Re: [CAD_CAM_EDM_DRO] Re: Gecko and Servos Again !

> The Bridgeport EZ-Trak (and apparently BOSS 7, too) use SEM motors
> with a peak rating of 100 V 26 A, or 3.5 Hp!
>
> I would not want to get in the way of one of these on a rapid movement.

Neither do I. So far I've broken several drill bits and dented a sheet
metal stool that happened to be between the end of the table and a workbench.

On my stepper lathe conversion at home, I was able to get from
miserable 8 ipm up to 30 ipm rapids by doubling the voltage into the
G210 to 50 volts, and setting EMC's acceleration parameter down to "1"
in whatever units it uses. At that speed I can stall the machine by
lightly braking the carriage handwheel, but not by pushing on the
carriage itself without the mechanical advantage of the geared rack
and pinion. So it should work okay for rapids, and at the few ipm I
intend to cut it has plenty of torque.

But the best part is this: if I program an erroneous Z-axis rapid
and crash the machine, the stepper will simply stall. When I do that
on the EzTrak and it tries to rapid a drill to 1" below the top
of the part, something breaks.

So stepper systems do have one advantage, at least for those of us
just starting.

But when I do the bigger lathe it will be using servos.

Chris