Re: Ball Bearings

Tesla List wrote:
> Original Poster: "Don Kemper" <de.kemper-at-worldnet.att-dot-net>
> Hope you all don't mind one more suggestion. Richard Staron has givin good
> advice about reducing hardness and could be used with this method if
> necessary. Several have given good ideas as well. This method may help with
> other problems as well.

There is info in the below-URLed HSM (HomeShop Machinist) site 
about making nice drawer etc. handles from ball bearings.


1. Heat to cherry red. 
2. Drop into a container (small tin can) filled with Lime. Must cover
3. Allow to it to cool by it's self. With some of the latest ball
   bearings, you may have to repeat the process.

> Not everyone has a milling machine, but most probably have a decient drill
> press. Buy an end mill as used in a milling machine and chuck it up in the
> drill press. End mills cut on both the sides and the flat "end" surface of
> the mill, they are not pointed on the end like drill bits. Put the ball

Do notice that an end-mill WILL have a force pulling the end-mill
DOWNWARDS and that will pull the tapered (with no pullbar like in mill)
drillholder off the spindle (with too heavy cut).. Those who have to 
use a drillpress for light milling usually use epoxy to permanently 
fix the tapered drillholder (morse taper usually) to spindle taper.

> bearing in a vice and carefully center the ball under the mill. (This is
> easier if one has one of those inexpensive cross vices.) Use a slow RPM on

Easier (and more correct:) way is to use center-drill to make the 
start and then a normal drill to drill the hole. A center-drill is 
just for that - starting the hole accurately where a normal drill 
would wander. It will work just fine on a slightly radiused/uneven 

> the drill press and a slow spindle speed rate and it will put a flat bottom

Usually something like 10-20 m/min is suitable for "normal" 
steel -> that gives (10000mm / (10mm * pi) RPM =) 
318RPM - 636RPM range on a 10mm dia drill / end mill.

> Drill presses and especially drill chucks aren't made to do milling so you
> obviously don't want to take heavy cuts with mills in drill presses, nor do
> a "lot" of "lighter work" this way. If you wanted a really smooth long cut
> you probably won't get it this way either. But it will get you through on
> those seldom occasions when dealing with round stock.

Very true. Do notice that the sideforces from taking a cut (with
cross-feed) are putting forces on drillpress that it was not designed
for.. So the bearing accuracy/life may be shortened.. 

As well a piece of trivia - when acquiring the end mill make certain to
get one that is designed to "drill".. Not all of them will..

  Kristian Ukkonen.