Re: [CAD_CAM_EDM_DRO] Re: Custom made bearing for lathes

It was more for fun than for necesity. BTW, I found
this
http://home.insightbb.com/~joevicar3/Air_Spindle_Plans.htm
- has anyone tried/ built this?
My lathe sits in a room - we have pretty constant
temperature there.

--- Steve Blackmore <steve@...> wrote:

> On Sat, 02 Feb 2008 07:01:02 -0000, you wrote:
>
> >my lathe is converted to CNC and I will attach
> linear encoders with 1
> >micron steps. I presume this is fairly precise (
> although I know at 1
> >micron there are vibrations, causing the encoder to
> signal them ). My
> >lathe has less then 9 micron shaft run-out. Do you
> think is enough?
> >At the "air spindle lathe" I want to be able to
> turn objects of about
> >5-6 centimeters (2 inch + ) in diameter.
> >I would need some plans or a solution somebody
> tried and worked, if
> >possible.
> >If this proves too hard. what about an oil bearing?
> What is the
> >typical run out / stiffness of it? Are they easier
> to build than the
> >air bearings?
>
> What's the problem with ordinary bearings?
>
> Abec9 or Class A bearing usually have a run out of
> less than 3 microns,
> it's about the best your going to get off the shelf,
> and probably more
> than accurate enough for you.
>
> A micron is a thousandth of a millimetre. Unless you
> temperature control
> your lathe it will likely expand and contract more
> than your minimum
> resolution.
>
> For example - suppose your lathe bed is Cast iron,
> it will
> expand/contract .0102 microns per millimetre per
> degree C.
>
> Steve Blackmore
> --
>

--------------

Best regards,

Cristian Giurgea

http://www.asmline.ro


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