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Post by theonlybull on Jan 2, 2010 12:00:00 GMT -4
that dual drive just gave me an idea on how to solve a problem that a customer of ours has with a 5 x 24' sliding tray...... thanks jan
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Creepy
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Post by Creepy on Jan 2, 2010 12:07:34 GMT -4
some systems use a driveshaft over to the other side, dual motors is superior.
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Post by theonlybull on Jan 2, 2010 12:20:47 GMT -4
is there anything to adjust for backlash in the rack and pinion? or do they just not worry about it?
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Creepy
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Post by Creepy on Jan 2, 2010 12:24:30 GMT -4
I'm sure somebody worried about it at some point There are small but heavy springs to keep preload. See how the motor plates pivot? Motors mounted pics coming up.
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Creepy
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Post by Creepy on Jan 2, 2010 12:47:37 GMT -4
stepper motor mount hardware did not fit thru. lame. this made me nervous. ah, its not too bad once clamped in the little mill. very easy to drill. Had to do all 16 holes. (4 in each motor) I don't understand why these motors have a beautiful micro-finish on the mount surface, yet the mount holes were chewed out by a rat. mounting stepper motors spring for preload. Accelleration of the motors is tuned for spring weight and mass of gantry. there is a calculation the designers did to make this a balanced system that has to do with accelleration and gear geometery. installing Z home switch. This is used to find the height of the work before cutting. The tip of the plasma will touch the work while shut off, and the "floating head" will make this switch and the controller will then know the height to pierce or cut at. small stuff. made switch. attached switch leads to a board in the power supply. the brown/yellow ones. I didn't need that trailer harness anyway. lots of expensive things to drill holes in. computer system. thx to rallyroach for system, Rob for monitor. the scary side lol had flakey communication between pc and bladerunner. The LPT1 port screws would not engage. What to do? Head back to 1939 and cut 'em down to size. I got a real kick out of this, it was 3am, sorta drunk and really tired. Take that, computer. communication is now perfect.
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Post by Blaisun on Jan 2, 2010 12:51:54 GMT -4
Looks sweet!!!
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Creepy
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Post by Creepy on Jan 2, 2010 12:52:24 GMT -4
out to the shop! I hope you guys have lots of questions for later. That was 2 months of work I just posted.
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Post by theonlybull on Jan 2, 2010 14:20:08 GMT -4
lol. i was gonna say you've worked your butt off in the last couple weeks. that's an interesting method of dealing with backlash. doesn't look very robust.. but it must work alright. i'm sure you'd have read about someone having issues by now if it didn't how long till ya put drive motors on the mill and lathe and try and run it off the same setup??
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'Roach
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InsurJeeper
...the man who decided to use torx on Jeeps should be beaten severely...
Posts: 1,002,222
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Post by 'Roach on Jan 2, 2010 14:48:43 GMT -4
That comment made me LOL. I also appreciate the lathe assisted computer work. Excellent
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Post by itsakeeper on Jan 2, 2010 15:57:37 GMT -4
looks like your almost there, should have dropped in today
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Creepy
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Post by Creepy on Jan 2, 2010 16:24:33 GMT -4
Remember there isn't any cutting force.
I was rapiding the X earlier and it was jumping. i found weird powdery corrosion in some of the teeth on the rack. the preload setting let it jump a tooth, and it didn't return to same zero.
lots to keep working on. Just getting into the hypertherm wiring schematics to install the DTHC card. no room in the case, going to have to get an external box.
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Post by theonlybull on Jan 2, 2010 17:37:14 GMT -4
no load, but the tinyest peice of dirt, or slag could cause a jump, which can break your cut, and throw your tolerance.. i'm sure you know what i mean... most things, a little bit off isn't gonna matter, but i'm sure your used to tolerance in the =/- 0.0001" range... when fitting parts, or machining, it can make a differnce. strange that a little corrosion would make it skip a tooth. both sides jump, or just one? i'm sure i could think of a million things that could go wrong... but i'll try not too have fun with those plasma schematics. they try to make them so most people can't understand them lol
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Creepy
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Post by Creepy on Jan 2, 2010 18:27:52 GMT -4
CNCZone.com has a Hypertherm forum with one of the engineers who has been there designing for 30 years answering questions. they provide unparalled support for doing this stuff. I have waded thru the schematics for the last hour, and was able to pare it down to two questions for the support forum. I just posted over there, should have my answer soon.
i hear ya on the tiny dirties. This was leaping from the rack, it would have fawked the part being cut. Some little turnbuckles might do the trick, but no-one else has issues with the springs. I dunno yet.
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Post by theonlybull on Jan 2, 2010 20:32:31 GMT -4
it might just need the tooling marks worn off the rack, and pinion to make it work smooth. some felt, or leather wipers might solve and issues with dirt on the track, if it becomes an issue...
wish you were a little closer, i'd love to eye it up in person
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Creepy
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Post by Creepy on Jan 3, 2010 23:24:06 GMT -4
Well i got the table zooming around at 100% feed and under G-code. FINALLY!!!!!! kernel speed was wrong, so stepper motors weren't counting right, and they were jerking around. dropped from 65000Hz to 35000Hz, rapid travel smoothed right out. Now to finish installing that circuit board in the plasma. The hypertherm guy i mentioned above ok'ed my progess thus far, i posted pics on CNCZone.com of the disassembled 45. lol poke poke Raw arc voltage signal - i installed those doubled up ring terminals on J19 and J21. here is the control board that collects the plasma signals, and converts to serial cable back the the BladeRunner. I got the raw arc voltage done, need to do "torch on/off" at rear port, and "arc transfer" whick i have no idea where it is. yet. Then make a box for that card, because the PM45 is too compact to fit anything else in there.
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