#linuxcnc | Logs for 2012-12-28

[00:02:30] <tjb1> Been quiet here
[00:02:33] <tjb1> Everyone dead?
[00:31:28] <theos> yup
[00:39:04] <tjb1> Someone spoke!
[01:13:52] <mrsun> hmm thinking of building a length feed for the lathe .. just a gear that goes to the rack thingie on the lathe (i have no seperate feed axle on the lathe, just the leadscrew) think this would be a good idea? :)
[01:14:10] <mrsun> some kind of wormgear and maybe a stepper motor or something =)
[01:49:55] <archivist> drive the leadscrew
[01:52:51] <mrsun> ye sure but isnt the seperate drive on lathes there to not do extra wear on the leadscrew ? :)
[01:55:32] <archivist> only on the better quality lathes was a separate feed shaft often added if the lathe has powered cross feed
[01:56:24] <archivist> or they put a slot in the leadscrew for that function
[01:56:44] <archivist> my southbend has a slot
[01:59:43] <DJ9DJ> moin
[09:03:49] <JT-Shop> morning
[10:00:28] <IchGuckLive> hi all out ther
[12:14:44] <IchGuckLive> Hi all B)
[12:38:10] <skunkworks> well - I think I am over the hump of a cold/flu... yay
[12:38:47] <archivist> cant blame me I was far away
[12:39:01] <archivist> mid november for me
[12:39:07] <skunkworks> heh
[12:39:34] <skunkworks> christmas time - too many people.
[12:46:03] <IchGuckLive> so best to go onliine shopping for flu
[12:46:12] <IchGuckLive> O.O B)
[14:25:33] <Loetmichel> re at home
[15:11:06] <r00t4rd3d> http://i.imgur.com/JqdVT.jpg
[15:11:44] <Jymmm> lol, is that yours?
[16:46:14] <tom3p> google translate really butchers this http://cnc-club.ru/forum/viewtopic.php?f=15&t=2430&p=47969#p47969
[16:46:33] <tom3p> anybody speak Russuin and willing to read the page?
[16:47:13] <tom3p> i see they use 'EDM' and 'LinuxCNC' and i see the toolpath reversing , so i'm interested
[16:50:00] <tom3p> dang! Russian ( -10sp)
[16:51:30] <PCW> roooshians
[16:53:45] <tom3p> they invented it :) the Lazerenkovs, husband wife team invented the servo controlled EDM, before that it was hand controlled ( ugly!)
[16:57:46] <PCW> That interesting, you mean the arc? voltage feedback
[16:59:37] <rob_h> does that not change code from G02 to G03 vis versa from looking at vid.. as one code has a / on it when he presses
[16:59:45] <rob_h> + or - it changes up and down code tree
[17:08:23] <tom3p> PCW in EDM the gap sense voltage is used just like an r-c servo, the motor seeks to equalize the actual voltage and the setpoint voltage, but in cnc, it's along a path
[17:09:39] <tom3p> rob_h, it doesnt go around the corner either, its bounded by startpoint, and in Russian they discuss this problem (afaict )
[17:10:14] <rob_h> i see
[17:10:41] <tom3p> rob_h, that is to say, it cant back up more than 1 geometric description ( its important for WEDM but not the strategy used in rela EDM ( SINK :)
[17:10:42] <rob_h> yea if only i could reaplce the crap agie CNC control on our CNC EDM
[17:11:06] <tom3p> what model? i was head of AGie sink edm for many years
[17:11:30] <rob_h> cant rember of top my head, but no one at Agie wants to know as some things dont work as should on it
[17:11:41] <rob_h> but as its older than 10 years they dont care
[17:12:27] <tom3p> you can buy a Heidenhain, Aerotec Pmac or (whazzat SPansih one i used for 8 axis edm drills? ) Senza maybe
[17:12:32] <rob_h> it has a problem with low Gen settings too, i fixed it alittle but not quite 100%, never got its electrode changer to work ether
[17:13:13] <rob_h> take it replaced the Generator then too?
[17:14:59] <tom3p> no, the geerator is another story, try RedLine of Austria, rack mount EDM supplies, 80 amps per slot
[17:15:07] <tom3p> generator
[17:15:13] <rob_h> but we Mill 90% our mould tools now days, only sink stuff u cant get a cutter into
[17:15:30] <tom3p> ribs, subgates, suckers
[17:15:37] <rob_h> ye
[17:15:38] <tom3p> square corners
[17:16:10] <rob_h> we are mainly high pressure die, for Alli & mag, dont get into plastic realy
[17:16:19] <rob_h> unless its own products for our own machines
[17:16:43] <tom3p> oh yeah, theres retrofits fdrom Belmont, esp if you are west coast
[17:16:53] <rob_h> i am UK
[17:18:47] <tom3p> avoid the lo gen settings, use higher with a ballast resistor ( reliable work around )
[17:19:15] <rob_h> tend to use lower for finishing/polishing
[17:21:04] <tom3p> yes peak drops from ruf to fin. your little AGie surface fin chart and example plate lists them with triangles v rough vv prefin vvv fin vvvvv damn fine :)
[17:21:17] <rob_h> i think its the 3/4amp an below it has problems does not switch into them some times.. its odd prob
[17:21:18] <rob_h> yea
[17:21:49] <rob_h> prob is we had machine 2nd hand dont have many manuals for it, was silly cheap tho at mo time and had its 3R so was bargin realy
[17:22:23] <tom3p> older agie generator is 3amps per transitor ( big european BDY transitors ), easy to fix
[17:22:49] <tom3p> less power is achieved with balast resistor built into top of box
[17:23:35] <tom3p> 60L power supply maybe?
[17:23:54] <rob_h> its the 2U model
[17:24:36] <tom3p> ooh! you got new stuff with the U line. newer that 1990 maybe newer
[17:24:42] <rob_h> http://www.ise.osu.edu/research_labs/MPL/manufacturing/Agie%20EDM.htm
[17:24:46] <rob_h> ;like that, big ass cabnet behind it
[17:24:52] <rob_h> chiller for dialectric etc
[17:25:25] <rob_h> i think it does fancy monitoring and adjusts it self, as when it gets stuck it trys to fix its own flushing and stuff
[17:25:30] <rob_h> more annoying sometimes than good
[17:26:49] <tom3p> haha turn off the fuzzy, no back seat drivers
[17:27:23] <rob_h> tryed to get manual from Agie but they never called back one we got seems for slightly diff machine in places
[17:27:58] <tom3p> how do i get a bew page on wiki? notes say use a placeholder LikeThis and you should get LikeThis[?] back and you can click on the [?] to goto new page
[17:28:08] <tom3p> ^^^ doesnt work :/
[17:28:45] <cradek> edit your url and you'll go to a blank page which you can then edit
[17:29:03] <tom3p> rob_h, AGie never released useful manuals to user, only blockschildiagramms ( block diagrams)
[17:29:09] <tom3p> cradek thx
[17:31:39] <tom3p> cradek, i had it couched in a <pre> </pre> doh!
[17:32:08] <tom3p> works fine without
[17:35:10] <DJ9DJ> gn8
[17:55:52] <tom3p> are any of these formats allowed on wiki? jpg , ogg , mp4
[18:05:20] <tom3p> will need to locate $MaxPost but look at http://wiki.linuxcnc.org/cgi-bin/wiki.pl?BlenderHalEDM in the meantime for Blender as a tool to explain Hal networks
[18:05:25] <tom3p> gnite
[18:45:30] <JBFromOZ> any comments on TB6560 control boards?
[18:50:58] <jdh> tehy are inexpensive
[18:52:35] <Connor> JBFromOZ: I have one. I had to replace one of the drivers and replace the caps to keep it from driving my wife nutz due to high pitch squel it caused.
[18:53:04] <jdh> so, they are inexpensive and good for annoying wives and small pets.
[18:53:13] <Connor> Don't bother with it. Get a Gecko g540 and be done with it.
[18:53:48] <jdh> $250 vs. $60 is a pretty big difference.
[18:54:27] <Connor> Time involved trying to get it to work right.. it's worth it.
[18:54:36] <Connor> brb. need to restart
[18:57:17] <Connor> jdh: You upgrade the bearings on your spindle yet ?
[18:57:44] <jdh> nope.
[18:57:59] <jdh> not planning on it unless I do belt + motor
[18:58:20] <Connor> I have the spindle torn down. Ready to install new bearings..
[18:58:34] <jdh> got lube?
[18:58:36] <Connor> I Aways have hard time with bearings.. getting them on the shafts..
[18:59:13] <Connor> Yea. I purchased the freaking Kluber Isoflex NBU 15
[18:59:57] <jdh> heh
[19:00:30] <Connor> I've read that it's not a good idea to do the heat/freeze trick on the spindle..
[19:00:49] <Connor> you get one shot at it.. and makes it impossible to take apart.
[19:00:57] <jdh> yeah, that would suck.
[19:01:40] <Connor> from what I've read, most people are using very fine sand paper to remove burrs and hand pressing them on..
[19:01:54] <Connor> makes me a tad nervous.
[19:02:05] <jdh> it's only money
[19:02:13] <t12> i think shrink fit is more for very large things
[19:03:01] <Connor> I need to clean it up real good.. and try to re-assemble it..
[19:04:40] <Connor> I'm looking at maybe getting this... http://www.automationtechnologiesinc.com/products-page/laser-engraving/40w-co2-laser-machine-software-training
[19:06:48] <Connor> okay, something like this... http://www.automationtechnologiesinc.com/products-page/hybrid-servo-system/nema-34-hybrid-servo-motor-kl34-8n-1000-rated-torque-1128-oz-in
[19:07:05] <jdh> a laser and a motor?
[19:07:28] <Connor> wouldn't use anything with linuxcnc's pid stuff.. would just be a simple step/dir setup.
[19:07:37] <Connor> jdh: switching subjects :)
[19:08:41] <t12> thats pretty cheap
[19:08:53] <Connor> servo or laser cutter? :
[19:09:11] <t12> laser cutter
[19:09:36] <Connor> yea. I like the 50w better.. bigger area.. not a "hobby" laser cutter.
[19:13:24] <jdh> cheap.
[19:13:32] <jdh> I'd buy one if I had some free space.
[19:42:11] <jdh> quite a price difference for 10 watts
[19:52:30] <ReadError> so
[19:52:33] <ReadError> i decided
[19:52:43] <ReadError> im going to atleast try the 3d printed gear 4th axis
[19:52:54] <ReadError> these herringbone gears dont have much backlash
[19:54:56] <Connor> More than just 10w diff.. look at the diff in the area and the platform etc..
[19:55:06] <Connor> okay.. My freaking bearing is stuck half way on/off..
[20:01:11] <jdh> hammer?
[20:20:46] <Connor> Well... Sh!t!!
[20:21:18] <Connor> I need to take the bearing back off.. because I forgot to put the shims under it.. ended up separating the bearing..
[20:21:48] <Connor> Looks like I'll even have to use a bearing splitter to get the bearing off the spindle.. because I don't see a way to get it off.
[20:22:14] <jdh> what's the ID?
[20:22:32] <Connor> I don't remember.. why ?
[20:22:54] <jdh> got a big wrench or somethign you can put on and tap it off?
[20:23:19] <Connor> No. No way to get between it and the shoulder.. it's flush..
[20:29:29] <jdh> my foot is numb from diving
[20:30:13] <ReadError> whats the best way to remove that red grease they pack parts in
[20:30:15] <ReadError> gasoline ?
[20:30:22] <ReadError> just soak it in there for a bit?
[20:30:48] <jdh> kerosene
[20:30:54] <jdh> rags, chip brushes
[20:31:01] <Tom_itx> the red grease is cosmolene
[20:31:09] <Tom_itx> probably
[20:31:16] <jdh> carb cleaner seems to work well also
[20:31:18] <ReadError> it makes this self centering chuck really hard to turn
[20:31:23] <Tom_itx> kero is less volatile than gasoline
[20:31:25] <ReadError> i dont have many fancy chems here ATM
[20:31:34] <ReadError> but have a bunch of gasoline
[20:31:39] <Tom_itx> too volatile
[20:31:53] <ReadError> iso alcohol ?
[20:31:57] <ReadError> wd40 ?
[20:32:11] <Tom_itx> iso won't comply with it
[20:32:48] <ReadError> i need to get some bigger nitrile gloves
[20:32:52] <ReadError> 1 size fits all, yea right
[20:33:44] <ReadError> let me see what i got around here
[20:34:28] <ReadError> mostly wd40..
[20:38:06] <jdh> try it
[20:42:53] <Connor> jdh: Dropped the spindle shaft too in the process.. (had it in a clamp).. fell from about 2.5" feet. Not sure if it's damaged or bent...
[20:45:00] <jdh> ouch
[20:46:24] <RyanS> I don't get why a lot more 'hobby' CNC machines dont use hobby/RC servos. You get feedback, the servos are much lighter than steppers and have more torque for a similar price. drivers for them are also very common
[20:46:55] <jdh> more tourque?
[20:48:19] <RyanS> yeh/.. http://www.pololu.com/catalog/product/1648/specs vs http://www.homanndesigns.com/store/index.php?main_page=product_info&cPath=25&products_id=84 servo is cheaper and about eight times lighter
[20:49:38] <Connor> RyanS: For one. That servo only turns about 180 degrees. Two: It's far too slow.
[20:50:08] <RyanS> Is that because it's all via gearing?
[20:50:25] <Connor> yea. The motor is just way to small.
[20:51:30] <RyanS> So it would be like getting a tiny stepper & gearing it
[20:51:38] <Connor> exactly.
[20:53:02] <Connor> Servo nothing more than a motor with feedback. IE. DC or AC motor with a encoder. in the case of those hobby servo's, a potentiometer. Steppers will move a known distance when sized correctly for the application unless they miss steps. It's a trade off.
[20:58:29] <RyanS> I'm trying to design a motorised copy stand http://www.digicelinc.com/images/copystand.gif to support 3kg. all I need to do is position the camera remotely from a computer, speed is not at all important. I wonder if continuous rotating RC servos will be any good
[20:59:36] <ReadError> eh
[20:59:43] <ReadError> stepper atleast you know it will move
[20:59:44] <ReadError> in steps
[20:59:48] <ReadError> rc servo is meh
[21:00:00] <RyanS> Because you can get USB 10 channel servo controllers for $30
[21:03:00] <RyanS> If something like this existed for steppers it would be perfect, http://www.pololu.com/catalog/product/1350 I haven't managed to find anything cheap
[21:05:00] <Connor> You need a screw and a stepper. Steppers and stepper drivers needed for that would be pretty cheap.
[21:07:03] <jdh> scrounge a printer
[21:07:18] <RyanS> a couple of round shafts with pillow blocks & a trapezoidal or ACME leadscrew would do the trick?
[21:10:15] <Connor> yea.
[21:10:38] <Connor> if not using acme, lap the screw with lapping compound for easier travel.
[21:12:43] <RyanS> Something like metric threaded rod?
[21:12:45] <jdh> for full travel each way, backlash doesn't matter. Don't even need stepper/servo, just hard switches?
[21:14:55] <RyanS> it needs positioning control but yehh I would say backlash probably doesn't matter
[21:15:14] <RyanS> Although if I want repeatability of the position?
[21:16:23] <Connor> shouldn't be a problem with it being Z axis.. and if it is.. you can always go past the desired point and back it to compensate for the lash.
[21:16:54] <RyanS> ah yeah
[21:17:17] <Connor> other possibility might be a belt drive setup...
[21:17:36] <Connor> though, 3kg might be too much for that..
[21:18:11] <Connor> jdh: Would you trust a beaing that's been separated?
[21:18:17] <Connor> Or just get a new one?
[21:27:19] <jdh> I searated one of my ACBs, seems fine. But, not the same scale/speed
[21:34:48] <RyanS> http://www.phidgets.com/products.php?category=13&product_id=1062_1 this is really what I'm looking for. however It seems expensive and only 1/2 step..
[21:35:08] <RyanS> *very expensive
[21:43:37] <Jymmm> Hmmm, Open Source/Hardware Car