Hi I have a large esab plasma table with old servo motor and gearboxes
If I was to convert to steppers,
Will steppers perform better driven through gearboxes or direct drive
Printable View
Hi I have a large esab plasma table with old servo motor and gearboxes
If I was to convert to steppers,
Will steppers perform better driven through gearboxes or direct drive
Steppers are generally best used at low speed. Normally a 2:1 reduction is OK. There is a lot more that goes into the calculation. What torque and speed is required? To use a stepper motor I would multiply the servo torque by 3 to get a starting point for the stepper required torque. But keep in mind that stepper torque drops off dramatically with increasing RPM.
Ok
I will calculate the weight of the gantry tomorrow
And see what gear ratio the servo gearboxes on the table are
Quote:
Originally Posted by Jim Dawson
Steppers definitely need reduction gearing for plasma. Try and get somewhere around 1" of movement per motor revolution. Mine does about 30mm which is still ok and even down to 15mm is good too.
If the servos are still OK, an alternative might be to retrofit with Linuxcnc and a Mesa 7i92 ethernet board and a Mesa 7i77 6 axis servo/encoder daughter card. Add to that a Mesa THCAD board for torch voltage sensing.
Regardless of if you use steppers or servos, the Linuxcnc plasmac configuration is now without doubt the best plasma controller available on the market place for under $10k because all the THC control is so tightly integrated with the Linuxcnc motion controller and Linuxcnc's PID controllers. Having arc voltage and full access to motion control parameters lets Plasmac do things other external THC's can't even dream of. Full documentation of Plasmac is here PlasmaC User Guide
Ok thankyou for the input
Regards
Quote:
Originally Posted by rodw