#emc-devel | Logs for 2007-10-25

[02:53:07] <cradek> I still don't think arc vels are right
[02:53:50] <cradek> if I do line->small arc->line at 1% FO (which is about 1ipm), I still get a slow arc
[02:54:04] <cradek> this is on a relatively high accel config
[02:56:49] <cradek> strange, the task issued velocity looks believable though
[03:08:27] <cradek> I also get accel violations on my small arcs :-/
[03:08:39] <cradek> not much, maybe 10%
[03:19:48] <cradek> wonder if it's a different/old problem
[03:26:53] <cradek> but, the 1% FO thing still seems wrong
[03:29:46] <cradek> ohhhhhhhh
[03:30:12] <cradek> it's 1% of requested velocity
[03:46:55] <cradek> argh
[03:47:01] <cradek> the thing I thought was a simple fix isn't
[03:47:15] <cradek> say my machine's max speed is F100
[03:47:20] <cradek> I program F1000 in my gcode
[03:47:27] <cradek> I set FO to 1%
[03:47:37] <cradek> should I get 1 or 10?
[03:47:54] <cradek> I know I'm talking to myself. I'm going to bed now.
[03:49:10] <SWPadnos> night
[03:49:13] <SWPadnos> :)
[03:49:28] <cradek> I lied, I didn't go yet
[03:49:35] <SWPadnos> heh
[03:50:48] <cradek> in the above case, in my tree now, you get F1 for lines and F10 for arcs...
[03:51:08] <cradek> what should FO% be applied to?
[03:51:16] <cradek> the "feed", I know
[03:51:19] <SWPadnos> requested feed
[03:51:27] <cradek> sure, but emc has never worked that way
[03:51:34] <SWPadnos> before limiting for machine accel/vel
[03:51:41] <SWPadnos> ok, that's my opinion though
[03:51:55] <cradek> since forever, if you set it to 1%, you get no more than 1% of the machine's feed
[03:52:09] <SWPadnos> 1% of the maxvel?
[03:52:41] <cradek> 1% of min(machine constraint, F word)
[03:52:49] <SWPadnos> in the example, I think arcs are right at F10, and lines are wrong at F1
[03:53:08] <SWPadnos> ok. I think it should be min(machine limit, 1% of F word)
[03:53:28] <cradek> I wonder how anything else does it
[03:53:32] <SWPadnos> so you could take something written for a fast machine, and run it on a slow machine at 25%
[03:53:50] <SWPadnos> damfino
[03:53:53] <cradek> I'm tempted to say I agree with you
[03:54:07] <cradek> I'm nervous about such a huge change though
[03:54:10] <SWPadnos> unles it's stupid for some reason I don't know :)
[03:54:39] <SWPadnos> http://cgi.ebay.com/New-Haas-TL-1-CNC-Tool-Room-Lathe_W0QQitemZ280166419203QQihZ018QQcategoryZ97230QQssPageNameZWDVWQQrdZ1QQcmdZViewItem#ebayphotohosting
[03:54:43] <SWPadnos> I wonder what the reserve is
[03:54:57] <cradek> $501
[03:55:08] <SWPadnos> damn! gotta bid at least $510
[03:55:44] <cradek> that's a few miles from you...
[03:55:52] <SWPadnos> several
[03:55:57] <cradek> dozens even
[03:56:07] <SWPadnos> a few dozen hundred
[03:56:36] <cradek> looking for a lathe?
[03:56:51] <SWPadnos> I don't recall why I started browsing tonight
[03:57:20] <SWPadnos> when I should be (a) finishing the waveform generation component and (b) packaging an RT OS on an SSD drive
[04:01:49] <cradek> sure is easy to buy stuff with ebay+paypal - too easy maybe
[04:02:43] <SWPadnos> yeah, that may be true
[04:03:29] <cradek> I used to go to the post office, get a money order and envelope/stamp, take it home, type a note with the auction number, and put it in the mailbox
[04:03:43] <SWPadnos> too much of a PITA that way
[04:03:59] <SWPadnos> click click - done and charged on a credit card
[04:04:00] <cradek> if I planned ahead (typed the note and took it along), I could mail it from the post office
[04:04:06] <cradek> yep exactly
[04:04:19] <SWPadnos> then at the end of the month - "oh shit" + click click, and the credit card is paid :)
[04:04:24] <cradek> haha
[04:04:37] <cradek> that's all automatic...
[04:04:57] <SWPadnos> it's funny - I haven't signed up for any automatic payments
[04:04:59] <cradek> numbers in, numbers out
[04:05:21] <SWPadnos> it seems to me the only recourse you have in many cases is to withhold payment
[04:05:29] <SWPadnos> which is harder if things are paid automatically
[04:05:56] <cradek> true
[04:06:06] <SWPadnos> I only have a few bills that can't be paid online, and online is fast enough that it isn't much of a burden
[04:06:20] <cradek> I use an actual credit card for larger stuff where I think I might have trouble.
[04:06:34] <SWPadnos> heh - I charge as much as I can to get the miles
[04:06:58] <SWPadnos> I even pay the phone bills (landline and cellular) with a CC
[04:07:28] <cradek> it's because of you the CC companies have to screw the other guy so bad
[04:07:34] <SWPadnos> heh
[04:08:07] <SWPadnos> I have one that i use and pay monthly, then there's the $20k or so (just went under 20, actually) that I have on the *other* cards ...
[04:08:33] <cradek> ouch
[04:08:35] <SWPadnos> those are low interest though - 3.99 and 4.99% I think
[04:08:37] <cradek> so you ARE the other guy
[04:08:44] <SWPadnos> yeah - down from $65k a year or two ago
[04:08:49] <SWPadnos> I am both guys
[04:10:28] <cradek> now I really should go to bed... goodnight
[04:10:32] <SWPadnos> night
[04:10:45] <cradek> let's argue about FO tomorrow when everyone can pop their forehead veins
[04:10:50] <cradek> I mean, chip in
[04:14:06] <SWPadnos> excellent - I won't be here :)
[04:14:20] <SWPadnos> hmmm. halmeter never calls hal_ready()
[04:14:29] <SWPadnos> nor halscope
[04:14:39] <SWPadnos> (at least, they all show as initializing)
[12:12:54] <jepler> SWPadnos: that's not too grave a problem, since I don't think either one creates pins or parameters. but it should be fixed..
[12:14:54] <jepler> .. I'll look at it
[12:15:10] <jepler> useful to know what files have hal_init but not hal_ready: grep -l hal_init *.c | xargs grep -L hal_ready
[12:16:27] <jepler> oh ick, I'd forgotten about joystick.c
[12:27:43] <steves_logging> steves_logging is now known as steve_stallings
[12:29:21] <steve_stallings> regarding feedrate override issue - I think it should be handled the same as other machine dynamics limitations, like blending. The machine should do the best it can to follow what is requested in the G code. If the machine paramaters for max vel or accel change the results will change.
[12:31:46] <steve_stallings> Yes, I know that will possibly make significant changes in how the slow paths are cut in relation to the fast paths, but does feedrate override slow down a blend move that is already limited by accel limits?
[12:32:48] <steve_stallings> Is there any way to get a backplot that color codes the segments that are speed limited by machine dynamics so the operator can visualize the problem?
[12:34:45] <jepler> steve_stallings: no, not really
[12:41:41] <steve_stallings> didn't think so, but I have learned to always ask, sometimes you get a nice surprise
[12:48:17] <skunkworks_> cradek when he was testing the tp had the plot change colors during a blending move. It was pretty cool. Don't think it was kept though.
[12:48:27] <skunkworks_> axis plot
[12:49:35] <skunkworks_> I think you can see it on the pictures here http://wiki.linuxcnc.org/cgi-bin/emcinfo.pl?TrajectoryControl
[12:49:46] <skunkworks_> (screen shots)
[12:57:31] <steve_stallings> interesting... cradek mentions a "simulated" machine, not the same as a backplot, but potentially useful still
[13:10:27] <jepler> steve_stallings: there's servo-sim which has a simple model of motor inertia using a low-pass filter, and check_constraints.hal which continuously tests that acceleration and velocity are within specific limits (making it easy to capture traces of constraint violation in halscope)
[13:10:44] <jepler> I'm not sure exactly which of those chris was referring to
[13:31:46] <steve_stallings> ok, later, got to run now, thanks
[13:32:01] <steve_stallings> steve_stallings is now known as steves_logging
[17:19:48] <skunkworks_> well - I could have done that ;)
[17:20:38] <skunkworks_> * skunkworks_ likes to use the 'summon' command though
[17:21:38] <alex_joni> heh
[17:21:56] <alex_joni> that reminds me of the wraith
[17:25:33] <skunkworks_> roll playing game?
[17:26:36] <alex_joni> skunkworks_: stargate atlantis
[17:26:55] <alex_joni> but yeah, it's usually in rpgs
[18:18:29] <jepler> 11:18:22 up 3:32, 5 users, load average: 66.18, 93.11, 125.36
[18:18:42] <cradek> ouch
[18:21:29] <alex_joni> oops
[18:24:57] <alex_joni> good night all