Re: [ATM] flex rocker azimuth stickiness

["Don Clement" <don_clement@charter.net>]

Aluminum does not work as a bearing surface with roller bearings. Aluminum
is too soft and will easily gall. Unlike Teflon that distributes load over a
large area, roller bearings concentrate the load about a thin line and will
quickly damage soft material like aluminum. Hardened stainless steel strip
is a better choice. I use ½" diameter solid carbide end mills regularly on
the vertical mill running at 6K rpm to mill aluminum with excellent results.
Vortex air-cooling is used. YMMV.

Don Clement
Running Springs, California


Jay Kirkland wrote:
>     On the re-build of the 20, I didn't even consider teflon - just went
> straight to sealed ball bearings. I used 4 sets of three bearings each,
> a bolt with it's head cut off for the axle. Instead of ebony star, I
> used 1/16" aircraft grade aluminum. That was a mistake. It works fine,
> but it was too hard to router into a ring w/o losing a whole lot of
> weight (in sweat that was scared out of me). If you go to an aluminum
> ring, use regular 6061, maybe a bit thicker, and cut it in several
> passes with an upcut spiral bit, preferably with a 1/2" shank to help
> with the heat, and - very important - NOT carbide tipped.

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