Re: [CAD_CAM_EDM_DRO] Re: Resonable Stepper Speed under simple Unipol ar drive ?

Mark Thompson wrote:

>Thanks Guys
>
>I just wanted to know that I wasn't completely insane.
>
>This is on an old Jet 9X44 Mill running 3:1 on the original
>lead screws.
>
>It works great as a CNC machine it just slow a snail on a salt lick.
>
>I have tried to drive the system with the following drivers:
> Mach1
> EMC (Linux)
> Wave Tek (pulse generator)
>
>What I found was that if I pass through the resonate point at just the right
>acceleration I can get the motors to around 400-500 rpms. But it is imposable
>to operate near the resonate point with the L/R drives.
>
>

You can install either viscous dampers or electronic damping. The viscous
dampers have heavy oil-like materials and a heavy steel washer inside a
ring-shaped cavity. Electronic damping can be done with a capacitor and
resistor in series between the two outer legs of each winding. You
could try
something like a 100 uF motor start cap and a 10 Ohm resistor.

But, you'd still have very poor performance. You can get better
performance,
at the cost of more heat, by using a 30 V or so power supply, and increasing
the resistance and the power rating of the big power resistors in the
driver.
But, you'd still never get anywhere near the Gecko's performance.

Jon