#emc | Logs for 2008-07-02

[01:06:02] <LawrenceG> SWPadnos, new version of grill.py uploaded, now does round, oval, rectangular arrays of holes http://wiki.linuxcnc.org/cgi-bin/emcinfo.pl?Simple_EMC_G-Code_Generators
[01:45:39] <LawrenceG> skunkworks, opps. maybe the previous line was for you... new version of grill.py uploaded, now does round, oval, rectangular arrays of holes http://wiki.linuxcnc.org/cgi-bin/emcinfo.pl?Simple_EMC_G-Code_Generators
[02:23:37] <skunkworks> I think it was for SWPadnos... He was talking about being able to do ovals and such.
[02:23:43] <skunkworks> Nice work
[02:37:10] <fenn> what no hex grid!! :)
[04:24:56] <dave__> hi
[06:06:16] <lerman___> lerman___ is now known as lerman
[06:14:27] <lerman___> lerman___ is now known as lerman
[08:56:32] <Sweeper> can emc handle a really dumb h-bridge driver?
[08:57:44] <Sweeper> like, a activation + direction wire for each winding, instead of using logic on the board to combine to step + direction?
[10:00:00] <Sweeper> oh holy crap.....
[10:00:24] <Sweeper> has anyone here ever tried to build a servo motor using a small stepper + large dc motor?
[10:04:26] <archivist> er what
[10:05:10] <archivist> steppers dont make servos
[10:18:23] <Sweeper> yes they do :D
[10:18:40] <Sweeper> http://www.projects-lab.com/?p=401\
[10:18:42] <Sweeper> http://www.projects-lab.com/?p=401
[10:20:12] <archivist> thats a shaft encoder not a stepper used as a motor
[10:20:46] <Sweeper> but an encoder + dc motor = servo (or servo-isch)
[10:20:49] <Sweeper> *ish
[10:22:16] <archivist> check response, resolution and max speed of that encoder
[10:22:39] <Sweeper> response is the only issue I see
[10:23:10] <Sweeper> speed probably depends on how well you isolate the circuit
[10:23:37] <archivist> as you rotate faster generated volts may break the IC's unless protected
[10:23:53] <Sweeper> yea
[10:24:04] <archivist> I only see one diode
[10:24:16] <Sweeper> it's the concept that rocks :P
[10:24:36] <Sweeper> making encoders for $5 from junked floppy drives = win
[10:25:26] <Sweeper> resolution could be improved with gearing at cost of speed
[10:25:38] <Sweeper> but your average stepper motor is 1.8 degrees
[10:26:05] <Sweeper> encoders at that res are freaking expensive
[10:26:12] <Sweeper> well, except for opticals
[10:27:00] <Sweeper> with accurate tooth cutting, you could diy an optical for the cost of 2 optointerrups and a slice of plastic
[10:27:22] <Sweeper> but it's either gonna be really low res or really really big XD
[10:38:04] <archivist> I would worry that a very slow rotation may not trigger the IC and therefore get no output
[10:43:12] <Sweeper> true
[10:43:26] <Sweeper> I shall build a testbed
[12:07:08] <jepler> Sweeper: That device will not properly keep position when the motor stops, because when it does the quadrature goes from any position => 00, violating the quadrature state machine. A similar problem exists when starting to move the shaft. This might be OK if you don't mind a lossy MPG but I don't think you can get reliable positioning this way.
[12:17:56] <cradek_> cradek_ is now known as cradek
[12:28:52] <anonimasu_> hello
[12:28:58] <anonimasu_> anyone got any idea about sheetcam?
[12:29:56] <Sweeper> jepler: mmm, you could cheat tho
[12:30:22] <Sweeper> I mean, on a dc motor, do you REALLY need quadrature? :P
[12:32:29] <anonimasu_> does the preheat work on the emc post?
[12:45:08] <alex_mobile> Sweeper: you do. Without quadrature you do not know the direction it turns.
[12:45:56] <Sweeper> alex_mobile: depends. if I hooked the red wire up to positive and the black one to negative, I'm pretty sure I know which direction it turns ;)
[12:46:08] <Sweeper> that's why I said "cheat"
[12:46:29] <SWPadnos> you were talking about an encoder
[12:46:32] <archivist> nope its ac out from the stepper when used like that
[12:47:16] <Sweeper> archivist: I mean the drive motor, not the encoding stepper
[12:47:18] <alex_mobile> not if you want to control it as a servo for position control
[12:48:58] <alex_mobile> then it gets turned both ways. And while idle it actually hunts between positions
[12:49:11] <Sweeper> sanity check: the drive a modern inket uses, which is dc motor + optical encoder, is this a "servo"? because that's about the level of functionality and precision I want
[12:49:21] <Sweeper> I am suspecting I am using wrong terms :D
[12:50:13] <SWPadnos> yeah, it's probably a servo
[12:50:18] <alex_mobile> Dc motor + encoder = servo
[12:51:04] <jepler> and dc motor + unreliable encoder = broken parts, tooling
[12:51:17] <SWPadnos> the main differnece between a servo and a "regular motor" is that servos are designed to run smoothly at all speeds, generally have lower inertia, and usually are meant to run the same in both directions
[12:51:24] <Sweeper> aight. well, in that application, and in cnc, I don't see that you really need to know what direction the encoder is going in, esepcially if using a screw drive
[12:51:39] <SWPadnos> yes, you do
[12:51:45] <SWPadnos> if you ever want to reverse travel
[12:51:50] <Sweeper> you're supplying voltage!
[12:51:51] <archivist> you DO need to know the encoder direction
[12:52:04] <Sweeper> so it's nit's like...half-open loop
[12:52:35] <SWPadnos> when you cedelerate, the voltage you're trying to drive may be opposite from the movement of the motor
[12:52:47] <SWPadnos> unless you're measuring the motor voltage (which is also hard at very low speed)
[12:52:53] <SWPadnos> err - decelerate :)
[12:52:59] <Sweeper> oh, like braking?
[12:53:31] <SWPadnos> PID output could be negative relative to the direction the motor is moving
[12:53:53] <Sweeper> PID? :/
[12:54:19] <SWPadnos> that's how you'll get the motor to move somewhere. how do you expect to use the feedback?
[12:54:39] <Sweeper> I'm not sure what the acronym means :P
[12:55:07] <SWPadnos> proportional integral derivative - it's a commonly used control method for controlling devices with feedback
[12:55:44] <Sweeper> oh D:
[13:06:03] <skunkworks_> wait - you could have a slip clutch on the motor shaft with 2 switches.. Then if the motor was going cw - one of the switches would be closed.. and if it was going ccw - the the other switch would be closed... (maybe I should get a patent)
[13:06:35] <cradek> hey, you know what's a really good, commonly used, solution for this problem? quadrature!
[13:06:52] <skunkworks_> whatever! there has to be another way... ;)
[13:06:55] <SWPadnos> um. yeah. because that's so much easier and less expensive than a $20 encoder ... :)
[13:50:04] <Sweeper> I wonder if there's a cheap low-cost way to get quadrature independantely
[13:50:25] <SWPadnos> a cheap encoder
[13:52:36] <archivist> learn to scrounge
[14:09:11] <skunkworks_> what is your definition of 'low cost' ?
[14:10:10] <skunkworks_> most ball mice have quadture encoders in them....
[14:11:10] <skunkworks_> this is me spinning a mouse encoder... http://www.electronicsam.com/images/KandT/servostart/Fastermouse.png
[14:17:30] <skunkworks_> or http://usdigital.com/products/encoders/incremental/rotary/shaft/
[14:18:03] <skunkworks_> or http://usdigital.com/products/encoders/incremental/rotary/kit/
[17:40:51] <Guest747> http://www.cnczone.com/forums/showthread.php?p=471206#post471206
[17:41:01] <Guest747> Guest747 is now known as skunkworks_
[17:58:48] <pjmcabbb> evening
[17:58:53] <pjmcabbb> pjmcabbb is now known as pjm
[18:05:36] <skunkworks_> Good evening
[18:09:20] <gefink> hi
[18:13:45] <cradek> jepler: I'm getting private [grr] email about your/john's solids simulator. it might be nice if one of you would blog about and/or release it.
[18:14:08] <Sweeper> archivist: I am scrounging! I have lots of scrounged steppers! this is why I liked the idea :P
[18:14:35] <cradek> why not use the steppers for positioning? or are they no good for that?
[18:15:11] <cradek> doing truly cheap servo systems is going to be much harder than steppers.
[18:17:19] <jepler> cradek: it's jmkasunich's code so I'm reluctant to post it to my own blog..
[18:17:50] <cradek> of course
[18:17:59] <cradek> maybe he'll do it. it's a neat hack.
[18:19:37] <cradek> but it might attract a lot of people bothering him, asking why it is what it is, instead of what they want it to be
[18:19:51] <jepler> yes that is inevitable
[18:28:45] <mdynac_> hi all i just got done whipping up a tiny cnc machine
[18:29:19] <cradek> cool, what kind?
[18:30:29] <mdynac_> homemade, i had an old u/v axis off a japax edm and i used it for a tiny xy table 1" in y and 1.2" in x hooked a dremel moto tool drill press on top
[18:30:39] <cradek> ha
[18:30:45] <cradek> you can make custom sugar cubes?
[18:30:53] <mdynac_> you bet
[18:31:16] <mdynac_> i am up in cheeseland at my dads place and built this thing
[18:31:30] <cradek> too bad you didn't bring it to cnc workshop
[18:31:58] <mdynac_> just finished it about 10 minutes ago
[18:32:15] <cradek> ah
[18:32:24] <mdynac_> how do i get you some pics?
[18:32:33] <cradek> try imagebin.org
[18:32:52] <mdynac_> i got about 75 pics
[18:33:06] <cradek> pick a couple good ones :-)
[18:33:10] <mdynac_> k
[18:35:25] <Sweeper> cradek: these are pretty small steppers :P
[18:35:43] <mdynac_> version .2.5 rocks.....so does stepconf
[18:35:55] <Sweeper> unless you've got a cheap way to run 5 steppers in parallel.... :D
[18:39:26] <skunkworks_> Sweeper: did you see my links above?
[18:42:19] <mdynac_> two pics at imagebin 21869 , 21870
[18:42:42] <jepler> http://imagebin.org/21870 http://imagebin.org/21869
[18:42:53] <jepler> ^^ for those who can't pick the right ones out of the list :-P
[18:43:21] <jepler> mdynac_: is Z motorized? I don't see how.
[18:43:30] <mdynac_> its not
[18:43:46] <mdynac_> just used what i had laying around
[18:44:04] <cradek> what a wild and crazy 90 degree motor mount
[18:44:06] <mdynac_> thez motor is sitting behind
[18:44:17] <gefink> nice. first itaught you mean foot, but ist inch
[18:44:41] <mdynac_> edmnetwork throws these tables away
[18:45:03] <anonimasu> :)
[18:45:05] <anonimasu> nice
[18:45:06] <mdynac_> built like a thank
[18:45:13] <skunkworks_> even have home switches.. nice :)
[18:45:13] <anonimasu> * anonimasu nods
[18:45:32] <jepler> why not direct-drive? to make it smaller?
[18:46:24] <gefink> what want you manufacture with it?
[18:46:52] <mdynac_> it was designed to fit in a rectangular box, it is upside down in pic, it actully hung off the z axis with upper flush head attached
[18:47:22] <mdynac_> it puts taper on the wire
[18:48:40] <mdynac_> got that mechatronics board off ebay
[18:49:42] <mdynac_> it uses allegro A3977SED stepper chips, all ic's socketed
[18:50:44] <mdynac_> guess i'll engrave some stuff now, albiet small stuff....
[18:51:01] <anonimasu> ^_^
[18:51:18] <anonimasu> 10┬Ám cubes anyone?
[18:51:21] <cradek> you can set the scale of the AXIS splash screen by changing one number at the top...
[19:38:34] <archivist> hmm nice toy I can see uses for a small machine
[19:43:09] <mdynac_> it is cool
[20:42:14] <lerman____> lerman____ is now known as lerman
[20:52:32] <Sweeper> skunkworks_: I did now!
[20:52:53] <Sweeper> I forgot about mouses
[20:54:28] <Sweeper> skunkworks_: I'm googling now, but iirc, hasn't someone done optical mouse encoders?
[20:56:17] <anonimasu> it's been tried but they suck in general
[20:56:58] <anonimasu> http://www.hackaday.com/2008/05/16/how-to-scavenge-a-mouse-for-parts/
[20:57:29] <alex_joni> good night all
[20:57:30] <Sweeper> no, I don't mean the mouse wheel one
[20:57:42] <Sweeper> I mean the actual laser+ccd
[21:00:20] <Sweeper> http://www.martijnthe.nl/optimouse/arduino-optical-mouse.html <-- AHA!
[21:00:22] <alex_joni> * alex_joni is off to bed
[21:24:21] <lerman____> lerman____ is now known as lerman
[21:54:58] <davidf> hi
[21:55:49] <davidf> Just installed ubuntu 8.04 and emc2 - getting error on starting emc2
[21:56:36] <davidf> I have: /usr/realtime-2.6.24-16-rtai
[21:57:24] <davidf> EMC2 wants: /usr/reattime-2.6-24-19-generic/modules etc.
[21:58:49] <cradek> you have to boot the realtime kernel
[21:58:55] <cradek> pick it on the initial boot menu
[21:59:44] <davidf> Hi Chris. hmm, "initial boot menu?"
[21:59:52] <cradek> hi
[22:00:01] <cradek> yeah it will list the available kernels.
[22:00:13] <cradek> sometimes it is hidden by default so you have to hit escape to see the menu
[22:00:20] <cradek> (which is a bit irritating)
[22:00:55] <davidf> I don't understand where it is though. ubuntu?
[22:01:19] <cradek> yes at the very beginning of the boot, before that colorful ubuntu logo on the splash screen
[22:01:51] <cradek> for a few seconds it will say something like 'press escape for the menu'
[22:02:23] <davidf> Oh. I didn't notice that. So it is part of ubuntu starting up. Right?
[22:02:27] <cradek> yes
[22:02:38] <cradek> boot the kernel that says -rtai
[22:02:50] <davidf> OK. That box is downstairs. I'll go try that. Thanks.
[22:02:52] <davidf> bbl
[22:02:56] <cradek> welcome
[22:22:40] <davidf> cradek, I picked that, but it isnt there after starting up. Tried it twice. ??
[22:23:52] <fenn> cat /boot/grub/menu.lst | grep realtime
[22:24:39] <fenn> does that show anything?
[22:24:59] <SWPadnos> grep rtai I think
[22:25:04] <fenn> oh
[22:25:19] <fenn> mine still says magma :)
[22:25:25] <SWPadnos> heh
[22:27:02] <fenn> SWPadnos: ever do anything with that openmoko?
[22:27:36] <SWPadnos> actually, I finally got around to updating it (so it could boot) yesterday
[22:27:45] <SWPadnos> it's got a really great screen
[22:28:16] <fenn> yeah 640x480 is how many dpi?
[22:28:42] <fenn> about 300?
[22:28:44] <SWPadnos> many
[22:28:51] <SWPadnos> the screen is only 4" or so
[22:29:04] <toastydeath> it depends on the pixel density of the screen, or so i thought
[22:29:08] <SWPadnos> oh - 3"
[22:29:22] <davidf> It shows kernal is 2.6.24-16-rtai
[22:30:22] <SWPadnos> did you install from the liveCD?
[22:30:27] <SWPadnos> the EMC2 liveCD
[22:30:29] <davidf> What I don't get is when I first installed emc2, I tried axis-sim and it ran fine.
[22:31:09] <davidf> No, I installed ubuntu 7.01, upgraded to 8.04 and installed binary emc2 via net
[22:31:49] <SWPadnos> ok, so it should have pulled in the correct RT kernel debs
[22:33:45] <davidf> In the boot menu, I can see the right one, but I picked that, pressed enter, the OS booted, and it is still the 16 rtai, not 19-generic.
[22:34:19] <SWPadnos> have you ever compiled EMC on this box?
[22:35:13] <SWPadnos> err - wait. when you say it shows you the right one, is it listed in the grub menu as 2.6.24-19, but it boots up and is really 2.6.24-16?
[22:35:41] <davidf> yes.
[22:35:56] <SWPadnos> oh. then there's probably a borked symlink in /boot
[22:36:05] <SWPadnos> have you uninstalled any kernel packages?
[22:36:49] <davidf> No I don't think so.
[22:38:42] <davidf> When I booted just before this started, I got an error message at startup - someting about the system corrected a root partition error and requested a restart, then it did. Dang I hate stuff like that that gives you 1.5 seconds to read a whole screen.
[22:39:22] <SWPadnos> hrh
[22:39:24] <SWPadnos> heh
[22:40:09] <davidf> I sure appreciate all the folks who work so hard on this stuff, but there are a copule I'd like to shake a bit. ;)
[22:40:27] <SWPadnos> heh
[22:40:54] <fenn> i think you will need a sturdy donkey to navigate the mountain passes
[22:41:09] <davidf> In the terminal error output, it shows EMC2_DIR = ie, nothing. Is that right?
[22:41:26] <davidf> Hah!
[22:42:11] <fenn> so, just to be double clear what's going on, when you type uname -a what does it say?
[22:42:25] <davidf> just a sec.
[22:42:56] <SWPadnos> 2.6.24-19-generic, I'm betting
[22:43:29] <davidf> 2.6.24-19-generic #1 SMP date, etc...
[22:43:42] <davidf> yup.
[22:43:57] <SWPadnos> that's clearly not correct
[22:44:08] <fenn> perhaps an ubuntu kernel update switched the default around or something?
[22:44:24] <SWPadnos> check in /boot for files named "*2.6.24*rtai*"
[22:44:40] <davidf> It worked before I did anything though. ...
[22:44:48] <SWPadnos> I'm betting that some removal of a kernel package caused a symlink to get pointed back at the default 8.04 kernel
[22:45:02] <fenn> davidf: emc2-sim doesn't need a realtime kernel, that's why it's called sim
[22:45:12] <davidf> I edited the .hal and .ini files.
[22:45:25] <SWPadnos> but you can run the sim/axis config with RT EMC2, it just uses no hardware drivers
[22:45:33] <davidf> fenn, thanks. But, even it doesn't run now.
[22:46:07] <davidf> I get the same error when I try sim.
[22:47:38] <davidf> I did do a ubuntu update between when it worked and when it stopped working. 254 files updated.
[22:47:49] <SWPadnos> you need to look at /boot, to see if you have the correct kernel/SystemMap/initrd
[22:48:01] <davidf> 'k...
[22:48:07] <SWPadnos> you also need to look at /boot/grub/menu.lst to see what file it's trying to load
[22:48:09] <davidf> cd /boot
[22:48:12] <SWPadnos> when you select the rtai kernel
[22:48:18] <SWPadnos> error: path not found
[22:48:21] <davidf> sorry wrong keyboard!
[22:48:23] <SWPadnos> heh
[22:53:05] <davidf> menu.lst looks right I think...
[22:53:59] <SWPadnos> any missing / incorrectly symlinked entries in /boot?
[22:54:37] <davidf> SWPadnos, in the /boot dir, a ls shows two columns. Are those mappings, or just the way it lists out the dir?
[22:54:52] <SWPadnos> just the way the dir is listed
[22:54:57] <davidf> 'k
[22:55:05] <jepler> davidf: "ls" shows things in columns by default; look at "ls /" and you'll see more than 2 columns.
[22:55:08] <SWPadnos> ls -l | grep ^l will show you all symlinks and what they point to
[22:55:36] <davidf> I see System.map-2.6.24-19-generic. Should I look at that file?
[22:55:41] <SWPadnos> no
[22:55:49] <SWPadnos> ls /boot/*rtai*
[22:56:06] <SWPadnos> or even ls -l /boot/*rtai* :)
[22:56:10] <davidf> ls /boot/*rtai*
[22:56:17] <SWPadnos> on the other keyboard
[22:56:32] <davidf> o fer petes sake.
[22:56:38] <jepler> $ ls -l /boot/vmlinuz*rtai
[22:56:39] <jepler> -rw-r--r-- 1 root root 1911992 2008-06-02 07:58 /boot/vmlinuz-2.6.24-16-rtai
[22:56:59] <SWPadnos> I'm assuming that computer isn't connected to the LAN/net??
[22:57:25] <Gamma-X> any word on the absolute encoders? in terms of can emc support them?
[22:57:34] <SWPadnos> no, never got to that at Fest
[22:58:04] <davidf> ls -l | grep ^l doesnt do anything.
[22:58:20] <davidf> SWPadnos, no.
[22:58:39] <SWPadnos> then there are no links (I think - there could be a space before the permissions in ls -l output)
[22:59:02] <jepler> why did we sidetrack into symlinks? (I don't have any symlinks in the /boot on this working system)
[22:59:08] <SWPadnos> what about ls -l /boot/*rtai* ?
[22:59:35] <SWPadnos> because if menu.lst appears "correct", but the wrong kernel boots, that could be a symlink problem
[23:00:43] <davidf> guys, I'm going to put the other box online so I can cut and paste. back in a few.
[23:01:09] <SWPadnos> ok - as long as you can ssh into it, you can look at this kind of stuff
[23:01:33] <skunkworks> I just disabled the annoying seatbelt alarm in the toyota corolla.. (yes I wear my seatbelt) hold odo button for 20 seconds - fasten seat belt - odo dispay changes to 'b-on' push odo button again to change it to 'b-off'
[23:02:48] <davidf> ls -l /boot/*rtai* shows 4 files...
[23:03:30] <jepler> http://www.mail-archive.com/emc-users@lists.sourceforge.net/msg07479.html
[23:04:57] <davidf> /boot/config-2.6.24-16-rtai , /boot/initrd.img-2.6.24-16-rtai , /boot/System.map-2.6.24-16-rtai , /boot/vmlinuz-2.6.24-16-rtai.
[23:08:38] <jepler> you rebooted and used the boot menu? which entry did you pick from the list?
[23:09:37] <davidf> 19-generic.
[23:09:54] <davidf> twice...
[23:09:59] <jepler> you need to choose 2.6.14-16-rtai from the list
[23:10:29] <jepler> er, 2.6.24
[23:11:07] <davidf> Oh. the error output said emc2 quit because It couldnt find etc-19-generic...
[23:11:32] <davidf> now I'm really confused. :)
[23:12:10] <jepler> yes, that error message doesn't sound very helpful
[23:12:33] <davidf> Would it do any good to replace EMC2?
[23:12:40] <jepler> You shouldn't have to replace emc2
[23:12:53] <jepler> you should use the boot menu to choose 2.6.24-16-rtai
[23:13:17] <davidf> jepler, OK...
[23:15:42] <SWPadnos> the error was confusing because EMC2 was looking in /usr/realtime/`uname -r`/modules
[23:16:05] <SWPadnos> since the wrong kernel had booted, uname -r gave an unintended name
[23:17:15] <davidf> so you think some update set the default kernal to be loaded to the 19-generic huh?
[23:17:33] <SWPadnos> that's my suspicion
[23:17:55] <SWPadnos> if you reboot and select the rtai variant, I'm sure EMC2 will run
[23:17:55] <jepler> yes; if you installed from ubuntu media, you will get their kernel updates and when an updated kernel is installed it becomes the default
[23:18:00] <davidf> yay! sim is running!
[23:18:36] <SWPadnos> you can either change the default entry in menu.lst, or move the one you want to the top of the list. I'm not sure which is ickyest
[23:18:41] <jepler> (users who installed from the linuxcnc.org live cd don't have this problem as far as I know)
[23:18:47] <fenn> so.. why is rtai need for sim? i'm confused
[23:18:56] <jepler> fenn: "sim" is two things
[23:19:10] <SWPadnos> he's not running sim, he's running a configuration from the configs/sim directory
[23:19:13] <jepler> fenn: it's a way to configure emc to not use any realtime facilities *and* it also refers to a set of configuration files that don't require any particular attached hardware
[23:19:17] <SWPadnos> which don't use any RT drivers
[23:19:22] <SWPadnos> but still use the RT code
[23:19:31] <davidf> SWPadnos, is right...
[23:19:34] <SWPadnos> (ie, they don't load or connect to any hardware)
[23:20:11] <davidf> I just chose the sim.ini file.
[23:21:08] <davidf> Now comes the real mess... I have to see if my new .hal and ini will work sometime this year...
[23:21:12] <dmess> hi all
[23:22:20] <davidf> I had evrything working well, and my HD crashed, no backups. Lost a lot of stuff...
[23:22:28] <SWPadnos> you've still got ~6 months left
[23:22:28] <SWPadnos> ouch. bummer
[23:22:43] <davidf> yeah double bummer.
[23:23:10] <fenn> we can rebuild him, better, faster, stronger
[23:23:34] <fenn> it will only cost... a million dollars
[23:24:00] <davidf> Anyway, I want to thank you guys for all the help, and ESPECIALLY evryone responsible for a binary EMC2 pkg for ubuntu!!! I was overjoyed to find that!
[23:24:37] <SWPadnos> yeah, it's a real help
[23:25:15] <davidf> fenn, I am up and running on a free 10 gig HD from a comp. place, and 3 sticks of 128 M ram free, and a thrown-away 400 GHz PII. LOL.
[23:25:30] <dmess> any one here know if you can re-wire a 575 -3 phase motor to be 120 - single phase??
[23:26:13] <fenn> davidf: gratz. i hope to squeeze emc into a 200MHz amd k2 with 64MB ram and some small CF card
[23:26:27] <dmess> i bought a cute little Harding 2nd op lathe from our 5S auction... its still in the van for now..
[23:26:29] <fenn> like 256-512Mb
[23:26:47] <davidf> dmess, To answer literally, Yes, I KNOW for sure I can't.
[23:26:49] <fenn> davidf: 400GHz seems a bit fast tho :)
[23:27:24] <fenn> dmess: 575V not 440?
[23:27:29] <davidf> Ha! yeah, well, whats 3 orders of magnitude give or take?
[23:27:55] <skunkworks> I ran dapper for a long time on a 400mhz pent II. worked great
[23:28:22] <dmess> yes 575... we were feeding it 600
[23:28:57] <davidf> I had the old emc running on 64MB ram and 1.6 G disk space...
[23:30:01] <dmess> it would be SWEET to EMC this ADD on cross-slide machine..
[23:32:34] <dmess> Hi ray.. you'd know this .. what would it cost to flip a 1/2 HP motor from 3 phase 575v to single phase 120??
[23:33:11] <SWPadnos> $50 for a used replacement motor
[23:33:36] <SWPadnos> maybe less, but then there's shipping ...
[23:34:14] <fenn> 1/2 hp is not very big
[23:34:23] <dmess> but this has a very nice sliding mount so you can change speeds ... i dont want to batsardize any of it
[23:34:26] <davidf> motors are dirt cheap on ebay... I was looking awhile ago.
[23:35:00] <davidf> Could you put the mount on a different motor?
[23:35:16] <SWPadnos> I will go out on a limb here and say that you can't rewire a 575V 3-ph motor to run on 120V single phase
[23:35:16] <dmess> if a rewire is a few hundres bucks i'll do it...
[23:35:37] <fenn> dmess just get a VFD
[23:35:38] <SWPadnos> oh, get it rewound - that may be possible, but it'll still be 3-phase
[23:36:11] <dmess> dont wanna go thru the hassle of vfd
[23:36:18] <fenn> oh fff you are talking about rewinding the motors
[23:36:19] <davidf> I think the armature and field coil forms will be different for 3 ph and single.
[23:36:21] <dmess> why??
[23:36:27] <SWPadnos> getting the motor rewound is likely more hassle
[23:36:43] <SWPadnos> and waaaaaay more expensive, I'll bet
[23:36:53] <fenn> vfd is better anyway because you can control the speed
[23:37:31] <davidf> vfd = variable field density??
[23:37:40] <davidf> or what?
[23:37:48] <fenn> variable frequency drive
[23:37:48] <dmess> i'll call my cuzin he does that for a living.. a little goverment gob in the Siemens shop should go unnoticed... right??
[23:38:44] <davidf> got to get back to getting this mess back together... Thanks so much you guys.
[23:39:26] <davidf> bye.
[23:39:30] <jepler> see you davidf
[23:44:39] <rayh> hi dmess
[23:44:51] <dmess> hi ray
[23:45:20] <rayh> How much direction changing does this motor do?
[23:46:10] <dmess> it was set up for just 1 direction i believe
[23:46:19] <rayh> Okay that helps.
[23:46:40] <dmess> runs a drill and turns with tool UP in front of the part
[23:46:58] <rayh> Is this motor a common frame mount, c face or what.
[23:47:26] <dmess> i dont believe so... its a hardinge.. made in the USA
[23:47:40] <rayh> and what kind of link between it's shaft and the drill spindle.
[23:47:55] <dmess> belt drive
[23:48:07] <dmess> 3 speeds
[23:48:33] <rayh> Okay.
[23:49:01] <rayh> I'd try to replace the 575 with a 120 single phase motor.
[23:49:32] <rayh> You'll want one with capacitor start so that you can wire the proper rotation.
[23:49:48] <dmess> but there is 1 thing.... there is a knob on the back of the motor??? i have NO clue what it is or could be for... but will ask the old operator if it varied speed...
[23:50:15] <rayh> Okay. That's a start.
[23:50:33] <rayh> I've not see such a motor from Hardinge.
[23:50:57] <dmess> to what... it being a good 575 motor a or a decent 120 motor??
[23:51:15] <rayh> The 575 suggests to me that you're in CA
[23:51:33] <dmess> lemme see if i can get a phone cam shot BRB
[23:51:42] <dmess> no im in canada
[23:52:06] <dmess> we've been feeding it 600V
[23:52:35] <rayh> Canada is what I meant. I built a couple of process controllers using 575 a few years ago.
[23:56:01] <dmess> oh ok..
[23:57:57] <rayh> I don't see an easy VFD way. You could get a 575 VFD and a step up transformer but that is way UGLY!
[23:58:48] <dmess> http://imagebin.org/index.php last 3 from dmess