On Thu, 17 Nov 2011 17:25:33 -0500, Ed Huntress wrote:

"Tim Wescott" wrote in message
...

On Thu, 17 Nov 2011 13:35:16 -0800, Dave__67 wrote:

On Nov 17, 2:33 pm, Tim Wescott wrote:
So, I'm kinda thinking it'd be cool to make some moon disks, like
thishttp://www.mooneyesusa.com/shop/product.php?products_id=474, only
without the snap-on features and for model airplane use (yes, I'm on a
mission).

These are obviously spun -- but how do they do it? They're spun _all
over_, which leads to some obvious problems in part-holding. Do they
spin part of it, then change the holder, then spin the rest? What do
they do?

Anyone know? Anyone have a good guess?

--www.wescottdesign.com

I've seen some vids where they glue to a wooden form, maybe in this
case there is a small center piece that clamps tight enough to form the
very central part and also imparts enough pressure the backside form
can spin it.

Or, central part is formed in a special op, then it is transferred to
another machine.

Glue might work. The ones I've seen are "spun" right up to the center
of the disk, although they may have been formed by other means and then
had a tool run over them (as yet another operation, presumably) to get
the look.

--
www.wescottdesign.com

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Holding disks for spinning shallow cups typically is done with a
tailstock holding something like a ball-bearing center, but without the
sharp point. It's pressed up against the disk, sandwiching it between
the center and a wooden form block held in the headstock end.

It puts a fair amount of thrust load on your headstock bearings. Lathes
made for the work have big thrust bearings.

I was figuring that since I'm doing it with thin material for an itty
bitty part, I could get away with it even if my lathe is cheap and Indian.

--
www.wescottdesign.com