Just a thought

Hey all, my I3 has both Z motors connected to one output. It's voltage like all the others was 5.0 volts. Splitting that between two motors can't be good. I've already bumped up the voltages of the steppers to 7.0 volts. What would be a safe voltage for the Z motors? Have had issues with uneven movements making leveling a pain. I'm thinking that the low voltage is not enough to keep them in sink. Nema 17's and Melzi board.

If you wired them parallel, you have to raise the Vref ( I assume you meant 0.5 and 0.7V?).
That will push the driver to the limit.
Better wire the steppers in series and keep the Vref at 0.5V
-Olaf

If your that concerned about it you can hack annother stepper driver onto your board and drive it from that

Marlin firmware already supports dual stepper drivers for Z axis

Yes Olaf I did mean .7 volts. I'm fairly good at electronics but can't see how they can be put in series. Have a schematic? Thanks.

After searching the subject and finding nothing it dawned on me that I would for instance connect green to the driver out to the motor and out blue to the green of the second stepper and out blue to the driver. Is that correct? Thanks.

Quote
elwood127
After searching the subject and finding nothing it dawned on me that I would for instance connect green to the driver out to the motor and out blue to the green of the second stepper and out blue to the driver. Is that correct? Thanks.

I´m not sure about the colors, but if they represent one of the coils ( A or B ) you are right.
-Olaf

Thank you sir.