#emc-devel | Logs for 2007-12-25

[02:50:59] <jmkasunich> is axis supposed to look at the value of [DISPLAY]LATHE, or does its mere presence, even if set to zero, result in lathe mode?
[02:51:17] <jmkasunich> I thought LATHE=0 would get me mill mode but it doesn't look that way
[02:51:33] <jepler> whee -- now on the arduino you get 6 ADC, 6 PWM DAC, and 6 digital pins that can be used as ins or outs
[02:52:06] <jepler> jmkasunich: if you write LATHE=0 then the result of inifile.find is the string '0', which is not the empty string, so it is treated as a 'true' value
[02:52:16] <jepler> defensible behavior? maybe not ..
[02:53:50] <jmkasunich> documented behavior? (I dunno, I just guessed at what it might do and tried it)
[02:54:21] <jepler> it just suggests including LATHE = 1
[02:54:33] <jmkasunich> * jmkasunich removes and replaces the Z axis motor for the 4th time today
[02:54:43] <jmkasunich> (awkwardly located screws and all)
[02:54:51] <jepler> it doesn't say what LATHE = 0 means but I sure can see your expectations were violated
[02:55:32] <jmkasunich> would "MODE = LATHE" and "MODE = MILL" be more of a pain to implement?
[02:56:00] <jepler> oh not particularly
[03:03:35] <jmkasunich> page up and down are the Z jog controls aren't they?
[03:04:03] <jmkasunich> my mini keyboard doesn't have those keys :-(
[03:08:56] <jepler> hm that could be a problem for you then
[03:09:21] <jepler> of course in lathe mode, left/right is Z and up/down is X
[03:09:54] <jepler> you could put some lines in .axisrc to change the bindings. For example, bind_axis("bracketleft", "bracketright", 2) would make '[' and ']' move Z.
[03:10:03] <jepler> which is fine right up until you get a rotary axis
[03:10:07] <jmkasunich> I was gonna ask about rebinding things
[03:10:23] <jmkasunich> I'll probably have a jogwheel long before I have a rotary, so thats OK
[03:10:38] <jmkasunich> now I'm finding another annoyance (probably operator error)
[03:10:52] <jepler> this sort of thing happens when you actually spend time being an operator
[03:11:10] <jmkasunich> I have home_offset for Z = 0, I home it, it finds the switch and the home icon turns on, but the display shows 1.3something
[03:11:19] <jmkasunich> I tried g92.1 and homed again, no change
[03:11:36] <jepler> try using the menu to clear G54 offset?
[03:12:19] <jmkasunich> that did it
[03:12:28] <jmkasunich> thats stored in the var file, right?
[03:12:35] <jmkasunich> (I copied my lathe var file)
[03:12:42] <jepler> yes
[03:13:26] <jmkasunich> now to put limits in for Z (this is the first axis with a switch, so limits are new....)
[03:23:19] <cradek> jmkasunich: did you figure out the 1.3 offset?
[03:23:38] <jmkasunich> I think it was in the var file
[03:24:34] <cradek> have you seen http://wiki.linuxcnc.org/cgi-bin/emcinfo.pl?CoordinateSystems#So_if_you_re_lost_what_should_you_do
[03:25:06] <jmkasunich> good link, thanks
[03:25:13] <jmkasunich> now I have another weird thing going on
[03:25:31] <jmkasunich> my first homing worked (at least the moves were all in the right direction)
[03:25:42] <jmkasunich> now its going the wrong way (and into a hard stop, ouch)
[03:26:11] <cradek> yikes
[03:27:44] <jmkasunich> I didn't change search vel, I wonder if it thinks its on the switch
[03:27:49] <jmkasunich> * jmkasunich fires up halscope
[03:30:19] <jmkasunich> did you see the 5-axis rigid tapping in that last vid?
[03:30:54] <cradek> no
[03:31:08] <cradek> I don't see a link
[03:32:14] <cradek> oh I see it
[03:32:32] <cradek> just one at the very end
[03:33:18] <jmkasunich> duh, figured out my homing issue
[03:33:30] <jmkasunich> max limit needs to be greater than min limit ;-)
[03:33:36] <cradek> oops
[03:36:37] <jmkasunich> ze quill, she works!
[03:38:00] <SWPadnos_> SWPadnos_ is now known as SWPLaptop
[03:38:27] <cradek> woo! you have a mill?
[03:38:38] <SWPLaptop> no
[03:38:38] <jmkasunich> I do
[03:38:42] <SWPLaptop> heh
[03:39:04] <jmkasunich> SWPLaptop: you missed me saying "ze quill, she works!"
[03:39:11] <jmkasunich> homes and limits and all that neat stuff
[03:39:15] <cradek> wow
[03:39:15] <SWPLaptop> cool!
[03:39:30] <SWPLaptop> and it's semi-portable ;)
[03:39:37] <jmkasunich> soft limits that is - I'm going to do without limit switches
[03:39:37] <SWPLaptop> (raltive to the Van Norman or a BP)
[03:39:42] <SWPLaptop> relative
[03:39:51] <jmkasunich> 700 lbs in the basement - NOT portable
[03:39:51] <SWPLaptop> gah - it's hard to type on a laptop
[03:39:54] <SWPLaptop> heh
[03:39:59] <SWPLaptop> semi, semi :)
[03:40:09] <cradek> on my lathe I use a home switch for one X limit
[03:40:32] <jmkasunich> my quill home switch trips 0.044 before physical end of travel
[03:40:44] <jmkasunich> I've set the offset to -0.040, so I can use that extra travel
[03:41:06] <cradek> wow that seems pretty close
[03:41:08] <jmkasunich> (the total travel is only 3.3", so every little bit helps)
[03:42:08] <SWPLaptop> heh, < 1/20" seems like "a little bit"
[03:42:43] <SWPLaptop> but I guess if it lets you machine something that's 1" thick with the right tool, instead of something that's 0.95" thick, then it really does helop
[03:42:45] <SWPLaptop> help
[03:42:55] <cradek> you think the switch will repeat within .004 for a long time?
[03:43:04] <jmkasunich> dunno
[03:43:09] <cradek> since you don't have index...
[03:43:54] <jmkasunich> I just stuck a piece of 0.005" feeler gage stock between the banjo and the bottom of the casting - it never got pinched during a home and a rapid to zero from 3" away
[03:44:15] <jmkasunich> (the 0.044 measurement is a bit conservative, might be more like 0.048 or so
[03:44:55] <jmkasunich> interesting point though, I can do a repeatability test
[03:46:24] <SWPLaptop> well, I should sign off - I just wanted to see if IRC worked through this connection (I hate the Nomadix portal system)
[03:46:50] <SWPLaptop> see you tomorrow maybe
[03:48:35] <cradek> I don't see how you can ever use both an end mill and drill bits on the same job with 3.3" of Z and no knee
[03:48:57] <cradek> I crank the knee constantly and I have 5"
[03:49:36] <cradek> I guess you could spot drill in the cnc, and use a drill press later, and do fairly well
[03:52:59] <jmkasunich> now you know why I have a knee mill
[03:53:06] <jmkasunich> and a floorstanding drillpress
[03:53:42] <jmkasunich> I did 6 trials - home ; G0Z-0.35 ; G1F1Z-.40
[03:54:05] <jmkasunich> indicator readings were 0.0000, 0.0002, 0.0005, 0.0007, 0.0000, 0.0001
[03:55:12] <cradek> I wish there was an easy way to get just index (homing for steppers)
[03:55:26] <jmkasunich> you mean a one channel encoder?
[03:55:34] <jmkasunich> (index channel)
[03:55:36] <cradek> yeah, but cheaper than an encoder
[03:55:49] <jmkasunich> opto-interrupter and a disk with a slit in it?
[03:56:16] <cradek> sure, that might do it
[03:56:28] <jmkasunich> my machine is 20 turns of the stepper per inch, a 1" dia wheel has 3.14" of perimeter, so you have a 62.8:1 multiplication factor
[03:56:48] <jmkasunich> any uncertainty in the detector would be divided by that ratui
[03:56:50] <jmkasunich> io
[03:57:01] <jmkasunich> (and I could easily do a 2" disk)
[03:57:39] <jmkasunich> I have an idea I'd like to explore that would play nicely with that concept
[03:58:05] <jmkasunich> for lathe Z, you can't really do a home switch because the chuck or tailstock is likely to block the ends of travel
[03:58:32] <cradek> right
[03:58:43] <jmkasunich> a N bit linear feedback shift register generates a stream of (2^N)-1 bits with no N bit sequence repeated
[03:58:54] <jmkasunich> my screw is 10 TPI
[03:59:16] <jmkasunich> make a linear part with the output of an 8 bit LFSR milled in it, 0.100" per bit
[03:59:31] <jmkasunich> when you home, start moving, and sample the opto-sensor on every index
[03:59:49] <jmkasunich> after 8 revs, you have a bit pattern that tells you where you are to within one turn
[03:59:55] <jmkasunich> the next index gets you your location
[04:00:36] <jmkasunich> one opto-interrupter looking at the linear "scale", and one looking at the disk on the screw
[04:00:55] <jmkasunich> and a custom HAL component to match up the bit pattern with the LFSR code
[04:01:29] <cradek> wow, so this is just for homing?
[04:01:43] <jmkasunich> yes
[04:02:06] <jmkasunich> its a very cheap "absolute" encoder
[04:02:11] <cradek> I still want 'typewriter margins'
[04:02:33] <jmkasunich> well, that is SMOP, once you have your absolute location
[04:02:55] <jmkasunich> heck, I want keepout areas
[04:03:05] <cradek> sure, another SMOP
[04:03:16] <jmkasunich> so I can have it avoid the chuck, but still pull to the front and then move left so I can get the tailstock in close for drilling
[04:03:17] <cradek> I want joint constraints
[04:03:37] <cradek> it would have to change with every tool
[04:03:44] <cradek> (keepouts)
[04:03:55] <jmkasunich> NNSMOP
[04:03:59] <jmkasunich> oops
[04:04:02] <jmkasunich> NSSMOP
[04:04:07] <jmkasunich> (not-so-simple)
[04:04:13] <cradek> and every workpiece?
[04:04:20] <cradek> (it's maybe even impossible)
[04:04:25] <jmkasunich> I'm assuming that you want to cut the workpiece
[04:04:52] <jmkasunich> on my list of wants, thats actually pretty far down
[04:04:53] <cradek> well that's true. but the jaws or dog could be anywhere (for instance)
[04:04:56] <jmkasunich> I was just being a smartass
[04:06:09] <jmkasunich> I wish the splash screen g-code wasn't so big
[04:06:28] <jmkasunich> I suppose I could truncate it and just do the EMC2
[04:07:21] <cradek> edit the scale
[04:08:20] <jmkasunich> hmm, where is it?
[04:08:39] <cradek> first couple lines in the gcode
[04:09:12] <jmkasunich> I mean, where is axis.ngc - its not in ~/emc2/nc_files or the examples dir under that
[04:09:21] <cradek> file/save gcode as...
[04:09:27] <cradek> then you have your copy to edit
[04:09:53] <jmkasunich> handy
[04:10:11] <cradek> that's handy with the various input filters too
[04:10:12] <jmkasunich> man, that keyboard is not the nicest thing to type on
[04:10:43] <jmkasunich> I'm doing all my editing and such here
[04:12:49] <jmkasunich> scale 0.0003?
[04:13:00] <cradek> yes
[04:13:06] <cradek> see how it's multiplied by everything later
[04:13:07] <jmkasunich> I guess they were _really_ big
[04:13:23] <cradek> they were in truetype units (postscript points maybe?)
[04:15:39] <jmkasunich> SH is what? safe height?
[04:16:08] <cradek> yes
[04:34:29] <jmkasunich> that program doesn't turn the spindle on!
[04:34:47] <cradek> did you happen to notice at the beginning where it says it's not for milling? :-)
[04:35:46] <jmkasunich> yeah
[04:35:55] <jmkasunich> I also noticed the lack of M3 before I ran the program
[04:54:13] <jmkasunich> http://jmkasunich.com/pics/first-milling-1782.jpg
[11:17:07] <alex_joni> jmkasunich: yay
[15:28:23] <jmkasunich> ;-)
[15:39:26] <alex_joni> jmkasunich: youtube next :)
[15:39:41] <jmkasunich> I don't have a video capable camera
[15:40:00] <jmkasunich> (I don't think - my point-n-shoot might be able to do some very limited video)
[15:40:06] <jmkasunich> have to RTFM
[15:43:12] <alex_joni> :)
[16:15:24] <skunkworks> merry christmas everyone... (sorry chris)
[19:12:49] <cradek> I can't reproduce andy's problem but his screenshot is unmistakable
[19:13:22] <cradek> I'd like to let his message through but it's pretty big. I wish we could remove the image and let the rest through.
[19:13:43] <alex_joni> ah.. I entered admin interface.. but didn't find anything
[19:13:52] <alex_joni> (maybe send it yourself? and put the image on pastebin?
[19:13:55] <cradek> I didn't do anything wiht it
[19:13:57] <cradek> with
[19:13:57] <alex_joni> imagebin actually)
[19:15:21] <alex_joni> hmm.. I also got the full message, I can do the above if you want
[19:15:42] <cradek> please do
[19:18:11] <alex_joni> done
[19:18:13] <alex_joni> bbl
[19:18:21] <cradek> thanks!
[19:41:01] <jmkasunich> I bounced his message and asked him to put it on pastebin
[19:41:24] <cradek> ok, I guess alex did the work for him then
[19:41:37] <jmkasunich> didn't realise it was an image, or that you were discussing it in here
[19:41:39] <cradek> it's a good bug report now, but unfortunately I still can't make it happen
[19:41:51] <jmkasunich> (actually I think I bounced it before the discussion started)
[20:50:55] <alex_joni> jmkasunich: I think you did.. when I looked in the admin interface it wasn't there anymore..
[20:50:59] <alex_joni> that was before the conv.