Old Guy Wants to Make a NEMA 17 Stepper Motor Turn 100 RPMS

I am making a Rube Goldberg Fitbug shaker for a friend at work. Our employer came up with an incentive for our health care program that includes the use of a 3 axis pedometer, which upset some of my friends. I told him I would make him a fitbug shaker to make sure he hit his step goal everyday. It has wooden gears and parts that move back and forth to make it interesting but I am having trouble finding a motor that is reliable.
My next step was to buy the stepper motor, an Adafruit MotorShield v2.3, and I already had an Arduino Duemilanove with ATMEGA328 chip I’ve been dying to use for a few years. I thought getting the Arduino programmed would be fairly “easy” and I’d be glowing in my fellow employees admiration in no time! Well I was wrong and this 61 year old guy is having a hard time asking for help.
What I was hoping for at the beginning was that I would be able to find a sketch I could copy and paste to my Arduino, because though I love drawing and making the mechanical parts on my homemade CNC, but programming the Arduino is alittle beyond me right now.
I’m hoping some people can help us “fight the man” by helping me get my stepper motor turning.

The chances are very good that the Adafruit motor shield will not work with your motor. It can supply only 600 mA/winding without overheating and many motors require much more.

NEMA 17 just defines the size of the faceplate and is otherwise not informative. You need to know whether the motor is bipolar or unipolar (how many wires to the coils), the maximum current rating or the maximum voltage rating and the resistance of the windings. A link to the motor datasheet or product page would be helpful.

You will have much better luck with the more modern and capable motor drivers from Pololu (A4988 and DRV8825).

can you offer more data about the stepper ?

you should be able to make it spin with a simple sketch.

but, the more speed and power you need, means more voltage and amps.

a 200 step motor in half step (best step mode if you do not have any particular requirements.)

that would mean 400 steps per revolution.
100 RPM times 400 steps is 40,ooo steps per minute or 666 hz

so far, it would seem you do have have any major road blocks.

you said : Adafruit MotorShield v2.3,

the TB6612FNG chip on the driver board limits you to 15v, so, you would be best to use a 12v power supply.
current rating is 1.2A so, you should be fine there as well. make sure the power supply can deliver about 3A at 12v to offer a huge margin of safety.

the real question comes as to what the motor is.

and how much power you need to move things.

steppers have coils. the coils have to charge, the higher the voltage, the faster they can charge, the faster the motor can move and the more power it can deliver.

if anyone tries to tell you that you just need to use high(er) voltage more larger motors without really understanding the APPLICATION, it would be best to look for advise from people who actually understand steppers. I find that there are many people who have s smidge of knowledge and just love to toss out un-realistic information.

if you have a resistor that is rated for 100 volts, and wanted to light an LED, why on earth would you use 100 volts ? if 5 volts will WORK FOR THE APPLICATION, then like stepper voltage, anything not used is wasted.

As I see your problem it is either wiring or programming.

if you need to get the I2C working that is programming.

assuming you have the motor connected
that you have a 12v power supply
that you set the current limiting for the motor coils.
then all you need is to run the library

You have a fully functional, homemade CNC YET you think programming the arduino is beyond you :o

Surely that CNC uses stepper motors. I'd have thought this would be childs play to you. Nevertheless you need to give us the specs of the motor and, as others have stated, it's quite possible that the adafruit thingamibob isn't going to be up to the current requirements.

The Thread stepper motor basics may be helpful. It also has a link to some simple stepper code.

I won't tell the motor your age if you promise not to.

...R