Re: [CAD_CAM_EDM_DRO] Re: spindle motors

Hi Guys:
My machine has a 10,000 rpm spindle.
It is dirt-simple: a couple of angular contact bearings, pressed into an
aluminum housing.
There is probably a wave spring for preload. The bearings are sealed and
run in grease (I think)
I can try to get the spec.
The key things are:
1) the spindle is short and light. (5" long and maybe 1.5" dia)
2) the spindle is balanced.

I have done all sorts of abusive things to this spindle with never a burp!
I have crashed, I have run unbalanced cutters at 7000 rpm (flycutters and
stuff), I have taken heavy cuts, I have run at 8000 rpm from a cold start,
and I have never, ever serviced the spindle.

Maybe the sensitivity of these systems is overstated??

The spindle is R8 with a pneumatic unclamp.
Clamping pressure is provided by a stack of heavy Belleville washers.

Cheers

Marcus
-----Original Message-----
From: Jon Elson <jmelson@...>
To: CAD_CAM_EDM_DRO@egroups.com <CAD_CAM_EDM_DRO@egroups.com>
Date: Tuesday, December 12, 2000 10:36 PM
Subject: Re: [CAD_CAM_EDM_DRO] Re: spindle motors

>
>
>Carlos Guillermo wrote:
>
>> Thank you Wally and Smoke for the reality checks,
>>
>> The separate high-speed motor approach is making more sense for
>> the light load, high-speed work. I'm still looking into how much
>> speed I can get out of the R8 spindle setup. It would be nice to
>> have the higher speeds (~5k rpm) available for some metal cutting
>> jobs, where the high-speed motors just don't have enough rigidity.
>> I've heard of VMC spindles that are good for 5-6k rpm with metal
>> bearings, and some up to 10k rpm with ceramic bearings. How do
>> they get away with this?
>
>They use super-exotic bearings, special lubricants, and active cooling
>systems to keep the bearings from getting hot. And, they have to
>replace the bearings fairly often, too. (Really often if coolant gets
>into them.)
>
>Jon
>
>
>Welcome to CAD_CAM_EDM_DRO@...,an unmoderated list for the

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