Welcome! Log In Create A New Profile


Dual X and Y stepper Motors?

Posted by MegaRocketPenguin 
Dual X and Y stepper Motors?
April 05, 2017 06:57PM

I am building a printer, and need some help on figuring out how to go about connecting the stepper motors.
I currently have 4x 2a NEMA17 motors, and some a4988 Pololu drivers.
If I understand correctly, I could only drive one motor per driver, due to the current rating. However, I need to have two X and two Y motors, due to design. I've read about wiring in series/parallel, but I'd much rather dedicate one driver per motor. I will not have any extruders, and the Z axis will actually be a solenoid or a servo. So, theoretically, of the five drivers, 4 of them need to be used to drive 4 motors, two on Y, and two on X.
What would need to be modified in Marlin? Is there a guide that could help me with this?

Apologies in advance if I posted this on the wrong board; there are so many of them (many of which are very specific, and also inactive) that I thought the general would be the best place to start.

Re: Dual X and Y stepper Motors?
April 08, 2017 06:59AM
Connecting your motors in series would be a really good idea here, not sure why you're down on the idea.
Re: Dual X and Y stepper Motors?
April 08, 2017 08:22AM
Wouldn't I lose torque/precision? How would the drivers hand it, considering the motors are rated for their max? (Or do I understand the rating incorrectly? I've read a few things about individual coil current draw being different, and that I wouldn't actually set the value on the drivers to their maximum potential.) I found the lines for dual x and dual y in Marlin, is this what I'm looking for? Does it allow each motor to have its own driver?

Now, the motors are a little beefy for the project, and one of the big things is that this will be battery powered. So If I wired them in series, would that significantly lower power draw?


Edited 1 time(s). Last edit at 04/08/2017 08:23AM by MegaRocketPenguin.
Re: Dual X and Y stepper Motors?
April 08, 2017 09:12AM
Stepper drivers autmatically increase the voltage over the coils until the current is what you set it to be.

Put two steppers in series, the coil impedance doubles and so the driver will increase it;s output voltage and the current through the motors will still be what you set.

each stepper doesn't "know" anything is any different, you won't lose precision or torque.

series/parallel/separate drivers won't really change the power draw much aside from impact of efficiencies in the drivers. At the end of the day your stepper draws a certain power however you connect it (crudely, it's rated current * it's rated voltage).
Sorry, only registered users may post in this forum.

Click here to login