Jaws for Eclipse chuck

[Roger HartParticipant @rogerhart88496]

How to slit the jaws?

[Roger HartParticipant @rogerhart88496]

Attempting to make new jaws for an Eclipse 160 pin chuck. Essentially the jaw assembly is a 4mm stem drilled 2.5mm plus a biconical jaw about 6mm dia in one piece of hard(ish) steel. My problem is slitting the jaws – the stem tends to bend under the saw pressure despite very gentle progress and it is very difficult to get the saw to run exactly along the centre line. The slit runs down through the jaws and about 5mm along the stem. My next attempt will glue the jaw assembly to some hardwood for support but surely Eclipse had an easy production technique – what?

[Michael GilliganParticipant @michaelgilligan61133]

Roger,

I don't know for certain,but I would imagine that they were supported on a grooved steel mandrel.

They would certainly be cut with a [circular] Slitting Saw.

MichaelG.

.

P.S.  There are some useful ideas included here.

Edited By Michael Gilligan on 21/10/2013 09:27:04

[Russell EberhardtParticipant @russelleberhardt48058]

Failing all else you could try slitting them by hand using a piercing saw.

Russell.

[Sub MandrelParticipant @submandrel]

Does anyone have a list of the capacities of Eclipse pin chucks? I have a series from large to small, only two are Eclipse, there is a 'gap' which appears to be two chucks wide (if that makes sense?) but the Eclipse numbering suggests only one chuck to fit in the gap?

I haven't decided whether to make one or two to fill the gap or wait for them to appear at car boots…

Neil

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Stub Mandrel on 21/10/2013 10:39:39:

Does anyone have a list of the capacities of Eclipse pin chucks?

Neil

.

Neil,

For the 160 … start here

… and for the Pin Vices, here

MichaelG.

Edited By Michael Gilligan on 21/10/2013 11:10:51

[Sub MandrelParticipant @submandrel]

Sorry, me being stupid again, I meant tap wrenches…numbered 141 to 146, they are here but no capacity information.

The two eclipse ones I have are

Eclipse 143 ~0.284 ~ 0.340

Eclipse 141 ~0.058- ~0.092

Also:

Eclipse pin vice 123 claims 0.055 – 0.122, more than a 2:1 range which surprises me.

Perhaps my capacity estimates are probably a bit conservative I wonder if 141 actually covers the same as the pin vice, and that 142 is 0.125-0.250 and 143 should be 0.250 to 0.325?

Any ideas?

Neil

[Michael GilliganParticipant @michaelgilligan61133]

The Tap Wrenches are "stepped" inside, so each fits two [nominal] sizes of Square.

The Pin Chuck and Pin Vice collets are continuously adjustable over their specified range [provided you're not too fussy about where it's gripping!].

So … They are not really comparable [think Apples & Oranges]

MichaelG.

[Roger HartParticipant @rogerhart88496]

To All,

Thanks for the advice. I epoxied the half-cut chuck to a piece of cut-out hardwood and added a brass shim in the first cut to help get a 90 degree cut for the second. Worked pretty well, a lot easier than the free-standing attempt. So I reckon Eclipse must have used some sort of jig to constrain the saw.

I seem to remember seeing a utube of a fountain pen knib being slit by a VERY thin saw and that was constrained by 'rollers' either side of the rotating blade.

[NJHParticipant @njh]

Roger

I must admit my first thought on reading you post was " why bother making new jaws? Out of curiosity I had a look at the price of a new chuck. Now I see why! I'll bet that if we went out to our workshops and added up the replacement cost of all those little bits and pieces gathered over the years we would be shocked. Maybe best not to know !

For the record I have the 160 set bought many years ago and still in its (rather dirty now) box. It often gets used. I also have a similar sized "cheapo" version bought in a weak moment at a show somewhere. It's rubbish ! – it could no doubt be saved by making new collets but unlikely that I will ever get round to that!

Norman

[Sub MandrelParticipant @submandrel]

> The Tap Wrenches are "stepped" inside

Thanks for that Michael, it's not exactly obvious on a casual examination!

Neil

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