Re: [CAD_CAM_EDM_DRO] Re: burning Gecko drive

theokspindoctor wrote:

>Thanks everyone for all the input!. Now I have a hope of at least
>wiring safely! I will try the battery-bulb trick tonight...
>
>I am using a 75v 16 amp DC power supply.
>
>

OK, you have a very serious problem. A number of people have had
good performance with old BOSS retrofits using Gecko drives. They
did need to use 70 - 75 V power supply, and the Geckos run REAL
hot at that voltage and full current, but they work. Most have gotten
60 - 90 IPM rapid feeds. I believe everybody used a 1:1 drive scheme
from motor to 5 TPI ballscrew.

Does your machine have a lot of friction?

I will note the old BOSS machines used motors designed as 60 Hz synchronous
motors to be run from a 120 V AC line. Running in half-winding mode
means the
winding needs close to 60 V at 60 Hz to reach rated performace, which would
be at 72 RPM. This is the equivalent of 240 full steps/second, or 2400
microsteps
per second. So, you are already doing better than that. In other
words, you start out
with motors not designed from the ground up for stepper motor performance.

I still recommend the headphone test I mentioned earlier, as jagged step
pulse timing
could definitely cause the problems you see.

Jon