Re: [CAD_CAM_EDM_DRO] Speaking of VFDs

Sven Peter wrote:

> Hello Tim generally you shouldn't go over 6000 revs
> and a healthy limit is some 4300 revs. Just my estimate.
> The bearings limit is generally 7500 revs but you have more parts
> involved like the varimatic belts. So i would go
> really seldom over 4000 revs.
> good luck with BB
> Sven Peter
>
> Tim wrote:
> >
> > I now have a VFD on Bridgett (Bridgeport Series II with Gecko G320s
> > installed). Question is, how fast can I turn the spindle safely. The
> > stock mill has a allows you to crank it up to 3500 rpm. The VFD I have
> > will do 180 hz so it could push the spindle up to something like 10500
> > rpm. Now I know that is way too fast and something would get destroyed,
> > but what would be a reasonable top speed to run for light cuts and small
> > end mills?

The Bridgeport 2J head with the dual-speed motor allows you to get 4250
RPM maximum. I have heard from a few people that if you run the
machine at that speed a lot (making mold cavities with small carbide
tools, for example) the main spindle bearings won't last very long, maybe
about a year, if you are lucky! That soundls like an expensive proposition
for a home shop!

Jon