@dc42 said in More info on higher voltage stepper mod?:

FWIW we are considering revising the Duet 3 design to rate it to 50V.

Any info when that might be the case?

Thanks for your suggestion. Stepping up the motors reduces acceleration, while improving max. velocity. Since I am optimizing for small line segments, acceleration is more important to me. The max. possible system acceleration is reached when the reflected load inertia matches the motor inertia. I calculated all gear ratios based on this principle, which is why my motor pulleys range from 15 to 70 mm in diameter depending on the use-case.

Since different motors have different inertias and different torque ratings, I select the best motor from a large table of possible motors, where I assume for every motor that it will be driven with it's individual optimum gear-ratio.

So unfortunately I can not improve system performance by changing to a different motor or gear ratio (if I didn't make any mistakes, I should already be at the optimum)

My limitation is therefore voltage and current. My self-built setup allows me to run at 48V@3A_rms. Raising at least one of these two would allow me to run new motor/gear-ratio combinations, that are not possible right now.

Thanks, so it seems it's possible with a little bit of soldering.

Since Klipper isn't available for the Duet 3, I might have to go away from Klipper to follow ths path. The main reason I'm using klipper are the high step rates I can achieve. With my SKR Pro over 900k steps/s are possible (bottom table): https://github.com/KevinOConnor/klipper/blob/master/docs/Features.md

What is the maximum steprate the Duet 3 can output?

I'm developing high-speed custom pen-plotters, that work basically like a 3D-printer. Since I'm running at very high speeds (up to 5000 mm/s) I need very high voltages to drive the steppers (6 steppers per printer). At the moment I'm running at 48V @ 3A_rms and would like to go higher.

The TMC5160 allows input voltages of up to 60V, is there any possibility to make a high-voltage version of the Duet 3? Or modify the Duet 3 to at least 48V? I'm good at soldering, I just need to know which components to replace.