Re: DA 200 collets

I have seen this type of problem before. This is enough on-topic to
seem to get an answer, but it really is off topic.

the specifics of collet angles or the nuisances of actual diameter of
ground drill bits are not mainstream with the Cad-cam-edm-dro topic
of how to make, run and troubleshoot machines.

I need to make an internal collet so expansion will hold the part.
The ID is 0.38". this means if I use a 1/4 thread to hold the
expander in a pull fashion, the theoretical maximum OD of the plug
would be 0.378, leaving a 0.001" outer ring. In reality, I would
prefer to use a 1/16 wall but that would leave only 0.005" for the
entirety of the expanding plug, 0.0025" per side.

Machinery's Handbook : a taper will self-lock, depending on the
finish of the ramp surfaces, at some angle between 8 and 12 degrees.
This means my length of contact is rather short as well.

Since I have to locate the operator 14 inches away from the expanding
collet, I think that a pull expansion is preferred to a push style.
I have not started actual testing as yet.

I posted my problem to the 7x10minilathe group as that is a
unmoderated group that has really wide discussions of not only the
mini lathes, but metals, welding, painting, politics and religion,
but even discussions on the speed of light.

http://groups.yahoo.com/group/7x10minilathe

Although I did not get a good answer, I did get the reference to
machinery's handbook.

You may find your answer in a more mechanically oriented machine
group. I would deffinatly sufggest that group. Most of the people
there use small machines and would have intimate knoledge of those
dimmentions and angles.

Dave

--- In CAD_CAM_EDM_DRO@y..., "P. J. Hicks" <hickspj467@a...> wrote:
> Guys,
> I had asked this question several months ago and never received a
reply. Maybe no one knew the answer; I sure can't find it in my
referrances. Does anyone know the closing and back angles on size
200 double angle collets?
> PJH
>
>
> [Non-text portions of this message have been removed]