RE: [CAD_CAM_EDM_DRO]spindle plans (was VFD Selection)

Since it will take me a while (crazy with work) let
me go over some of the design concepts now.

This is a thermally stable 3 bearing system.

Near the work end of the tool there are two back-to back 25
degree angular contact bearings adjacent to each other. These
are supplied with the inner face slightly recessed (only microns)
such that when they are squeezed together by a retaining nut
a specific preload occurs (5% of max dynamic load). Further
tightening of the nut does not increase the preload once the
faces are forced into contact.

These bearings are press fit on the shaft but a push fit on
the housing. A shoulder and bolted ring secure the outer
bearing edge. A shoulder formed on the shaft secures the inner ring, but
it must be of a very specific size to allow bearing removal by
pushing on the INNER ring only (with a special tool).

The shaft has a short threaded portion for the retaining nut.

Moving away from the tool end the shaft necks down slightly.
This facilitates installing the angulars since they won't have
to be pressed all the way down the shaft.

At the back end there is another reduction in shaft diameter
to provide a shoulder for press fitting a deep groove ball
bearing. The outer part of this bearing will be allowed to
float, but it will be very lightly preloaded with a Bellville
washer to prevent ball scuffing. It is secured with a retaining
nut as well.

Thats basically it except for the engineering details.
Pretty much a standard design that has been used for eons.

Les

Leslie M.Watts
L M Watts Furniture
Tiger Georgia USA
(706) 212-0242
http://www.lmwatts.com
Engineering page:
http://www.lmwatts.com/shop.html
CNC surplus for sale:
http://www.lmwatts.com/forsale.html
CNC carved signs:
http://www.lmwatts.com/signwp.html




-----Original Message-----
From: Vince Negrete [mailto:vnegrete@...]
Sent: Wednesday, April 14, 2004 10:52 AM
To: CAD_CAM_EDM_DRO@yahoogroups.com
Subject: Re: [CAD_CAM_EDM_DRO]spindle plans (was VFD Selection)


Les, Would it be possible to have a write-up/drawing on a site in PDF w/
availability of a full kit?
I'm primarily interested in design concept with exact specs/demensions to
follow for building one from Stock.
So far there are Several folks interested since last nights post.. :)

Vince