Need Help!- Tiny Stepper Motor Control

[RiseUp]

I just finished a nano CNC machine that I call Nanite. It has a travel of 2"X, 1.75"Y, and 2""Z. It's footprint is about 3"x4.5".
I had small DC motors coupled to the leadscrews just for fun, but my original intent was micromilling gears and parts, and tiny PCBs for nano sumo robots. I have 4 small bipolar stepper motors, but am unsure of which circuit to use for their control. I don't have any datasheets(elusive little buggers), so any info as far as deg/step, voltage, current, etc, is all guess work. At the bottom is a stock photo of one of the motors.
My question is, how simple of a circuit can i use to make this thing tick?
Any help is much appreciated.

[elparadise]

This motor appear like a stepper floppy motor's. It's bipolar and you can drive it with normal bipolar controller (h bridge output).

http://www.epanorama.net/circuits/diskstepper.html

[RiseUp]

Thank you for the link,but i was looking for something along the lines of a circuit. I've seen some through my efforts of Googling, but for such small power needs and microstepping, which would be the recommended one?

[tumutbound]

You might consider an EasyStepper driver .
As long as your motor doesn't draw more than 750ma, it will do the job.

[Mariss Freimanis]

Originally Posted by RiseUp I just finished a nano CNC machine that I call Nanite. It has a travel of 2"X, 1.75"Y, and 2""Z. It's footprint is about 3"x4.5". I had small DC motors coupled to the leadscrews just for fun, but my original intent was micromilling gears and parts, and tiny PCBs for nano sumo robots. I have 4 small bipolar stepper motors, but am unsure of which circuit to use for their control. I don't have any datasheets(elusive little buggers), so any info as far as deg/step, voltage, current, etc, is all guess work. At the bottom is a stock photo of one of the motors. My question is, how simple of a circuit can i use to make this thing tick? Any help is much appreciated.

The motor driver will pretty much have to be a full-step, half-step drive. What you have there is called a "tin-can motor" which means the motor is made from stamped sheet-metal instead of machined end-caps and a laminated steel stator. They are not suitable for microstepping because of their non-linear electrical to mechanical angle transfer function. It doesn't mean the motor isn't good; it just can't be microstepped.

The best suited type drive is a unipolar L/R type.

Mariss

[RiseUp]

Originally Posted by Mariss Freimanis The motor driver will pretty much have to be a full-step, half-step drive. What you have there is called a "tin-can motor" which means the motor is made from stamped sheet-metal instead of machined end-caps and a laminated steel stator. They are not suitable for microstepping because of their non-linear electrical to mechanical angle transfer function. It doesn't mean the motor isn't good; it just can't be microstepped. The best suited type drive is a unipolar L/R type. Mariss

YES! Thank you. That's the best <i>type</i>, but any chance of a link to a circuit perhaps? I've searched for a bit, and the only thing coming up is products and promotions.

[irving2008]

http://www.instructables.com , search on 'stepper' has several examples that will suffice...

or

http://pminmo.com/

[elparadise]

http://www.educypedia.be/electronics...stepdriver.htm

Here you can find severl circuit for bipolar stepper driver.

[lancut]

Try the "univelop" stepper driver. I'm in the process of experimenting with the driver, and it drives the little tiny "FD" stepper just fine. I'm using pc PS. Hope this helps.

[martinw]

Dear RiseUp,

We had to build a small linear positioning gizmo using a similar linear stepper motor arrangement. We used the SAA1027 driver chip which is about as simple as any that used to be available. ( You may have trouble finding them, but they are out there somewhere).

http://www.phys.au.dk/elektronik/SAA1027.pdf

They really are a very simple way to get started.

Good luck,

Best wishes,

Martin

[vger]

Here is a link to one that should work for you. They sell just the bare circuit board for $2.50 and you can populate it yourself. I have several of their older version 1.2 boards that work fine. The documentation for the new 2.2 board is not finished yet but the silk screen on the board labels part values.

http://store.rrrf.org/index.php?main...products_id=91

I built a small PCB mill myself (5" x 7") that uses 1/2 10 acme. At full step I get .0005" steps. Used a dremel as a spindle with self made carbide engraving bits (1/8" carbide drill bit cut off and diamond ground V shape).

Best of luck and enjoy the build.

Steve