Re: DC motor controller

Hi Les,

How important is figuring the gear ratio? I was just going to do it
like you did. But thinking on it the gecko power supply is good
for 68 volts - 12 amps. (It came from Homeshopcnc.com for anyone
who's interested). That'd run the motor at about 3400 rpm...right?
so I should gear it closer to 2:1.

I'm probably missing something here, but not sure just what.

I've played around with lots of DC motors and this one looks
to be very well made. The brushes are at 180 to each other.
For the price I'd think everyone should have 1-2 on hand just
for the heck of it. Lots you can do with a motor like this.

John

--- In CAD_CAM_EDM_DRO@yahoogroups.com, Leslie Newell <lesnewell@...>
wrote:

>
> Hi John,
>
> The servo drive will have to work to reduce the effect of the cogging.
> Modern drives are pretty good and can mask most of it. On my mill, if I
> watch the pulleys very closely I can just see the motor speed varying
> slightly at certain feed rates. It appears to have no discernible
> effect on accuracy or surface finish so I don't worry about it. Higher
> CPR encoders make it easier for the drive to compensate.
>
> Les
>
>
> John Hansford wrote:
> > Hi Dave,Ron,
> >
> > Pictures...
> > http://www.flickr.com/photos/26361144@N00/
> >
> > I took the CW to mean the nut would probably fly off if it ran
> > the other way. I opened it ...Nothing flew apart.
> >
> > What's the Bad news...How _BAD_ could they be as servos?
> >
> > I wouldn't have noticed the very slight cogging if I weren't
> > trying to find it.
> >
> >
> > John
> >
>