Re: [CAD_CAM_EDM_DRO] follw-up on pacific bearings was Re: shafting question

Tom wrote:

> In my many hours of browsing the coveted McMaster catalog, I've
> wondered about a few things:
>
> 1. While obviously not suitable for serious machines, unsupported
> shafting and sintered bronze bearings has got to be the cheapest way
> to build a small machine. Anyone tried this?
>
> 2. Why in the world are the drilled shafts and their supports orders
> of magnitude more expensive???
>
> - Tom S.

1. Plotters and printers use the bronze bearing on shaft method, so if you
can live with the deflection it will work. Just be mindful of the
possibility
of wear.

2. My theory is that they know they have you where they want you.
Have you ever tried to machine the stuff? Actually, after you grind
thru the case hardening, you can machine it pretty well. I don't know
how they do it. I don't think the price is really that different. My
favorite
outlandish price is for the flanges that go on precision acme screw drive
nuts. They charge $39 for the flange, which must cost them all of $1.23
to make. It would cost you at least $39 to have your machinist make one.
Actually, this is the case since our machinist had more trouble trying to
match the wierd thread that they used.

Eric