#emc | Logs for 2009-10-19

[00:02:53] <Valen> oh damn sorry guys
[00:03:08] <Valen> I was trying to fill somebodys MSN up, pasted into the wrong window
[02:12:28] <jymm> Valen: NO EXCUSES!!! For that, you must DIE!
[02:12:47] <Valen> cmon it was the black knight scene
[02:15:03] <jymm> What, you think you're batman now?!
[02:15:34] <jymm> Wait, that was "Dark Knight"
[02:15:46] <Valen> batman is cool and all, and getting with cat woman sure but really
[02:15:54] <Valen> monty python man
[02:16:39] <Valen> http://www.youtube.com/watch?v=zKhEw7nD9C4
[02:17:11] <jymm> Eh, I get it, but not into the the Monty Python humor
[02:17:25] <Valen> your american?
[02:17:32] <jymm> y
[02:17:44] <Valen> they don't get python ;->
[02:18:22] <jymm> IT's the damn Brit *DRY* ass humor
[02:19:16] <jymm> Benny Hill and Mr Bean are cool though
[02:20:50] <Valen> Mr Bean does less for me
[02:21:52] <jymm> Oh, and I like that show, um, they work in a department store, 70's, argh
[02:22:05] <Valen> are you being served
[02:22:31] <jymm> that it
[02:22:36] <Valen> you just like that for all the dirty things they say
[02:22:36] <Valen> ;-P
[02:22:37] <jymm> I think I have the whole series
[02:23:17] <jymm> They never "SAY" anyhting dirty =)
[02:23:26] <tom3p> 'goodness gracious me' it's MASSIVE ( thats brit humour )
[02:27:27] <tom3p> http://en.wikipedia.org/wiki/Goodness_Gracious_Me_(BBC)
[07:24:57] <MarkusBec_away> MarkusBec_away is now known as MarkusBec
[08:23:43] <MarkusBec> MarkusBec is now known as MarkusBec_away
[08:44:52] <archivist> model engineer pictures http://www.collection.archivist.info/archive/djcpd/PD/2009/2009_10_16_model_engineer/
[08:52:29] <wavez> archivist, very cool. Where were the first couple photos taken?
[08:52:58] <archivist> at the show
[08:53:28] <archivist> probably the best model
[08:53:38] <wavez> ya, I'm wondering what kind of a show it is
[08:53:50] <archivist> model engineering
[08:54:04] <wavez> I see
[08:54:12] <wavez> I'm new to all of this
[08:55:35] <archivist> that first model I have seen at another show running
[08:56:15] <MarkusBec_away> MarkusBec_away is now known as MarkusBec
[09:04:45] <archivist> ah he didnt have the radiator done when I first saw it
[10:00:46] <i-pink> hii all
[10:00:58] <micges_work> hi
[10:01:17] <i-pink> do you know python?
[10:01:27] <micges_work> yep
[10:01:41] <i-pink> BRB OS
[10:02:01] <micges_work> bbl lunch
[10:05:51] <i-pink> hii agin
[10:07:48] <i-pink> micges_work
[11:14:39] <micges_work> i-pink: I'm back
[11:14:54] <micges_work> i-pink: what's up?
[11:15:29] <i-pink> ok
[14:55:42] <MattyMatt> that linear drive I got on ebay arrived. not bad at all. 10mm pitch, sounds like recirculating balls, shielded screw. no more than 0.5mm backlash anywhere
[14:57:03] <archivist> kalf a mm !!! thats rattling loose
[14:57:39] <MattyMatt> close enough for woodwork :)
[14:58:34] <MattyMatt> it could have been slippage in the skin on my thumb holding the spindle. 10mm pitch gives no mechanical advantage
[15:02:09] <MattyMatt> in fact I'll probably have to gear it down, to save on motor size and get some resolution
[15:44:20] <MattyMatt> I was hoping it was a motor on it, but it was just a chunky square bearing housing , no encoder either
[17:39:30] <micges> I have question about general machining: if material is harder then is it better(faster?) to slowly mill it at desired depth or make high speed machining on it?
[17:39:58] <micges> I made tests but no reasonable results
[17:42:07] <archivist> depends on heat and tooling, and some material you need to cut under the skin to avoid rubbing
[17:42:39] <archivist> * archivist out for a bit
[17:43:13] <micges> sheet of steel, hrc50-55
[17:43:27] <micges> hardened steel
[17:57:41] <archivist_attic> logger_emc: bookmark
[17:57:41] <archivist_attic> Just this once .. here's the log: http://www.linuxcnc.org/irc/irc.freenode.net:6667/emc/2009-10-19.txt
[19:31:44] <archivist_attic> allo robh pics from Friday http://www.collection.archivist.info/archive/djcpd/PD/2009/2009_10_16_model_engineer/
[19:45:51] <robh> Hi archivist_attic sorry was away from computer
[19:46:07] <robh> did ya get them mill converted then u should of had them done by end day ;)
[19:47:35] <AchiestDragon> http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=310173603845&ssPageName=STRK:MEBIDX:IT hate it when they do that , start at 99p with a reserve that you cant hit , still high bidder also
[19:49:30] <robh> reserve prob 400 lo
[19:50:07] <AchiestDragon> prob ,,, would rather that be a starting price though
[19:51:18] <AchiestDragon> would know i was wasing my time bidding then
[19:51:51] <robh> just looking over ya pics now
[19:52:41] <AchiestDragon> some good items there archivist_attic
[19:53:02] <AchiestDragon> would of liked to have gone there
[19:53:20] <AchiestDragon> seems i could not get anyone interested in making the trip from here
[19:53:48] <robh> where is here?
[19:54:00] <AchiestDragon> near wrexham north wales
[19:54:12] <robh> aah wrong side country for us
[19:54:24] <robh> i am east anglia
[19:54:55] <AchiestDragon> yea like a 270 mile round trip for me
[19:56:45] <AchiestDragon> money like always ,,, seen a nice little xy table go on ebay last week for £50 would of got it but low on cash then ,, now got some and can only find ones from the usa at like £570
[19:57:12] <AchiestDragon> like they know and do it just to tease you into thinking you can afford one
[19:59:51] <archivist_attic> for that money get a complete mill
[20:00:13] <AchiestDragon> am in a perticuly miffed off mood today so going to abstain from chat incase i offend anyone
[20:02:49] <AchiestDragon> not that its anyones fault here
[20:18:11] <cradek> archivist_attic: what is this escapement? http://www.collection.archivist.info/archive/djcpd/PD/2009/2009_10_16_model_engineer/IMG_0390.JPG
[20:20:41] <archivist_attic> why it says on the bottom of the pic Grasshopper
[20:20:58] <cradek> oh hey, a scrollbar
[20:21:06] <archivist_attic> odd that it uses two wheels though
[20:21:39] <cradek> yeah I'd like to see it run - hard to understand the action from a still photo
[20:23:20] <cradek> that brass click wheel surprises me - that must be quite a spring in there
[20:23:57] <archivist_attic> light spring, it was running
[20:24:05] <cradek> the dial is neat
[20:24:30] <archivist_attic> shutting up time here back in a mo
[20:24:49] <cradek> http://en.wikipedia.org/wiki/File:Grasshopper-escapement-005.gif
[20:25:11] <cradek> bizarro
[20:27:07] <jymm> What causes the the right most arm to lift?
[20:27:45] <cradek> the circles are weights
[20:28:19] <cradek> the weights go down as soon as the escape wheel isn't pulling them up
[20:28:29] <jymm> I get that, it just seems that it's still engaged (maybe the animated gif is just slightly off)
[20:28:53] <cradek> hitting the other pallet causes it to disengage because the wheel reverses
[20:28:57] <cradek> (same for both)
[20:29:16] <andypugh> Ahh! Grasshopper?
[20:29:24] <cradek> very funky action
[20:29:54] <andypugh> Go on, did I guess right?
[20:30:42] <cradek> yes
[20:30:49] <jymm> OH, it is off a bit. The right arm disengages by the tooth behind the one that is hooked.
[20:31:05] <jymm> I think =)
[20:31:22] <andypugh> As the mechanism releases at zero load, there is no wear.
[20:31:42] <andypugh> The drawback is that if both pallets disengage at the same time, the clock explodes :-)
[20:32:14] <MarkusBec> MarkusBec is now known as MarkusBec_away
[20:33:14] <andypugh> Is there a low-pass filter in HAL?
[20:33:39] <andypugh> I have failed to find a list of hal components, searching the wiki only brings up the logic components
[20:35:57] <skunkworks_> http://linuxcnc.org/docs/2.3/html/man/man9/lowpass.9.html
[20:37:45] <andypugh> Thanks, not the implementation I was expecting, but I suspect it is equivalent.
[20:47:27] <kanzure> does anyone know what format .sldprt "display lists" are in? .sldprt is in a COM format and can be pried open with `gsf list` but other than that i'm stuck.
[20:51:34] <archivist> andypugh, the explode cannot happen unless the arm hinges seize or the springs break
[20:52:52] <archivist> exploded clocks are entertaining usual cause is barrel spring failure
[20:53:01] <andypugh> I thought that the pallets were biased off, and in the neutral position neither touched the escapement? I read that as the reason that Harrison invented his "maintaining power" so that there was no risk of disaster when the weights were lifted.
[20:53:49] <archivist> yes but the arm rotates so the other is engaged
[20:54:33] <archivist> you see that engagement is at full retraction
[20:55:13] <andypugh> I was just quoting Wikipedia: The natural tendency of the pallets to move out of the way of the wheel has a couple of serious consequences. The first is that any time that the drive to the escape wheel is interrupted the pallets lose contact and when the drive is restored, the escape wheel is not restrained and accelerates rapidly and uncontrollably. To prevent this, Harrison invented his longest-lasting mechanism, a
[20:55:14] <andypugh> http://en.wikipedia.org/wiki/Maintaining_power which is still widely used in clocks and watches.
[20:55:15] <cradek> this can't be used with a pendulum can it? seems like there is no freedom whatsoever
[20:55:29] <andypugh> http://en.wikipedia.org/wiki/Grasshopper_escapement
[20:56:09] <andypugh> It was originally used with a pendulum. I don't think balance wheels existed until Harrison invented them, and he did the Grasshopper first.
[20:56:19] <archivist> it is used with a pendulum
[20:57:01] <andypugh> I was wrong about the balance wheel though, they were invented long before Harrison used the,
[20:58:48] <cradek> ah, the stops (springs) can give
[21:00:12] <archivist> that one in the pic at the model engineer I think is pendulum but pendulums are boring didnt take a rear pic
[21:00:37] <cradek> 'Another disadvantage is that, in common with other escapements of its time, the grasshopper pushes the pendulum back and forth throughout its cycle; it is never allowed to swing freely.'
[21:00:40] <andypugh> Is this the animation you were looking at>
[21:00:43] <andypugh> http://commons.wikimedia.org/wiki/File:Grasshopper-escapement-005.gif
[21:00:46] <cradek> yes
[21:01:16] <archivist> there is another on the web but that one is better
[21:01:35] <archivist> I have seen the Harrison in the flesh
[21:01:57] <andypugh> The wooden one?
[21:02:27] <archivist> its brass plates with wooden parts
[21:03:01] <archivist> they are in Greenwich Maritime Museum
[21:03:19] <andypugh> Not the Observatory?
[21:03:23] <archivist> have guarded some reproductions as well
[21:03:42] <archivist> the museum is at the observatory
[21:05:12] <archivist> you must visit as you are near enough, but beware of boredom at yet another perfect ship model as you walk round
[21:06:17] <AchiestDragon> Cast Iron Worktable 400x145mm 3rd item down on page http://www.arceurotrade.co.uk/Catalogue/Machines-Accessories/Milling-Accessories would this take a stepper conversion ?
[21:06:49] <andypugh> I have been, we polished the Meridian as it was rather tarnished (we had arrived by 1916 fire engine, so had plenty of brass polish to hand)
[21:07:04] <archivist> AchiestDragon, its weeny get a better one
[21:07:46] <AchiestDragon> cant seem to source a better one for less than a sieg x2 mill compleate
[21:07:59] <archivist> AchiestDragon, I have seen that with steppers, crap
[21:08:11] <AchiestDragon> k ty
[21:09:13] <AchiestDragon> thinks im back to plan a of building one from scratch
[21:10:31] <archivist> 142 £ from a company elsewhere would be better
[21:11:23] <andypugh> http://www.axminster.co.uk/category-Drill-Vices-and-Drill-Accessories-208137.htm
[21:13:15] <archivist> http://www.gandmtools.co.uk/ I think had one at the model engineer, they also sell on fleabay
[21:16:53] <archivist> AchiestDragon, 290361069823
[21:18:09] <AchiestDragon> bit small
[21:18:30] <AchiestDragon> need 100 by 200mm travel min
[21:19:37] <aystarik> http://www.optimum-machines.com/products/accessories/1/cross-tables/index.html
[21:20:10] <archivist> ah I didnt scoll down to the larger arc euro one thats not so bad
[21:20:42] <AchiestDragon> kool the larger one is the one i was looking at so that ok then
[21:20:42] <archivist> my comment was against the weeny one at the top of page
[21:20:58] <andypugh> 280x155 for £80?
[21:21:00] <andypugh> http://www.axminster.co.uk/product-Axminster-CT1-Compound-Table-21825.htm
[21:21:16] <AchiestDragon> i got 220nm 10mm shaft nema 23 steppers that i will be using
[21:21:23] <archivist> I think the complete mill may use the same table, but thats after ballscrews are added
[21:22:23] <archivist> or get an old denford, it will already have ballscrews
[21:23:55] <AchiestDragon> the one from arceuro i think should be ideal realy £165 and 330mm by 145mm travel fits whats needed
[21:24:14] <AchiestDragon> they say its the same as the Super X1L Mill table
[21:24:48] <AchiestDragon> basicaly just looks like its a diferent base casting
[21:26:06] <AchiestDragon> next will be eather sorting out a pilar drill or fixing the quill play in the one i have and adding a z axis
[21:28:10] <AchiestDragon> FERM TABLE DRILLING MACHINE FTB-16 / 500 item 180419207946 any good ?
[21:29:30] <AchiestDragon> cant seem to find any specs that give expected quill slackness
[21:29:59] <AchiestDragon> the one i have would need reboring and a brass liner fitting
[21:30:19] <AchiestDragon> but its only a cheap thing
[21:31:00] <MrSunshine> hmm, a stepper, someone told me it just draws about 2/3 of the marked power, is that true ?
[21:31:08] <MrSunshine> so a 1.8A driver would be able to drive 2A steppers? :)
[21:31:18] <archivist> for milling you need a good spindle, drills dont cut it
[21:31:49] <archivist> I use a 2A driver for a 2A motor
[21:32:21] <MrSunshine> archivist, well a 1.8A 4 axis driver is easy accessable for me ... :)
[21:33:43] <andypugh> The stepper current is usually fixed by the driver, so a 2A stepper at 1.8A will work, but won't make quite the torque it would at 2A
[21:33:58] <andypugh> The big thing is voltage, you need lots.
[21:34:09] <MrSunshine> the driver can take 36V maximum
[21:34:18] <andypugh> Use 36V then
[21:34:27] <andypugh> Regardless of motor spec.
[21:35:09] <MrSunshine> aye, that much i have figured, was the amparage .. as the driver can handle max 1.8A
[21:35:29] <MrSunshine> http://www.brundin.biz/images/datasheets/4-axisdriverboard.htm
[21:35:54] <andypugh> Don't worry about what the driver can manage, it will self-limit
[21:36:48] <MrSunshine> ahh ok =)
[21:36:59] <MrSunshine> just so the motor doesnt get any more then 1.8A then ? :)
[21:37:35] <andypugh> Indeed.
[21:37:49] <MrSunshine> so 2052SEK and i have 3 steppers, 1.85Nm, 4 axis board with easy parallelconnect (parport connector) and 36V 9.7A power supply, sounds like a reasonable setup ? :)
[21:38:14] <andypugh> Sounds reasonable, yes.
[21:38:39] <MrSunshine> and then i would need couplings also :/
[21:38:41] <MrSunshine> dammit =)
[21:38:43] <andypugh> Unless it is a Bridgeport conversion...
[21:39:14] <MrSunshine> andypugh, and that means ?
[21:39:30] <andypugh> Converting a full-size mill.
[21:39:44] <MrSunshine> andypugh, its a X1 seig mill
[21:39:46] <MrSunshine> small one
[21:40:10] <andypugh> Sounds fine then.
[21:45:32] <MrSunshine> ye, one on an electronics channel have converted his X1 using those stepper motors =)
[23:50:14] <L84Supper> once RTAI for ARM is stable it could be interesting to add a FPGA carrier board with isolated IO http://www.technexion.com/