02:07:56] <toastydeath> done
[02:08:17] <Skullworks-PGAB> I pulled the table and saddle
[02:08:29] <fenn> what for?
[02:08:29] <Skullworks-PGAB> removed the head & motor
[02:08:36] <Skullworks-PGAB> then the column
[02:08:58] <Skullworks-PGAB> so I could move it myself and fit everything in my mustang
[02:09:02] <toastydeath> oh
[02:09:19] <fish> do spider couplers give backlash?
[02:09:25] <Skullworks-PGAB> I've had an X3 since january
[02:09:25] <toastydeath> yes
[02:09:38] <fenn> Skullworks-PGAB: how'd you fit the knee in?
[02:09:38] <toastydeath> well
[02:09:39] <toastydeath> most do
[02:09:41] <fish> damn, everything gives backlash
[02:09:46] <toastydeath> yes.
[02:10:03] <Skullworks-PGAB> X3 is a mini -bed mill - there is no knee
[02:10:07] <skunkworks> I don't understand why people like to use lovejoy couplers.
[02:10:07] <fenn> no, not everything
[02:10:19] <fenn> membrane couplers don't, preloaded ballscrews dont
[02:10:20] <fish> well the steppers aren't rotating that fast, anyone have experience with just a solid piece of coupler?
[02:10:36] <Skullworks-PGAB> http://images.grizzly.com/grizzlycom/pics/jpeg500/g/g0463.jpg
[02:11:12] <fenn> Skullworks-PGAB: oh i thought you were talking about a bridgeport
[02:11:22] <fenn> sorry
[02:11:40] <skunkworks> hmm - I thought the x3 was bigger than that for some reason.
[02:12:07] <skunkworks> Jymmm: http://www.youtube.com/watch?v=dKz81fY1OjY
[02:12:28] <fenn> the HF clone is 12-7/8'' (X), 5-3/4'' (Y), 8-5/8'' (Z) 18" swing
[02:12:38] <Skullworks-PGAB> no - If anything I'll pick up a Hurco KM3 with ballscrews ready to go - they show up cheap from time to time - and they usually have a 3hp motor
[02:15:13] <Skullworks-PGAB> Almost every part of a BP weighs more than I want to lift alone...
[02:15:40] <toastydeath> we have two horizontals at work
[02:15:49] <toastydeath> i wouldn't want to try moving one of those alone
[02:15:57] <toastydeath> i'd probably be okay moving a bridgeport with two dudes
[02:16:00] <Skullworks-PGAB> manual?
[02:16:02] <toastydeath> me being one of those two dudes
[02:16:05] <toastydeath> Skullworks-PGAB: yeah
[02:16:15] <toastydeath> they're the biggest machines in the shop, 50 hp
[02:16:20] <skunkworks> * skunkworks loves horizontal machining centers - love the chip removal.
[02:16:23] <toastydeath> well, except for the planers, which are 100
[02:16:24] <Skullworks-PGAB> I used to run an old Cinci
[02:16:32] <toastydeath> but the planers aren't mills
[02:16:41] <toastydeath> nor do they turn on
[02:17:01] <toastydeath> they are neat machines!
[02:17:16] <toastydeath> we have some big cutters for them
[02:17:20] <toastydeath> nobody really uses them much
[02:17:36] <toastydeath> one of the cutters is 12" diameter, 7" wide
[02:17:48] <fish> can someone explain to me how this thing works?
[02:17:50] <toastydeath> stagger tooth cutter thing
[02:17:50] <fish> http://www.aanrip.nl/backlashmoer2.jpg
[02:17:59] <fish> I see some O-rings...
[02:18:08] <toastydeath> the o-rings provide clamping force
[02:18:14] <toastydeath> on the threads in the nut
[02:18:19] <toastydeath> which takes the backlash out
[02:18:20] <fish> and that reduces backlash?
[02:18:30] <toastydeath> yeah, mostly
[02:18:37] <fish> doesnt seem like a lot of clamping force
[02:18:47] <toastydeath> it's not, but you're not really going to be hogging metal off
[02:19:10] <fish> well what's hogging metal off
[02:19:14] <fenn> supposedly the o-ring can stretch after a while with that design
[02:19:28] <toastydeath> fish, 5 horsepower cuts
[02:19:33] <fish> ok
[02:19:35] <toastydeath> i would say "hogging" starts
[02:19:38] <fish> so for the x2, that would work?
[02:19:42] <toastydeath> yep
[02:19:41] <fish> haha
[02:19:45] <fish> ok
[02:19:46] <fenn> here is a design that doesnt have that problem, but its more complicated: http://www.dumpstercnc.com/leadnuts.html
[02:19:48] <fish> seems like a simple solution
[02:20:05] <fish> I like the dumpstercnc address
[02:20:07] <fish> that appeals to me
[02:20:10] <toastydeath> ha
[02:20:20] <fenn> me too
[02:20:30] <Skullworks-PGAB> good for engraving, PCB and light routing
[02:21:34] <cradek> I use those nuts and they work well
[02:21:39] <fish> would doing PCBs and engraving work with a CNC converted X2, assuming your piece is small enough?
[02:21:52] <toastydeath> sure, they're both mills
[02:21:59] <fenn> you dont need very much rigidity for pcb's
[02:22:04] <toastydeath> the x3 is just bigger and beefier
[02:22:05] <fish> ok just checking
[02:22:23] <cradek> any backlash will kill a pcb though
[02:22:27] <fenn> a mill is actually probably a bad choice because the spindle doesnt go fast enough
[02:22:35] <toastydeath> you can use weights for pcb drilling
[02:22:38] <toastydeath> and get very good positioning
[02:22:44] <fenn> weights?
[02:22:46] <toastydeath> yar
[02:22:49] <fish> will a few thou backlash really affect pcbs?
[02:22:54] <fenn> to hold it in place you mean?
[02:22:56] <toastydeath> that's a trick they used on jig borers
[02:23:01] <toastydeath> they attached a line and a pulley to the table
[02:23:03] <toastydeath> and hung weights on it
[02:23:11] <toastydeath> kept the table up against the leadscrew
[02:23:15] <skunkworks> cradek: you maxnc - you made some sort of spring loaded double nuts - right?
[02:23:15] <fenn> ah
[02:23:24] <cradek> consider that it's common to want to cut traces .006-008 wide
[02:23:30] <cradek> skunkworks: yes I use those dumpstercnc nuts
[02:23:34] <fish> oh?
[02:23:36] <skunkworks> ah
[02:24:10] <fish> wow ok
[02:24:19] <toastydeath> teeny!
[02:24:22] <fish> so if I wanted to do pcb work, definitely go with ballscrews?
[02:24:37] <cradek> that's not necessary, you just need a solution for backlash
[02:24:39] <toastydeath> definately use something that takes the backlash out of the leadscrew, or go to ballscrews
[02:25:18] <cradek> before I got those acme screws and dumpstercnc nuts, I used a spring between two nuts on triangular threads
[02:25:20] <fish> are the solutions you guys provided me enough?
[02:25:24] <toastydeath> sure
[02:25:39] <toastydeath> any of those spring/o-ring thingies will work
[02:25:58] <fish> for pcbs?
[02:26:02] <toastydeath> sure
[02:26:07] <fish> excellent
[02:26:15] <maddash> * maddash just cracked wep
[02:26:19] <toastydeath> i KNOW there are people using those who are doing really light stuff in aluminum
[02:26:53] <fish> why not just use bigger springs for the dumpstercnc screws
[02:26:59] <toastydeath> more wear
[02:27:00] <fish> and then use 400 oz in steppers
[02:27:02] <toastydeath> higher static friction
[02:27:10] <fish> wear I can deal with
[02:27:18] <toastydeath> and you still get follow error
[02:27:19] <fish> just replacing the parts every once in a while
[02:27:19] <cradek> I've cut Al with those
[02:27:30] <cradek> they're not as weak as you think
[02:27:33] <maddash> i wonder how much bandwidth #emc takes up
[02:27:34] <fenn> i bet there's a point where you get more "backlash" because of stiction/elasticity in the screws
[02:27:37] <fish> I was planning on doing light cuts in steel
[02:27:42] <toastydeath> fenn: yes, follow error
[02:27:49] <toastydeath> that the machine can't see
[02:28:08] <toastydeath> it will show up in cuts
[02:28:19] <fenn> points on a circle
[02:28:33] <fish> I see
[02:28:34] <toastydeath> or rounding in sharp corners
[02:28:45] <toastydeath> if the feed changes direction at a good clip
[02:29:12] <toastydeath> you can see it if you use a scale on the table instead of the leadscrew
[02:29:19] <toastydeath> for positioning
[02:29:23] <fish> well thanks for the help guys
[02:29:24] <fish> good night
[02:29:27] <toastydeath> cya!
[02:30:35] <fenn> i guess they really hate cleaning out t-slots: http://machineshop.olin.edu/equipment/media/original/bridgeport_mill.jpg
[02:30:50] <fenn> doubt it ever gets used tho
[02:30:56] <maddash> what's the point of the t-slot?
[02:31:02] <toastydeath> mounting
[02:31:08] <fenn> to collect swarf so it doesnt fall on the floor
[02:31:14] <toastydeath> mounting crap to the table.
[02:31:18] <toastydeath> like, vises.
[02:31:32] <fenn> thats silly, if they were serious they'd just put an array of tapped holes
[02:31:40] <toastydeath> judging from the corners of that room
[02:31:44] <toastydeath> that machine indeed does not get used
[02:31:47] <maddash> there's a plate covering the entire tray of that bridgeport
[02:31:55] <toastydeath> i vacuum after i use the crap at work, and there's still chips stuck in the corner
[02:32:11] <toastydeath> yeah, it keeps the chips out of the slots
[02:32:15] <maddash> fenn: I don't think an array of tapped holes could never be as good as t-slots
[02:32:22] <maddash> toastydeath: magnets.
[02:32:32] <toastydeath> aluminum isn't magnetic?
[02:32:46] <maddash> sucks to be you
[02:32:53] <maddash> flush it out with oil
[02:33:01] <fenn> maddash: why not?
[02:33:02] <toastydeath> or just keep it out of the slots in the first place.
[02:33:21] <maddash> fenn: tapped hole array don't allow arbitrary positioning
[02:33:23] <fenn> besides the fact that everything is designed for t-slot mounting
[02:33:35] <toastydeath> there is stuff with holes
[02:33:48] <toastydeath> usually measurement stuff
[02:33:57] <fenn> eh?
[02:33:59] <toastydeath> t-slots allow the most rigid setup possible
[02:34:10] <toastydeath> while tapped holes are fast to use
[02:34:43] <toastydeath> master rotary tables and angle masters use tapped holes
[02:34:54] <fenn> why?
[02:34:54] <toastydeath> some granite surface plates have a section of holes
[02:35:00] <toastydeath> why to which part
[02:35:11] <fenn> why do "master" rotary tables use tapped holes?
[02:35:37] <toastydeath> two reasons - one, it's faster and you don't need t-nuts
[02:35:39] <fenn> because you can use locating pins in a counterbored hole?
[02:35:40] <jmkasunich> fenn - given a choice between slots and holes I'd take slots every time
[02:35:51] <toastydeath> they don't want anyone using any sort of indicator
[02:36:00] <toastydeath> to try and use the slots to indicate the table in
[02:36:16] <toastydeath> no center hole, no slots, just a bunch of tapped holes in a grid
[02:36:19] <jmkasunich> slots: can position clamps anywhere, easy to clean
[02:36:39] <jmkasunich> holes: limit where you can put clamps, get crap and chips in them and are a bitch to clean out
[02:36:48] <toastydeath> but they're fast!
[02:36:57] <jmkasunich> not when they're dirty
[02:37:01] <toastydeath> true.
[02:37:03] <maddash> isn't that what I said before?
[02:37:07] <maddash> "arbitrary positioning"
[02:37:12] <toastydeath> yes, it is
[02:37:14] <fenn> do they make "rotate in" nuts like for 8020, but to use on machine tables?
[02:37:21] <toastydeath> rotate in?
[02:37:27] <jmkasunich> yes
[02:37:44] <fenn> you tilt them about 60 degrees and it slides into the slot.. err
[02:37:45] <jmkasunich> tee nuts that have the corners of the flange cut off, so you can drop em into the middle of a slot
[02:37:49] <fenn> * fenn finds a picture
[02:37:51] <toastydeath> oh
[02:37:57] <jmkasunich> as you tighten them then turn into position to grip
[02:37:58] <toastydeath> that's kind of cool
[02:38:00] <maddash> once 3d-printing becomes practical, machining should be mostly obsolete
[02:38:07] <toastydeath> looool
[02:38:08] <maddash> sorry, guys.
[02:38:23] <toastydeath> perhaps, but i'm not going to hold my breath
[02:38:25] <fenn> i for one welcome our laser overlords
[02:39:03] <fenn> * fenn gives up on finding a picture
[02:39:04] <toastydeath> it would be interesting to see a laser printer beat a progressive die
[02:39:12] <toastydeath> or see it beat a multispindle screw machine
[02:39:15] <jmkasunich> lol
[02:39:26] <fenn> well you just gotta parallelize
[02:39:35] <toastydeath> or make the dies for either
[02:39:35] <jmkasunich> don't be silly
[02:39:43] <fenn> but i like being silly
[02:39:45] <jmkasunich> (fenn)
[02:40:03] <jmkasunich> have you ever seen progressive stamping?
[02:40:11] <fenn> i meant for lasers
[02:40:16] <toastydeath> pew pew pew
[02:40:17] <fenn> but laser is the wrong way to do it anyway
[02:40:27] <fenn> they dont make silicon chips with lasers
[02:40:45] <Jymmm> cynied
[02:40:47] <toastydeath> OR DO THEY
[02:40:49] <Jymmm> cynied gas
[02:41:06] <skunkworks> damn keyboard on this portable finally died
[02:41:06] <maddash> cyanide?
[02:41:12] <Jymmm> yeah
[02:41:17] <maddash> rofl
[02:41:24] <skunkworks> jymmm: did you see the video?
[02:41:26] <fenn> there's more ways to etch silicon than you can shake a stick at
[02:41:25] <Jymmm> I used to work at NSC
[02:41:33] <toastydeath> it will be interesting to see if 3d printing in metals ever makes stuff faster than traditional machining
[02:41:35] <Jymmm> skunkworks: yeah, cool
[02:42:03] <toastydeath> it certainly won't make stuff fast enough in plastics to beat mold injection
[02:42:11] <fenn> well it depends on the shape
[02:42:26] <jmkasunich> holy crap: http://www.youtube.com/watch?v=W_YnaHNcISw
[02:42:40] <toastydeath> hahah i saw that
[02:42:46] <toastydeath> i cringed
[02:43:30] <jmkasunich> they are sitting IN the fscking press!
[02:43:47] <fenn> lets see what happens when the management decides to raise production rates
[02:44:02] <cradek> jeez
[02:44:23] <cradek> the back guy leans out from under it to get the next piece just as it comes down
[02:44:30] <jmkasunich> the very fact that they can affort to have about 8 guys loading and unloading a single press boggles the mind
[02:44:44] <skunkworks> relatives of the owner
[02:44:44] <toastydeath> compared to the cost of that die
[02:44:52] <toastydeath> it's nothing
[02:45:12] <toastydeath> they still load dies like that by hand here, too
[02:45:14] <fenn> oh come on, it looks like a food pan or something
[02:45:15] <Jymmm> Gaqwd lets hope you never have to sneeze
[02:45:22] <toastydeath> fenn:
[02:45:34] <toastydeath> that's probably a half million to three quarter million dollar die
[02:45:45] <toastydeath> doesn't matter that it's dog pans
[02:45:51] <toastydeath> the size of it is what determines the cost
[02:45:57] <jmkasunich> toastydeath: they only load by hand for fairly short runs
[02:46:07] <jmkasunich> if it was volume they'd have some kind of automation
[02:46:11] <toastydeath> not necessarily, man
[02:47:04] <toastydeath> the cost of manpower to run the die is small compared to maitnence, and is completely puny compared to the profit generated by it
[02:47:09] <toastydeath> even loaded by hand, every part
[02:47:30] <toastydeath> high speed presses are autofed, sure
[02:47:42] <toastydeath> but slow ones like that, it still makes sense to load them by hand
[02:47:48] <skunkworks> hmm - looks like $17 + $20 shipping will get me a keyboard on ebay ;)
[02:47:52] <jmkasunich> like I said, it depends on the run size
[02:48:01] <toastydeath> even for a million parts, dude
[02:49:48] <jmkasunich> I find it hard to believe an american company would do a run of a million of anything with manual loading
[02:50:45] <toastydeath> some places just don't use automation.
[02:51:11] <toastydeath> i've got aquaintences who just retired from the die industry, working on large production dies
[02:51:13] <toastydeath> continual jobs
[02:51:18] <jmkasunich> places that make a million of something do, or they see the job go to china, or a competitor that does
[02:51:51] <toastydeath> and again, that's a generalization
[02:52:01] <toastydeath> automation is the darling of trade magazines
[02:52:07] <toastydeath> not necessarily actual shops
[02:52:26] <toastydeath> plenty of places do it, plenty of places don't
[02:52:38] <jmkasunich> I don't neccessarily means robots and such
[02:53:20] <toastydeath> what do you mean, then
[02:53:32] <Jymmm> ppl sitting in a press machine
[02:53:36] <Jymmm> no robots required
[02:53:45] <toastydeath> people don't sit in the die here in america
[02:53:50] <jmkasunich> mechanical feeders, pneumatic widgets, transfer lines
[02:53:54] <toastydeath> they wait for the die to open, go over, pull the thing out, and move it
[02:54:02] <toastydeath> someone else drops the new sheet in
[02:54:35] <jmkasunich> I saw a press making rocker arms at the Ford engine plant here - about one stroke per second, flat blanks in one end, rocker arms out the other
[02:54:48] <toastydeath> yeah, that's also common
[02:54:51] <jmkasunich> about 10 stages of transfer in the press, all pretty much mechanical
[02:55:10] <toastydeath> that is not, strictly speaking, an automated press
[02:55:13] <jmkasunich> nfw humans could do that, chinese or otherwise
[02:55:55] <jmkasunich> it sure ain't manual
[02:56:15] <toastydeath> autmated presses are ones with robots to load and unload sheets
[02:56:23] <jmkasunich> the only operation action was to dumb huge bins of blanks into one hopper and remove hoppers of finished parts (forklift driver did that)
[02:56:28] <toastydeath> and automatically lubricate the die, make sure it wasn't double fed, et cetera
[02:56:52] <jmkasunich> ok, no wonder we're arguing - we have different definitions of automated
[02:57:14] <fenn> i'd say automated is when you dont have a guy pressing a button
[02:57:14] <toastydeath> yeah
[02:57:29] <toastydeath> those presses still have human attendants, is what i am saying
[02:57:31] <toastydeath> even the high speed ones
[02:57:55] <toastydeath> to load the rolls into the die, et cetera
[02:57:58] <toastydeath> and hit "go"
[02:58:04] <toastydeath> and wait for the roll to run out
[02:58:09] <jmkasunich> right, but they don't handle every part
[02:58:15] <toastydeath> right
[02:58:25] <toastydeath> screw machines aren't automated
[02:58:33] <Skullworks-PGAB> you should see the 12 station rotary dies that makes machine gun belt links...
[02:59:00] <fenn> automated vs automatic
[02:59:05] <toastydeath> right
[02:59:08] <fenn> automatic has a guy pressing a button
[02:59:15] <Skullworks-PGAB> ribbon sheet in - links FLY out - 1100 a minute
[02:59:15] <fenn> that press was not automatic
[02:59:32] <skunkworks> * skunkworks still likes watching how chain is made.
[02:59:36] <toastydeath> lol
[03:02:22] <toastydeath> i like rolling mills
[03:02:44] <jmkasunich> big stuff there
[03:02:53] <toastydeath> srs
[03:03:30] <toastydeath> i know some of you guys were interested in error compensation
[03:03:38] <toastydeath> does emc has compensation maps or something?
[03:03:40] <jmkasunich> for work I had to go the LTV steel rolling mill in Cleveland - there was over 100,000HP of motors in one room
[03:03:47] <toastydeath> hahaha
[03:03:47] <jmkasunich> yes, emc2 can do screw error comp
[03:03:57] <toastydeath> like, how so?
[03:04:06] <toastydeath> is it a lookup table
[03:04:09] <toastydeath> or like a per-inch error
[03:04:14] <jmkasunich> read the find manual for details, but yes, its a table
[03:04:17] <toastydeath> cool
[03:04:17] <jmkasunich> up to 256 points
[03:04:25] <toastydeath> that was all i wanted to know
[03:04:29] <toastydeath> ty
[03:04:31] <jmkasunich> you enter the nominal, and either the actual or correction, for forward and reverse
[03:04:53] <jmkasunich> (so it can also correct for backlash, even lash that is not uniform over the length of the screw)
[03:05:16] <cradek> it interpolates, right? (doesn't step)
[03:05:22] <jmkasunich> right
[03:05:34] <cradek> linear or some kind of curve fit?
[03:06:17] <toast_> arrrgh
[03:06:20] <cradek> (rtfs?)
[03:06:26] <jmkasunich> linear
[03:06:30] <toast_> rtfs?
[03:06:37] <toast_> i missed a big chunk of something i think
[03:06:39] <toast_> oh well
[03:06:46] <toast_> what's the command to ask the bot for the log
[03:07:00] <Jymmm> http://www.youtube.com/watch?v=AqKvYUO7C7w&mode=related&search=
[03:08:04] <jmkasunich> logger_emc: log
[03:08:08] <jmkasunich> logger_emc: bookmark
[03:08:08] <jmkasunich> Just this once .. here's the log: http://www.linuxcnc.org/irc/irc.freenode.net:6667/emc/2007-08-09.txt
[03:08:18] <toast_> ty
[03:08:44] <toast_> linear is a good way to do it
[03:09:04] <toast_> best fit curves have shown to have poorer performance in experementation
[03:09:48] <jmkasunich> the adjustments are usually small, the variation in adjustment from one point to the next is even smaller
[03:10:02] <jmkasunich> so the change from one very small slope to another very small slope is nothing to worry about
[03:11:11] <toast_> indeed
[03:11:39] <toast_> and even then, best fit tends to generate a larger true position error than linear methods do
[03:15:22] <skunkworks> jmkasunich: where you running your geckos directly from the printer port initially - or did you only hook them up to the mesa card?
[03:16:23] <Skullworks-PGAB> geckos almost always require a breakout board
[03:16:28] <jmkasunich> I think I ran them from the parport
[03:16:45] <jmkasunich> I definitely ran them using software stepping with the 5i20 simply action as an I/O board
[03:17:01] <jmkasunich> s/action/acting/
[03:17:27] <jmkasunich> I think I'm gonna do something smart for a change and go to bed early
[03:17:28] <jmkasunich> night folks
[03:17:35] <skunkworks> Night
[03:19:36] <skunkworks> I think I am going to call it a night also.
[03:19:37] <skunkworks> night
[03:19:37] <toast_> pew pew pew
[03:19:40] <toast_> cya!
[03:19:46] <toast_> does anyone who is left know how shipping works on ebay
[03:20:05] <toast_> i am looking at this indicator and the seller says shipping is 12 bucks or so, but it's not included in the buy it now price
[03:20:35] <fenn> you add the shipping to the buy it now price.. that's the total
[03:20:44] <cradek> if the shipping price is specified, it'll get added in at checkout time
[03:20:55] <skunkworks> it will probably show up when you check out.
[03:20:56] <skunkworks> right
[03:21:13] <cradek> if it's not specified and there's not a way to calculate it on the page (like entering your zipcode) the seller probably screwed up
[03:21:32] <toast_> it's a flat rate so i hope it will be in the total
[03:21:39] <cradek> yeah it'll work then
[03:21:40] <toast_> ty folks
[03:25:20] <toast_> jesus
[03:25:33] <toast_> electronic levels are more expensive than autocollimators
[09:59:49] <anonimasu> Skullworks-PGAB: Why do they require a breakout board?
[12:15:44] <anonimasu> Skullworks-PGAB: hey..
[12:16:01] <anonimasu> Skullworks-PGAB: I read your earlier message why do you require a breakout board for geckos?
[12:16:51] <a-l-p-h-a2> a-l-p-h-a2 is now known as a-l-p-h-a
[12:18:21] <skunkworks> me?
[12:18:39] <anonimasu> yeah
[12:19:01] <anonimasu> whom05:19 < Skullworks-PGAB> geckos almost always require a breakout board
[12:19:07] <anonimasu> or someone :)
[12:19:08] <skunkworks> I am running the parker drives directly from the printer port. No issues.
[12:19:17] <anonimasu> me too
[12:19:18] <skunkworks> yes - it was him that said that
[12:19:26] <anonimasu> I just wanted to know why he said that..
[12:19:33] <anonimasu> they work great from the parport..
[12:19:52] <skunkworks> did you see my video?
[12:19:55] <anonimasu> no
[12:20:10] <archivist> Jymmm winding him up about breakouts?
[12:20:16] <anonimasu> oh
[12:20:27] <archivist> he seems to like em
[12:20:28] <anonimasu> someone should beat sense into him with a stick.
[12:20:35] <archivist> a big one
[12:20:37] <anonimasu> yeah..
[12:20:50] <skunkworks> http://www.youtube.com/watch?v=dKz81fY1OjY
[12:20:59] <anonimasu> I dont get what the big problem is, I mean making parts is what im interested in with a cnc...
[12:21:22] <skunkworks> I have not blown out a printer port yet.. :)
[12:21:39] <anonimasu> geckos are optoisolated..
[12:21:41] <anonimasu> :)
[12:21:47] <archivist> heh
[12:21:48] <skunkworks> so are the parkers
[12:21:58] <archivist> then they dont need a thing
[12:22:03] <anonimasu> yep
[12:22:35] <anonimasu> :)
[12:23:04] <archivist> he does seem to worry his little head about the wrong things
[12:24:04] <anonimasu> yeah
[12:24:26] <skunkworks> he is a 'over doer':)
[12:26:22] <anonimasu> well,:/
[12:27:07] <skunkworks> but we let robin take care of that ;)
[12:27:13] <anonimasu> http://www.youtube.com/watch?v=1AMZlDHwebw&mode=related&search=
[12:27:22] <anonimasu> _nice_ cut
[12:29:03] <anonimasu> I dont have any sound right now so I cant hear how it sounds
[12:30:05] <anonimasu> sounds nice
[12:32:23] <skunkworks> uh oh - his evil twin
[12:32:34] <archivist> * archivist copies to self to look http://www.youtube.com/watch?v=1AMZlDHwebw&mode=related&search=
[12:35:53] <archivist> thats not messing about!
[12:36:18] <archivist> http://www.youtube.com/watch?v=dKz81fY1OjY
[12:37:03] <anonimasu> :)
[12:38:07] <skunkworks> jepler pointed out that the comment at the top of the 'EMC2 AXIS' program says 'not for milling' ;)
[12:38:39] <anonimasu> :)
[12:38:57] <skunkworks> I never noticed that
[12:39:06] <archivist> steppers are nearly as noisy as the cutting head
[12:39:26] <skunkworks> or - the cutting head is pretty quiet..
[12:39:54] <archivist> or the microphone was near the steppers
[12:40:14] <skunkworks> The 2 S6 drives are definatly a bit noisier than the OEM650 drives. The S6 drives are a bit older.
[12:40:25] <skunkworks> the microphone was on the cam corder
[12:41:16] <skunkworks> I am going to use all OEM650's but I need to make a power supply. I grabbed 2 of the S6 drives as they have power supplies internally.
[12:41:54] <skunkworks> seem to work just fine though :)
[12:42:36] <skunkworks> you can see at the end of the video - I pan behind the engraver - the 2 big black boxes are the S6 drives and the small grey thing is the OEM650.
[12:47:01] <anonimasu> :)
[12:48:03] <anonimasu> I want to cut steel like that.
[12:48:19] <archivist> yeah that was good
[12:48:36] <anonimasu> * anonimasu is still struggling to get good cuts
[12:48:47] <anonimasu> im too scared of chiploads ;)
[12:49:03] <archivist> a good solid machine is needed for that sort of cut
[12:49:12] <anonimasu> yeah
[12:50:56] <anonimasu> hm I need to cad this roller throttle body idea out..
[12:50:57] <anonimasu> cad/cam
[12:53:40] <archivist> skunkworks, design issue with the bridge http://news.bbc.co.uk/1/hi/world/americas/6938245.stm
[12:55:14] <skunkworks> interesting.
[12:55:47] <gnix_oag> hello
[12:56:16] <archivist> I thought it was standard to load test when built almost like they were when repairing
[15:07:50] <JymmmEMC> It's too quiet in here
[15:09:22] <anonimasu> hm
[15:09:23] <anonimasu> yeah
[15:09:25] <anonimasu> * anonimasu is happy
[15:09:39] <anonimasu> I got the mill at work to interpolate corners..
[15:10:03] <anonimasu> short line segments, with < 10 degrees of direction change
[15:10:14] <JymmmEMC> cool beans
[15:10:23] <anonimasu> so im going to try doing some 3d contouring at it someday
[15:11:21] <anonimasu> I got kind of pissed off last time I tried because it'd exact stop :)
[15:11:39] <JymmmEMC> exact stop instead of contoure?
[15:11:46] <anonimasu> yeah
[15:12:03] <anonimasu> it's not the most amazing control out there but it works well
[15:12:11] <anonimasu> heidenhain tnc-310
[15:12:15] <JymmmEMC> Sorry to say it, but I wish that was the worse of my troubles.
[15:12:54] <anonimasu> :/
[15:13:13] <anonimasu> stupid old machine has less then 0.001 of backslash.
[15:13:17] <anonimasu> mm
[15:13:33] <JymmmEMC> that's awesome
[15:13:55] <anonimasu> one of the axes has 0.004
[15:14:06] <anonimasu> I think the screw's more worn there
[15:14:13] <anonimasu> that's still damn good :)
[15:14:20] <JymmmEMC> Replace the balls
[15:14:51] <anonimasu> nah
[15:15:16] <bill2or3> * bill2or3 nods off.
[15:15:24] <anonimasu> that's be overkill
[15:15:51] <JymmmEMC> :)
[15:15:59] <JymmmEMC> Gawd I love PS
[15:16:02] <anonimasu> ps?
[15:16:08] <JymmmEMC> PS == PostScript
[15:16:16] <JymmmEMC> PS != EPS
[15:16:24] <anonimasu> sorry, didnt mean to brag or anything.. it's just so cool with a machine that's damn old :)
[15:16:48] <JymmmEMC> anonimasu: Oh no, it's all good.... That's awesome for brand new too!
[15:16:56] <bill2or3> that is cool. has it just not been used much, or is it really that durable?
[15:17:07] <anonimasu> it's durable I guess
[15:17:13] <anonimasu> though the control has been replaced a few years back
[15:17:24] <bill2or3> I wish I had any time to do machining.
[15:17:27] <JymmmEMC> anonimasu: that's the easy part=)
[15:17:27] <bill2or3> stupid baby.
[15:17:30] <anonimasu> so they might have replaced screws and stuff :)
[15:17:35] <anonimasu> im trying to learn
[15:17:39] <bill2or3> ok, maybe not stupid, but still.
[15:17:44] <JymmmEMC> LOL @ bill2or3.... you play, you pay!
[15:17:52] <bill2or3> yep.
[15:18:08] <anonimasu> does anyone know polish?
[15:18:14] <anonimasu> http://cadcam.fme.vutbr.cz/?page=heidenhain&sub1=labyrint
[15:18:32] <bill2or3> of course, poland is a huge country, they all speak it over there.
[15:18:36] <bill2or3> :-)
[15:18:41] <JymmmEMC> bill2or3: Say it with me.... CON-DOM
[15:19:02] <bill2or3> nah Jymm, it was planned, but that doesn't mean I'm any less exhausted.
[15:19:02] <anonimasu> I want to know what that part is
[15:19:35] <JymmmEMC> bill2or3: So, you PLANNED to have a stupid baby huh? I think you need to fire your planners =)
[15:20:08] <bill2or3> totally.
[15:20:09] <archivist> whats the G code for baby
[15:20:11] <bill2or3> * bill2or3 fires himself.
[15:20:23] <anonimasu> that part is pretty cool :)
[15:20:25] <bill2or3> anonimasu, interesting part, if you figure out what it is, tell me.
[15:20:55] <anonimasu> i trying to
[15:21:34] <anonimasu> it's czech..
[15:22:15] <anonimasu> I think it's a labyrinth seal
[15:22:31] <anonimasu> or something
[15:22:40] <anonimasu> or a mold for something
[15:27:28] <JymmmEMC> http://pastebin.ca/651187
[15:28:01] <bill2or3> some of the other pages there show what looks like parts of a rotary engine
[15:28:07] <bill2or3> perhaps it's related to that.
[15:28:11] <anonimasu> hm,,
[15:28:14] <anonimasu> maybe..
[15:29:15] <JymmmEMC> anonimasu: That be PS, so easy to use/edit even in text form
[15:30:49] <anonimasu> * anonimasu nods
[15:31:43] <JymmmEMC> I love the fact that's really a programming language too.
[15:31:51] <bill2or3> this will translate it, kind of. http://www.translation-guide.com/free_online_translators.php?from=English&to=Czech
[15:32:53] <bill2or3> but it still doesn't tell me what the part is.
[15:33:48] <JymmmEMC> LOL, convert it to PDF and it's only 821 Bytes!!!!
[15:34:25] <archivist> it looks very similar to a labyrinth seal
[15:34:46] <bill2or3> I dont know what that is.
[15:34:49] <bill2or3> * bill2or3 googles
[15:34:54] <archivist> and the title of the page is near enough for me
[16:57:09] <toast> i recieved the most crushing news at work today
[16:57:18] <toast> we apparently were all set up to own the LODTM, from lawerence livermore
[16:57:26] <toast> OWN
[16:57:27] <toast> at our shop
[16:57:35] <toast> but couldn't afford the move
[16:58:33] <toast> at least we know the folks who are getting it
[16:58:34] <toast> and can go visit =(
[17:52:52] <anonimasu> :/
[18:34:56] <toast> pew pew pew
[18:58:38] <cradek> does anyone know about the bridgeport boss-8 (says R2E3 on the front)?
[18:59:33] <toast> nab!
[19:01:45] <skunkworks> jone had posted some info on them.. let me look. I think it is steppers.
[19:02:16] <cradek> this one is definitely servo
[19:02:25] <jepler> X Axis 30" Y Axis 15"
[19:02:28] <jepler> Quill Travel (Z) 5" Knee Travel 13"
[19:02:31] <jepler> Horse Power 2 3 Phase
[19:02:35] <jepler> ^^ the intarwebs gives this information
[19:02:48] <cradek> for one thing I wonder if it has encoders
[19:03:05] <jepler> http://www.cnczone.com/forums/archive/index.php/t-9643.html says it homes to an index pulse
[19:03:08] <skunkworks> BOSS 3 through 6 are stepper. Only the BOSS 7 amd 8 are
[19:03:15] <skunkworks> servo. Then there's the R2Ex series, etc
[19:03:19] <cradek> jepler: ah, nice find
[19:04:44] <jepler> here's a bridgeport that's actually *in* bridgeport .. http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=290038162008
[19:04:47] <cradek> there's a couple of these machines very nearby but the guy is very "optimistic" about their value
[19:04:50] <jepler> says it's boss 8 with "nc400 servos"
[19:05:17] <skunkworks> I hate 'optimistic'
[19:05:38] <skunkworks> cradek: did you buy the servo interface for the mesa card?
[19:05:55] <cradek> skunkworks: nope
[19:07:07] <cradek> http://www.cnczone.com/forums/archive/index.php/t-26311.html
[19:07:08] <cradek> definitely encoders
[19:07:11] <cradek> that's nice
[19:08:12] <cradek> maybe it's tach + encoder
[19:08:37] <anonimasu> hm
[19:16:57] <skunkworks> sweet. are you hoping to use the boss controller? ;)
[19:26:54] <cradek> skunkworks: part of the reason he's so "optimistic" is that the controllers are still working
[19:27:47] <cradek> not that I care about that...
[19:28:22] <cradek> I wish someone could tell me if I can use the motors, encoders, amps, etc as-is - that really would add a lot to what it would be worth to spend on it
[19:37:10] <skunkworks> cradek: http://groups.yahoo.com/group/CAD_CAM_EDM_DRO/message/72541
[19:37:43] <skunkworks> http://groups.yahoo.com/group/CAD_CAM_EDM_DRO/message/6222
[19:37:53] <skunkworks> looks like +/- 10v
[19:39:13] <cradek> thanks
[19:39:19] <cradek> that's good news
[19:39:53] <cradek> #emacs emcfreqmot.c
[19:39:57] <cradek> Scroll down until you find a line that says:
[19:39:58] <cradek> static int PERIOD=20;/* fundamental period for time interrupt */
[19:40:01] <cradek> ... holy cow
[19:42:24] <cradek> looks like Jon E knows a lot about these machines, maybe I should talk to him
[19:42:25] <cradek> (maybe that's what his is)
[19:43:23] <skunkworks> could be
[19:45:29] <jepler> cradek: is that how you used to have to change BASE_PERIOD?
[19:45:32] <skunkworks> the period was hard coded at one point?
[19:45:38] <cradek> yep
[19:45:40] <jepler> bleh
[19:45:42] <cradek> apparently in 2000
[19:46:05] <jepler> New in 15-Mar-2000:
[19:46:10] <jepler> So, PERIOD = 0.0000167 sets the frequency task period to 16.7
[19:46:10] <jepler> microseconds, equivalent to the original "static int PERIOD = 20" that
[19:46:10] <jepler> was hard-coded in C.
[19:46:38] <skunkworks> that wasn't that long ago.. you guys have come a long way.
[19:47:11] <cradek> before my time...
[19:49:15] <skunkworks> sounds like they are noisy - low pwm freqency
[19:49:35] <cradek> better than steppers...
[19:49:48] <skunkworks> right - I would be able to put up with it :)
[19:50:03] <skunkworks> I am good at ignoring things.
[19:50:37] <cradek> the original control rapids at 250
[19:51:20] <skunkworks> nice
[19:51:29] <skunkworks> I wonder what the max contouring is
[19:52:00] <skunkworks> like our laser is like 100ipm cutting - 400ipm rapids
[19:52:16] <cradek> I think he drip feeds from a PC, so it might stop after each move
[19:52:27] <cradek> he wasn't real clear about it
[19:57:23] <skunkworks> depends on how many blocks it can read in at a time.
[20:31:28] <skunkworks> good read http://finance.groups.yahoo.com/group/geckodrive/message/12405
[20:34:01] <anonimasu> omfg..
[20:34:04] <anonimasu> I hate cnczone so much
[20:34:13] <anonimasu> http://www.cnczone.com/forums/showthread.php?t=41553&page=3
[20:34:22] <bill2or3> DUDE I AM MAKING HELIKOPT3R PARTS!
[20:34:44] <toast> uh
[20:34:57] <anonimasu> fuck it.
[20:35:07] <toast> if someone sets out to build a cam measuring machine and fails
[20:35:09] <toast> they are idiots
[20:35:19] <anonimasu> yeah..
[20:35:20] <anonimasu> it's a damn simple thing
[20:35:50] <toast> making a CNC version would add complexity, though
[20:35:52] <anonimasu> but that guy NC_CAMS turned it(like all other fscking threads he's involved into into a "IM THE L33T CAMGRINDER"
[20:35:56] <anonimasu> toast: cnc?
[20:36:02] <toast> non-analog
[20:36:12] <anonimasu> toast: measure/rotate the cam measure jerk/acceleration and lift..
[20:36:22] <anonimasu> I mean, it's a rotart to linear translation..
[20:36:25] <anonimasu> and a angle encoder..
[20:36:43] <skunkworks> no - it is way more complicated then that ;)
[20:36:56] <toast> the stuff that measures accurately
[20:37:00] <toast> is kind of nonlinear
[20:37:13] <toast> so you could get a general overview of the cam that way, yes
[20:37:41] <toast> but you'd need a function generator and a differential probe
[20:37:50] <toast> and, a spindle, natch
[20:37:57] <anonimasu> toast: I'm not following..
[20:38:04] <toast> ha ha cam joke
[20:38:08] <toast> "i'm not following!"
[20:38:10] <toast> anyway
[20:38:14] <anonimasu> toast: the commerical cam measurement machines has a probe(roller) that goes on top of the cam.
[20:38:19] <anonimasu> and a angle encoder for the rotation of the cam..
[20:38:21] <anonimasu> :)=
[20:38:24] <toast> yeah
[20:38:32] <toast> like i alluded to
[20:38:38] <toast> it depends on how accurately you want to measure the cam
[20:38:47] <toast> couple tenths, that's an awesome way to do it
[20:38:53] <anonimasu> tenths!
[20:39:00] <anonimasu> that's huge.
[20:39:34] <toast> i'm telling you how the followers work when they need to be more accurate than that
[20:39:52] <toast> it doesn't just follow the cam, because the equipment that measures more accurate than tenths is nonlinear
[20:40:07] <toast> so it requires a little more fenagling
[20:40:09] <toast> is that how you spell that?
[20:40:13] <toast> fenagling?
[20:40:25] <toast> yeah, apparently it is
[20:41:10] <anonimasu> toast: encoders are linear afaik..
[20:41:27] <fenn> hmm i think art fenerty is full of crap
[20:41:27] <toast> they're not using encoders
[20:41:34] <toast> to measure the linear distance past tenths
[20:41:41] <toast> LVDT's, capacetence sensors, etc
[20:42:12] <toast> there are a couple ways to get that kind of measurement, but it all kind of sucks
[20:42:34] <skunkworks> fenn: He didn't seem to be slamming emc - that atleast counts for something
[20:43:31] <fenn> well its hard to slam someone else when your software is obviously inferior
[20:43:34] <toast> hahahah
[20:43:41] <skunkworks> ouch :)
[20:43:49] <cradek> I wonder why people are so scared to just try it - it's free after all
[20:44:15] <anonimasu> toast: yeah, there are lots of ways to measure, though good/cheap..
[20:44:37] <toast> good/cheap/quick
[20:44:43] <toast> the whole pick two thing.
[20:44:49] <anonimasu> I have some 0-20mm inductive sensors ;)
[20:44:56] <anonimasu> analog out.
[20:44:55] <anonimasu> :p
[20:45:00] <toast> i still love analog
[20:45:04] <anonimasu> if you have a 16 bit adc..
[20:45:11] <toast> we have analog amps
[20:45:16] <toast> for that kind of gear
[20:45:19] <toast> they're very versatile
[20:45:27] <anonimasu> that gives you 20/65535 mm
[20:45:55] <anonimasu> ofcourse not optimal for doing that kind of thing ;)
[20:46:10] <toast> what kind of thing
[20:46:19] <anonimasu> a analog inductive sensor..
[20:46:33] <toast> for measuring cams?
[20:46:37] <toast> or for digitizing
[20:46:40] <anonimasu> yeah
[20:46:58] <toast> why not?
[20:47:08] <anonimasu> * anonimasu is mostly pissed off because of the attitude..
[20:47:27] <toast> pew pew pew!
[20:47:33] <toast> analog lasers!
[20:47:43] <anonimasu> I mean, if someone wants to build something and you keep talking about your buisness
[20:47:45] <anonimasu> and how much better you do it..
[20:48:08] <anonimasu> *sigh*
[20:49:10] <toast> =(
[20:49:32] <fenn> ok, measuring a cam, how is that hard?
[20:49:43] <toast> measuring it accurately is hard
[20:50:11] <toast> unless you spend a lot of money using tools that are linear over the entire cam's throw
[20:50:48] <fenn> how bout a dial indicator
[20:50:56] <anonimasu> how about a encoder?
[20:51:04] <anonimasu> and a lever..
[20:51:07] <fenn> a dial indicator _with_ an encoder :)
[20:51:09] <anonimasu> yeah..
[20:51:29] <toast> lol.
[20:51:50] <toast> for anyone in home shop machining that would need to make their own cam, both of those methods would work!
[20:52:46] <toast> make an eccentric EMC measuring machine
[20:52:55] <fenn> i guess if feeler gauges are "yardsticks" then so are gauge blocks
[20:53:07] <toast> ?
[20:53:14] <anonimasu> well, or just buying a lvdt..
[20:53:28] <fenn> Our linear encoders break a lift down to millionths of an inche. Do we need to do it that fine? Probably not. Then again, some guys measure piston clearance with yard sticks (feeler gages), some use micrometers to 0.001" and others to 0.0001". How accurate do you want/need to be?
[20:53:31] <anonimasu> my reseller selld ones down to 1.5um..
[20:53:39] <anonimasu> sells..
[20:53:42] <toast> and this brings me back to my poing about nonlinearity
[20:53:49] <toast> LVDTs are ridiculously nonlinear
[20:53:50] <anonimasu> 0.2% linearity..
[20:54:08] <toast> .2% over the entire envelope?
[20:54:31] <anonimasu> yes
[20:54:39] <toast> is that total error along the entire measure
[20:54:49] <toast> or is that at the two limits
[20:55:31] <anonimasu> 0,3% is standard
[20:55:34] <anonimasu> 0,2% is optional
[20:55:40] <toast> because that's .0005" over the travel
[20:55:40] <anonimasu> http://www.hemomatik.com/bild_pdf/Oversikt/59/SM_LVe1_h.pdf
[20:56:06] <toast> and that's not very linear for something outputting in micrometers
[20:56:33] <anonimasu> toast: that's 0.0127mm..
[20:57:11] <toast> a .25" lvdt
[20:57:18] <toast> with .2% linearity
[20:57:31] <toast> has five tenths of error
[20:57:58] <toast> if that lvdt is outputting millionths, which is almost assuredly is, that's five hundred units of measurement
[20:58:01] <toast> in error
[20:59:06] <toast> that's a specific case with one of our LVDTs
[20:59:06] <toast> at work.
[20:59:09] <anonimasu> * anonimasu nods
[20:59:18] <toast> that's what i am saying, nonlinear
[20:59:32] <toast> because you can resolve at millionths, but you can't use it as a length measure
[20:59:44] <toast> unless of course you hook it up to something like EMC
[20:59:52] <toast> and do an error map and correct it digitally.
[21:00:13] <anonimasu> well, you end up doing that for any measurement...
[21:00:31] <toast> not in the same way
[21:00:44] <toast> LVDT error maps look like a drunken college student trying to find their way home
[21:00:50] <anonimasu> ok
[21:00:55] <toast> there's no real coherence for it, is what i'm saying
[21:01:04] <toast> not that it's an inherently DIFFERENT kind of error map
[21:01:17] <toast> just that a lot more points are necessary
[21:01:43] <anonimasu> yep
[21:01:43] <toast> than say, leadscrew errors.
[21:02:54] <anonimasu> * anonimasu nods
[21:03:18] <toast> pew pew pew!
[21:03:38] <skunkworks> anonimasu: your mentioned http://www.cnczone.com/forums/showpost.php?p=329418&postcount=30
[21:03:44] <skunkworks> :)
[21:04:34] <toast> i think if you looked in the books, you'd know how to interpret the data
[21:04:44] <toast> that's the cool thing about reading, there's usually related information in books
[21:04:45] <anonimasu> heh
[21:04:51] <fenn> where does the nonlinearity come from btw?
[21:05:02] <toast> the coils
[21:05:11] <fenn> physical inaccuracy in the coils?
[21:05:12] <toast> they're not uniform
[21:05:14] <toast> yeah
[21:05:16] <skunkworks> is it consistant nonlinearity - or does it change each time?
[21:05:19] <toast> and you have three of them
[21:05:22] <toast> oh, it's ultra-consistant
[21:05:31] <skunkworks> ah - then just map it once.
[21:05:36] <toast> they make awesome dial test indicators
[21:05:35] <fenn> so you can use it to measure position to within a millionth?
[21:05:36] <toast> for that reason
[21:05:43] <toast> fenn: if you correct them, yes
[21:05:59] <toast> but you really do need a very dense error map
[21:06:02] <anonimasu> skunkworks: the same guy runs in/out at all threads with IC discussion talking about how _great_ he's skills are..
[21:06:05] <anonimasu> :)
[21:06:33] <anonimasu> im sure he really are.. but it's not like you have to tell everyone about it
[21:06:45] <toast> and also temperature control
[21:06:53] <toast> and all the other crap that goes along with millionth measurement
[21:07:06] <toast> you could probably get .00002-3 in a home shop environment with a little work
[21:07:13] <toast> and an error map
[21:07:27] <skunkworks> anonimasu: did you read the tread in emc? where he had no clue what emc could do - but was sure it wasn't good enough
[21:07:28] <toast> without spending too much money
[21:07:33] <anonimasu> skunkworks: yes
[21:08:16] <skunkworks> kill him with kindness I say
[21:08:36] <anonimasu> ah well, I'll just ignore it..
[21:08:44] <anonimasu> I think I should kill my cnczone user someday soon
[21:08:49] <toast> kill him with an EMC voltron
[21:10:56] <skunkworks> don't you like the mach biased message board? ;)
[21:11:38] <anonimasu> heh
[21:11:40] <anonimasu> no
[21:12:02] <anonimasu> i'm very very tempted to write back
[21:13:06] <anonimasu> "I hope you realize that you already told us about yourself at several other places at this board", and that hobbyists have vastly different requirements then professional teams do.
[21:14:59] <anonimasu> but, it's not worth the pain.
[21:15:45] <skunkworks> you know nc-cams has tons of supporters.. So it would be a loosing battle.
[21:16:01] <anonimasu> yep
[21:17:02] <anonimasu> I guess he's yet another engine builder.
[21:17:08] <anonimasu> they are all kind of odd ;)
[21:18:35] <anonimasu> skunkworks: btw http://www.audietech.com/
[21:18:58] <anonimasu> :)
[21:19:44] <skunkworks> he had mentioned that company I think
[21:19:55] <anonimasu> yeah
[21:22:31] <skunkworks> Hey fish
[21:22:57] <fish> howdy
[21:23:00] <fish> i'm back with more questions :)
[21:23:01] <skunkworks> How is the backlash work coming?
[21:23:12] <fish> I think I'm gonna go with ballscrews actually
[21:23:18] <fish> because they're cheaper than I thought
[21:23:38] <skunkworks> hmmm - cheap and zero backlash ball screws normally don't go togather..
[21:24:09] <anonimasu> hehe
[21:24:10] <anonimasu> no
[21:24:38] <fish> well not zero backlash
[21:24:43] <skunkworks> ah
[21:24:50] <fish> the ones on homeshopcnc
[21:25:47] <fish> he claims the standard nut/screw has a backlash of 1-4 thou
[21:26:03] <skunkworks> If I where to make a machine with cheap ball screws - I would use 2 nuts and preload them with belvel springs. But that is just my crazy talk.
[21:26:10] <fish> so the preloaded ones are even better than that
[21:26:28] <skunkworks> preloaded ballscrews if done right - have no backlash
[21:26:53] <anonimasu> * anonimasu nods
[21:27:03] <anonimasu> or you could get oversize balls and load them
[21:27:10] <fish> i've read some good things about homeshopcnc
[21:27:18] <anonimasu> until you end up at a reasonable level or precision
[21:27:22] <anonimasu> though that's lab work almost
[21:27:45] <skunkworks> I have no experience with home shopcnc stuff
[21:28:02] <fish> they seem to be the cheapest source for ballscrew
[21:28:05] <fish> and mcmaster
[21:28:58] <fish> anyone know how long the Z-axis screw on the x2 would have to be?
[21:29:12] <anonimasu> skunkworks: btw..
[21:29:38] <anonimasu> http://www.cnczone.com/forums/archive/index.php/t-38452.html
[21:30:23] <anonimasu> skunkworks: nice project :)
[21:30:39] <skunkworks> heh - I read that tread a bit.
[21:30:43] <skunkworks> thread
[21:31:08] <anonimasu> :)
[21:31:11] <anonimasu> he's there too
[21:31:29] <skunkworks> fish: I don't know of anyone that has an x2 on here. maybe jonE but he isn't on here much at all.
[21:31:55] <fish> what kinda mills do y'all have?
[21:32:44] <skunkworks> http://www.electronicsam.com/images/KandT/DSCCurrent.JPG
[21:32:50] <anonimasu> haha
[21:32:53] <skunkworks> http://www.electronicsam.com/images/KandT/DSCgantry.JPG
[21:33:06] <skunkworks> http://www.electronicsam.com/images/engraver/engraver.JPG
[21:33:28] <fish> jeeze
[21:33:30] <fish> you dont' mess around
[21:33:54] <skunkworks> the first one isn't running at the moment. It is going to be converted to emc22
[21:33:59] <skunkworks> or emc2 even
[21:34:25] <fenn> * fenn gets the whip
[21:34:37] <skunkworks> yah yah - I am slow
[21:34:41] <skunkworks> :)
[21:34:52] <fish> lol
[21:34:55] <fenn> i want that thing rigid tapping by friday
[21:35:01] <skunkworks> I can't wait.
[21:35:08] <skunkworks> that thing is going to be a beast
[21:35:19] <skunkworks> compared to its functionallity before
[21:35:26] <anonimasu> skunkworks: 20cm cuts in steel ;)
[21:35:26] <anonimasu> frrrrrp
[21:36:14] <skunkworks> we have ripped a bunch with it. 10" facing mill and such
[21:36:20] <anonimasu> hehe
[21:36:36] <skunkworks> well - I have to drive home. BBL
[21:36:41] <anonimasu> what are you going to make with it?
[21:36:58] <anonimasu> got any plans?
[21:37:04] <skunkworks> I don't understand the question.. ;)
[21:37:20] <anonimasu> or do you just want it?
[21:37:24] <skunkworks> There is stuff I want to make - large stirling engine and such
[21:37:32] <lerneaen_hydra> skunkworks: cool
[21:37:33] <anonimasu> hehe
[21:37:41] <anonimasu> _large_ is relative :)
[21:37:42] <lerneaen_hydra> what type of sterling?
[21:38:15] <skunkworks> I want to start with a 4 cylinder - where the hot from one gets fed into the cold of the next.
[21:38:29] <lerneaen_hydra> oh, four stage
[21:38:34] <skunkworks> right
[21:38:55] <skunkworks> I have to take pictures of the solar collector yet..
[21:38:56] <lerneaen_hydra> I take it you have a regenerator on each stage?
[21:39:26] <skunkworks> Yes - probably experiementing initially with stainless wool
[21:40:02] <skunkworks> and going from there - I have piston shape ideas also. - to transfer the heat better
[21:40:11] <lerneaen_hydra> hmm I see
[21:40:26] <skunkworks> but - remember I like to wing it.
[21:40:27] <lerneaen_hydra> which temperatures (or delta temp actually) are you going to run?
[21:40:32] <lerneaen_hydra> wing it?
[21:40:36] <anonimasu> skunkworks: maybe you should ask nc_cams about it :)
[21:40:43] <anonimasu> skunkworks: im sure he has some good input on pistons
[21:40:44] <skunkworks> oh - good idea
[21:40:48] <skunkworks> :)
[21:40:58] <skunkworks> I will be back later.
[21:41:45] <skunkworks> lerneaen_hydra: ambient and 120 square foot of sunlight to begin with
[21:42:01] <lerneaen_hydra> what medium to transfer the heat?
[21:42:08] <lerneaen_hydra> sodium?
[21:42:12] <lerneaen_hydra> or something less exotic?
[21:42:46] <skunkworks> nothing that exotic - to begin with - I am putting the hot side into the focal point of the solar collector
[21:43:03] <lerneaen_hydra> oh, it's a reflective collector
[21:43:04] <skunkworks> the cold side will be cooled with water.
[21:43:17] <lerneaen_hydra> how are you going to focus on all four heads?
[21:43:29] <lerneaen_hydra> got a lake nearby?
[21:43:36] <skunkworks> heh - no
[21:44:12] <fenn> nice and fast: http://video.google.com/videoplay?docid=-2285657714531903438
[21:44:40] <skunkworks> all 4 heads will be in the same focal point (same assembly)
[21:45:37] <lerneaen_hydra> skunkworks: huh?
[21:46:28] <skunkworks> let me find a picture
[21:58:05] <skunkworks> hmm - not finding one.. BBL
[22:23:42] <toast> pew pew pew
[22:30:47] <skunkworks> lerneaen_hydra: like this in effect http://www.whispergen.com/main/wobbleyoke/
[22:31:26] <skunkworks> and this http://www.whispergen.com/main/stirlingcycle/
[22:31:32] <skunkworks> the second flash down
[22:33:47] <lerneaen_hydra> skunkworks: oh, I see
[22:34:00] <lerneaen_hydra> so no middle piston
[22:34:03] <lerneaen_hydra> that's quite a neat setup
[22:34:33] <skunkworks> right - sort of 'double acting'
[22:35:15] <lerneaen_hydra> what size are we talking about
[22:35:22] <lerneaen_hydra> over or under 10kw?
[22:35:28] <skunkworks> I don't really know yet..
[22:35:32] <skunkworks> under
[22:41:00] <skunkworks> I have a mosfet with a top row 'M T' Next row 'P2955E' bottom row R404 M < motorola symbol
[22:41:15] <skunkworks> The 9 Maybe a g?
[22:41:21] <skunkworks> I can't find anything on it.
[22:41:39] <anonimasu> heh
[22:41:49] <anonimasu> *reading the thread about emc with nccams involved..
[22:43:45] <skunkworks> I think I got it.
[22:43:49] <skunkworks> 12a 60v
[22:43:59] <toast> anonimasu: link to thread
[22:44:02] <skunkworks> anonimasu: funny huh
[22:44:24] <anonimasu> http://www.cnczone.com/forums/showthread.php?t=40309&highlight=nc_cams
[22:44:34] <toast> ty
[22:45:44] <anonimasu> it's hillarious
[22:50:04] <anonimasu> I kind of think the discussion misses the whole point..
[22:50:07] <anonimasu> ;p
[22:50:19] <anonimasu> also, who said that integration is simple..
[22:52:35] <toast> why does that one guy ramble about cars for like twenty minutes every post
[22:52:51] <anonimasu> toast: because he knows he's shit.
[22:55:06] <toast> lol
[22:56:27] <lerneaen_hydra> dude... that thread's... insane
[22:56:48] <anonimasu> lerneaen_hydra: I managed to piss him off in another thread :D
[22:56:52] <anonimasu> that's why we are at it..
[22:56:56] <lerneaen_hydra> haha, sweet
[22:56:59] <lerneaen_hydra> what are you called there?
[22:57:00] <anonimasu> <- is atleast
[22:57:02] <anonimasu> an0n
[22:57:21] <anonimasu> http://www.cnczone.com/forums/showpost.php?p=329418&postcount=30
[22:57:26] <anonimasu> the other thread
[22:58:20] <skunkworks> * skunkworks samco
[22:58:47] <toast> this nccams dude is like
[22:58:51] <toast> an idiot
[22:58:56] <toast> like, i am an idiot
[22:59:00] <toast> and i know this guy is a bigger idiot than i am
[22:59:35] <lerneaen_hydra> * lerneaen_hydra seconds toast
[22:59:48] <lerneaen_hydra> err. the bit about nccams
[22:59:59] <anonimasu> * anonimasu is kind of disturbed at him
[23:00:33] <toast> lerneaen_hydra: ahhaha
[23:00:39] <toast> ty for the clarification =)
[23:00:41] <anonimasu> We have and see them in our masters du to the logic we use to cut them (point to point milling as oppsed to curve fitting - we've tried both, long story). Via hand lapping and polishing, we get around the issues. Why bother? CNC ground masters take 7-10 days plus 1-2 days shipping and cost 2-3 time what it costs us to do them ourself - we get ours in 24-48 hours and they are made on site.
[23:01:23] <anonimasu> uys have tried to use step/direction to operate cam and OD grinders over the years. You can literally "see" the difference in the finish between a servo controlled grinder and a S/D controlled grinder.
[23:01:32] <anonimasu> well, woohoo what a fucking relevation
[23:01:40] <toast> s/d?
[23:01:41] <lerneaen_hydra> O_o
[23:01:46] <anonimasu> step/dir
[23:01:57] <lerneaen_hydra> and that has nothing to do with the input_scale, noo
[23:02:03] <anonimasu> haha
[23:02:20] <anonimasu> I should add him to my buddy list
[23:02:24] <lerneaen_hydra> have a 1:1000 timing belt and I promise you it'll be good enough
[23:02:28] <anonimasu> :)
[23:02:51] <anonimasu> agreed
[23:03:08] <lerneaen_hydra> the movement by touching the table will be greater than a couple steps
[23:03:22] <anonimasu> :9
[23:03:36] <anonimasu> well, obviously you shouldnt use step/dir on a ultra precise machine
[23:04:19] <lerneaen_hydra> of course, still it's not a flaw of step/dir
[23:04:26] <lerneaen_hydra> HAHA WTF "HOw you get counts per rev to mean something takes programming and math/calculus skills that not a lot of people posess. Heck, a lot of people don't even know what differentiation means let alone how to do it."
[23:04:36] <lerneaen_hydra> dude, seriously
[23:05:04] <toast> why do servos jitter
[23:05:28] <lerneaen_hydra> the jitter is dependant on the accuracy of the encoder
[23:05:34] <toast> oh
[23:05:33] <anonimasu> toast: because you have two phases, and no place for them to reach equillibrum..
[23:05:46] <lerneaen_hydra> as it needs to move a bit before it knows it's in the wrong place
[23:05:51] <anonimasu> and a encoder with counts it bounced between
[23:05:51] <lerneaen_hydra> then it pushes it back again
[23:06:17] <toast> oh
[23:06:20] <lerneaen_hydra> err, s/accuracy/number of counts per rev
[23:06:25] <anonimasu> lerneaen_hydra: hope that made any sense too
[23:06:27] <anonimasu> :)
[23:06:28] <toast> now this is kind of tangental but still related
[23:06:35] <fenn> whats all this about jitter? why not just set your deadband correctly
[23:06:39] <lerneaen_hydra> anonimasu: yeah, got it
[23:06:58] <toast> having said the encoder issue, someone mentioned being able to use encoderless servos and use a different input
[23:06:59] <anonimasu> fenn: that dosent keep your motors from bouncing between counts or does it?
[23:07:02] <lerneaen_hydra> fenn: I don't see how you can't have some minimal movement of the servo with a changing load
[23:07:13] <toast> i.e. table scales
[23:07:17] <toast> or some other nonsense
[23:07:37] <toast> is this true, and if so, would that eliminate the jitter
[23:07:41] <lerneaen_hydra> unless deadband is a type of hysteres and the load it low
[23:07:50] <lerneaen_hydra> *is
[23:07:51] <anonimasu> toast: the mill at work uses resolvers on the servos(might be tachos) and feedback with linear scales
[23:07:59] <toast> ah, so they're different items
[23:08:18] <lerneaen_hydra> anonimasu: resolvers, was that something that gives an analog sin/cos output?
[23:08:21] <anonimasu> yeah
[23:08:25] <lerneaen_hydra> ok
[23:08:27] <anonimasu> I think it's tachos..
[23:08:35] <lerneaen_hydra> crap, it's late
[23:08:41] <anonimasu> really
[23:08:43] <lerneaen_hydra> 'night all
[23:08:48] <anonimasu> night lh
[23:08:57] <dmessier> g'nite
[23:08:57] <toast> could always make a HAL thing to control a fast tool servo
[23:09:00] <toast> to correct the jitter
[23:09:02] <dmessier> and Hi all
[23:09:10] <anonimasu> fast tool servo?
[23:09:19] <anonimasu> toast: the jitter is between two encoder counts..
[23:09:31] <toast> anonimasu: there are a couple different types but the type i'm talking about is a piezoelectric actuator
[23:09:31] <anonimasu> or well a few.. depending on your pid..
[23:09:40] <toast> so that vibration or other position error
[23:09:46] <dmessier> any thoughts on hoe a linear motor will react to EMC2???
[23:09:48] <toast> is cancelled out at the tool or some other spot
[23:09:49] <anonimasu> it's not position error..
[23:09:57] <toast> it's vibration into the axis, right?
[23:10:04] <anonimasu> it's so extremely little..
[23:10:15] <anonimasu> ofcourse the coarser encoders the bigger it gets..
[23:10:18] <toast> it's still positioning error
[23:10:35] <fenn> skunkworks: i think mach steprate is actually faster than emc, or maybe that was turbocnc that was faster. anyway there is a stepper driver in tuxcnc that is faster than either of them, i dunno if it ever got integrated into emc
[23:10:37] <toast> put a fast tool servo between the main servo and the leadscrew
[23:10:44] <toast> have it watch the jitter and counteract it
[23:10:47] <toast> analog
[23:11:03] <anonimasu> toast: the jitter is _extremely_ fast..
[23:11:13] <toast> the acuators are faster
[23:11:18] <toast> but expensive
[23:11:22] <anonimasu> toast: how will you compute how much to actuate?
[23:11:29] <anonimasu> toast: is this actually a real problem?
[23:11:28] <toast> analog tuning
[23:11:34] <toast> yes, it's really in real machines
[23:11:46] <anonimasu> toast: tell me about what commercial machines that does this..
[23:11:55] <anonimasu> dont bring diamond turning lathes into this..
[23:11:55] <toast> ultraprecice grinders, for one
[23:12:05] <toast> semiconductor equipment
[23:12:13] <toast> some microscopes
[23:12:24] <toast> roll lathes use BIG ones
[23:12:27] <toast> hydraulic
[23:12:31] <anonimasu> toast: if you have a 5000cpr encoder..
[23:12:34] <toast> to turn around keydrives
[23:12:45] <anonimasu> in quadrature that's 4x the amount of pulses..
[23:13:01] <anonimasu> that's 20 000 counts per rev.. if I remember it right
[23:13:14] <anonimasu> let's say the jitter is 5 counts..
[23:13:18] <toast> sure
[23:13:44] <anonimasu> that's 360/20 000
[23:14:05] <anonimasu> *5
[23:14:17] <anonimasu> 0.09 degrees
[23:14:39] <fenn> how is jitter going to be 5 counts?
[23:14:50] <anonimasu> fenn: it's probably more like 1 count..
[23:14:57] <toast> piezoelectric actuators can position in tenths of nanometers
[23:15:01] <anonimasu> fenn: bad pid loop..
[23:15:03] <fenn> i thought it was <2 by definition
[23:15:08] <toast> at very high frequencies
[23:15:08] <anonimasu> fenn: you are probably right
[23:15:18] <anonimasu> 0.018 degrees in that case..
[23:15:24] <anonimasu> that's how much the servo is ~
[23:15:50] <anonimasu> if one rev of the leadscrew is 5mm
[23:16:06] <anonimasu> (5/360)*0.018
[23:16:18] <anonimasu> 0.00005mm
[23:16:29] <toast> it's obviously more than that if it's affecting surface finish
[23:16:33] <anonimasu> fenn: please correct my math is it's wrong..
[23:17:33] <toast> okay, so a millionth of an inch or so
[23:17:52] <anonimasu> yeah
[23:17:57] <toast> a) that's a positioning error
[23:18:07] <toast> and b) a fast tool servo will cancel it out
[23:18:16] <toast> practically, they're used for surface finish
[23:18:40] <toast> so you can use sub-par stuff in other parts of your machine, where you don't need real darn good true positioning
[23:18:44] <toast> but want a nice surface finish
[23:19:48] <toast> i'm not trying to make any sort of like, arguement here that people should be going out and buying all sorts of equipment
[23:20:04] <fenn> anonimasu: i get .0005mm
[23:20:17] <toast> i'm just saying that there is that option out there
[23:20:47] <anonimasu> fenn: that's probably more accurate
[23:20:58] <toast> that would def. affect visible surface finish
[23:21:55] <anonimasu> toast: well, I guess cnc machines arent good at all..
[23:22:00] <toast> huh?
[23:22:15] <toast> cnc makes fast tool servos even better
[23:22:16] <fenn> yep cnc is crap
[23:22:28] <fenn> what is wrong with you people
[23:22:31] <toast> because then you can develop comprehensive error maps
[23:22:32] <Ziegler> hehe
[23:22:34] <anonimasu> toast: I dont know of any cnc mill that does that kind of stuff.. or has a need to..
[23:22:52] <toast> okay, i said this in response to a grinder statement by nccams
[23:23:11] <anonimasu> toast: Okay, but what he really were talking about were stepper motors..
[23:23:30] <anonimasu> not servo motors..
[23:23:41] <toast> all i am saying, and have been saying
[23:23:51] <toast> is that fast tool systems are used to correct surface finish and small positioning errors
[23:24:00] <toast> i don't know how this grew into "toasty hates cnc"
[23:24:02] <fenn> toast: what about active vibration damping?
[23:24:04] <toast> and "no mills use it"
[23:24:22] <toast> that damps vibrations, not necessarily positioning or asynchronous errors that would hurt surface finish
[23:25:11] <toast> vibration isolation is certainly an excellent thing
[23:25:18] <anonimasu> yeah I see them in use in dtl's..
[23:25:37] <toast> they're used in all sorts of things!
[23:25:38] <toast> even on big roll lathes!
[23:26:10] <fenn> wow nice tape reader skunkworks
[23:26:12] <toast> semiconductor fabrication equipment
[23:26:30] <toast> laser mirrors
[23:26:58] <fenn> i'm curious about active damping for hexapods
[23:27:13] <fenn> since they dont have the mass or cast iron, you need to use a hi-tech solution
[23:27:23] <anonimasu> hm, im curious about the actuation of them
[23:27:24] <toast> when you say active damping, what parts of it do you want to damp
[23:27:30] <fenn> like viscoelastic shear or piezo actuators
[23:27:49] <fenn> toast: well, i mean put piezo actuators where the struts meet the platform
[23:27:58] <anonimasu> * anonimasu nods
[23:28:00] <toast> i thought they were pretty stiff?
[23:28:13] <fenn> * fenn shrugs
[23:28:45] <fenn> what if $200 of vibration damping saves you $3000 in monstrous ballscrews
[23:29:14] <toast> what you are describing IS a fast tool system
[23:29:15] <skunkworks> fenn: ?
[23:29:20] <fenn> yes
[23:29:24] <fenn> skunkworks: http://www.electronicsam.com/images/KandT/conversion/frntcontroller.JPG
[23:29:26] <anonimasu> fenn: http://www.physikinstrumente.com/en/products/prdetail.php?sortnr=700800
[23:30:04] <fenn> anonimasu: that just uses servos doesnt it?
[23:30:13] <anonimasu> I dont know
[23:30:23] <anonimasu> Actuator Resolution to 0.005 ┬Ám
[23:30:23] <anonimasu> :D
[23:30:23] <skunkworks> ah - yes - we only used it for a bit before desciding it was for the birds. The computer (386sx) turned into the tape emulator.
[23:30:30] <fenn> the M-850 uses custom high-load precision screws and servo-motors
[23:30:54] <fenn> anonimasu: resolution doesnt mean active damping, you have to have the actuator bandwidth too
[23:31:00] <anonimasu> yeah
[23:31:01] <anonimasu> ofcourse
[23:31:07] <anonimasu> it were pretty good :)
[23:31:19] <anonimasu> 200kg load capacity
[23:31:28] <fenn> piezos are several orders of magnitude faster than servos
[23:31:48] <anonimasu> they have one with screws or direct drive actuators
[23:31:55] <fenn> 10000g acceleration i read in some article
[23:31:59] <anonimasu> which I think means piezoelectric/linearmotor
[23:32:00] <anonimasu> yep
[23:32:03] <anonimasu> that's right
[23:32:08] <fenn> no direct drive just means the motor is attached to the screw directly
[23:32:19] <anonimasu> ah, that way :/
[23:32:47] <fenn> not sure that's an advantage either.. you get heat from the motor warping the screw
[23:32:57] <fenn> but it looks pretty :)
[23:33:04] <anonimasu> http://sfb528.tu-dresden.de/c3/4-Y%20Verzweigung%20mit%20HEXAPOD1_.jpg
[23:33:27] <toast> the motor might be low temp
[23:33:32] <toast> or they might be heated ballscrews
[23:34:00] <fenn> they might brag about it if they had such fancy stuff
[23:34:07] <fenn> but they dont
[23:34:07] <anonimasu> yep
[23:34:09] <toast> perhaps!
[23:34:41] <anonimasu> toast: I think that it's just you :p no offence but you are precision insane..
[23:34:54] <fenn> anonimasu: wood :(
[23:35:01] <toast> anonimasu: it's kind of what i do?
[23:35:11] <dmessier> i hate carpenters too
[23:35:12] <anonimasu> fenn: nist has one with plastic
[23:35:14] <anonimasu> me too
[23:35:26] <anonimasu> http://www.hskworld.com/hexapod_1.jpg
[23:35:33] <fenn> nist uses theirs for making aluminum calibration fixtures
[23:35:44] <dmessier> linear motors??
[23:35:50] <fenn> that thing is so ugly
[23:35:54] <fenn> looks like robbie the robot
[23:36:18] <anonimasu> toast: what?
[23:36:31] <toast> huh?
[23:36:43] <anonimasu> 01:38 < toast> anonimasu: it's kind of what i do?
[23:36:52] <fenn> he carps about precision
[23:36:58] <toast> it's true, i do!
[23:36:59] <anonimasu> yeah :)
[23:37:04] <toast> at work, that's the kind of stuff i do
[23:37:08] <anonimasu> http://tww.fh-duesseldorf.de/DOCS/FB/MUV/Hexapod.JPG
[23:37:09] <fenn> carp is the opposite of carpent
[23:37:10] <toast> and that i'm getting into as a career
[23:37:31] <anonimasu> im happy if my parts are > 0.01mm
[23:37:33] <anonimasu> from where I want
[23:37:40] <fenn> eek
[23:38:02] <toast> my current chafe is the lathe i've been working on will turn surfaces flat to 20 millionths
[23:38:10] <toast> but the workholding warps them
[23:38:32] <toast> 18" rings
[23:38:36] <Ziegler> can emc do hexapod?
[23:38:39] <dmessier> send it in the machine...LOL
[23:38:50] <toast> ?
[23:38:52] <dmessier> i could DO em
[23:39:31] <skunkworks> Ziegler: yes (at least they say it does) ;)
[23:39:37] <dmessier> i Love tome tolerances...makes me remember why i am...
[23:39:44] <toast> tome?
[23:39:52] <dmessier> then
[23:39:58] <dmessier> them
[23:39:59] <toast> haha
[23:40:03] <Ziegler> is this hydraulic: http://sfb528.tu-dresden.de/c3/4-Y%20Verzweigung%20mit%20HEXAPOD1_.jpg
[23:40:16] <fenn> no
[23:40:18] <anonimasu> no
[23:40:21] <toast> isn't it?
[23:40:24] <anonimasu> you see the motors on the side
[23:40:25] <toast> I DO NOT KNOW
[23:40:25] <fenn> see the orange and green wires at the bottoms?
[23:40:30] <Ziegler> yeah
[23:40:32] <dmessier> fingers are disfunctional this evening
[23:40:32] <anonimasu> big servos :)
[23:40:37] <toast> oh, i thought those were servohydraulics
[23:40:48] <anonimasu> ick
[23:40:55] <Ziegler> sweeet
[23:41:11] <toast> dmessier: we could do them too, if we redid the workholding
[23:41:12] <Ziegler> so what does a config look like for that??!
[23:41:33] <fenn> well, it could be hydraulic servos, but i dont see why you would do that in a research project - too fiddly
[23:41:36] <toast> the problem is known, nobody wants to spend the time to make the chuck to hold the part
[23:41:38] <dmessier> hydro-static cnc machines DO exist... MOOG-hydra-point...is 1
[23:41:50] <toast> cincinati hydrotel
[23:41:52] <anonimasu> yes
[23:42:01] <dmessier> so you need tool holding help??
[23:42:09] <skunkworks> Ziegler: http://cvs.linuxcnc.org/cgi-bin/cvsweb.cgi/emc2/configs/hexapod-sim/
[23:42:15] <Ziegler> danke
[23:42:23] <toast> dmessier: no, we know what the problem is and what the fix is
[23:42:35] <toast> nobody will spend the man-hours to do it
[23:43:01] <toast> it's in tolerance at present, so we're going to leave it
[23:43:26] <fenn> toast: nothing's perfect
[23:43:31] <toast> it's just irritating to know the machine will do much better
[23:43:34] <anonimasu> heh
[23:43:43] <dmessier> slap a plate on the lathe you are gonna use.. face it...c/bore to hold part.. drill hold down clamp holes and bolt FLAT..
[23:44:12] <toast> and when you clamp it
[23:44:15] <toast> the part distorts
[23:44:20] <toast> and you don't get it any flatter than when you started
[23:44:32] <toast> it sits at 2 tenths
[23:44:35] <dmessier> some fixture require retruing every set-up
[23:45:05] <Ziegler> X Y Z R P W ?
[23:45:12] <dmessier> shim 1 side.. skim and flip and skim..
[23:45:28] <dmessier> can you??
[23:45:36] <toast> i'm seriously telling you
[23:45:46] <toast> that doesn't work in the range the machine will do
[23:46:08] <dmessier> we worked some part from both sides /001"-.002" at a time...
[23:46:28] <anonimasu> dmessier: 0.05mm right?
[23:46:29] <toast> and got it parallel to 20 millionths?
[23:46:47] <dmessier> .001-.002" tool nose radius...
[23:46:53] <anonimasu> ah ok
[23:47:02] <toast> dmessier: what was your final flatness
[23:47:01] <fenn> shimming to millionths of an inch :(
[23:47:13] <toast> you can't shim to millionths of an inch, that's the point
[23:47:15] <anonimasu> well, werm it with your hands..
[23:47:21] <anonimasu> ;)
[23:47:37] <dmessier> we also used mag chucks if we could.. once it was getting really flat..
[23:47:53] <toast> on aluminum?
[23:48:30] <anonimasu> well with enough power it'll work ;)
[23:48:33] <dmessier> alum.. Titanium.. hardened 4340... made no differance to us
[23:48:50] <toast> dmessier: you still haven't told me what your final, verified parallelism and flatness numbers were
[23:48:51] <dmessier> hardinge superlant lathes
[23:49:06] <dmessier> +/-.0001"
[23:49:07] <anonimasu> obviously it'll pull tools from the machines in the shop too
[23:49:23] <anonimasu> *grins*
[23:49:25] <anonimasu> night guys
[23:49:30] <toast> dmessier: i'm getting +.0002/-.0000
[23:49:43] <dmessier> 4 micron finish
[23:49:47] <toast> i want to get +.000020/-.000000
[23:50:02] <dmessier> same stuff..
[23:50:07] <toast> uh, what?
[23:50:14] <fenn> how do you use magnetic chucks on aluminum?
[23:50:22] <toast> dmessier: there's another zero
[23:50:25] <toast> in there
[23:50:25] <dmessier> some machines in that shop would do it..
[23:51:02] <toast> hookay
[23:51:15] <dmessier> aluminum was a pain..but the best air chuck in japan is made in the usa
[23:51:39] <toast> the proper fixture to turn to that accuracy
[23:51:45] <toast> is a special kind of 2-part chuck
[23:51:52] <dmessier> hardinge SUPER-precision... chnc II.. conquest
[23:51:55] <toast> you can load it vertically, stress free
[23:52:10] <toast> get all your torque values even and your part stress even
[23:52:18] <toast> and measure it to make sure it didn't bend at all
[23:52:31] <toast> then reconnect the chuck, and it will hold
[23:52:49] <dmessier> map it... ive seen it done on 18' pcs.. not 18"...
[23:53:12] <toast> 20 millionths of an inch over 18'?
[23:53:19] <toast> are you drunk?
[23:53:31] <anonimasu> ^_^
[23:53:45] <dmessier> no.. but to holg .0005" over 18'... you map it
[23:54:02] <toast> okay but i'm not talking about .0005" over 18"
[23:54:03] <anonimasu> dmessier: you are missing a zero to get where toast is talking about
[23:54:06] <toast> we can talk about baseball
[23:54:12] <toast> if you want to talk about things that are not what i am talking about
[23:54:24] <dmessier> i aint drunk.. im just drinkin'... ; )==~~~~
[23:54:23] <anonimasu> .0005"
[23:54:26] <anonimasu> +.000020
[23:54:30] <anonimasu> .000020
[23:54:32] <anonimasu> err there..
[23:54:35] <toast> .0002
[23:54:37] <toast> .00002
[23:55:07] <fenn> this is why we should use the metric system :P
[23:55:12] <anonimasu> fenn: thanks!
[23:55:13] <toast> i'll convert it
[23:55:22] <dmessier> can you grind it..??
[23:55:28] <anonimasu> 0.0508mm
[23:55:34] <dmessier> .001 MM
[23:55:35] <toast> grinding isn't as accurate as these lathes
[23:55:43] <toast> anonimasu: .0005 mm
[23:55:51] <dmessier> pls/...
[23:55:51] <anonimasu> toast: No.
[23:55:53] <fenn> heh anon that's wrong
[23:55:56] <toast> that's what google said =(
[23:55:59] <anonimasu> *25.4
[23:56:03] <toast> .00002 == .0005
[23:56:03] <toast> mm
[23:56:08] <toast> i am using google do not blame me!
[23:56:20] <dmessier> 1/2 micron... all you had to say
[23:56:25] <toast> i don't know metric yet =(
[23:56:33] <toast> at least know metric quickly
[23:56:34] <toast> i am trying!
[23:56:45] <dmessier> im BI
[23:56:56] <anonimasu> http://www.google.se/search?hl=sv&q=0.00002+inch+to+mm&btnG=S%C3%B6k&meta=
[23:57:10] <toast> si!
[23:57:12] <anonimasu> 0.002 inch = 0.0508 millimeters
[23:57:18] <anonimasu> 0.00002 inch = 0.000508 millimeters
[23:57:22] <toast> yes!
[23:57:25] <toast> that is what i said!
[23:57:30] <anonimasu> and what I said.
[23:57:36] <toast> yaaay team
[23:57:41] <anonimasu> though I calced dmess's value first :)
[23:57:53] <toast> it is so frustrating
[23:57:58] <toast> it goes from "damn this is a nice lathe"
[23:57:58] <anonimasu> dmessier: well, you are off by almost a planet :/
[23:58:01] <toast> to "damn this is a crappy chuck"
[23:58:12] <anonimasu> toast: better get used to it :)
[23:58:15] <dmessier> ok... so what material are you turning???
[23:58:20] <toast> 6061 aluminum
[23:59:09] <dmessier> stringy shite....tool nose rad??
[23:59:15] <toast> doesn't matter, it's diamond
[23:59:23] <dmessier> pcd??
[23:59:24] <toast> yep
[23:59:49] <dmessier> surface speed?? and tool holder type??
[23:59:57] <toast> dude, surface speed doesn't matter on diamonds