Low-current stepper drivers

I am designing a tiny 3D printer which will make use of some unipolar steppers which use 0.28A.
Are there any cheap/more suitable controllers i could use instead of the pololu/stepsticks i see all over ebay?

Hi,
Did you check [arduino.cc] ?
All you need is a few transistors, in the example above they are using a ULN2003A chip which is just a few transistors in a DIP package. Pololu-style carrier boards are definitely overkill in your case.
Good luck with your project,
Andrew

Edited 1 time(s). Last edit at 02/23/2015 03:15PM by AndrewBCN.

I wasnt sure if there as a certain way i needed to interface to the RAMPS board; in the given example would i just use the pins where the carrier board would plug in?

I should also clarify that the motor is a 6 wire unipolar

Edited 1 time(s). Last edit at 02/23/2015 03:48PM by Zomzilla.

... 6-wire motors can be used as unipolar (both middle-pins connected) or bipolar (middlepins ignored).

The RAMPS board delivers only STEP+DIR signals for a monolithic driver, for driving a stepper direct you doesn't need the RAMP Shield, a single Arduino with the transistor-arrays would do ... but you'll have to change the firmware for direct driving the solenoids.

But the easiest way is to use the motors in bipolar wiring with RAMPS and Pololus, adjusted to the motor current ...

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Viktor
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I'll probably still have to use a RAMPS board for the extruder stepper so i'll wire the unipolars to some cheap drivers

If your motors are 6-pin ones, then as VDX says, you can use them as bipolar steppers. In which case, the simplest option is to use cheap stepstick drivers sourced from eBay and turn the current down low. This will be easier than building your own drivers and possibly modifying the firmware, and may cost less too.

Edited 1 time(s). Last edit at 02/24/2015 12:35PM by dc42.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

Hi,
If you are going to use a Mega 2560 + RAMPS + Pololu-style drivers for the extruder + Marlin firmware, then the simplest route by far with the least waste of time and money is to follow Viktor's suggestion and just use Pololu drivers for all your steppers, and wire the small steppers as standard bipolar. You can find how to do that in the wiki.
As Viktor wrote above, you can adjust the current in the Pololu-style drivers to match your small steppers, this is also explained in detail in the wiki.
Good luck with your project,
Andrew