#emc | Logs for 2009-09-29

[00:04:07] <Mire> cradek: yes. ! I'm so pleased.
[00:04:34] <cradek> yay!
[00:04:51] <cradek> that's a really big accomplishment, congrats
[00:05:02] <andypugh> Sorry, I don't know what happened to the rest of the HAL
[00:05:04] <andypugh> http://pastebin.ca/1583469
[00:05:37] <Mire> Say, I discovered just how easily we can put handles on these things. Ought to put a handle override button that inhibits servoamps for this purpose.
[00:06:02] <andypugh> I tried to get a higher-resolution plot
[00:06:17] <cradek> andypugh: I'm puzzled by setp encoder.0.position-scale 1.000000
[00:06:27] <cradek> I thought you said you had 50? lines
[00:06:32] <andypugh> Was it encoder.position-interpolated you wanted?
[00:06:55] <cradek> how about both of them, interp and not
[00:06:56] <archivist> setp encoder.0.position-scale 1.000000 should be 50
[00:07:18] <andypugh> It has, that setting it over-written in custom.hal
[00:08:07] <cradek> ok I see that now
[00:08:28] <andypugh> Thing is, you can't really usefully plot encoder.position as it ramps up continuously
[00:08:40] <cradek> you can right after index
[00:08:46] <cradek> since it resets
[00:10:03] <andypugh> I hadn't bothered homing etc and running the g-code
[00:10:30] <andypugh> I have the raw data if that is any use?
[00:12:18] <andypugh> http://pastebin.ca/1583481
[00:12:42] <cradek> brb
[00:18:54] <archivist> time for me to drive home
[00:20:03] <andypugh> I thought you were in the UK?
[00:20:23] <andypugh> Shoiuldn't you have been home about 6 hours ago?
[00:31:04] <andypugh> The data in a slightly more friendly format is at http://pastebin.ca/1583502
[00:31:42] <andypugh> The interesting column is the last one, which shows the difference between each successive encoder position
[00:32:21] <andypugh> And that does look worryingly irregular at each encoder rising edge
[00:52:05] <andypugh> Sorry all, but I need to log off now. If cradek or anyone else comes back with any ideas, can you send them to bodgesoc@gmail.com otherwise I will miss them.
[00:52:13] <andypugh> Thanks for your help so far.
[01:17:29] <Bridgeport_II> cradek: When you get back, I've found an interesting thing, would like your advice as to what we are doing wrong(?) Real simple test program, middle of table, x only. Moving from X15 to X16, then back to X15.
[01:19:23] <Bridgeport_II> If I put the feedrate to max (80 IPM), then X doesn't make it all the way to X16, maybe X15.750 or so, can't really measure while it's changing, but obviously not going to the end.
[01:20:22] <Bridgeport_II> If I reduce the feed quite a bit, then it will make it to the end where X = 16. Any suggestions?
[01:21:04] <Bridgeport_II> 40 IPM will make it, maybe 60 IPM also, I didn't do any calculations.
[01:21:20] <Bridgeport_II> Just watching axis display readout.
[01:22:31] <eric_unterhausen> does this problem manifest itself on a program where it matters?
[01:22:50] <eric_unterhausen> did you try to turn off blending?
[01:23:47] <Bridgeport_II> Are we having a conflict with our max accel limits? Do max accel limits take priority over final destination? With no warning? If so, can we get a warning?
[01:23:52] <Bridgeport_II> Hi eric_unterhausen
[01:24:41] <eric_unterhausen> hi, I would think turning around halfway would increase your acceleration
[01:25:05] <Bridgeport_II> eric_unterhausen: We are just at the point of doing final adjustments. I wanted to make a little test program for tuning to use with halscope.
[01:25:53] <Bridgeport_II> I don't know what we have blending set to, but I'll look
[01:55:38] <Valen1> Valen1 is now known as Valen
[02:13:37] <fenn> so i guess "save halscope plot" idea never went anywhere
[02:15:32] <eric_unterhausen> sounds like a performance hog?
[02:18:01] <cradek> Bridgeport_II: are you saying the DRO doesn't go to the expected number, or the table travel doesn't?
[02:26:14] <cradek> ok after a few more re-reads I think I understand what you are seeing. the program reverses and you don't see it reach the endpoint before reversing. if it is more than an ferror's difference, you are in fact seeing motion blending - the "corner" gets rounded off because of limited acceleration. You can get less of a rounding several ways including increasing acceleration (I bet you have it VERY low if you're seeing this much deviation)
[02:26:33] <cradek> hm, wonder if that was cut off
[02:26:49] <cradek> You can get less of a rounding several ways including increasing acceleration (I bet you have it VERY low if you're seeing this much deviation)
[02:27:06] <Bridgeport_II> eric_unterhausen (& cradek): It looks like we had blending set to G64. This happened by accident because we loaded the example "spiral.ngc" which has a G64, which we were pretyy much clueless about, and so were astonished when strange things happened.
[02:27:15] <cradek> running in G61 mode will make it reach the exact endpoint
[02:27:29] <cradek> running with G64 P[tolerance] will make it reach within tolerance of the endpoint
[02:28:01] <cradek> you said maxvel is 80 = 1.33; what is the acceleration?
[02:28:50] <Bridgeport_II> Yes, we are playing around with spiral and G61, G61.1, G64, and G64 Pwhatever. BTW, the docs are not at all clear on the difference between G61 exact path mode and G61.1 exact stop mode
[02:29:21] <cradek> well, I think there is actually no difference and those docs are "historical"
[02:29:55] <cradek> to get very close path following without extraneous stops, program G64 P[small]
[02:30:14] <Bridgeport_II> Max accel on X is 2.0. No difference between G61 and G61.1?
[02:30:16] <cradek> because G61 will come to a full stop even if the adjacent moves are along the same line
[02:30:22] <cradek> right, I think there is no difference
[02:30:50] <Bridgeport_II> What was the historically intended difference?
[02:30:53] <cradek> hmm, that's most of a second to get up to speed. does it stall if you try to accelerate faster?
[02:31:31] <cradek> I think the idea was that "exact path" would not stop if the lines were colinear. But no version of EMC ever actually had that functionality to my knowledge.
[02:32:07] <cradek> I would hope for an acceleration of more like 15 from a machine that goes 1.33 (0.1 seconds to full speed)
[02:32:53] <Bridgeport_II> We were having some stalling issues because John wanted to get as fast a rapid as possible, so we were pushing it pretty far. But since we went back down to 80IPM (what the original 1973 BP2 docs say) no problems. John is not amused. We may be able to get it to 90IPM before we're done.
[02:32:54] <cradek> you will get much better contouring/path performance if you can get that accel up
[02:33:18] <Bridgeport_II> So we can now come back and increase the accel
[02:33:31] <cradek> good, I bet you'll be happier with that side of the compromise
[02:34:12] <cradek> have you tried various microstep settings? maybe including half steps?
[02:34:20] <skunkworks_> ipm doesn't matter much if it takes 3 seconds to get to that speed.
[02:34:40] <cradek> yeah you'll often not even get up to it
[02:35:03] <cradek> I'm thinking about things like peck drilling - you need the accel to get the heck out of the hole
[02:42:45] <Bridgeport_II> cradek: first test of max_accel from 2.0 to 10.0 brought back stalling. And X is the lightest (least massive) axis. Although it is currently carrying the 4th axis loose for testing. Dave says 8.0 seems OK. He'll try 9.0 next.
[02:44:23] <cradek> yay, that'll be much better than 2
[02:45:15] <cradek> do you think the limitation here is just the motors? if I remember right he is using the original motors?
[02:46:56] <Bridgeport_II> John has got X at 9.5 now, no stalling. We'll have to run a loop move to look for missing steps. Yes, original motors, 42 size, 900 in-oz.
[02:47:25] <skunkworks_> who is Bridgeport_II? John is the one with the 2 bridgeports and jonE pico systems boards.. right? was at witchita..
[02:47:56] <cradek> skunkworks_: Kim K and John who were at wichita
[02:48:10] <cradek> not Jon E
[02:48:10] <skunkworks_> ah - kim K - Hi!
[02:48:34] <Bridgeport_II> He's starting on Y. He's going back and put X at 9.0. skunkworks_ yes, that's the right John. I'm KimK, i came up here to help out.
[02:48:45] <cradek> John has been working on this retrofit for years :-)
[02:48:57] <cradek> where are you guys?
[02:49:34] <skunkworks_> I thought john was Bridgeport_II but Bridgeport_II was talking about john... Sorry - trying to get rid of some champagne for recycling. :)
[02:49:41] <Bridgeport_II> Speaking of which, what can you tell me about tuning (PID) for steppers? Same as for analog servos?
[02:50:10] <Bridgeport_II> We are in Minneapolis. I drove up Friday night.
[02:50:37] <cradek> I have not done it, but I understand the pico board takes velocity command. I think this means you can tune with mostly P and FF1.
[02:51:09] <cradek> if they have a gain adjustment you might set FF1 to 1 and then turn the gain until the steady state following error (during cruise) is nulled
[02:51:39] <cradek> er, 'they' = pico board
[02:51:46] <cradek> (I'm not sure how it tunes)
[02:52:58] <Bridgeport_II> OK, tuning that way sounds good. BTW, we ran across a parameter "PID_MAX_VEL=30", not in docs, what is that?
[02:53:22] <cradek> no special meaning to emc - so check for it being used to set something in your hal file
[02:55:37] <cradek> setp pid.0.maxoutput [AXIS_0]PID_MAX_VEL
[02:57:26] <Bridgeport_II> John says he can only get Z up to accel=2, but that's a big chunk of iron, w/ air counterbalance. In fact it started stalling only on the way down after the air compressor came on, so we are checking the air assist setting, maybe too high?
[02:58:09] <cradek> looks like the default univstep config uses the same SCALE for encoder in and velocity out. so maybe you want to just tune FF1 to be whatever nulls the cruise error
[02:58:57] <cradek> are you getting lube everywhere? those darn little metering valves are always plugged
[02:59:23] <Bridgeport_II> OK. What about Pgain? I've had that all over from 100 to 5000 (found it at 1500, thought that was high), with no observable change.
[03:00:04] <Valen> in my servo system I'm running P at 2.4 or so atm
[03:00:16] <cradek> I bet it won't matter much because all the heavy work is done by the FF1
[03:00:19] <Valen> dunno if thats Pgain
[03:00:53] <cradek> the values are highly dependent on the configuration of the scaling - it's apples and oranges unless you carefully match your ... apples
[03:01:06] <Valen> lol
[03:01:29] <Valen> * Valen DCC's a beer to cradek, he's funny when he's wasted ;->
[03:01:35] <cradek> there's some evidence that the "velocity" command for ppmc is in Hz, not velocity at all
[03:01:53] <Valen> oh wait it was skunkworks that was toasted :-<
[03:01:55] <cradek> Valen: haha thanks, I've got some
[03:02:01] <cradek> yeah I'm always this way
[03:02:17] <Valen> I really need to play with the tuning on ours again
[03:02:20] <cradek> doesn't get much worse when I'm liquored up :-)
[03:02:42] <Valen> now that we have "enhanced" the driver boards it looks like we can wind the gains up somewhat
[03:03:13] <Valen> http://www.youtube.com/watch?v=4pAxqw5yeZM
[03:03:39] <Bridgeport_II> Pgain, P, not sure, I forgot. John says there's lube on the ways everywhere, but we do have some seeping hoses.
[03:04:45] <cradek> Valen: looks nice!
[03:04:52] <Valen> getting there
[03:05:05] <Valen> need to square up the head, its all sqewif atm
[03:05:15] <Valen> doing some nice cuts though from time to time
[03:09:38] <skunkworks_> toast?
[03:11:30] <toastydeath> skunkworks_:
[03:15:18] <roh> .oO(does machining make sense when sober?)
[03:17:15] <Bridgeport_II> Z is being finicky. It's the biggest one with the same motor size for all. And the only one not horizontal. We're working on it.
[03:18:00] <toastydeath> bridgeport_ii: counterweight?
[03:18:10] <cradek> I bet the air setting is critical considering how little headroom you have with those motors
[03:22:17] <Bridgeport_II> toastydeath: air counterbalance. About a 6" cylinder. About 2000 lbs force, give or take a few hundred lbs. cradek: Yes, and I wish we had real encoders so I could look at the servo lag and know what to set the air to, but we can fake it by going up and down and varying the air and looking for stalls.
[03:24:10] <cradek> can you pull the belt off the motor and balance it by eye? is it really free?
[03:25:36] <cradek> maybe you could see what psi moves it up, what moves it down, then set halfway between
[03:25:51] <cradek> hmm it'll be hugely different with and without the rotary table won't it
[03:27:28] <toastydeath> if it's a 12" rotab absolutely, if it's like a 6, not realy
[03:27:35] <Bridgeport_II> John says yes it is free, but no, it's a job to remove the belt. We're sort of doing that now by trial and error ^N^N^N statistical scientific analysis
[03:27:51] <cradek> haha
[03:31:13] <Bridgeport_II> Yes, the book says we are allowed a 1000 lb workpiece, and the 4th axis weighs maybe 250-350 lbs(?) So, yes, I agree, a lot of tinkering with the air setting, probably. But that's OK.
[03:46:39] <Bridgeport_II> So when people talk about stepper tuning, is that what they are referring to, max velocity, max accel, stuff like that? Not the usual P, I, and D stuff? If so, makes sense to me, but I got the idea that EMC2 really does some kind of stepgen pulse stream adjustment and so really used some kind of PID loop. True? False? Both?
[03:48:27] <Bridgeport_II> Or maybe it's not so much EMC2's internal stepgen as external pulse gen add-ons by vendors?
[03:58:42] <cradek> the internal stepgen and the on the mesa don't use pid as emc knows it. you are right that people using these and talking about stepper tuning are really talking about vel/accel and maybe the step timing parameters for their drive
[03:59:44] <cradek> I think they work more in the position realm [I am not an expert], unlike the pico board which takes velocity command and looks completely like a servo system, complete with pid, to emc
[04:01:19] <cradek> the pico products were developed in the emc1 days and everything was a servo to emc1. you got pid whether you wanted it or not - there was no position output.
[04:02:04] <Bridgeport_II> But you say the pico PID (now) only uses FF1?
[04:04:37] <cradek> no - pico takes velocity command - FF1 is the pid parameter that is proportional to the commanded velocity - so it is the one that dominates
[04:05:47] <cradek> the pico board itself doesn't know or care how you come up with a velocity command for it
[04:08:07] <cradek> I better get going - goodnight
[04:08:41] <Bridgeport_II> John is pretty happy with the performance of the machine as we have it now, he says it's as good as it used to be for sure, maybe better. But maybe we should run it by Jon E before pronouncing it done, just to be sure we have not overlooked any performance-enhancing adjustments? (We still have to set FF1, but that won't do too much I expect.)
[04:09:29] <Bridgeport_II> OK, goodnight, thanks for your help, and thanks for everyone's help.
[04:09:42] <Bridgeport_II> We'll be here awhile yet.
[04:16:27] <Valen> for PID to work there has to be an error, if your using steppers, there cant be an error
[04:16:45] <Valen> PID works on the difference between commanded and actual positions
[04:16:54] <Valen> if you have that with steppers your kinda sunk
[04:17:31] <Valen> at least as far as i can work out, because there's no feedback for it to work off
[04:26:03] <Bridgeport_II> Yes, I agree with you. But I am told that the pico board takes the generated pulses in as encoder counts and runs a PID loop. True, still no outside feedback, but has some PID tuning, I am told? I am not very familiar with the pico boards, so I can't elaborate.
[04:27:01] <Valen1> Valen1 is now known as Valen
[05:42:03] <Valen1> Valen1 is now known as Valen
[06:05:47] <MarkusBec_away> MarkusBec_away is now known as MarkusBec
[07:06:34] <alex_joni> Valen: you have errors even for steppers
[07:06:43] <alex_joni> because you have the motion controller and the step generator
[07:06:59] <alex_joni> ideally they do the same thing, but the step generator will always be a step behind
[07:07:17] <alex_joni> emc2's stepgen uses an internal pretuned PID to do it's thing, so there's nothing for the user to do
[07:07:34] <Valen> true but a PID loop seems like a bad solution to that problem
[07:07:38] <alex_joni> but if you're using a pico board where you need to supply a velocity command, then surely there's an PID
[07:07:47] <Valen> there there would be
[07:08:19] <Valen> would that not be in the controller itself rather than EMC?
[07:14:25] <alex_joni> the controller is separate
[07:14:30] <alex_joni> it might have it's own thing
[07:14:43] <alex_joni> emc2 sees this: there's a device I feed velocities into, and it outputs position
[07:14:46] <alex_joni> like a true servo
[07:16:35] <Valen> some you feed torque into
[07:16:43] <Valen> that seems "truer" as far as servo goes
[07:16:44] <alex_joni> right
[07:16:53] <Valen> otherwise you need 2 PID loops
[07:16:57] <Valen> which seems messy
[07:17:09] <alex_joni> it seems, but it doesn't need to be ;)
[07:17:20] <alex_joni> traditional (old) systems most use velocity
[07:17:24] <alex_joni> +/-10V for vel
[07:17:33] <alex_joni> but I guess it depends on the amps
[07:45:50] <Valen1> Valen1 is now known as Valen
[08:28:44] <micges_work1> micges_work1 is now known as micges
[08:46:05] <Valen1> Valen1 is now known as Valen
[08:54:45] <JbLb_> JbLb_ is now known as JbLb
[09:51:03] <piasdom> g'mornin all
[10:30:34] <Valen1> Valen1 is now known as Valen
[10:45:38] <micges_work1> micges_work1 is now known as micges
[11:04:48] <jthornton> http://www.linuxcnc.org/component/option,com_kunena/Itemid,20/func,view/catid,10/id,880/lang,en/
[11:10:53] <archivist> he is not stating if HIGH acceleration is commanded or what his amps are set too
[11:11:30] <jthornton> I don't know enough about servos to open my mouth :)
[11:12:19] <archivist> I know enough about inertia and loops to know there is a miss match if set slow
[11:12:42] <archivist> halscope to find out
[11:13:14] <Valen> probably backlash would be my guess
[11:13:26] <Valen> with high accel the motor powers through it quickly
[11:13:36] <Valen> with low accel it'll sit there flapping for a while
[11:14:39] <archivist> or stiction
[11:14:48] <Valen> yeah that would do it too
[11:15:08] <Valen> He did say linear encoders though, and didn't mention backlash
[11:16:49] <jthornton> seems to me and I don't know that what Valen said high acc the motor follows the commanded position better so less ferror
[11:17:09] <Valen> ferror shouldn't be affected by accel
[11:17:28] <jthornton> hmm
[11:18:09] <jthornton> your right because at low accel the commanded position is different...
[11:19:19] <Valen> accel should actually make things worse because it'll have less tome to correct things
[11:20:08] <jthornton> with feedback is ferror just a straight forward math commanded position - actual position = ferror?
[11:21:37] <Valen> I believe so
[11:29:43] <micges> jthornton: from source: joint->ferror = joint->pos_cmd - joint->pos_fb;
[11:30:02] <jthornton> thanks micges
[11:31:41] <Valen1> Valen1 is now known as Valen
[11:57:52] <JbLb_> JbLb_ is now known as JbLb
[12:33:06] <Valen1> Valen1 is now known as Valen
[14:43:20] <archivist> wires falling off--
[14:44:21] <jymm> duct tape to the rescue
[14:44:50] <archivist> pfft solder!
[14:45:04] <jymm> wuss
[14:50:46] <jymm> archivist: Why weren't they soldered up originally? huh? huh? huh?
[14:53:04] <archivist> it was
[14:53:26] <archivist> it broked
[14:53:56] <jymm> So, like I said.. duct tape to the rescue!!! LOL
[14:54:27] <Valen1> Valen1 is now known as Valen
[14:56:17] <jymm> archivist: is this on a connector?
[14:58:53] <archivist> back of a D type, was just boxing the lathe up to stop pull in the wires
[14:59:12] <archivist> and of course that was the last straw
[15:01:58] <jymm> Heh, Lot less headaches if you spend the money and buy a crimpter.
[15:02:22] <Valen> we crimp and solder, but then we have a dodgy crimper
[15:07:48] <jymm> A PRE-SCHOOL TEST FOR YOU
[15:07:48] <jymm> Which way is the bus below traveling?
[15:07:51] <jymm> To the left or to the right?
[15:08:02] <jymm> http://imagebin.ca/view/UPtoRfv.html
[15:08:58] <jymm> Pre-schoolers all over the United States
[15:09:01] <jymm> were shown this picture asked the same question.
[15:11:01] <archivist> should have had a 50% direction response
[15:11:19] <cradek> I bet they say right, drivers say left (in US)
[15:11:19] <jymm> Well, what is your answer?
[15:11:31] <archivist> not traveling
[15:11:38] <jymm> archivist: wrong
[15:12:05] <jymm> 90% of the pre-schooler's gave this answer.
[15:12:05] <jymm> 'The bus is traveling to the left.'
[15:12:05] <jymm> When asked, 'Why do you think the bus is traveling to the left?'
[15:12:05] <jymm> They answered:
[15:12:06] <jymm> 'Because you can't see the door to get on the bus.'
[15:12:10] <Valen> its not a bus?
[15:12:16] <Valen> damn
[15:12:53] <jymm> You are dumber than a pre-schooler!
[15:12:53] <cradek> jymm: where is this study?
[15:13:17] <jymm> US of A
[15:13:49] <cradek> no I mean where can I read it?
[15:14:05] <jymm> In my email
[15:14:09] <cradek> haha
[15:14:11] <cradek> ok I see
[15:15:22] <jymm> But I do think it's interesting that they used logical reasoning to deduce the direction due t the abscenes of a door being shown.
[15:17:11] <cradek> http://languagelog.ldc.upenn.edu/nll/?p=1767
[15:17:57] <Valen> I'd wager that if such a study ever existed one kid might have given that answer
[15:19:33] <alex_joni> cradek: it should be FTW :D
[15:19:50] <Valen> Allie said, September 25, 2009 @ 10:04 am Obviously they should have used "Federation of Tourism in Wisconsin".
[15:22:04] <archivist> http://www.warwickfoos.co.uk/images/h20090326/59.jpg
[15:23:48] <jymm> Well, I can't see anyone that knows/uses "wtf" would ever visit Wisconsin
[15:24:17] <skunkworks_> heh - that is funny :)
[17:20:23] <Dave911> Is it possible to put Gcode command inside of an Mcode ??
[17:21:04] <Dave911> I thought I saw an example of that and printed it out but now I can't find the printout or the reference!
[17:21:33] <archivist> use subroutines
[17:22:09] <Dave911> OK..... so is that a no ? ;-)
[17:43:25] <Dave911> OK, I will take that as a no..
[17:43:27] <Dave911> One more question. I saw someplace that M100 and M101 was at on time used to test an input?? Is that still present? Or was that removed?
[18:05:35] <cradek> argh, andypugh never made the plot I asked (several times) for
[18:07:06] <skunkworks_> some peoples kids!
[18:07:14] <cradek> looking at the code again, it does look like it's probably very sensitive to bad feedback
[18:07:32] <archivist> whats the relation of max_acceleration and stepgen_maxaccel
[18:07:58] <cradek> it expects that (revs - previous-revs)/cycle-time (consecutive servo cycles) is a good estimate of current velocity
[18:08:09] <cradek> which it IS if your feedback is good
[18:08:35] <archivist> mark space/quality of encoder
[18:08:37] <cradek> but these systems where you get no change for a dozen servo cycles and then a big change of 0.05 revs will really screw with it
[18:08:52] <cradek> yes maybe even that too
[18:09:27] <archivist> his printed on paper could be horrible in that respect
[18:09:53] <cradek> I wrote it all testing on systems with good spindle feedback (500-2000 counts/rev)
[18:10:05] <cradek> er maybe the one is 4096/rev - something like that
[18:10:14] <archivist> ah that explains a thing or two
[18:10:32] <cradek> yes his may be so bad that even the interpolated output is wobbly. that is why I want to see a decent plot of it!
[18:10:45] <cradek> *for each servo cycle*
[18:11:17] <cradek> yours is low resolution but high quality, so the interpolated counter can fix it up pretty well
[18:11:37] <archivist> one has to have hardware counting for that encoder qty not crappy parports
[18:12:25] <cradek> actually the 1024 line encoder went to a crappy parport - I used one channel only, and counter mode, and could get up around 1000 rpm iirc
[18:12:53] <archivist> hmm I do have a 600 lying around
[18:13:10] <cradek> er one channel plus index of course
[18:13:18] <archivist> but was going to use it on the mill for hobbing
[18:16:06] <archivist> spose someone should poke him to get on irc at the machine and follow halscope instructions
[18:20:28] <cradek> yeah my calcs are right - assuming 20usec base period, 1000 rpm, counter mode, you could use an encoder that's up to 1500 lines, around 1000 is better for safety
[18:20:56] <cradek> I think folks who say you need very few lines haven't actually done the math
[18:21:38] <cradek> hmm, I guess with full quadrature (required for tapping) you can only have half that
[18:22:00] <jymm> cradek: With the limitation being?
[18:22:08] <cradek> but I bet still 400-500 lines is where you want to be
[18:22:18] <cradek> jymm: the speed at which the parallel port signals can be read
[18:22:39] <jymm> cradek: And mesa card (or equiv) being the alternative?
[18:22:51] <cradek> yeah with real encoder counters there is no practical limit
[18:23:08] <jymm> cradek: Think a pico board would do it?
[18:23:12] <cradek> which is why I was so oblivious to this problem :-)
[18:23:17] <jymm> (just curious)
[18:23:28] <cradek> sure the pico stuff works approximately the same way as the mesa
[18:23:54] <jymm> heh, well I wouldn't exactly say that, but I understand.
[18:24:09] <pcw_home> "<archivist> whats the relation of max_acceleration and stepgen_maxaccel"
[18:24:11] <pcw_home> I was wondering that also apropos gtoms following error problem
[18:24:12] <pcw_home> I would expect a low stepgen_maxaccell would cause following errors
[18:24:37] <cradek> well it's true - they both count the encoder signals in hardware, and then every servo cycle they tell emc the latest count
[18:24:58] <archivist> I asked the question because stepconf only asks for one number
[18:25:04] <cradek> the exact means of communication is different but they communicate approximately the same data and same amount of data
[18:27:11] <Dave911> There is a program called flowsnake.ngc and flowsnake.py in the example programs.
[18:27:12] <Dave911> If I follow the Integrators manual properly - the Python file is a filter for the NGC file. Are there any docs on how the filter file interacts with the Gcode file? I found the [FILTER] section on page 30 in the Integrators Manual. Or should I just look at the "Wizard" code and ask questions. I asked a question before about putting Gcode into Mcodes - I think this is what I was...
[18:27:14] <Dave911> ...really looking for. Thanks!
[18:28:17] <cradek> Dave911: filters are passed a program name on the command line and they send the (possibly) filtered contents to stdout, which is read by AXIS
[18:31:26] <Dave911> OK, so that is something different than the flowsnake.ngc and flowsnake.py programs are doing? I thought they were interacting but perhaps not.
[18:33:38] <cradek> sorry I don't understand what you are asking
[18:34:11] <cradek> the program "python" is sometimes used as an AXIS filter. It takes the name of a file on the command line (somefile.py) and generates gcode on stdout.
[18:34:19] <cradek> this is how you can run flowsnake.py, for instance
[18:35:35] <cradek> other filters might take an image file and generate gcode
[18:36:03] <cradek> or, take as input a foreign dialect of gcode and generate emc gcode (I use one like this sometimes)
[18:37:04] <Dave911> So flowsnake.pv is generating the flowsnake.ngc code ?
[18:37:15] <skunkworks_> archivist: stepconf automagically takes the max_accelleration + percent = stepgen_maxaccel. (or the other way around)
[18:37:36] <cradek> it is likely the flowsnake.ngc code you have was generated by just redirecting the output of flowsnake.py to a file
[18:37:58] <archivist> I was hand editing the result and needing the magic, I guessed
[18:38:24] <skunkworks_> I usually add a good 20 to 30%
[18:38:26] <Dave911> OK. I think I need to try some things.. ;-) Thanks!
[18:57:54] <jepler> cradek: no, I think you're mistaken about that. flowsnake.ngc demonstrates recursion directly in emc gcode using O-call.
[18:58:42] <cradek> oh sorry, I didn't even look at it
[18:59:20] <cradek> but now I remember ken wrote it, so that makes sense
[19:11:51] <MarkusBec> MarkusBec is now known as nenunad
[19:23:28] <Dave911> >>flowsnake.ngc demonstrates recursion directly in emc gcode using O-call.
[19:23:30] <Dave911> So recursion - is basically code calling itself... So is the python code creating the code to do so or is it actually interacting with the G code?
[19:23:31] <Dave911> I haven't looked the code again yet
[19:34:35] <Dave911> OK, forget the last question.. I looked at it again. The python program is clearly generating the Gcode file but at a different level of Gcode than I am used to seeing! Pretty interesting. Thanks.
[19:37:30] <ChanServ> [#emc] "This is the #emc channel - talk related to the Enhanced Machine Controller and general machining. Website: http://www.linuxcnc.org/, wiki at http://wiki.linuxcnc.org/"
[19:55:02] <Himanshu12> Hello, I decided to write my own GUI for EMC2 .. where should i start.. i mean to say any documentation regarding CORE LIBRARY
[19:56:16] <Himanshu12> hello alex_joni,cradek u there??
[19:57:39] <cradek> to understand how the GUIs work, you should study the existing ones
[19:57:51] <cradek> I recommend starting with xemc or halui because they are the simplest
[19:58:12] <Himanshu12> yes thats what i am doing and even i Learned Python for understanding AXIS..
[19:58:32] <cradek> ok good
[19:58:47] <Himanshu12> one quick question.. i am new to linux . but experienced windows programmer.. which path should i take, GTK+ QT or anything else
[19:59:01] <Himanshu12> i am good at C, C++ , JAVA and C#
[19:59:01] <alex_joni> whatever you're more comfortable with ;)
[19:59:18] <cradek> there is no answer to that question. there are many toolkits because people have different preferences.
[19:59:20] <alex_joni> start with a windows GUI then ;)
[19:59:27] <alex_joni> we have plenty of linux GUIs
[19:59:32] <Himanshu12> all that are new for me thats why i need guidence.. which is more powerful and which have more options like IDE and all
[19:59:57] <alex_joni> if you use an IDE like Eclipse, I think there are modules for most any language
[20:00:16] <cradek> but that has nothing to do with what gui toolkit to use
[20:00:23] <cradek> or even what language
[20:00:48] <cradek> you will need to do some studying to decide those things
[20:01:06] <jepler> One goal you might keep in mind when choosing a GUI toolkit is to add as few new requirements as possible. Using Qt or C# would add many new requirements, since emc doesn't use them now. Using Python, Tcl or C/C++ with Tk or Gtk would add few or none.
[20:01:23] <cradek> that is very good advice
[20:01:55] <cradek> if it is something you eventually hope to contribute to the emc2 project, Gtk is the toolkit to use
[20:01:59] <Himanshu12> yaa thats true.. C# was just example.. i am more comfortable with C++
[20:02:11] <cradek> if it is something you will only use for yourself, your options are open
[20:02:29] <jepler> If the lack of documentation bothers you, then you can help others by contributing documentation as you learn from reading the source code.
[20:02:33] <Himanshu12> i will definately contribute..
[20:02:55] <Himanshu12> @jepler i am good at coding not documentation
[20:03:15] <Himanshu12> you wont belive but my Master Thesis documentation was done by my friends
[20:03:16] <cradek> that is a very common affliction
[20:03:35] <cradek> ... that is not
[20:03:40] <cradek> :-)
[20:03:56] <Himanshu12> :)
[20:04:15] <Himanshu12> anyways thanks guys.. so GTK will be more apropriate right??
[20:04:25] <cradek> sounds like
[20:05:20] <Himanshu12> and yes one thing i forget to mention i am planning to port all this things on Puppy Linux..
[20:05:27] <Himanshu12> like that coolcnc guys
[20:06:05] <alex_joni> Himanshu12: sounds like a good idea to go with gtk then
[20:06:15] <alex_joni> puppy is all about small systems
[20:06:26] <alex_joni> I don't think I've seen a puppy with Qt on it
[20:06:33] <jepler> umm unless I'm mistaken, the coolcnc puppy-based distribution is very old and not being updated
[20:06:38] <Himanshu12> yes thats why i choose it.. coz the machine running EMC dont need hi fi system like UBUNTU
[20:06:53] <alex_joni> jepler: they tried and failed
[20:06:59] <Himanshu12> yaa i know but i recompiled puppy kernel and ported 2.3.3 on it
[20:07:04] <alex_joni> so if Himanshu12 wants to do a new one, then it's great
[20:07:29] <Himanshu12> @alex_joni do you know the reason for failure.. so i can take care..
[20:07:50] <jepler> On IRC, write "<name>: ..." to address someone. "@name" is not the style.
[20:08:13] <Himanshu12> ok jepler .. i am new to IRC too.. i use yahoo for PMs
[20:08:17] <alex_joni> Himanshu12: they patched a kernel which would crap out on some machines
[20:08:28] <alex_joni> then there was a compiler problem
[20:08:33] <alex_joni> causing random segfaults
[20:08:50] <alex_joni> then there were some more issues, and after 2-3 weeks the guy gave up (can't say I blame him)
[20:09:32] <Himanshu12> oh i see.. i patched .. now still i get few error like emc.nml not found
[20:09:54] <Himanshu12> but i think it will be solved its due to the wrong library i used few library from Debian Lenny that too pre compiled
[20:20:58] <ZeroFlex1> http://www.youtube.com/watch?v=AV2MehkFcTw&feature=related
[21:05:41] <BJT_Shop> Yippie! I have permanent electricity and internet in the shop...
[21:06:05] <archivist> welcome to the 1900's
[21:06:28] <ZeroFlex1> whehe
[21:06:42] <BJT_Shop> 200 amps of power :)
[21:06:53] <ZeroFlex1> owkeej !!??
[21:07:09] <ZeroFlex1> hmm here the single phase goes only up to 16amps
[21:07:10] <BJT_Shop> now I can roll up the extension cord to the house
[21:07:26] <ZeroFlex1> and 3 phase up to 30amps
[21:07:37] <toastydeath> what, 30 amps?
[21:07:42] <ZeroFlex1> yha
[21:07:47] <toastydeath> for the WHOLE building?
[21:07:56] <ZeroFlex1> no
[21:07:57] <ZeroFlex1> thats for my workshop
[21:07:59] <toastydeath> oh
[21:08:03] <ZeroFlex1> just 16 for whole house
[21:08:08] <ZeroFlex1> 16amps
[21:08:17] <toastydeath> that is insane, our house is a 200 amp main
[21:08:17] <ZeroFlex1> 230 volts
[21:08:36] <toastydeath> or rather my parent's house, seeing as how I'm in an apt
[21:09:07] <BJT_Shop> 16 is enough for some lights and a small toaster at least
[21:09:08] <ZeroFlex1> 230volts and max 16amps stots
[21:09:32] <ZeroFlex1> 2 groups of 16 amps for the oven and cooking plate
[21:09:40] <toastydeath> oh, that's just each breaker, whew
[21:10:05] <toastydeath> i thought you were talking about the maximum draw for the house was 16 amps
[21:10:34] <ZeroFlex1> less then 16 amps
[21:10:55] <toastydeath> zeroflex1: you just said there were at least two 16 amp breakers, so that means you cannot have 16 amps for the whole house draw.
[21:11:18] <ZeroFlex1> every house here in the netherlands
[21:11:45] <archivist> I dont think 16 covers it
[21:11:47] <ZeroFlex1> has i think max 30 amps breaker in the street connection
[21:12:05] <ZeroFlex1> 25amps in the breaker closset
[21:12:06] <archivist> far too low
[21:12:13] <ZeroFlex1> and per connection 16 amps max
[21:12:25] <ZeroFlex1> shower a bit lower 10 amp or so just for lights
[21:12:47] <ZeroFlex1> ? why not
[21:13:05] <ZeroFlex1> does it already over far before i was born :)
[21:13:08] <archivist> electric cookers , immersion hearter,
[21:13:14] <ZeroFlex1> electric cooker
[21:13:33] <ZeroFlex1> i can do up to 3600 watts on a 16 amp
[21:13:36] <archivist> 20 a on its own, pluas any other load
[21:14:32] <archivist> they are reducing britich houses from 80A to 60A
[21:15:37] <archivist> no way 25 could handle kettle shower immersion heater and lights
[21:15:58] <BJT_Shop> dang rolling up 300' of 6-4 SO cord is hard work
[21:15:59] <ZeroFlex1> it does
[21:16:11] <ZeroFlex1> but over here we have a lightnet of 230 volts
[21:16:24] <archivist> 230 here
[21:16:36] <toastydeath> 240v, 200 amp
[21:16:56] <alex_joni> * alex_joni did some welds today with 120kAmps
[21:17:12] <BJT_Shop> nice... was it loud
[21:17:14] <archivist> resistance welds
[21:17:20] <alex_joni> archivist: yeah
[21:17:29] <alex_joni> BJT_Shop: nope, the cleanest process ever ;)
[21:17:43] <alex_joni> no sparks, no sounds (from the weld at least)..
[21:17:55] <BJT_Shop> cool
[21:17:56] <ZeroFlex1> nope not 240 200 amp
[21:18:03] <archivist> bit of a hummmmmmmmmmmmmm from the welder
[21:18:03] <BJT_Shop> happen real fast?
[21:18:05] <alex_joni> only a couple volts though
[21:18:06] <toastydeath> zeroflex1: i am talking about MY place
[21:18:10] <ZeroFlex1> oh
[21:18:14] <ZeroFlex1> that way
[21:18:17] <toastydeath> is 240v/200a
[21:18:42] <ZeroFlex1> nope here industry power for normal gear like a mill or a lathe is 3 phase 230v 30amps
[21:19:06] <toastydeath> one of our lathes can draw 30 amps easy
[21:19:06] <ZeroFlex1> a normal car mechanic shop does not have more
[21:19:11] <ZeroFlex1> hmm
[21:19:16] <toastydeath> like, EASY.
[21:19:24] <ZeroFlex1> yha my welding inverter tig is 200amp ac/dc
[21:19:31] <ZeroFlex1> works fine
[21:19:31] <alex_joni> that's output
[21:19:35] <ZeroFlex1> yha
[21:19:37] <ZeroFlex1> :)
[21:19:43] <alex_joni> a 200 amp tig inverter is only 10-15kW
[21:19:49] <ZeroFlex1> works on a 230v 16amp line
[21:19:54] <alex_joni> barely ;)
[21:20:22] <ZeroFlex1> nope works fine even with a wire on a roll (dont know how to call it in englisch) with 30meters wire
[21:20:25] <toastydeath> zeroflex1: one of our machines will draw 125 amps
[21:20:31] <toastydeath> on accel/decel
[21:20:37] <ZeroFlex1> owkeej
[21:20:39] <ZeroFlex1> hmm
[21:20:49] <ZeroFlex1> what herz ?
[21:20:53] <toastydeath> 60
[21:21:12] <toastydeath> the breakers to banks of machines are all 300 amp breakers
[21:21:29] <BJT_Shop> anyone got time to help me lift up that extension cord... it weighs a ton
[21:21:33] <toastydeath> 2-3 machines per breaker
[21:21:38] <alex_joni> big machines are all 400V over here..
[21:21:45] <alex_joni> 63A breakers are most common
[21:22:04] <alex_joni> then there's 100, 150, etc
[21:22:05] <BJT_Shop> big machines here run on 4160V
[21:22:13] <alex_joni> BJT_Shop: not that big :P
[21:22:24] <BJT_Shop> what my cord?
[21:22:26] <alex_joni> I mean bigger than a desktop mill
[21:22:26] <mozmck_work1> you mean 460V?
[21:22:35] <ZeroFlex1> ac 230v 50hz whole west europe ic on wiki
[21:22:36] <toastydeath> mozmck_work1: no, 4160 is for industrial applications
[21:22:41] <BJT_Shop> no 4160, 480 is very common
[21:22:41] <toastydeath> like rolling mills and arc furnaces
[21:22:45] <alex_joni> ZeroFlex1: except three phase
[21:22:48] <alex_joni> which is 400V
[21:23:09] <ZeroFlex1> 3 phase is just 3 times 230 line over here
[21:23:22] <alex_joni> that's what I'm talking about
[21:23:24] <mozmck_work1> never heard of 4160V other than power lines. wow!
[21:23:24] <ZeroFlex1> r s t
[21:23:40] <toastydeath> mozmck_work1: power lines are much higher than 4160
[21:23:42] <alex_joni> ZeroFlex1: but it's measured phase-to-phase , and it's 400V
[21:23:43] <ZeroFlex1> r 230 s 230 t 230
[21:23:43] <BJT_Shop> power lines are a lot higher than that
[21:23:51] <toastydeath> the 4k range is referred to as industrial service
[21:24:05] <BJT_Shop> and underground to pad mounted transformers
[21:24:16] <ZeroFlex1> but ten i have a big breaker of 30amps between it (30amps times 3)
[21:24:18] <andypugh> Seriously big motors tend to be very high voltage as you can have much thinner windings for the same current.
[21:24:30] <BJT_Shop> some older underground is 3k
[21:25:01] <toastydeath> rolling mills tend to run on those high voltages, it's hard to get a pair of 3000 hp electric motors running on 400 volts
[21:25:56] <toastydeath> at 4160, that's a ~600 amp load - not unmanagable
[21:26:04] <alex_joni> the servos we have on the latest robots are all 600V AC
[21:26:31] <toastydeath> or a 5000 amp load at 400 volts, and now your stuff resembles substation switchgear
[21:26:52] <toastydeath> I have made the connectors for a 3000 amp switch, I don't want to know how big a 5000 amp switch is
[21:27:09] <alex_joni> heh.. reminds me of soem weldign machine we installed (also resistence spot welding)
[21:27:21] <alex_joni> it was a 500kVA or so machine
[21:27:37] <alex_joni> had wires about 150 mm^2 per phase
[21:27:42] <toastydeath> hahah
[21:28:19] <alex_joni> that's about 15 times 0000 AWG
[21:28:26] <alex_joni> to convert it to funny US metrics
[21:28:53] <toastydeath> well that's about the same size as the barrels for the 3000 amp switchgear
[21:28:55] <alex_joni> might have been more than that, though
[21:29:00] <toastydeath> the tubes are 5" in diameter, which is about 150 mm
[21:29:14] <alex_joni> toastydeath: this was 150 mm*mm
[21:29:18] <alex_joni> not 150 diameter
[21:29:24] <toastydeath> oh, dang
[21:29:33] <toastydeath> ohhh nvm
[21:29:33] <alex_joni> probably 1.5" or so
[21:29:45] <alex_joni> small stuff :D
[21:29:54] <alex_joni> still scary
[21:29:57] <toastydeath> well, you don't really see much 1.5" wire lying around
[21:30:11] <alex_joni> we used 3 cables / phase
[21:30:14] <andypugh> 12,000 hp rolling mill engine, and it reverses in less that one rev: http://www.youtube.com/watch?v=89Sto6U2-ME
[21:30:29] <clip9> I worked at a smelter when i was in high school. There we switched 35 000 Amps manually. Crazy shit.
[21:30:46] <toastydeath> holy crap
[21:30:56] <toastydeath> that is an insane reversal
[21:31:10] <andypugh> And I _think_ my great grandad used to run it.
[21:31:33] <toastydeath> what is that whistling
[21:31:34] <clip9> Wow awsome engine.
[21:31:34] <toastydeath> is that the steam in the pipes?
[21:31:50] <andypugh> Or leaking past the pistons.
[21:31:54] <alex_joni> love the last comment
[21:33:01] <ZeroFlex1> hmmm
[21:33:24] <ZeroFlex1> i work with catalysator systems behind big engines, 4 up to 8 megawatt
[21:33:57] <ZeroFlex1> those engines are a lot smaller than that one in the video
[21:34:42] <alex_joni> probably a bit newer too ;)
[21:34:54] <toastydeath> 12k hp = ~9 mw
[21:35:03] <andypugh> Anyway, now I have bribed you with steam engine videos, how about you all fix my threading problems?
[21:35:29] <ZeroFlex1> yha a lot newer
[21:36:00] <ZeroFlex1> a factory in the neighbour hood here, build even bigger engines (til 30 years ago i believe) for big ships
[21:36:12] <ZeroFlex1> stork is the company name
[21:36:42] <andypugh> As big as this? http://people.bath.ac.uk/ccsshb/12cyl/
[21:36:59] <archivist> andypugh, you need to do a halscope at the zoom that cradek asked for
[21:37:08] <andypugh> How big must the milling machine be to make that crankcase?
[21:38:02] <andypugh> I pastebinned the raw data, I think that is probably more useful?
[21:38:13] <ZeroFlex1> not that big i think, you just need to mill a shovel to dig the hole for the mold
[21:38:17] <ZeroFlex1> :d
[21:39:11] <alex_joni> andypugh: did you try a finer thread?
[21:39:52] <andypugh> Yes, it is a little better, but I rather need the M39x4mm one :-)
[21:40:22] <andypugh> And I have scrapped a lump of 4" stainless :-(
[21:40:42] <archivist> andypugh, he needs to see the it for a servo cycle
[21:41:14] <andypugh> OK, so we want a halscope image at what zoom and what channels> I can do it now
[21:43:40] <alex_joni> archivist: I saw it the other night, and I'm a bit lost what else to investigate
[21:44:02] <alex_joni> there was an post on the forum though which suggested trying imperial instead of metric for the units
[21:44:42] <alex_joni> although the spindle units aren't really in mm vs. inches
[21:44:49] <andypugh> That was from me. I created a whole imperial setup for the machine, and it was marginally better, I think. But only marginally.
[21:44:51] <archivist> mine it set to imperial
[21:45:30] <andypugh> I was wondering if the controller that handles G76 was picking a gain based on the machine accell, and not converting. It was worth a shot.
[21:46:06] <alex_joni> no, it doesn't know much about machine limits
[21:46:26] <andypugh> Is it a software PID in there?
[21:46:37] <alex_joni> nope, no PID there
[21:46:50] <alex_joni> just tracking the position from the encoder
[21:47:06] <alex_joni> but if the axis can't keep up, it might feel link a pid
[21:47:22] <andypugh> It oscillates like a badly tuned PID.
[21:47:22] <alex_joni> andypugh: maybe try to replicate your config on a sim machine, and increase z-accel and vel
[21:47:36] <alex_joni> sim/lathe.ini should be ok for that
[21:47:43] <alex_joni> see if more accel/vel helps
[21:48:01] <andypugh> Worth a try. Is there a way to introduce encoder dither?
[21:48:02] <archivist_emc> how I had halscope set http://pastebin.ca/1585007 and we zoomed to 10ms
[21:48:17] <alex_joni> you can run off the same encoder
[21:48:34] <BJT_Shop> alex_joni: http://imagebin.ca/view/S-tKD8.html
[21:48:37] <alex_joni> have the rest simulated, only the spindle live
[21:49:19] <andypugh> Ah, yes, good plan. But my quiche is burning.
[21:49:23] <alex_joni> BJT_Shop: err.. ?
[21:49:32] <alex_joni> 1am coming up here ;)
[21:50:00] <BJT_Shop> the cord that ran between my house and the shop 300' of 6-4 SO
[21:50:08] <archivist> andypugh, cradek and I were discussing earlier best change is to make a much higher resolution encoder disk
[21:50:16] <BJT_Shop> it's too heavy for me to pick up :(
[21:50:19] <alex_joni> heh
[21:50:32] <andypugh> But then I think I would run out of p-port speed?
[21:50:32] <alex_joni> * alex_joni suggests growing a muscle then :P
[21:50:43] <BJT_Shop> I'll have to tie it to the back hoe I think
[21:50:49] <alex_joni> andypugh: what's the current base thread?
[21:51:00] <andypugh> Base thread is 50uS
[21:51:09] <alex_joni> pick one end up, and respool it ;)
[21:51:13] <alex_joni> andypugh: oh, why so slow?
[21:51:19] <andypugh> I think I can run 30
[21:51:40] <andypugh> Not sure, it is half what stepconf chose....
[21:51:56] <alex_joni> stepconf choses doublestepping by default
[21:52:19] <alex_joni> and it choses the biggest number that still satisfies your need to output pulses
[21:52:24] <archivist> andypugh, quoting yeah my calcs are right - assuming 20usec base period, 1000 rpm, counter mode, you could use an encoder that's up to 1500 lines, around 1000 is better for safety
[21:52:26] <andypugh> I need 1.5uS per step, and have 2.5uS latency
[21:52:41] <alex_joni> I think it doesn't think about counting encoders
[21:53:23] <alex_joni> lets see.. 20 usec means 50000 changes / second
[21:53:27] <andypugh> I am concerned that the dither between 2 and 3 samples per encoder line will cause huge problems?
[21:54:01] <alex_joni> you can count about 20k transitions (to be safe) / second
[21:54:30] <alex_joni> at 1000 rpm = 16.67 rps -> 1200 counts
[21:55:09] <alex_joni> 1200 counts means a 600 slot encoder
[21:55:16] <andypugh> I think I have been fooled by halscope running in the servo thread and making it look like I drop counts at 20lines and 1000rpm
[21:56:00] <alex_joni> andypugh: can you try to adapt one of the stepper configs, and try that?
[21:56:09] <archivist> as he is running a lot slower base thread a 240 slot giving 480 changes
[21:56:11] <alex_joni> e.g. a config without doublestep
[21:56:44] <alex_joni> archivist: no reason against running a faster base thread
[21:57:13] <alex_joni> BJT_Shop: aren't there 2 cables in that pic?
[21:58:35] <BJT_Shop> yea you caught me one is 25' long
[21:59:20] <alex_joni> :P
[21:59:36] <alex_joni> you can still pick up one end, and respool it somewhere else :D
[21:59:45] <alex_joni> but backhoe is easier
[22:00:38] <BJT_Shop> I tied it up and rolled it like a flat tire
[22:00:46] <BJT_Shop> it rolled
[22:00:56] <andypugh> I see a drawback with the 1000 line encoder idea, I don't have a 0.3mm milling cutter...
[22:01:27] <archivist> slitting saw
[22:02:11] <alex_joni> make two disks then overlap them :D
[22:02:22] <archivist> I would not go all the way too 100, have some headroom for higher spindle speeds
[22:02:59] <alex_joni> andypugh: surely there is something else going on too
[22:03:01] <andypugh> Slitting saw is a plan.
[22:03:15] <alex_joni> there are people using 1 pulse/rev and it's working ok
[22:03:41] <andypugh> Maybe I should try that too?
[22:03:46] <archivist> I bet they are not making coarse threads
[22:04:18] <archivist> your 4mm pitch needs some control
[22:05:06] <jymm> ...Try #bdsm, I'm sure you'll be able to find a dominatrix for some control
[22:06:02] <andypugh> I think that the problem is lack of accelleration, but it isn't that slow.
[22:06:14] <andypugh> What max accell do tohers use?
[22:06:33] <andypugh> (Not that I know what the units are)
[22:07:22] <andypugh> I have 300 mm/s2 which is 12"/s2 Enough to get from 0 to max speed (1500mm/min) in 1mm
[22:08:33] <archivist> max acc is 12" and max veloc is .9 stepgen_max acc is 18
[22:09:00] <andypugh> 0.9 and 18?
[22:09:25] <archivist> .9 is the max velocity
[22:09:42] <andypugh> Ah, yes, sorry.
[22:10:01] <andypugh> What _is_ stepgen max accell?
[22:10:10] <alex_joni> 300 should be enough
[22:10:23] <andypugh> I tried it at 1000 in G61.1 mode and it almost worked
[22:10:29] <alex_joni> someone else said 512 should be enough ;)
[22:10:34] <alex_joni> or was it 640
[22:11:16] <andypugh> IfI need more, where can I find it?
[22:11:40] <alex_joni> * alex_joni was joking..
[22:11:59] <andypugh> Yes, but if that is the problem...
[22:13:16] <andypugh> However, I don't think it is. There must be _some_ sort of controller in there that converts position error into steps. And I think the gain doesn't suit my system.
[22:13:16] <alex_joni> more voltage to your steppers
[22:13:42] <jymm> UG UG UG MORE POWER!!!! UG UG UG
[22:13:45] <andypugh> I could rewire them parallel and get a bigger controller.
[22:14:26] <jymm> If you rewire them, you'll need a flux capcitor too
[22:14:49] <SWPLinux> 1.21 gigawatts
[22:15:04] <jymm> SWPLinux: Maybe double that.
[22:15:11] <SWPLinux> inflation strikes again
[22:15:18] <jymm> SWPLinux: So, what planet are you on now?
[22:15:35] <SWPLinux> one that's "mostly harmless"
[22:15:49] <jymm> SWPLinux: Utah?
[22:16:02] <SWPLinux> Chicago O'Hare
[22:16:03] <andypugh> Seriously, they are rated 2.5A series and 4.5A parallel, so I am running series to suit the 2.5A controllers I have.
[22:16:08] <SWPLinux> waiting for my flight home
[22:16:17] <jymm> SWPLinux: Where are you?
[22:16:22] <SWPLinux> Chicago O'Hare
[22:16:24] <SWPLinux> waiting for my flight home
[22:16:26] <BJT_Shop> have a cold one on me SWPLinux
[22:16:34] <SWPLinux> err
[22:16:38] <alex_joni> andypugh: I think you asked for the code at some point.. right?
[22:16:56] <alex_joni> andypugh: what voltage rating and PSU?
[22:17:03] <jymm> SWPLinux: Dang dude, you must have like a bazillion miles saved up
[22:17:06] <alex_joni> what controllers?
[22:17:13] <SWPLinux> jymm: ~350k
[22:17:18] <andypugh> Motion Control Products
[22:17:20] <alex_joni> jymm: he spends them on flight attendents
[22:17:27] <SWPLinux> shhhh
[22:17:37] <jymm> alex_joni: Why, they get their own damn miles!
[22:17:41] <SWPLinux> I may go to Omaha next week too
[22:17:48] <alex_joni> errr.. business services
[22:17:59] <SWPLinux> nah, just "Service"
[22:18:02] <andypugh> http://www.motioncontrolproducts.com/drives/msd325-microstepping-drive.php?cat=2
[22:18:04] <BJT_Shop> you guys have all the fun
[22:18:17] <jymm> alex_joni: You do know that many of the "flight attendants" are 1) old, 2) male
[22:18:31] <SWPLinux> now why would the word "fun" come up so soon after the word "Omaha"?
[22:18:34] <alex_joni> andypugh: 32VDC max
[22:18:37] <alex_joni> that's a bit low
[22:18:40] <BJT_Shop> lol
[22:18:53] <alex_joni> jymm: not over here
[22:18:59] <andypugh> Looking at the motor spec, the difference in torque-at-speed is not huge for a doubling of current
[22:19:10] <alex_joni> they are mostly 1) young 2) female 3)good looking
[22:19:19] <jymm> alex_joni: 4) vampires
[22:19:25] <BJT_Shop> and single
[22:19:37] <alex_joni> andypugh: nope, but doubling the voltage should definately make a big difference
[22:19:38] <andypugh> Hmm, I am running at 24V anyeay
[22:19:45] <BJT_Shop> except when you fly air france
[22:19:58] <jymm> SWPLinux: You'll be home for a while, or just a layover?
[22:20:30] <archivist> at 30v and parallel they will be faster
[22:20:57] <SWPLinux> err, good question
[22:21:07] <jymm> SWPLinux: http://notalwaysright.com/why-hello-pheven/1501
[22:21:32] <andypugh> I am not sure I need more speed though, as much as more accelleration.
[22:22:03] <andypugh> And I am not totally convinced I need that.
[22:22:08] <archivist> you get better acceleration as well with a higher voltage
[22:22:27] <archivist> its rate of change of current
[22:22:37] <alex_joni> andypugh: the good thing is that you can easily test that
[22:22:54] <alex_joni> hm.. can you try a simple thing?
[22:22:54] <BJT_Shop> andypugh: are you limited to 24V power on your drive?
[22:22:59] <alex_joni> or is the machine down?
[22:23:09] <andypugh> Easily for the cost of a bigger power supply and drive, you mean?
[22:23:21] <alex_joni> no.. I mean using sim
[22:23:25] <alex_joni> and halscope
[22:23:31] <andypugh> Machine is off at the moment, but can go on
[22:23:33] <BJT_Shop> your not going to get much acceleration with 24v on a stepper
[22:23:47] <andypugh> I get 12" !
[22:23:53] <alex_joni> try a faster servo-thread and see how it behaves
[22:24:03] <andypugh> How fast?
[22:24:20] <alex_joni> now it's at 1msec, try .5 msec
[22:24:45] <alex_joni> also.. you can run the machine with the motor drives switched off
[22:24:49] <alex_joni> only spindle running
[22:25:04] <andypugh> It was at 0.5mS when I came in for my dinner.
[22:25:04] <alex_joni> then you'll get a 'simulated' machine
[22:25:06] <jymm> FASTER BABY FASTER!!!!
[22:25:22] <alex_joni> then you can play with accel and speeds and see what happens
[22:25:31] <alex_joni> (see = halscope for the same threading move)
[22:25:50] <andypugh> Yes, I will be trying that tomorrow.
[22:25:57] <alex_joni> andypugh: any difference at .5 than 1msec?
[22:26:02] <alex_joni> better/worse?
[22:26:05] <jymm> alex_joni: You know, that wouldn't be a bad thing to add-on... a PID tuner
[22:26:33] <alex_joni> jymm: there's a component called at_pid
[22:26:58] <alex_joni> jymm: http://www.linuxcnc.org/docview/html//man/man9/at_pid.9.html
[22:27:22] <jymm> alex_joni: Does it loop thru settings to find the optimum configuration?
[22:27:23] <andypugh> (I will have to turn off the amps in the ini file, the same switch controls the computer monitor, the pwm for the spindle motor, etc
[22:29:07] <SWPLinux> jymm: it uses math to calculate usable settings
[22:29:31] <SWPLinux> based on feedback from a specific type of output it does
[22:29:39] <andypugh> alex_joni: You seemed about to point me at the source code? I have it downloaded, just need to know which file to look in.
[22:29:40] <jymm> SWPLinux: Ah, ok.
[22:29:58] <alex_joni> andypugh: I was about to past a link to the line :D
[22:30:14] <jymm> SWPLinux: Oh, what's math?
[22:30:18] <SWPLinux> 1+1=3
[22:30:18] <alex_joni> let me look it up again
[22:30:22] <alex_joni> http://git.linuxcnc.org/gitweb?p=emc2.git;a=blob;f=src/emc/kinematics/tp.c;h=033198b6b0401d58edfff961aa01cb15ca97c03d;hb=HEAD#l896
[22:30:44] <andypugh> Experience at work is that autotuning is rarely optimal, and we run some very exotic controllers (mapped gains, for example).
[22:31:00] <jymm> SWPLinux: I got 1.5
[22:32:54] <andypugh> 1+1 = 10?
[22:33:35] <geo01005> '1'+'1'=11
[22:33:56] <andypugh> (A diesel engine ECU is a hundred or so controllers all arguing with each other)
[22:34:06] <jymm> http://notalwaysright.com/a-match-made-in-size-7/1490
[22:36:41] <nenunad> nenunad is now known as MarkusBec
[22:43:47] <alex_joni> good night all
[22:43:52] <SWPLinux> see you
[22:44:23] <andypugh> Thanks for the souce link, it is going to take me a while to figure it out
[22:44:48] <andypugh> But it does look simplistic, if I may say so.
[22:50:50] <skunkworks> SWPLinux: how is it going?
[22:59:13] <SWPLinux> uh - ok
[22:59:46] <SWPLinux> here's where I was on Friday: http://www.worldamazingrecords.com/2009/09/most-cameras-used-in-creed-live-concert.html
[23:14:14] <MarkusBec> MarkusBec is now known as MarkusBec_away
[23:17:17] <cradek> andypugh: did you read the logs and see my comments about your problem earlier today?
[23:18:27] <cradek> I suspect the cause is your poor quality encoder and you should try 1ppr if you can't try a real encoder
[23:18:50] <cradek> also I still want to see the plot I've asked for several times
[23:19:57] <cradek> bbl.
[23:36:32] <jymm> SWPLinux: As a concert goer or setting up AV gear?
[23:36:48] <SWPLinux> making the cameras work so they could break the world record
[23:37:07] <SWPLinux> s/they/we/, but you know how that goes
[23:37:49] <jymm> Yeah, I was JSUT thinking that actually. Too bad it's not a film, as you would be in the credits.
[23:38:01] <SWPLinux> har har
[23:38:10] <SWPLinux> I've worked on films, but never been credited
[23:38:18] <jymm> SWPLinux: You wouldn't? (I was being serious)
[23:38:22] <jymm> oh
[23:38:50] <jymm> well shit, get up in imdb and add yourself to the uncredited list!
[23:39:04] <SWPLinux> and they didn't invite me to the press conference for this record, or have me be involved when accepting the award
[23:39:20] <SWPLinux> heh, yeah - I ought to
[23:39:36] <SWPLinux> I've only worked on two mainstream films though, and helped out a friend on another
[23:39:37] <jymm> SWPLinux: You need to start building in back doors
[23:39:54] <SWPLinux> like the one where nobody but me can operate the new digital system?
[23:40:36] <jymm> SWPLinux: Or where you're the only one that get the system back online ater you've hit the button on the remtoe control
[23:41:08] <SWPLinux> oh, I don't need that level of complexity
[23:41:17] <jymm> heh
[23:41:26] <SWPLinux> I just based everything on Linux, and the bunch of mac-heads can't even set it up :)
[23:42:42] <jymm> SWPLinux: I think you need to start getting credited - put it in your contract or something.
[23:42:59] <SWPLinux> eh - it's no biggie
[23:43:09] <SWPLinux> what I've done is "work for hire", so I don't own it
[23:43:22] <SWPLinux> it would be nice to get some credit, but that's often not how it works
[23:43:38] <SWPLinux> (it's always the manager / executive that takes credit for what the engineers did)
[23:43:45] <jymm> SWPLinux: Actually it is. It builds up a reputation for one, free advertsing for another.
[23:44:21] <jymm> SWPLinux: No, no, I mean in the tiny print. Not above the line or anything, but at least something.
[23:44:55] <SWPLinux> understood
[23:45:04] <SWPLinux> brb
[23:45:09] <jymm> k
[23:47:35] <SWPLinux> ok - flight is still on time
[23:47:50] <jymm> SWPLinux: how long?
[23:48:34] <SWPLinux> I'll have to go board in about 20 minutes
[23:48:51] <jymm> SWPLinux: How long was the layover? 4 hours?
[23:49:03] <SWPLinux> about 3 hours
[23:49:12] <SWPLinux> not planned, my original flight this morning was cancelled
[23:49:20] <jymm> ?!
[23:49:28] <jymm> they just cancel flights like that?
[23:49:44] <SWPLinux> so they re-routed me through Chicago, with a 3 hour layover
[23:49:47] <SWPLinux> not too often
[23:50:00] <jymm> Did they say why it was canceled?
[23:50:15] <SWPLinux> the flight from Washington DC to San Antonio was canceled this morning, so there was no plane to fly back there
[23:50:19] <SWPLinux> no, I don't think so
[23:50:45] <jymm> bastards.... probably you the only one on the flight!
[23:51:00] <SWPLinux> heh. no, I think there were at least 8 seats sold :)
[23:51:18] <jymm> You coulda have 4 sexy flight attendants all to yourself
[23:51:32] <jymm> 3 of them female! LOL
[23:51:38] <SWPLinux> I get home only 4 hours later, and they put me in first class on the way here (still waiting to see if that happens going to Burlington)
[23:51:41] <SWPLinux> heh
[23:52:33] <jymm> SWPLinux: Do they have a private lounge for you in ORA?
[23:53:27] <SWPLinux> ORD
[23:53:36] <jymm> ok, ORD
[23:53:47] <SWPLinux> I'm a Red Carpet Club member, so I've been in the business center all this time
[23:53:57] <SWPLinux> free snacks, coffee, and internet (and power)
[23:54:13] <SWPLinux> well, free once you pay a few hundred dollars a year
[23:54:25] <jymm> What, no reclining chairs or beds?
[23:54:49] <SWPLinux> sure, but I chose to use the business center instead
[23:54:49] <Bridgeport_II> SWPLinux: Hi, this is KimK. I'm chatting from John's in Minneapolis. If you get to Omaha and I'm back let me know, maybe I can buy you lunch or something.
[23:54:53] <SWPLinux> (no beds anywaqy)
[23:55:01] <SWPLinux> oh, great
[23:55:31] <SWPLinux> I may be there for not very long - we might shoot the Creed concert in (that Iowa town next to Omaha) so we have more footage for the DVD
[23:55:44] <Bridgeport_II> Council Bluffs?
[23:55:47] <SWPLinux> (fly in one day, work a 20-hour day the next day, fly out the next)
[23:55:49] <SWPLinux> yes, that's the one
[23:56:03] <jymm> You mean BFE?
[23:56:21] <SWPLinux> ?
[23:56:26] <jymm> SWPLinux: http://notalwaysright.com/why-you-never-ever-share-toothbrushes/1482
[23:56:29] <Bridgeport_II> Sure! Like Mexican food? I'll introduce you to Alvarado's.
[23:56:36] <SWPLinux> sure do
[23:56:47] <SWPLinux> email me your contact info, I don't see your phone number in my phone
[23:56:47] <jymm> SWPLinux: BFE == Bum Fsck Egypt = Middle of nowhere
[23:56:51] <SWPLinux> heh
[23:56:57] <SWPLinux> no, it's right next to Omaha ;)
[23:56:57] <Bridgeport_II> Nothing special, but it's open 24 hours
[23:57:08] <jymm> SWPLinux: Like I said....
[23:57:16] <jymm> =)
[23:57:19] <SWPLinux> and Omaha is only an hour from Lincoln
[23:58:11] <Bridgeport_II> Well, there you go!
[23:58:35] <jymm> SWPLinux: Anytime you fly ove a place and it looks like a checkerbaord = BFE
[23:58:39] <jymm> over
[23:58:59] <SWPLinux> that's most of the country
[23:59:10] <jymm> I stand by what I said.