What power stepper motors do I need?

[Robin Hewitt]

3.1Nm holding torque tells you very little, it's like judging a car's performance by the quality of the hand brake.

Our American chums started this by buying motors purely on holding torque. "I've got Zillion ounce inch motors, the reeel McCoy! Incidentally, why can't I feed faster than 30 inches per minute?" :heehee:

What you want is a graph showing torque against steps per second for the voltage you plan to drive it with. It will be there somewhere, if it isn't, try somewhere else :tup:

[Monty_jon]

Thank you,

Just out of interest, what sort of machining accuracy should I expect with the above CNC’d ?

[Robin Hewitt]

Just out of interest, what sort of machining accuracy should I expect with the above CNC’d ?

Clamp a DTI to the bed.
Run a tool up against it.
Lean on the spindle and measure the deflection.
That tells you what is possible.
Achieving 'possible' is the tricky bit :naughty: