stepperman:

Hi

I'm looking for advice on choosing the correct stepper motor and driver for an arduino project.

I would like to use the stepper motor to turn an object precisely 30 degrees, around 12 times a second, with a delay between each turn.

The delay needs to be at least (preferably more than) the same amount of time it takes for the motor to turn the object 30 degrees.

So around 1/24 second to turn 30 degrees and then 1/24 second delay, but ideally more like 1/48 to turn and 3/48 delay

The object's maximum weight will be approximately 1kg but probably less.

I'm assuming the basic 5V motor (28byj-48) that comes with the starter kit below wouldn't have the speed?

http://www.ebay.co.uk/itm/Ultimate-UNO-R3-Starter-Kit-for-Arduino-1602-LCD-Servo-Motor-Relay-RTC-LED-/272317374211?_trksid=p2385738.m2548.l4275

In addition, what driver would people recommend to fit the requirement?

Any suggestions?

You have to do the math (this looks totally infeasible at first glance, the angular accerations are extremely large

with large inertial mass as load).

The weight of the object is irrelevant, however, all that matters for rotation is the moment of inertia (MoI) which

is strongly dependent on the object size and geometry, not just the mass.

To accelerate and decelerate from 0 to 30 degrees in 41.7ms means acceralating to 15 degrees in 20.8ms,

which takes 1210 rad/s/s angular acceleration, with a top speed of 25 rad/s (250rpm)

A 1kg mass with effective inertial radius of only 2cm has 4.0e-4 kg m^2 MoI

The torque to accelerate that at 1210 rad/s/s is 1210 x 4e-4 ~ 0.5Nm

Note the peak power is 0.5Nm x 25 rad/s = 12.5W mechanical. Not going to happen for a NEMA17 I don't think.

For 1/48th second the accelerations/torques are 4 times larger and the peak power 8 times larger...