Re: [CAD_CAM_EDM_DRO] stepper driver-transformer sizing question

Hi Robin,

>
>one question. Assuming these are fairly modern motors with a corners speed of
>around 600RPM, (2khz) with gecko 201's thats 20Khz of pulses into the gecko
>.. is your machine geared such that you where able to put AT LEAST 20Khz of
>pulses into the drives, preferably twice that??
>
>
>

The motors are the original ancient motors that came with the machine so
their corner speed is probably much lower than 600rpm. The maximum pulse
rate that I can use and be absolutely sure of not losing steps is about
9kHz. They will stall at about 16kHz. just moving the table.

>I suspect no, which is why you are only drawing minimal power from the
>supply. Also, if the motors are already getting hot, you are probably using
>too many volts ...
>
>
>

I don't think I am using too high a supply voltage because the motor
temperature only rises when moving at high speed for long periods of
time. Even then they are only slightly uncomfortable to hold. At idle
with no idle current reduction they run slightly warm.

>regardless of the acceleration, the motors CANNOT provide maximum power (ie
>draw the full &a at 65V from the power supply) below corner speed.
>
>
>

These are very old motors and I believe that I am running them at above
their corner speed. I may experiment with the gearing but to be honest
I expect I would end up running the motors to fast to get any useable
power out of them.

Les