Chuck help needed please

[LostWay]

Hi people,

I would really appreciate any advice you have on the following:

I have a basic Axminster AC240 lathe and I make wooden rings (mainly bentwood rings, but some solid ones).

I use a simple tapered spindle to hold the rings from the inside, so I can polish and cut channels on the outside.

BUT, holding the rings externally has proved to be impossible so far. I need to hold them externally so I can get at the inside to do things like tweak the diameter, sand, polish etc.

Does anyone have any advice on holding rings (up to 35mm ish diameter) externally on a lathe so that I can get at the inside?

None of the obvious solutions work. For example, Axminster chuck with internal jaws clamping INWARDS will only hold up to around 25mm diameter.

Please excuse my dreadful picture below. I'm not actually six years old, I was just in a rush.

I'm only going to be using this setup for spinning very light weight rings.

 

[SVB]

There are several different jaws Axminster do that would hold directly.

If you plan to to a lot of these then I would be tempted to buy a set of jaw plates, attach some waste timber and turn some step jaws like below. I have similar and very helpful for all sorts of light cut finishing of small items like box lids & bases, turn foot off small dishes, wooden jewellery like bangles etc etc.

 

[flh801978]

Either of these little chucks will do
They are only 50mm dia but will hold easily 60mm in the external jaws

 

[marcros]

What chuck are you using? This will determine what jaw options are available.

My immediate thoughts are (no particular order):

I have a small record rp2000 chuck which I use for small things. The standard jaw set works in compression mode between 23 and 47mm. Am not sure on the remounting jaws, but they may go small enough.

Could you make a Longworth chuck to hold in the jaws of your current chuck?

Could you make a wooden collect chuck (Google eg David Reed Smith). Not sure how much adjustment you would have on it.

 

[LostWay]

Thanks for the replies. At the moment I have NO chuck whatsoever, I've just been using the stock drive center.

Holding using external jaws is a bit sketchy as only a few mm of the ring will be in contact and the further out grips will be spinning right by my fingers I think.

I'm having a look at the record power stuff now.

 

[marcros]

Thanks for the replies. At the moment I have NO chuck whatsoever, I've just been using the stock drive center.

Holding using external jaws is a bit sketchy as only a few mm of the ring will be in contact and the further out grips will be spinning right by my fingers I think.

I'm having a look at the record power stuff now.

As well as the sales pages, look for the rp2000 manual. There is a pdf online, and a few pages in it gives you the details for the jaws. This info seems difficult to find elsewhere!

 

[LostWay]

Thanks,

Just had a chat with record power.... He said they have nothing they would recommend for even slightly safely holding things as small as rings. The standard compression jaws might cover the size range needed, but given that the rings are only 12mm or so deep, my tools will be only 1 or 2mm from the evil spinning metal bits forming the back of the four jaw plates. :-(
They also no longer sell external / internal step jaws at all. :-(

Their dome jaws might have been perfect, but only open up to 25mm diameter.

 

[Lazurus]

Consider the Versachuck from Beuford Ink, can use many different manufacturers jaws, I now have 3 of them and highly rate them. The only one that was better was the Axi super precision which is no longer made.

 

[LostWay]

Just had a chat with versachuck man, but he said it would take a day or so to work out what kind if diameters the step jaws can hold.

 

[Phil Pascoe]

I think I would devise some sort of chuck - a wooden disc on a faceplate with a groove turned to centre the ring and hot melt glue the ring to it. You wouldn't damage your tools if you hit it, and it shouldn't be that difficult to make something fairly accurate.
No matter what chuck jaws you use there'll be a danger of hitting them with your tools.

 

[Tris]

The wooden collet will be your cheapest option. If you take a spindle blank about 130 to 150mm long and ~50mm square, measure your headstock taper and draw it as a template. Turn one end of the blank to match your taper, insert that into the headstock then turn the rest of the blank to a cylinder. Drill a 25 mm hole to a depth of 5mm or so, then an 18mm hole for another 25mm.
On the outside of the cylinder cut a recess about 10mm from the tailstock end that will allow a jubilee clip to sit in it without the screw protruding, tidy up the ends.
Now make two saw cuts with the grain, at 90 degrees to each other and reaching to the bottom of the 18mm hole. Fit a suitable sized jubilee clip to tighten up the chuck and you are good to go.
I would recommend using a long screw through the headstock to prevent the chuck from working loose.

Hope this might be useful

Edit: just re read your OP, best change the blank to 65mm sq, and holes to 35mm and 28mm

 

[marcros]

How do you make these? Could you glue the blank to a long piece, or use a long blank held in whatever jaws and sort the inside out first? When that is sanded and finished, grip the inside using your taper and do the outside.

 

[pryere]

If you have a suitable chuck, these work well for small stuff.
https://www.axminstertools.com/axminster-115mm-soft-jaws-102166

 

[minilathe22]

Perhaps you could start with a solid piece of wood, bore out the inside, and finish the inside of the ring while it is still part of the wood. So it would look like a small bowl.

Then slice it off, and finish the outside of the ring how you were doing it before.

 

[Phil Pascoe]

A photo of a Versachuck, one pair of each engineering jaws. Fully closed it would hold about 33mm - 34mm internally.

 

[LostWay]

Thanks for the photo. My current thinking is a record power 2000 with a set of soft plastic jaws that I shape down and open up the center a bit.....?

Phil - Thanks - Is it easy find out what the largest diameter is you can hold with the external jaws (the ones in your photo running left / right) using the inside (tall) egde of the jaws for compression? No worries if not.

i.e (ASCII art time)

_=# <---?---> #=_

 

[Phil Pascoe]

About 45mm. There would be a 15mm - 18mm of jaw outside the chuck, though, so would be a bit of a liability.

 

[Cooper]

The wooden collet will be your cheapest option. If you take a spindle blank about 130 to 150mm long and ~50mm square, measure your headstock taper and draw it as a template. Turn one end of the blank to match your taper, insert that into the headstock then turn the rest of the blank to a cylinder. Drill a 25 mm hole to a depth of 5mm or so, then an 18mm hole for another 25mm.
On the outside of the cylinder cut a recess about 10mm from the tailstock end that will allow a jubilee clip to sit in it without the screw protruding, tidy up the ends.
Now make two saw cuts with the grain, at 90 degrees to each other and reaching to the bottom of the 18mm hole. Fit a suitable sized jubilee clip to tighten up the chuck and you are good to go.
I would recommend using a long screw through the headstock to prevent the chuck from working loose.

Hope this might be useful

A sketch or photo of such a collet would be brilliant .
Also you make turning the taper that is a good fit sound easy but I would have thought working free hand on a wood lathe its a very skilled job. Whats the trick?
Similar but different. I found it really difficult turning a tapered hollow to match the angle on the point on my live centre when I was making a support to fit on it, to turn croquet balls. Advice on that would be very welcome.
Thanks
Martin

 

[LostWay]

Thanks

re: Phil

So just to be clear, my rings almost never exceed 30mm in diameter, so I should be able to hold them like in my initial picture...?
The downside would be the protrusion of the outer edges of the jaws...?
Presumably if you are getting 15-18mm protrusion with a 45mm gap, I would be down to 8 - 11mm ish protrusion with 30mm rings...?

 

[Phil Pascoe]

I can't put my hand on it atm, but I have a wooden disc on a faceplate with a sacrificial cone going from 50mm or 60mm diameter to 25mm over about 100mm morticed into it. The end can be shaped as desired and things jammed or hot melt glued to it and the item turned off if need be. It doesn't matter if it's mutilated and it keeps small bits of work (and fingers) well away from the faceplate or chuck.