Re: re-selection of motors....avoiding another rathole - question ?

Reading this thread, I am to understand that the mini-mill is run
with servos from Geckos.

that the motor(s) may be undersized.

My question then is would an undersized motor be under higher power
to reamain on posisition (per encoder feedback) than a larger motor ?

or maybe stated differently, would a smaller motor get hotter than a
larger motor when used in this way ?

It may be as simple as calculating the ammount of work needed to hold
posistion as a figure of watts. if that is the case, then a larger
motor operating with the same wattt load would be cooler to the touch.

Dave




--- In CAD_CAM_EDM_DRO@yahoogroups.com, "etauch" <erictauch@a...>
wrote:

> Many are recommending the belt/pulley setup.
>
> Point is taken, BUT Unfortunately, My mill is already "moving
> around" with the direct drive setup which I have pretty much
> finished with brackets and helical beam couplings on xyz.
> I hate to start completely over.
>
> This is a small micromill (HF47158) that is not a super precise
> machine. A bit of backlash in the gears could be compensated for

in

> the controller, although I will check into this some more. Maybe
> there arent many folks using the gear motors. I also could sell my
> gecko 320 servo drives, and drop in some stepper drivers/stepper
> motors
>
> I think you are right, motor 2 is a bit weak, and motor 1 a bit
> slow, but not for cutting speeds, i would think. I see what
> you mean about the "electronics". They only go one way, but would
> be replaced by the geckos.
>
> Thanks for the info....Eric
>
> If the gearheads arent suitable either...now I have to find some
> steppers!!
>
>
>
> --- In CAD_CAM_EDM_DRO@yahoogroups.com, Jon Elson <elson@p...>

wrote:

> >
> >
> > etauch wrote:
> >
> > >Greetings,
> > >
> > >Recently I posted on the overheating servo drive issue. I have
> > >decided that instead of moving to belt and pulley, I would try
> > >a "gearhead" servo motor in the 160-500 rpm range. This is
> > >for running direct drive thru helical beam shaft couplers. I

will

> > >calculate the exact RPM I need based on my leadsrews (10:1) I
> believe
> > >and desired IPM and pulse rate of my current PC.