Hi, newbie question here.
I can't find any documentation to help me on a project, which at its core involves controlling 4 different microsteppers (with only one active at any time). Do I need 4 seperate shields, or is it possible to use buttons to make a toggle that'll only make one active at any time (ie just use 1 shield?).
Is this possible, stupid or...?
Can anyone point me to some URLs where this sort of question is under discussion?
Many thanks
Is this possible,
Yes
stupid or...
Possibly.
When a motor is no longer powered it not have any torque and so it is easy to move with an applied load. This is what would happen if you did this.
You would have to arrange a multi way switch or set of relays to switch the motors in and out of circuit
Not something many people want to do.
Ok, thanks Mike. So the proper way of doing something like would be to have 4 stepper shields, with all of them on?
Thank you again
nass:
Ok, thanks Mike. So the proper way of doing something like would be to have 4 stepper shields, with all of them on?
Yes that is the proper way.
Grumpy_Mike:
Is this possible,
You would have to arrange a multi way switch or set of relays to switch the motors in and out of circuit
Not something many people want to do.
And of course physically breaking the connection to a powered up stepper winding is likely to
both burn out the stepper driver and weld your relay contacts shut - unless you power down the
driver before switching.
The first rule of stepper motors is don't disconnect a powered up motor...
MarkT:
The first rule of stepper motors is don't disconnect a powered up motor...
Mark thank you. Can you suggest any websites which would inform on such things, basic stepper rules, do's and don'ts, drivers and shields and whatnot. I have a very specific thing I want to build but having a devil of a time finding out info about it. Ie the shields I'm seeing arn't stackable so you're limited to 2 steppers... I'm after 4 (and a bunch of other bits). Where to find some reading material covering projects like this with many bits?
Thank you
Look at the reprap project - the prusa mendel has five steppers driven by an arduino - it does it using some little pololu boards, one per stepper that just need a couple of pins apiece. In the case of the reprap, those daughter boards are attached to the main RAMPS board, but there's no reason you couldn't control them directly from the arduino.
Thank you very much wildbill, I'll do that.
Appreciate the pointers