#emc | Logs for 2010-07-04

[00:01:06] <andypugh> Yeah, but they don't do IRC at 1am sunday morning.
[00:02:36] <andypugh> A friend of mine is having lots of vehicle parts made (1908 Dennis truck he extracted from under the house that had been built around the caravan that the chassis had been converted into). He is using MDF, filler and red-oxide paint.
[00:02:58] <cradek> I'd guess they'd prefer wood... but yeah who knows
[00:03:27] <andypugh> I just don't have any MDF, but I do have a nice block of proto-foam from the car design workshops
[00:04:42] <theorb> theorb is now known as theorbtwo
[00:06:11] <andypugh> While I am asking off-topic and random questions. Suggestions how to join a 16.5mm OD x 14mm ID tube to a 16.5mm OD tool-steel rod. Strength is important. Best plan so far is a 0.6mm pitch 14.8mm thread.
[00:06:51] <andypugh> (No, that isn't in any thread standard)
[00:07:29] <cradek> turn a shoulder on the rod, hammer them together, done
[00:08:02] <cradek> oh strength is important (I misread that about ten times as "unimportant")
[00:08:10] <andypugh> I did consider that, but I want to be happy up to 3kN
[00:08:11] <cradek> strength which way?
[00:08:16] <cradek> in tension?
[00:08:25] <andypugh> Aye, tension. No torsion
[00:09:01] <cradek> can you put a 16.5mm ID collar around it and weld it?
[00:09:11] <andypugh> Silver soldering is possible
[00:09:17] <andypugh> And I have considered TIG
[00:10:27] <andypugh> Hmm, actually. Full depth TIG onto a thicker collar with a proper thread might work.
[00:19:26] <andypugh> Why do lathes have the tools they have? I am envisaging a lathe with an conical, rotating toolpost, only big enough on top to hold a single insert. Forget toolchanges, you just rotate the insert to suit, and the lack of toolholder bar and tailstock makes rear clearance a non-issue. Why wouldn't it work?
[00:23:27] <andypugh> (Thinks, well, you couldn't thread)
[00:50:02] <alex_chally> hmm, I got way7 too much continuous flex conduit when I ordered it on ebay
[00:50:12] <alex_chally> anyone wanna buy like 20ft of nice conduit?
[00:50:29] <alex_chally> It will be a couple weeks before I know exaclty how much extra I have
[01:09:45] <alex_chally> my thrust bearings need to be replaced :(
[05:23:59] <L84Supper> alex_chally: what size conduit? I might take some off of your hands
[05:30:02] <alex_chally> L84Supper, 3/4" ID trade size
[05:30:20] <alex_chally> works really great with water proof couplings I got from Mcmaster carr too
[05:30:29] <alex_chally> for about $3.50 a pop
[05:31:40] <alex_chally> L84Supper, http://superflex.thomasnet.com/viewitems/sealproof-electrical-products-/flexible-liquid-tight-conduit
[05:32:37] <alex_chally> although the dude on ebay I got it from still has more
[05:32:38] <alex_chally> http://cgi.ebay.com/SealProof-LiquidTight-Flexible-NonMetallic-Conduit-3-4-/200466245905?cmd=ViewItem&pt=LH_DefaultDomain_0&hash=item2eacb82911#ht_500wt_1154
[05:46:43] <L84Supper> ahh liquid tight... I thought it might be flexible cable carrier
[05:47:50] <L84Supper> http://www.igus.com/wpck/default.aspx?pagenr=3507&C=US&L=en#Section_3
[05:58:29] <Jymmm> Thats energy chain
[05:59:39] <Jymmm> http://search.ebay.com/energy+chain
[06:10:08] <L84Supper> yeah, it's referred to several ways
[07:05:37] <alex_chally> oh god, I have been working on my CNC machine too long
[07:05:37] <alex_chally> http://i.imgur.com/WNvuL.jpg
[10:39:41] <Fox_M|afk> Fox_M|afk is now known as Fox_Muldr
[13:49:17] <Fox_Muldr> Fox_Muldr is now known as Fox_M|afk
[15:01:17] <jthornton> wow I just wrote a Makefile... and it worked after I changed my tab back to a tab
[15:02:31] <jthornton> to tab or not to tab that is the question...
[15:07:18] <Jymmm> You sure you didn't have any control characters in there by chance
[15:08:09] <Jymmm> Python is the only thing I'm aware of that is sensitive like that
[15:09:17] <jthornton> gedit was changing my tabs to spaces and according to Advanced Linux Programming "The line with the rule on it must start with a Tab character, or make will get confused. "
[15:09:42] <Jymmm> ah ok
[15:12:00] <Jymmm> Now that's TWO things that I know that are sensitive =)
[15:12:29] <Jymmm> Anyone know where to buy solar tubes CHEAP?
[15:14:54] <jthornton> don't even know what a solar tube is...
[15:15:04] <Jymmm> http://www.veluxusa.com/Consumer/Products/SUN_TUNNEL_skylights
[15:18:18] <jthornton> I guess that won't work in Seattle most of the time...
[15:18:34] <Jymmm> Heh, sadly no.
[15:20:19] <jthornton> I think the tab thing for make has caused me some headaches in the past with the documents and the submakefile
[15:23:13] <Jymmm> At least it won't any more =)
[15:23:42] <Jymmm> Jsut setup your editor-of-choice to use TABS instead of SPACES on make files
[15:29:25] <jthornton> I'm using gedit can you set it up to do that with just make files?
[15:33:03] <jthornton> looks like Auto Tab can do that
[15:48:53] <DanielFalck> hi jthornton
[15:49:06] <DanielFalck> what you 'Making' ?
[15:53:31] <jthornton> nuthin atm just practicing my c++
[16:01:15] <Jymmm> Can't a make file be auto generated?
[16:58:38] <awallin_> use cmake to generate makefiles
[16:59:48] <awallin_> you put a lot of stuff into a file called "CMakeLists.txt" and then run "cmake .", that will generate makefile(s)
[17:00:35] <sealive> awallin_: hi
[17:01:05] <awallin_> hi, you were right about the football :)
[19:45:19] <lepton> Hey all (happy 4th of July if that's your thing)
[19:45:44] <lepton> I've got my gantry mill up and moving around (hurray!), but I'm currently trying to figure out why it's acting like an underdamped system when I jog it around
[19:46:07] <lepton> For example, I manually jog it (in axis) 10 inches, and when I stop jogging it'll move back 0.5 inches or so
[19:46:24] <lepton> (those are arbitrary / non-real numbers I just gave)
[19:47:07] <lepton> I'm currently setup as a type 0 step&dir stepper system with a Mesa 5i23 board, with no ferror things in my hal file
[19:55:13] <pcw_home> /join #emc-devel
[20:06:14] <Endeavour> Hello lepton
[20:09:41] <morfic> JT-Hardinge: i hate lathes biting, they have far more bite than mills :/ (just moving idle chat out of -devel ;)
[20:14:49] <JT-Hardinge> I'm glad EMC can fault out real fast and stop trying to turn the spindle into smaller bits
[20:15:23] <JT-Hardinge> I have a cold beer in one hand and the green button in the other hand... lets see what happens
[20:16:06] <Jymmm> push the blue button! push the blue button! push the blue button! push the blue button! push the blue button!
[20:16:58] <JT-Hardinge> which blue button?
[20:17:08] <Jymmm> YES!
[20:18:00] <Jymmm> Just smooooooooosh them all at the same time!
[20:18:07] <morfic> JT-Hardinge: one goal is to do some repoting on "high loads", since we found our "Y" off so often and noone knows anything about a crash since the last time the turret was recentered, so the turret must move on it's own, deciding to bend the tapered pins i guess ;P
[20:24:00] <Fox_M|afk> Fox_M|afk is now known as Fox_Muldr
[20:34:40] <lepton> So I started messing around with position feedback for the encoders on my steppers
[20:35:04] <lepton> In the process (modifying my .hal and .ini files) motion on each axis starting getting really rough
[20:35:07] <lepton> So I went back to known good hal and ini files
[20:35:11] <lepton> And the problem persists?
[20:35:18] <lepton> Any clues as to how or why that could be?
[20:39:32] <cradek> lepton: two ideas: you didn't put back the files you thought you did, and regardless of history you have a problem now, so you should just start troubleshooting
[20:40:38] <lepton> I'm pretty sure I've go back to the right files, we're pretty good with using SVN for version tracking and I've gone through some of the older files trying to figure this out
[20:40:53] <lepton> This is oddly similar to an issue we had last week with bad cabling
[20:41:12] <lepton> but we bought the motor driver manufactur's crazy expensive breakout cables, installed that two days ago, and everything was going nicely
[20:41:12] <cradek> oh so you may even suspect hardware?
[20:41:22] <lepton> Anything's possible, right?
[20:41:31] <cradek> so far I guess
[20:41:32] <lepton> it doesn't seem very likely that it's hardware
[20:42:02] <lepton> I haven't touched the wiring, it's in a nice enclosure, and I haven't gotten any errors off the motor drivers
[20:42:27] <lepton> It seems most likely this has to do with the feedback lines in my hal file that I've been messing with
[20:42:44] <cradek> can you give a summary of the setup - what stepgen, velocity or position mode, etc
[20:44:10] <lepton> from my hal file (I'll be refering to single axes, just assume the rest follow accordingly)
[20:44:11] <lepton> setp hm2_5i23.0.stepgen.00.step_type 0
[20:44:37] <lepton> net motor.00.pos-fb <= hm2_5i23.0.stepgen.00.position-fb\
[20:44:40] <lepton> net motor.00.pos-fb => axis.0.motor-pos-fb
[20:45:37] <cradek> so not using encoders?
[20:45:41] <lepton> ^that \ on the position-fb was a typo, not in the actual hal ;)
[20:46:02] <lepton> Honestly, I'm very unclear on how to properly use the encoders on the 7i47, or at least how to call it up in hal
[20:46:20] <lepton> I do have the encoder outputs of my stepper drivers wired up to the inputs on the 7i47
[20:46:36] <lepton> I've been looking for reference files, and there's even an old EMC forum posting where someone says they've posted their working files
[20:46:43] <lepton> but the files are saddly no where to be found :/
[20:46:57] <lepton> I was hoping to work on that this afternoon when this choppy motion issue came up
[21:00:02] <JT-Hardinge> steppers with encoders is generally not done so the configuration might be a bit more complex than normal
[21:05:02] <lepton> At this point I'll settle for getting back to smooth motion :<
[21:05:22] <lepton> Weirdly, my y axis is working alright
[21:05:35] <lepton> And switching cabling between the z and the y makes the z move alright
[21:05:42] <lepton> So now I'm wondering if it's my stepper drivers
[21:06:30] <JT-Hardinge> do you have your acceleration too high?
[21:08:20] <lepton> I've run it very low (1ips) while troubleshooting today
[21:08:45] <lepton> The drivers do have acceleration limit and closed loop control to avoid missed steps
[21:09:06] <lepton> I'm starting to think I should avoid doing any of that in software (max_accleration = 0) and just let the drivers handle it all
[21:09:51] <cradek> you can't move diagonally then
[21:10:47] <cradek> imagine a move from 0,0 to 1,3 with acceleration controlled by the max setting on the driver, and you'll see what I mean
[21:11:17] <lepton> hmm, good point
[21:13:02] <lepton> So I'm still at a loss for understanding my problems. So far, motion is jerky on axes X1,X2,Z, but okay on Y. If I switch the cable from my 7i47 to the Y with the Z, the Z moves okay and the Y starts having issues (suggesting that the Z output signals from EMC2/Mesa are okay)
[21:13:29] <lepton> Which suggests a driver issue, but they aren't giving me any errors
[21:20:32] <JT-Hardinge> Sweet! the part came out exactly correct :)
[21:22:18] <pcw_home> lepton: does a straight step motor config work?
[21:26:12] <lepton> pcw_home: What do you mean, exactly? As in, from a parallel port, or just a more simplistic hal setup for my mesa cards?
[21:28:29] <pcw_home> Using the example config hm2_step.hal or whatever its called
[21:29:06] <lepton> gotcha. hm2_step is almost line for line what I'm using right now
[21:29:35] <lepton> modified enough to fit my actual pinouts
[21:29:48] <lepton> We (the two of us in the shop) are starting to think this is a Vexta motor driver issue
[21:30:13] <lepton> 2 of our 4 drivers seem to be having the issue, and all the signal outputs from EMC2 / Mesa cards look fine
[21:30:52] <lepton> When we swap the axes to different drivers, the issues stay with the "bad" drivers, not with the "bad" axes
[21:30:55] <lepton> So I think this is hardware :<
[21:34:02] <pcw_home> Is it possible that your timings are marginal? (that might make the stepgen work on some drives and not on others)
[21:34:04] <pcw_home> as far as the config file goes, I was suggesting to leave the encoders out of it for now as it makes for a much more complicated setup
[21:34:05] <pcw_home> if you are debugging
[21:34:55] <lepton> oh, good idea! I hadn't though to try to try to extend the minimum timing numbers
[21:35:04] <lepton> I'll try that now
[21:37:29] <pcw_home> Are your drives differentially driven or single ended?
[21:37:31] <pcw_home> (+-opto inputs with no common allow differential step & dir connections to 7I47
[21:37:33] <pcw_home> commoned inputs must be driven single ended)
[21:37:36] <lepton> YES!!!!!!!!!!!!!!1
[21:37:40] <lepton> pcw_home: you are my hero!
[21:37:45] <lepton> Hurray!
[21:38:08] <lepton> You've brought tremendous happiness to the two of us at this shop :) :)
[21:39:26] <lepton> The values I had were the minimums from the motor driver datasheet, but I guess you were right, they were right on the cusp
[21:40:26] <lepton> If you hadn't suggested that, we could potentially have gone days and $1600 of replacement hardware before we figured it out... if we ever figured it out
[21:45:23] <JT-Hardinge> wee! I'm making parts now :)
[21:45:32] <pcw_home> Alway good to have a little margin above the minimums
[21:45:46] <andypugh> I gave up when I could no longer stand the wierdness. Why would the command "G0 X12.2" in the MDI window move the tool to some completely different (and much smaller) diameter? (and neither diameter or radius is 12.2, nor half or double that)
[22:20:18] <jepler> jepler has changed the topic to: EMC (Enhanced Machine Controller) is a linux-based opensource CNC control. | Latest release: EMC 2.4.2 | http://www.linuxcnc.org | http://wiki.linuxcnc.org