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Pwdr / Pwdr-Model-0.1

A powder substrate rapid prototyping machine
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Steppers #5

Open SungwonJ opened 12 years ago

SungwonJ commented 12 years ago

Hello,

Another question for stepper motors, is micorstepping used when driving the steppers? Is it possible to build a simple circuit using ULN2003 to power the motors, that is, without the driver boards? After some calculation, I think the precision is 1mm/(360/0.9)=0.0025mm for the Z motor, which surely suffices.

Any help is greatly appreciated.

Best, Eddie

Pwdr commented 12 years ago

Microstepping is used for all steppers (Z-steppers 16 steps/rev, all others 8 steps/rev).

It could be possible to power the steppers using ULN2003 chips and some electronics. However, you would have to rewrite the firmware as it now uses the AccelStepper class that handles all the stuff for the stepper motors.

nothinman commented 11 years ago

Just my few cents. You should be using highest microstepping available, unless your micro is super slow, or you need 99% of it's processing power to do something else. ULNs do no regulate current, can't reverse direction of current, so can only drive unipolar steppers. Now, these have less torque and are slower than bipolar steppers. Could work in this application as long as the design remains small. If you want to build a bigger one... you'll fail ;)

Pwdr commented 11 years ago

I'll just leave the questions on ULN and stick to commercial stepper boards.

For Model 1.0, a higher microstepping will be used, increasing the printers speed. Makers can do this on their own by connecting the correct contacts.

SungwonJ commented 11 years ago

Thanks nothinman for your input! I am now using 3 driver boards with 128 micro-stepping and 2 with 16 micro-stepping.