I sure would like to know how this story ended, as I have a similar problem. Was it the BOB in the end by chance?

Hi,

motors 40V tuned down to 38v.

I think that is too low, it wouldn't 'pull the skin off a rice pudding'

All steppers lose torque the faster they go, it the physics of steppers. Using low inductance steppers in the first line of defence agsint that degradation. Using
the highest possible driving voltage is the second.

If a given stepper has an inductance of 6mH, not an uncommon spec, then expect it to have less than 5% of its holding torque at 1000rpm. The same size motor but 1.5mH
will retain 40% of its torque at 1000rpm.

Look at the specs of your steppers and determine the inductance....is it 2mH or less?, in which case good, or is it 4mH or more?, in which case you may need to replace the steppers.

You really want drivers capable of 80V and use an 80V supply....then your steppers will take notice and vastly decrease the propensity to losing steps at speed.

Craig

Was this resolved? Experiencing similar issues and keep hitting unanswered dead ends on the forum