Re: [CAD_CAM_EDM_DRO] Re: spindle motors

Instead of using a big high speed motor for drilling PCB's, why not put an
adapter on the spindle mount that will hold one of these tiny (about 1/2
inch dia.) air powered units that run 100,000 RPM and up (depends on brand)?

Some are available with collet chucks as well as drill chucks.

Smoke
-----Original Message-----
From: Wally K <cnc4me@...>
To: CAD_CAM_EDM_DRO@egroups.com <CAD_CAM_EDM_DRO@egroups.com>
Date: Tuesday, December 12, 2000 11:59 AM
Subject: [CAD_CAM_EDM_DRO] Re: spindle motors

>--- In CAD_CAM_EDM_DRO@egroups.com, "Carlos Guillermo" <carlos@v...>
>wrote:
>> Thanks Wally and Tim for the motor website links!
>>
>> To answer Wally's question: I am building the headstock for my
>> ground-up benchtop milling machine, which has taken ALOT longer
>> than expected due to various events over the past 3 years (new
>> house, new baby, new job, etc....). But I'm finally making
>> progress. >
>
>> About the headstock: I'm just planning on making an R8 spindle,
>> and connecting the motor with a toothed belt, on a cast iron box.
>> I'm going to use a Hitachi VFD, which can output up to 600% of
>> line frequency, so I'm just trying to see if I can take advantage
>> of that to get extra speed for engraving, PCB milling, EDM
>> electrode milling, and other low power jobs. Of course, I'm
>> looking into what the bearings can take, but I also don't want the
>> motor to blow up. So I guess I'm looking for a "regular" 3-phase
>> AC motor, that can mechanically handle several times its rated
>> speed.
>>
>> Carlos Guillermo
>> VERVE Engineering & Design
>>
>
>I have a feeling your bearings will heat up at these RPM. And i
>think you are going about it the wrong way. Engraving, PCB milling,
>and EDM electrode milling are low HP high RPM. 6000 RPM is not very
>fast for these jobs. Jon Elson found a simple soultion to this
>problem. He made a simple spindle adapter plate to fit on his main
>spindle and hold a separate small high speed motor. For a picture of
>this go to Jon's air spindle page at this URL.
>
>http://ascc.artsci.wustl.edu/~jmelson/wwspndl.html
>
>He has a write up there that will help you.
>
>
>The VFD drive is still a good idea but stay away from the 6000 rpm.
>
>
>Wally K.
>
>
>
>
>
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