Re: Centripetal-chucking

Aug 11, 2003 5 Replies

As a lather, my reaction is that you won't grip tight enough to resist the forces of cutting.



Try cross-posting to uk.rec.models.engineering?



I have to make a bunch of small parts on my lathe. No real problem because I
> have an old Toshiba lap top turning the handles for me.
> I could stand there all day chucking up the blanks, but then I thought, how
> much better if I could automate the chucking process and make myself a bit > redundant.
> The problem seemed to be opening and closing the chuck, then I thought I
> might use centripetal force. Anyway, I've started making a sort of 3 jaw
> chuck with 2 fixed jaws and the other sprung lightly shut, but having a fly
> weight to pull it tight.
> Motor off = a loose grip while I feed it.
> Motor on = a tight grip while I cut it.
> Has anyone else played with anything like this?

Hi Airy

I was more worried about it grooving the blank at startup and not slacking off enough to feed. However, it's been a quiet morning and I've just about finished it, so it won't be long before I find out if you're right :o)

Here's a pic, not that it looks like much yet, but it gives the scale. I'm just adding the counterbalance.

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best regards

Robin G Hewitt

All done, picture updated, can't try it out because I can't find any 10mm brass and that's the only thing it grips :o(

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best regards

Robin G Hewitt

Nice looking!

Does it work?

Absolutely not, it has a grip like a lettuce eating poof with nerve damage. However, I sat down last night and designed in a second fly weight, this one having a 12:1 lever advantage. I will report back when I try that :o)

best regards

Robin G Hewitt

Hi Mike

That would pre-suppose I knew the required force :o)

OTOH I just faced off a piece of stainless held in it. Okay it slipped when I tried to cut down the length, but I have yet to add the official fly weight and the pukka pivot bolt that will boost the leverage.

I think I am winning, picture updated.

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best regards

Robin G Hewitt

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