programming stepper motors

Hi I'm brand new to Arduino. I have NO Electronic knowledge. I have NO programming experience. A sad guy really, but not a bad one. My first objective is to get a Model Railway (I did say sad) turntable up & running using a Stepper Motor. (of which I I have no experience either) So, my first question is, Can anybody out there give me some guidance? I am told that this has been attempted before. Regards Ridleyn123

Any particular turntable? If so details are useful. Any deep reason why you want a stepper motor?

There is a very useful and extensive Thread about motorizing a turntable here even if you are not interested in using DCC.

...R

See this video: https://www.youtube.com/watch?v=yC7mlnhO0zo There is a link at the end to project. Looks to be the same link as Robin2 posted above?

I forgot to mention that if you are starting from scratch don't use a motor shield to drive a stepper motor. Use a proper stepper motor driver - for example the Pololu A4988. Of course you must make sure that your stepper driver can comfortably supply the current required by your motor. These motors should be perfectly suitable for a model railway turntable and the easily work with the A4988.

...R

Robin2: I forgot to mention that if you are starting from scratch don't use a motor shield to drive a stepper motor. Use a proper stepper motor driver - for example the Pololu A4988. Of course you must make sure that your stepper driver can comfortably supply the current required by your motor. These motors should be perfectly suitable for a model railway turntable and the easily work with the A4988.

...R

Robin,

Why do you advise a newbie to NOT use a motor shield, but use a "naked" stepper motor driver instead? I would think a shield would be easier for a beginner because it's plug-and-play, and there will be libraries to use it.

ridleyn123: Hi I'm brand new to Arduino. I have NO Electronic knowledge. I have NO programming experience. A sad guy really, but not a bad one. My first objective is to get a Model Railway (I did say sad) turntable up & running using a Stepper Motor. (of which I I have no experience either) So, my first question is, Can anybody out there give me some guidance? I am told that this has been attempted before. Regards Ridleyn123

Steppers are bigger, heavier, more power-hungry, and more expensive than servo motors. Unless you need the fine, precise control they give you, I would think a servo motor would be a better choice for this application.

Steppers are bigger, heavier, more power-hungry, and more expensive than servo motors. Unless you need the fine, precise control they give you, I would think a servo motor would be a better choice for this application.

Servos are no good here. the track has to align perfectly or a derailment will occur.

DuncanC: Why do you advise a newbie to NOT use a motor shield, but use a "naked" stepper motor driver instead? I would think a shield would be easier for a beginner because it's plug-and-play, and there will be libraries to use it.

I don't know why you use the word "naked".

The simple answer is that a proper stepper motor driver board is a very different thing from a motor shield. Stepper motors are nothing like regular DC motors. Stepper motors need to be driven with a high voltage and a proper stepper motor driver board can limit the current in the motor coil so that the motor is not damaged by the high voltage. You will often see stepper motors with nominal voltage figures of 2 or 3 volts which are normally driven with 20 or 30 volt supplies - maybe even 50 or 80volts for professional systems.

As well as all that the proper stepper motor driver boards usually only need two connections to an Arduino - step and direction and can manage microstepping independently of the Arduino.

No contest.

...R

A train turntable is not a high-speed application(!), a high-impedance stepper driven either unipolar or via an H-bridge would be fine.

the track has to align perfectly or a derailment will occur.

Define "perfectly" in terms of an actual number please...

Define "perfectly" in terms of an actual number please...

perfectly 'Over the entire extent' Completely, all, entirely, fully, wholly, totally, altogether, utterly, in full, not partially. It's not a number.