RE: [CAD_CAM_EDM_DRO] step/dir servo (Gecko drives)

Carlos,

I have some of the Geckodrive servo units. I have not yet gotten them
attached to my machine (hopefully tomorrow. I got my last encoder hooked to
the motor), but I have been playing with then on some bare shaft motors. The
rapids I am getting depends upon the specific motor. I have one nema 42 unit
that is maxing out at 135 ipm (on my machine this works out to 1350 rpm),
but have a nema 34 that is fine to at least 180 ipm and a nema 23 that is
fine at 240 ipm. The question is how much of this speed will I be able to
retain when mounted on the machine?

I have communicated with another person that is trying out the Gecko servo
units and they have a mill drill that is getting 180 ipm rapids.

I can't say that I have found any drawbacks yet.

Tim
[Denver, CO]

> Some of you may remember how I've been really wishing for a decent
> step/dir input servo drive system. Well, the Gecko system has me
> drooling, and I want to know more... At the price Mariss is offering
> them for, especially when coupled to a surplus motor with an encoder,
> WHAT ARE THE DRAWBACKS over steppers?? Some of you have mentioned
> playing with them. What do you think? What are your thoughts on
> encoder wheel slot counts? How 'bout steprate output? 7kHz? 100kHz?
> What can the LPT port handle? What can the software handle? How's the
> performance? Speed? Resolution? System cost? Tune-ability? I still
> don't have my 'iron' together, but I want to get a Gecko drive just to
> play with it. Especially after playing with the last assembly machine I
> completed for a customer using a PLC with stepper output, and a size 17
> stepper. Man, did it GROWL! And I don't think it even got close to
> resonance. I had it doing rapids of 108 IPM at 7kHz, half-stepping
> with a 3A driver and very little load, and the whole time I was thinking
> "how fast could I get the servo system to go??". Mmmm...
> servo...servo...
> Carlos Guillermo
> VERVE Engineering & Design