Over the weekend I designed and built a UDN2559 (or UDK2559) stepper driver board, and a load of SVG stripboard objects for general use while I was at it. Simon is making a minor change in the general stepper driver board design to allow current limiting on over-spec'd motors, so it has those changes in it already. Once Simon OK's it, I'll put it up on the wiki for all together with the stripboard clip art.
NOTE: The board in the image above contains several wiring errors.
The UDN2559 driver will put out 700mA per channel and is a more current part (the ULN2803 being on last orders).
Adrian has the latest designs for the Stage Assembly, and when it all works I'll post one down to Simon for his tests - hopefully followed by a second one so he has a complete X-Y axis for software development.
Add to all that the imminent arrival of a donation of CAPA and nichrome samples from Forrest, and I'm going to have a busy week.
Vik :v)
So are you going to put one of your prototypes in Simon's workshop? That would be great in that he would have a fully-developed prototyper to test against. That will save him a LOT of time in creating test conditions. :-D
ReplyDeleteYup, that's the idea. The designs I've done are fairly modular, so he'll actually have a kit of parts for making a variety of RepRap variants.
ReplyDeleteHe's also kindy pointed out a few novel bits of wiring on the board I designed, which will need to be, er, slightly ammended...
Vik :v)
So, we're down to 700ma per channel? That adds up to a lot of paralleled chips to drive one of those NEMA 17 steppers to full power. Or am I missing something?
ReplyDeleteYes, Vik is using a lower capacity chip than the one that Simon is designing for the NEMA 17's. Simon's uses two 754110 chips which will supply 2.2 amps/coil. The NEMA 17 is designed for a maximum of 2.4 amps/coil.
ReplyDeleteThe only kicker is that he is designing the board for 12v instead of 24v, which will cut the NEMA 17's torque a bit. BTW, did you see my notes on NEMA 23's for sale at $7.95 at...
http://www.alltronics.com/stepper_motors.htm
in the Price Tips section at SourceForge. The catalog number is 25M002. It's a proper Applied Motion NEMA 23 stepper rated at 60 oz-in. That price is one-off. I'd found a cheaper one, but they ran out of stock. :-(
Those were the very NEMA 23s that I was originally planning to use, before I decided to go with the 17s to have some commonality with everyone else. LOL
ReplyDeleteSpeaking of Alltronics, I'm not quite sure how to evaluate their 22m004 stepper driver, but it seems like a decent price for something that would drive either the 17s or 23s at full capacity.
I guess it sure couldn't hurt to buy one to see. That data sheet on it is pretty skimpy. I'd call them and check to see that there's more documentation that comes with the board though.
ReplyDeleteI'm working on a 12V off-the-grid system. Does anyone have any experience of the Fujis or what kind of torque I need to move the system?
ReplyDeleteHow about the UCN5804B driver?