Re: 300W Mitsubishi AC servo motors and drives

Hi Dan,

Really appreciate your inputs, I didn't think of problem of
overspeed, but only overcurrent. Your suggestion of pulley ratio 6:1
will be used, as it is even better for my poor little servo motors.

I will not motorize the knee, but only the quill. Have to find a way
of removing the backlash in the quill to achieve accurate Z axis.

Thanks again.

Horace.

--- In CAD_CAM_EDM_DRO@yahoogroups.com, "Dan Mauch" <dmauch@...>
wrote:

>
> The calculations are
> .9(Nm)X141(oz in)X6.28(2pi)X3(ratio)X2.54(thread per in
> 1/.3937)X.9(efficiency of the ballscrew)16(oz in a lb)=341 lbs of

Force. If

> you plan to motorize the knee then you will probably have to

install

> counterbalancing air spring or a higher ratio on the knee

sacrificing speed.

> At 300 watts that mean the RPM is about 3400 RPM. So your

speed on the

> XY axis ballscrews2.54 TPI I would be
> 3400/3x .3936==446 ipm which is too high for a ballscrew . So a

higher ratio

> of 6 to 1 would probably be better
> Dan Mauch
> low cost stepper and servo motors.
> cases for Gecko drives
> kits and assembled 3-4 axis drives
> www.camtronics-cnc.com
> www.seanet.com/~dmauch
> ----- Original Message -----
> From: "Horace, T.L.Ho" <skyfroghorace@...>
> To: <CAD_CAM_EDM_DRO@yahoogroups.com>
> Sent: Tuesday, November 14, 2006 5:24 AM
> Subject: [CAD_CAM_EDM_DRO] 300W Mitsubishi AC servo motors and

drives

>
>
> > Hi I've got my AC servo motors and drives 3 sets, all 300W, but

kind of

> > regret I should have bought bigger ones. The continuous torque is
> > around 0.9 Nm only according to spec. I am wondering if it's

enough to

> > motorize X and Y axis of my knee-type mill. I will make pulleys

with

> > ratio around 3:1.
> >
> > My ball screw dia 36mm lead 10mm. for both X and Y axis. My mill

2hP

> > knee-type bridgeport copy. With these motors what best jobs can

I do

> > with my CNC mill ? will it comfortable to mill 3d shapes on

Aluminum

> > blanks ?
> >
> > Any helps would be appreciated.
> >
> >
> >
> >
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