Hi, I've been making my brain hurt looking at stepper motors, torque ratings,
etc. but I've noticed something a bit odd.

It appears that to get the best performance from a stepper it should be driven at ~20 times its rated voltage, or 32 times the square root of the coils inductance in mH (this makes more sense considering the step input voltage / current curve of an inductor).

Looking at several motors in the 1.8 to 3Nm range this would equate to a driving voltage of around 60 to 100V, but most (cheap) drivers seem to have output voltage limits of around 35 - 48V, which would imply not getting the best from the motors.

Anyone know of any drivers with higher voltage capability available in the UK that don't cost an arm and a leg?

I know drivers are available like the MCP MSD980 - 7.8A @ 90V, but £105+VAT per axis is too steep for me at the moment. :(

I look forward to any information you can share.