Re: [CAD_CAM_EDM_DRO] BP series 1

Jon Anderson wrote:

> Jon Elson wrote:
>
> > If you can hear it run, listen to the spindle bearings.
> > If they are noisy, you are looking at $700+ for a set of ABEC 7
> > bearings.
>
> There's an outfit in Oregon, C&M Precision Spindle, I think is the name.
> I've gotten a quote of under $400 to do an R8 spindle with what they
> call a quad-pack, four bearings at the taper end. They regrind the taper
> too, .0002 runout max.
> I'm sure they can handle a #30 taper spindle as well.
> If anyone is interested I'll see if I can dig out their brochure.

Right. What they do is use ABEC class 5 bearings, which have a greater
tolerance for runout. I suspect they twiddle the bearings around to
match the runout of the 2 main bearings as best they can, then
regrind the taper so that the tool runout will be close to zero when
installed in the machine. This may actually end up better than just
replacing the bearings if your spindle taper is banged up a bit.
But, I wonder if those bearings are as stiff or run as long as the
ABEC 7 that Bridgeport specifies.

Ary you saying they replace the two main ABEC 7 angular contact
bearings with 4 bearings? (The standard Bridgeport 1J or 2J
spindle has 2 big angular contact bearings at the taper end, and 2 smaller
bearings (I assume just plain radial ones) at the spline end.)

Jon