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

Tim -

Are you qouting those speeds using the same slot-count encoder with the same
pulse-rate output from the LPT software for each motor? What are those
numbers? For a given encoder and pulse-rate, what accounts for the
variation in max. feedrate? I would have guessed they should be the same as
long as there was enough torque to accelerate the system to speed.

Carlos

> -----Original Message-----
> From: Tim Goldstein [mailto:timg@...]
> Sent: Sunday, August 20, 2000 12:25 AM
> To: CAD_CAM_EDM_DRO@egroups.com
> Subject: 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
>
>
>
>
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