Stepper Motor Giveaway

[Heckler]

Sparkfun has this same chip on a nice little driver board... http://www.sparkfun.com/products/10267

[cncmachineguy]

Just a little confused. Here is the datasheet for the driver linked by RMTEO. I read it as having 1.5A output. Now I assume this is per coil. Am I wrong - again? The sparkfun board says .75A, so if I am correct, why half?

I am also baffeled by the motor supply current. 4mA max? this is on page 4, Ibb rating. Thats a pretty high gain by my book!

Edit: I see the SF unit is not the exact chip - that makes sense now. Still confused about the motor supply current

[Heckler]

Sorry Bert,

I should have looked closer at the part numbers...

I had just seen that little board on Sparkfun and remembered that it had an Allegro chip on it.

I can't give you any more insight on driving stepper motors. But I can give you another link . Here is a board that has been recomended to me for doing various CNC stuff... It is a 3 channel kit... http://www.hobbycnc.com/products/hob...ver-board-kit/ they also offer a slightly more expensive one that apparently has idle current reduction.

Again, I am a bit out of my league here, but have been doing a lot of reading and studying trying to decide how I am going to drive the motors that (hopefully) rmteo will be sending me soon. There are also tons of boards on ebay... search "stepper driver" but as usual, beware.

There is also a great, huge, group forum called cnczone.com, but goodluck navigating down through all the forums.

Sorry to have mislead you.

[cncmachineguy]

No problem Dwight. I will prolly build my own boards based on the driver reccommend by RMTEO. The easyCNC board you linked is for uni-polar only!! Will not work with these motors. But I do appreciate you sharing what you have found. I need to order some boards for another project, I think I can piggy back some for this on the same panels

[rmteo]

The A3987 is good for up to 1.5A per phase/coil. But make sure that you do not exceed a Tj of 150C - proper heatsinking etc. I measured 9.8 Ohms per phase and you should limit current to about 0.6A (per the data sheet) with an appropriate sense resistor. For best performance I would drive the motor with at least 12V, preferably in the 18-24V range.

[cncmachineguy]

Well I may have to re-think this. If the current draw is .6A, then the SF board will work fine.

[rmteo]

12 motors left.