Stepper motors running in parallel discussion

Zap-o

I was wondering if anyone has had success in wiring 4 stepper motors in parallel. Obviously the IC's would need to be able to handle the current.

My concern is - would they turn at the same speed? I think that this would be possible but not a 100 percent. I have an idea that requires 4 stepper motors possible up to 8 in the future that would have to turn at the same speed. Instead of installing 4-8 stepper drivers I thought that running them into one driver would accomplish the same thing. The steppers require very little current. Your thoughts?

Phil Pilgrim (PhiPi)

In theory, that should work fine, as long as the driver can handle 4x-8x the current required by one motor, and as long as none misses steps due to lack of enough torque or to resonance.

-Phil

kwinn

I have seen 3 steppers run in parallel to drive a sipper to the "home" position, but the motors had optical sensors to verify they were turning and it was done at a low step rate. After that the motors were run one at a time.

chaosgk

You can get some good stepper drivers off ebay for fairly cheap. If you need current under 2 amps, I would suggest the ones using the Toshiba TA8435 chips from mdfly. Here is a link to one of their current auctions.
The kit I ordered was two controller boards with two drivers each and a good parallel port breakout board. They seemed like good drivers for the price. I think I paid $89 for the kit, but you can buy just the driver boards for about $40 I think after shipping.
I had good luck with them until this week when I burned a couple of chips changing settings on them. I don't think it was a problem with the boards though, and I talked to them and they are going to warranty the chips for me.
The seller was usbflying if that helps.
I was looking at running some steppers in parallel as well, but after discussing it here, we decided it would be better to run a controller on each one.

Zap-o

I think that it all depends on what you intend on doing. I only need a stepper to run in one direction with that said its not so critical in my application. I am concerned only with the RPM control at low speed.

data sheet >focus.ti.com/lit/ds/symlink/l293d.pdf this has a large enough current rating for the small steppers that I wish to use at 1 amp per channel.

kwinn

Zap-o, low speed is not a problem as long as the steppers produce enough torque to step. It is at high speed/acceleration rates that you have difficulties. Essentially you end up limiting the speed to what the slowest one in the group can handle.