#emc | Logs for 2010-06-07

[18:33:59] <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/"
[18:37:45] <fragalot> logger_emc: ok! :)
[18:37:45] <fragalot> I'm logging. I don't understand 'ok! :)', fragalot. Try /msg logger_emc help
[18:37:49] <fragalot> Lawl.
[18:38:41] <bricofoy> lol
[19:13:30] <andypugh> I have a HAL function that auto-homes a servo motor and encoder. I am concerned that the process will trigger following errors as the encoder moves for no readily apparent reason. One solution might be for the module to have an amp-enable-in and amp-enable-out pin, so that the axis is only activated after the homing process. Do you think that will work, or have any better ideas?
[19:14:58] <SWPadnos> out of curiosity, when is your module a better idea than using the existing homing functionality?
[19:15:36] <andypugh> It homes the motor electrical origin to the encoder counts.
[19:16:12] <andypugh> The servo amp can't even move the motor until that alignement is done.
[19:16:44] <andypugh> Perhaps "motor alignement" is a better phrase than "homing"
[19:17:05] <Optic> * Optic homes your motors
[19:17:17] <andypugh> To themselves, yes.
[19:18:01] <SWPadnos> so the motor moves a little, and you don't want the encoder feedback to trip a following error when that happens?
[19:18:08] <andypugh> Yes
[19:18:15] <SWPadnos> hmmm
[19:18:22] <skunkworks> could be up to 1/2 turn?
[19:18:26] <frallzor> hmm am I wrong believing there was another live cd that was +8.04? :P
[19:18:28] <skunkworks> cw/ccw
[19:18:44] <SWPadnos> the "simplest" thing to do might be to turn off the encoder while you're doing that, unless you actually need the feedback for alignment
[19:18:52] <andypugh> Yes. Maybe more, worst case
[19:19:26] <JT-Work> andypugh: I hijacked the feedback on my THC comp to be able to raise and lower the torch based on voltage
[19:19:35] <andypugh> No, actually, never more than 5/6th of an _electrical_ turn, so 5/12 of a 2-pole
[19:20:03] <andypugh> Yeah, the encoder is what is being aligned.
[19:20:19] <SWPadnos> yeah, intercepting feedback is another option
[19:20:33] <SWPadnos> this is only done once per run though, right?
[19:20:51] <SWPadnos> oh, or whenever the amps are disabled/re-enabled
[19:20:58] <andypugh> encoder counts pass-through is an option (I can lie to the rest of the system)
[19:21:52] <andypugh> It needs to be any time the encoders go off, so I guess only the first time amp-enable goes high on power-up
[19:22:45] <andypugh> I was thinking that it needed to re-home if an unpowered motor was shifted, but the encoder will follow that
[19:23:12] <SWPadnos> that assumes that the encoder counters are always active
[19:23:29] <SWPadnos> and the count never changes (like at "home to index")
[19:23:39] <SWPadnos> err, never loses "sync" anyway
[19:23:40] <frallzor> any eta on this "June xx: emc 2.4.1 / Ubuntu 10.04 Live CD by Fest " =) or its old plans?
[19:23:49] <davidf> Hi
[19:23:56] <SWPadnos> frallzor, it's being worked on, but there are no promises
[19:24:19] <SWPadnos> there are experimental packages you could try on a stock 10.04 install though
[19:24:28] <SWPadnos> at http://www.linuxcnc.org/mozmck/
[19:24:30] <andypugh> The module pin is actually rawcounts, to allow for index homing (threading, for example)
[19:24:37] <SWPadnos> ok
[19:24:37] <frallzor> but I would still need to compile rtai and shit?
[19:24:46] <SWPadnos> packages ...
[19:25:05] <frallzor> oh
[19:25:29] <frallzor> any complaints on those?
[19:25:33] <frallzor> or they seem to do the job?
[19:25:35] <SWPadnos> dunno
[19:25:44] <andypugh> I guess the trick is to built a test config and see if folowing errors are a problem.
[19:25:56] <andypugh> Lets not borrow trouble.
[19:26:31] <SWPadnos> it may depend on how you expect the module to drive the motor - in position or velocity mode
[19:26:58] <SWPadnos> if it's position mode, you'll have all the problems that stepgen has with index homing and the like (unless you fix them :) )
[19:27:01] <andypugh> Torque-mode at the moment
[19:27:07] <SWPadnos> \oh
[19:27:11] <SWPadnos> -\
[19:27:31] <SWPadnos> is the encoder count actually used internally after sync?
[19:27:47] <andypugh> In fact, even that is not entirely true. It's voltage mode
[19:28:06] <SWPadnos> oh
[19:28:07] <andypugh> Yes, the phase voltages are calculated from encoder angle
[19:28:20] <SWPadnos> ah, ok
[19:29:04] <andypugh> I might write a velocity-mode variant at some point.
[19:29:35] <ries_> ries_ is now known as ries
[19:29:35] <andypugh> It is beautifully smooth and silent, much nicer than the trapezoidal one.
[19:29:51] <SWPadnos> cool
[19:31:51] <davidf> SWPadnos, andypugh hi. Just tuned in here. andypugh are you writing a new encoder hal component?
[19:32:20] <andypugh> No, a brushless motor drive component (two of them, actually)
[19:32:36] <davidf> aoh OK thanks
[19:33:01] <andypugh> Why, do you want a new encoder HAL component?
[19:33:16] <davidf> SWPadnos, I got my AMT encoder, (nice!) got it hooked up and it is semi-functional.
[19:34:01] <davidf> I was starting to do the "homework" you assigned me ie make a hal scope and view the encoder signals etc
[19:34:59] <davidf> First thing I came accross in the integrator manual is the encoder hal component is only good for 10 kHz to 50 kHz
[19:35:18] <andypugh> Well, it will go lower
[19:36:53] <davidf> andypugh, I don't necessarily want a new encoder component. Still trying to wrap my head around this one! LOL
[19:37:25] <skunkworks> andypugh: how integrated is it in the mesa hardware? Could you run a 3 channel h-bridge?
[19:37:43] <davidf> 10 khz means it can see 10,000 pulses per second right?
[19:38:03] <andypugh> Yes
[19:38:47] <davidf> so that's like 600,000 pulses per minute. Wow pretty fast even on the low end then.
[19:39:34] <andypugh> skunkworks: The bit I am writing now is totally independent of the Mesa hardware, but requires _something_ to create the PWM and handle the shoot-through protection.
[19:40:03] <andypugh> All this component does it calculate the three phase-amplitudes
[19:40:05] <skunkworks> I was figuring pwm out of the mesa card running the amp.
[19:40:34] <skunkworks> so it is more like a sinusoidal type drive vs the trapizoidal?
[19:41:14] <andypugh> Yes, that's exactly the idea. The 3pwmgen pins from the FPGA card can be connected to a Mesa daughtercard, or to anything else that takes 3 or 6 wires of PWM
[19:41:33] <andypugh> I have a trapezoidal driver written too.
[19:41:55] <skunkworks> heh - cool. (we have a bunch of trapizoidal style amps)
[19:42:41] <andypugh> The path is PID -> (bldc_hall or bldc_sine) -> 3ppwmgen -> Mesa FPGA -> arbitrary hardware
[19:42:42] <SWPadnos> davidf, that may be better said as "good to a maximum of 10-50 kHz"
[19:42:52] <SWPadnos> it can do one pulse per year too
[19:43:25] <JT-Work> SWPadnos: I'm on it like a chicken on a june bug
[19:43:31] <davidf> ha. Yes I realized that was maximum. :)
[19:43:34] <SWPadnos> heh
[19:43:39] <andypugh> skunkworks: You can almost certainly run those amps as sinusoidal amps with this, if you want.
[19:44:17] <morficmobile> hm, i never looked at the max rpm of servo based on the khz for the encoder
[19:44:40] <SWPadnos> morficmobile, you're planning to use mesa cards, right?
[19:44:45] <andypugh> davidf: Note that an encoder is 4 pulses per line, so a 1000 line encoder is a 4000 pulse encoder
[19:44:58] <SWPadnos> andypugh, it depends on the manufacturer ...
[19:45:00] <morficmobile> SWPadnos: indeed
[19:45:09] <SWPadnos> morficmobile, then you shouldn't have a problem
[19:45:18] <SWPadnos> think MHz, not kHz
[19:45:28] <morficmobile> the khz come into play for pc does it all?
[19:45:39] <SWPadnos> parallel port, yes
[19:45:57] <morficmobile> then i just say i knew that and that's why i never considered it as limit :>
[19:46:01] <SWPadnos> but it's in the MHz for Mesa
[19:46:02] <SWPadnos> heh
[19:46:58] <morficmobile> the part i took the .500 DoC in, someone crashed it on the mill, might be savable, still bums me out
[19:56:39] <morficmobile> $9k to redo the ballscrews of the Mori
[19:58:10] <archivist_attic> ew thats a nasty price
[19:59:43] <andypugh> hi Archivist, and thanks for the bidding, sorry you didn't win. I suspect a bidsniping service.
[20:04:05] <skunkworks> andypugh: using the trapizoidal amps... these are +/-10v and 3 hall sensors. Would there be hacking involved or would emc take over the phasing?
[20:04:56] <andypugh> Hacking, unfortunately.
[20:05:01] <skunkworks> ok :)
[20:05:46] <andypugh> Is the issue that you have hall-sensor amps and resolver motors?
[20:06:27] <andypugh> Otherwise I don't see why you wouldn't just use them as intended?
[20:06:50] <skunkworks> no - and I think the trapizoidal commutation will work just fine for us.
[20:07:42] <skunkworks> the little bit I played with the servos we had - rough tuning gave some pretty decent results.
[20:07:58] <archivist_attic> andypugh, I pushed it a bit and was getting a coffee during the last moments :(
[20:08:06] <skunkworks> but they clicked funny at each commutation change ;)
[20:09:04] <andypugh> Try all 6 hall wire combinations. There are 2 that sort-of work as well as the right one.
[20:09:28] <morficmobile> i never bought any 9k is as good as any price for a 60mm ballscrew, 38mm or so on X
[20:10:24] <andypugh> skunkworks: The explanation is on page 6 here: http://www.motion-designs.com/images/DTrends_May_2008.pdf
[20:11:14] <andypugh> Makes my 8mm on X look feeble, that's for sure.
[20:12:15] <skunkworks> cool - thanks. (the drives fault if the commutation isn't right..)
[20:12:48] <skunkworks> and I hooked them up per manual. I think I had them right but I could try other ones for s/g
[20:13:52] <andypugh> Are the motors and the drives from the same manufacturer?
[20:15:13] <skunkworks> no
[20:19:19] <andypugh> There are a surprisingly large number of hall sensor permuations.
[20:19:34] <skunkworks> heh
[20:19:55] <andypugh> I have 7 in the driver I have written, and none of them match my actual motor.
[20:23:47] <skunkworks> heh
[20:23:51] <skunkworks> these servos http://www.kelinginc.net/23BLMotor.pdf
[20:24:17] <skunkworks> driven by amc 'b' series drives
[20:37:58] <voxadam> Has anyone ever gotten around to implementing quintic interpolation in emc?
[20:38:40] <SWPadnos> I don't think so
[20:39:03] <voxadam> That's too bad, though hardly the end of the world.
[20:39:06] <SWPadnos> I believe we had some discussions a few years ago, but it gets pretty hard when you throw non-trivial kinematics into the mix
[20:39:31] <voxadam> I don't doubt it at all.
[20:39:44] <SWPadnos> actual, non-trivkins gets pretty hard anyway, when you start talking about joint and world constraints
[20:46:36] <voxadam> Is there a NML Python module?
[20:49:55] <SWPadnos> I don't think there's a generic NML module, but there is an "emc" module
[20:50:18] <SWPadnos> NML is a bit generic anyway, and isn't really useful without knowing a little more about the data that's being exchanged
[20:51:38] <SWPadnos> http://axis.unpy.net/01167419757
[20:52:15] <voxadam> Thanks...
[20:52:28] <SWPadnos> sure
[20:55:55] <voxadam> Now I just need to locate emc.py
[20:56:15] <SWPadnos> emcmodule.cc maybe
[20:57:53] <voxadam> I really should have seen that.
[20:58:04] <SWPadnos> yep ;)
[20:59:50] <davidf> Hi
[21:01:13] <davidf> On a lathe setup, is +Z towards the chuck or away? & +X toward operator or away? I think I might have had my axes backwards from the way g76 canned threading expects...
[21:01:32] <SWPadnos> X=0 means "center of rotation"
[21:01:48] <SWPadnos> so X+ means increasing radius from the center of rotation
[21:02:01] <davidf> so toward the op
[21:02:11] <SWPadnos> if your tools are on the front, yes
[21:02:21] <davidf> yes thery are. sprry
[21:02:28] <davidf> sorry
[21:02:31] <SWPadnos> sure
[21:02:42] <SWPadnos> I'd bet Z+ is away from the chuck, but I don't know for sure
[21:02:49] <davidf> so yes I had x backwards
[21:03:07] <davidf> I had z+ toward the chuck originally
[21:03:17] <SWPadnos> well, like I said I don't know for sure
[21:03:36] <davidf> Just crashed a brand new threading insert holder. Broke it. Darn.
[21:04:15] <davidf> Oh well it's only money.
[21:04:22] <davidf> Thanks SWPadnos
[21:05:44] <SWPadnos> bummer
[21:13:29] <jthornton> davidf, some lathes are set up with the imaginary Y axis pointing up and some with it pointing down
[21:15:18] <davidf> ok jthornton thanks Do you happen to know of anyplace the directional convention is documented for EMC? I can't find anything in the user's manual
[21:15:42] <jthornton> so for G2/3 I have to lay on the floor for it too look right on my lathe
[21:16:02] <jthornton> it follows the Cartesian coordinate system
[21:17:20] <davidf> Yes but I'm trying to figure out which way is up, so to speak. :)
[21:17:43] <jthornton> yes, I know what you mean
[21:17:58] <jthornton> give me a minute to wander out to the shop
[21:18:05] <jthornton> and get on the lathe
[21:18:09] <davidf> canned threading appears to expect a different orientation than I have set up.
[21:20:52] <JT-Hardinge> davidf: I'm out in the shop now
[21:21:42] <JT-Hardinge> on my lathe pressing the X+ makes the tool move toward me X- goes away
[21:21:43] <davidf> OK
[21:22:16] <JT-Hardinge> Z+ goes away from the spindle and Z- toward the spindle
[21:22:47] <davidf> OK Thanks JT-Hardinge
[21:23:05] <davidf> Does canned threading work on that lathe?
[21:23:35] <JT-Hardinge> you bet I cut some 1 5/16-20 threads yesterday
[21:23:50] <davidf> Great. Thanks!
[21:24:04] <JT-Hardinge> scroll down to Cartesian coordinates in three dimensions http://en.wikipedia.org/wiki/Cartesian_coordinate_system
[21:24:59] <JT-Hardinge> if you roll that figure so Z points to the left that is how my lathe is
[21:26:50] <davidf> So your spindle is on the right?
[21:26:59] <JT-Hardinge> as you can see my tools are on "my" side of the lathe in this photo http://i47.photobucket.com/albums/f163/johnplctech/Hardinge/P1010020.jpg
[21:27:00] <davidf> Your chuck, I mean?
[21:27:05] <JT-Hardinge> no
[21:27:39] <JT-Hardinge> I mean Z points to the right sorry
[21:28:02] <davidf> OK now we're talkin. :)
[21:28:14] <davidf> Had me real confused there! :)
[21:28:15] <JT-Hardinge> it gets cornfusing some times :)
[21:28:24] <davidf> Always it seems.
[21:28:44] <JT-Hardinge> are you using 2.4?
[21:28:45] <davidf> Been using this config for about 4 years and still had to double check.
[21:28:50] <Jymmm> * Jymmm installs road signs on JT-Hardinge lathe
[21:28:57] <davidf> On the machine I have 2.3.3
[21:29:09] <davidf> That OK?
[21:29:38] <JT-Hardinge> yes but you might want to look at the later docs on threading I think I explained it a bit better
[21:29:45] <davidf> jymmm too funny
[21:30:02] <JT-Hardinge> http://www.linuxcnc.org/docview/html//gcode_main.html#sec:G76:-Threading-Canned
[21:30:09] <davidf> kewl
[21:30:21] <JT-Hardinge> is that the page you have?
[21:30:50] <JT-Hardinge> Jymmm: are you going to replace my sticky notes with your road signs :P
[21:31:06] <Jymmm> JT-Hardinge: I could do that =)
[21:31:27] <JT-Hardinge> at one time my mill had about 27 sticky notes on it :)
[21:31:38] <Jymmm> JT-Hardinge: What might be cool is hit a army surplus store and have them make you custom dog tags that can be riveted on.
[21:32:03] <morficmobile> can i reverse the direction in which X+ points in Axis on lathe setup?
[21:32:22] <Jymmm> morficmobile: didn't you read the NO U TURN sign????
[21:32:29] <Jymmm> Eeeeeesh, some ppl
[21:32:38] <davidf> JT-Hardinge, I have that page on this box, in the office. The shop has the 2.3.3 page. I'll print this out and read through it. One thing in particular was I had a great deal of trouble trying to figure out what the initial x,z cods were. Not stated clearly.
[21:32:38] <morficmobile> o_O
[21:32:59] <davidf> coords i meant
[21:33:37] <JT-Hardinge> the initial position is where your tool is when the G76 starts
[21:33:50] <davidf> Right, but what numbers?
[21:34:09] <SWPadnos> ?
[21:34:10] <JT-Hardinge> ie it takes two lines of code one to set up the tool at the initial position and one to cut the threads
[21:34:26] <SWPadnos> like everything G-code
[21:34:37] <JT-Hardinge> scroll down and take a look at the example
[21:34:42] <davidf> ok
[21:35:25] <JT-Hardinge> the initial Z is the start of the threads for length, the initial X is the drive line
[21:37:58] <davidf> So the final z position shown is z = 0?
[21:40:43] <JT-Hardinge> in the example it starts at Z-0.500 and ends Z-1.000 so there is 1/2" of threads
[21:41:33] <davidf> JT-Hardinge, Oh OK
[21:42:18] <davidf> and is x=0 at the center of rotation in that example?
[21:42:49] <JT-Hardinge> yes on a lathe X0 is the center of the spindle
[21:45:35] <davidf> I got in the bad habit of writing code with x=0 at the stock surface. I do a lot of things with accurately dimensioned stock, and live tooling (tool post grinder) and found it easy to touch it off and type g92 x0.
[21:46:17] <JT-Hardinge> did that get you in trouble?
[21:46:27] <davidf> not really.
[21:47:17] <davidf> But in general it's inconvenient
[21:47:49] <davidf> Especially if you are making a part with several radii
[21:48:16] <davidf> Then x = 0 at center makes a lot more sense.
[21:48:44] <JT-Hardinge> yes it does
[21:49:11] <davidf> Well I'm making progress. :) Something makes sense.
[21:49:35] <davidf> Thanks for all the help I really appreciate it.
[21:49:42] <JT-Hardinge> np
[21:50:13] <JT-Hardinge> * JT-Hardinge just waiting for a Jerry Jeff Walker song to strap on the nail belt and grab a pile of shingles
[21:50:32] <KrashKing> train songs? ;)
[21:51:44] <JT-Hardinge> any Jerry Jeff Walker will do... when I put the roof on my Dads house it seemed to be the only artist that played even with random play
[21:53:18] <JT-Hardinge> I gave that radio away so I wouldn't have to do any more roofs :)
[21:53:39] <JT-Hardinge> but it didn't work I have to repair mine :(
[22:05:52] <JT-Hardinge> I guess Lather by Jefferson Airplane will be good enough to start slinging shingles
[22:21:53] <ries_> ries_ is now known as ries
[22:34:47] <Jymmm> JT-Hardinge: Here ya go... http://www.google.com/url?q=http://s0.ilike.com/play%23Scorpions:Rock%2BYou%2BLike%2Ba%2BHurricane:57084:s44496.15551.9033209.1.1.82%252Cstd_36a6caaaa1b8667d64fe3abb5f3a8678&sa=X&ei=3HMNTNDnAsPcnAet-NihDw&ved=0CBYQ0wQoADAA&usg=AFQjCNFuz3APqEg4UZ4EXHlRkl39oRb8Pg
[22:35:34] <pfred1> Jymmm bit.ly tinyurl por favor?
[22:35:57] <Jymmm> Nope, I don't do blind urls.
[22:36:35] <pfred1> beat the source for subtitle out of kuwon1
[22:37:22] <pfred1> 18:37 -NickServ(NickServ@services.)- Information on subtitle (account kunwon1):
[22:37:32] <Jymmm> I have no idea what you just said, but here's a bunny with a pancake on it's head.
[22:37:55] <pfred1> join ##politics then paste a URL
[22:38:42] <pfred1> kuwon1 won't give up the source for the bot though :(
[22:43:34] <andypugh> morfic: You can reverse the display of an axis in GEOMETRY
[22:44:06] <Guest294> Hello
[22:44:26] <pfred1> hi
[22:44:43] <Guest294> Is it possible to stop GNOME from running to try some things wil HAL?
[22:45:55] <Guest294> Just run HAL via command line, no gui
[22:46:17] <pfred1> you need to be in X I think
[22:46:30] <pfred1> but you don't need to run gnome to be in X
[22:47:04] <pfred1> you can choose another window manager
[22:47:46] <pfred1> whoot! I got this jazz to run!
[22:47:57] <Guest294> For wwhat I going to do I need No gui
[22:49:41] <Jymmm> pfred1: I hope that's not iomega jazz
[22:50:14] <pfred1> different jazz though I just saw one of those at a yard sale not too long ago I sort of laughed
[22:51:03] <Jymmm> SCSI was such a pita, now just expensive and not worth it.
[22:51:27] <Jymmm> Though I still do have a USB zip drive and discs around here somewhere.
[22:51:47] <pfred1> I have an old tape drive talk about a nitemare
[22:51:57] <pfred1> travan I think it is
[22:52:08] <Jymmm> paraport tape drive?
[22:52:15] <pfred1> write once read never
[22:52:25] <Jymmm> or was that floppy
[22:52:34] <pfred1> nah it was connected to the FDC IIRC
[22:53:03] <pfred1> it always worked until you wanted it to
[22:53:15] <morfic> andypugh: thanks, i look into that later, right now i just found out that building a full emc messed with my "in place" sim, so no "testing this real quick"
[22:54:02] <Jymmm> Those things were noisy, slow, and unreliable.
[22:54:19] <andypugh> If you put GEOMETRY X -Z then the Z will be displayed reversed
[22:54:53] <morfic> Z is fine, minus is to left, i guess i would put -X Z then since X+ going down is *sick* :)
[22:55:39] <pfred1> Jymmm it seemed to like to stretch the tapes a lot
[22:56:02] <andypugh> Changing the physical direction can be done anywhere, from inverting a direction pin to negating any scale
[22:56:26] <morfic> andypugh: i just mean the display
[22:56:29] <Jymmm> pfred1: I gave up on those far ebfore actually using them long term. The noise and speed was enough for me to toss them across the room.
[22:57:10] <pfred1> well i had mine on another machine and would network the files to it then back them up
[22:57:37] <pfred1> so the speed was never an issue really
[22:58:03] <Jymmm> pfred1: cradek is fond of tape, I just gave away a nice tape drive and case of 150 tapes.
[22:58:12] <pfred1> dats are nice
[22:58:47] <Jymmm> DAT2 or soemthing like that, dont recall what it was but is still being used by some today.
[22:59:01] <andypugh> A friend of mine has a petabyte(I think) robotic tape vault
[22:59:01] <pfred1> yeah they're OK
[22:59:17] <Jymmm> some DLT tapes tapes too. just gave it all to a local middle school
[22:59:49] <andypugh> Actually, I think it was 14 Petabytes 8 years ago, god knows what he has now.
[23:00:08] <Jymmm> when the tape industry stopped keeping up with the hdd industry, I gave up on them.
[23:00:30] <pfred1> I like my DVD burner
[23:00:41] <andypugh> HDDs are just unfeasible. I refuse to believe that they are possible.
[23:01:21] <morfic> andypugh: simulation now goes in right direction, thanks, scales are still backwards
[23:01:28] <Jymmm> DVD is ok for things like photos/video/docs, but I'm waiting for the 1TB optical =)
[23:02:17] <Jymmm> or for BD-R drives to get to $100 and blanks to $0.50 =)
[23:02:37] <Valen> you can get a bd player for $96 australian these days
[23:02:47] <Jymmm> Valen: burner?
[23:02:53] <Valen> dunno
[23:03:07] <Jymmm> yeah, I mostly see players for that, not burners though.
[23:03:37] <Jymmm> I have no need for any BD player, I need mass storage
[23:03:40] <Valen> still havent hacked BD sufficently well to play it in linux reliably yet :-<
[23:03:47] <Jymmm> ah
[23:04:44] <Jymmm> Darn sun! I'm wiating for sunset so I can give my genny an oil change
[23:05:24] <morfic> i'll check the ini file layout docs later, thanks andypugh
[23:10:52] <andypugh> OK, I think we can say that the 7i39 is supported hardware now :-) http://www.youtube.com/watch?v=H8fVKkjPAOQ
[23:12:06] <Valen> why wait?
[23:13:51] <andypugh> (As a puzzle, you might like to speculate on how the ballscrew cover works :-)
[23:16:25] <cradek> andypugh: is it completely silent?
[23:16:36] <andypugh> You can hear the belt.
[23:16:41] <cradek> neato
[23:16:44] <andypugh> But yes, the sound is on.
[23:17:36] <cradek> yeah, I heard background noise, but no motor
[23:17:41] <cradek> I bet that's a good sign
[23:17:57] <Valen> we moved ours to direct drive and now its way too quiet lol
[23:19:26] <andypugh> I have some much bigger servos that would work well for that axis, those little toys can be used for the rotaries
[23:20:12] <andypugh> Or I might keep the lathe as a stepper machine and convert a mill. It does actually work perfectly OK, after all.
[23:20:48] <andypugh> I have forgotten why I started this servo driver project now.
[23:23:15] <cradek> heh
[23:23:41] <cradek> are you going to assemble a patch to contribute to git master?
[23:25:49] <andypugh> Yeah, I have a bit of neatening up to do. The hall-sensor version needs to read a pattern from the modparam, and the sinusoidal one needs to not cause a following error during rotor alignment.
[23:26:07] <Jymmm> andypugh: I like how the PCB is JUST below where the swarf WILL go =)
[23:26:34] <Jymmm> and it's WAY TOO QUIET!!!
[23:26:37] <andypugh> Any ideas how to avoid the following error?
[23:26:56] <andypugh> The PCB is only there for testing, as you probably guessed
[23:27:09] <Jymmm> andypugh: I know =)
[23:27:24] <Jymmm> andypugh: If it was anyone else, I'd question it =)
[23:28:01] <cradek> andypugh: what happens? do you just get a bit of uncontrolled motion when it starts up?
[23:28:09] <Jymmm> Especially SWPadnos, he NEVER plans anything out!
[23:28:49] <andypugh> Current config is to do an alignment when amp-enable goes high. (ie amp-enable is wired to the bldc-sine.0.init pin
[23:29:26] <andypugh> I am thinking I could pass-through that pin so it only goes to the other things when it has finished.
[23:30:22] <andypugh> It might be better linked to a homing pin.
[23:30:49] <cradek> before turning machine-on, you cannot ferror because commanded follows feedback
[23:31:15] <cradek> so if you'd do the motor bootstrap when coming out of estop, you'd be fine
[23:31:20] <andypugh> Yes, but I am not happy powering the motors when the machine is meant to be off
[23:32:07] <cradek> yeah - you still would want them to turn off when you go to machine-off, because that's what a (real) ferror does
[23:32:50] <cradek> but there's no machine-on loopback (request it, then the hardware does something, then tells emc it's ready) like there is for estop
[23:34:44] <andypugh> I take it that the amp-enable turns on f-error checking, I can't take that signal and pass it on after init?
[23:35:31] <cradek> yeah that's what I was just saying - amp-enable is one instantaneous step
[23:37:54] <andypugh> Any way to increase F-error temporarily?
[23:38:04] <cradek> I don't see much alternative to bootstrapping the motors before machine-on
[23:38:55] <cradek> no, you have to restart emc to change ferror limits
[23:42:44] <andypugh> So, link iocontrol.0.user-enable-out to the init pin?
[23:43:23] <andypugh> I guess I can just provide an init-now input and an init-finished output and leave the implementation details to the user.
[23:43:40] <cradek> yeah I think that's the ticket
[23:44:07] <cradek> for instance I'd put it in my multistep come-out-of-estop ladder
[23:47:43] <andypugh> I possibly need a cleverer init sequence too, at the moment I swing from +120 degrees to zero while ramping up the current over the course of 1.2 seconds.
[23:48:40] <andypugh> I might be better going +120, -120, 0
[23:48:41] <cradek> how much motion do you get? is it up to half a turn?
[23:49:17] <andypugh> just ramping up the current at a fixed zero risks being in a position where there isn't enough torque to move the axis.
[23:49:46] <cradek> oh I see - so you want to command some various motion
[23:49:52] <andypugh> It's up to half an electrical turn, generally a quarter turn or a 6th
[23:50:45] <cradek> so like .050 inch on a normal screw - that's no big deal is it
[23:52:17] <andypugh> There are cleverer algorithms that PCW has hinted at, doing clever things with looking at velocities over very short pulses to infer rotor position, then taking the shortest route.
[23:52:31] <cradek> haha, hint hint