[Swansea Hackspace] Bits for 3D printing

[Justin Mitchell]

On Mon, 2015-08-03 at 19:23 +0100, Tim Moore wrote:
> Silly question using 3D technology:-
> 
> 
> I've got a Stepper motor which chuggs round in 1.8 degree steps and I
> need it to go through 180 degrees in approx 40 seconds....
> 
> 
> but the rub is its needs to be smooth, and it does an instant step.

If you are using a step-stick driver as some suggested then the minimum
move will be 1/16th of a step. i.e. 0.112 degrees

if you built your own stepper driver / h-bridge then you very likely
only get whole steps.

the only way then to make the step size smaller is gearing.

Getting there in a certain time is entirely down to the rate at which
you trigger the steps, you need to figure out what that is for the speed
you want to achieve. depending on the speed and inertia of the load you
may also need to accelerate and decelerate your step rate at the ends of
travel to prevent overloading the motor and skipping/slipping of the
drive.

these are all tricks that the 3d printer driver software uses, and you
can find various arduino libraries around to help you.