Re: [CAD_CAM_EDM_DRO] Re: burning Gecko drive

theokspindoctor wrote:

>Jon, I think I understand that the 210 will just make more steps and
>not fewer steps. I will keep working with the 201s for now. I hope
>you might look over this.
>
>Ok, just burned out my Gecko drive. the motor looks like this
>
>
> 3 2
>5 8
>
>6 7
> 1 4
>
>2-8 one winding
>3-5 "
>6-1 "
>4-7 "
>
>Originally it was wired as below to the Gecko by my installer. It
>worked that way but the maximum rapid I could get was 20 ipm
> phase A+ to 2
> phase A- to 1
> phase B+ to 8
> phase B- to 6
>
>I rewired it tonight as below and it burned it up. Why?
>

It is hard to determine which pair of wires are associated with which
phase. The two
windings of one phase act like a transformer. If you happen to wire the
two ouput
phases (A-B) and (C-D) of the Gecko to the two windings of the SAME
phase, they
interact, and can cancel out the the inductance that each phase is
supposed to present to
the driver. Woth the inductance cancelled out, the current rises
rapidly and causes
extreme overheating of the Gecko's power transistors.

> phase A+ to 1
> phase A- to 6
> phase B+ to 2
> phase B- to 8
>
>Les Newell said his were wired as below and worked fine for him.
>Shouldn't his have burned as well? It looks the same as mine above.
> phase A+ to 2
> phase A- to 8
> phase B+ to 1
> phase B- to 6
>
>
>

Yup, but his motors may not be wired internally as yours are! There
have been all sorts of
different wiring schemes in these, as they were custom motors.

Anyway, some small changes in exactly which winding you use is not going
to fix the performance
problem. If the motor moves correctly at low speed, it is wired right,
and you can only make
it go the opposite direction by wiring changes. Switching to a
different winding won't fix anything
unless that winding is bad.

What power supply voltage are you using?

Jon