Re: 10,000 RPM spindle speed on a BP

About 5k is the max you want to run a basic bridgeport spindle. The
lubrication system is just not there for anything faster. Also cooling
become an issue. Also the bearings themselvs are only rated for about
9000 max. Try this with a normal BP spindle and you will be forking
over $400 for new spindle bearings.

What I did was get a Vulcanaire jig grinding attachment. It is a small
(6" long ) air powered turbine that has an r8 taper arbor that fits in
the quill. At about 14cfm you get 60-65000 rpm. This is great for 1/16
endmills and I can run them about 1/32" deep full slot at 20ipm. There
are several other companies that make these types of units. Main thing
here is you are going to have to have a decent size compressor.

Spindle speeders are another option. Volstro makes one buy they have a
low duty cycle not suited for CNC. There is the bridgeport Quillmaster
which gives you 50% overspeed and the ability to rotate the quill up
to 90 degrees.

There are several other spindle speeders available but they are
usually cat40 taper only.


--- In CAD_CAM_EDM_DRO@yahoogroups.com, "Polaraligned"
<polaraligned@...> wrote:

>
> Why not? One of the biggest disadvantages of a BP is the lousy 4000
> RPM spindle speed. Certainly you can't do this with a varispeed head
> without loosing the varidiscs. If you are using a Vector based VFD you
> can use a modern motor and just eliminate the varidisc nightmare
> assembly. One would need to come up with some easy to change gearing
> that can send the speed up to the 10,000 range. I wonder if the
> spindle would need a quality high speed balancing job?
> Something to think about if you do a lot of aluminum or other soft
> material. Every VMC that I looked at had a spindle speed that went up
> to at least 15,000 rpm.
> Probably want to start out with a 2hp, 3450 rpm motor,have the ability
> to drive the spindle directly with a 3:1 ratio and get 10,000+ rpm's.
> Reverse the 3:1 ratio (reducing speed) and get all your lower speeds.
> (in conbination with the Hi/Lo setting.)
> Take a look at this picture of a setup done by Paul Babin of Babin
> Machinery.
>
>

http://img.photobucket.com/albums/v223/polaraligned/BP%20drive/BPwithoutvaridiscs.jpg

>
> A set of 2 stacked pulleys to reverse the ratio would work fine.
> Just one belt change and you are off into milling territory once only
> a VMC could handle.
>
> Of course, this is best used on your CNC mill and not your manual mill.
>
> Is this nuts?
> Any thoughts?
>
> Scott
>