Chuck help needed please

[Phil Pascoe]

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...?

7mm - 8mm, fairly accurately measured. These jaws seem expensive, but when you consider they don't need carriers/slides they're a lot more reasonably priced.
Both sets of Versachuck are sold together, the Axminster ones are sold seperately.
if you choose to go down this route to turn the insides, you're a braver man than me, Gunga Din.

 

[Tanglefoot20]

Hello.... have you thought of finishing the bore before parting off , then make a tapered mandrel and slide the r g on the fish the outside....no f gets in way of chuck...no chuck!....turn between centres. This setup is how it’s done on a grinding machine..
Seems you maybe over thinking what you need to do.

 

[Tanglefoot20]

PM me if you want info

 

[LostWay]

Hello.... have you thought of finishing the bore before parting off , then make a tapered mandrel and slide the r g on the fish the outside....no f gets in way of chuck...no chuck!....turn between centres. This setup is how it’s done on a grinding machine..
Seems you maybe over thinking what you need to do.

"...over thinking..."? Possibly, yes, knowing me.

I think I need to try making some kind of jig as per an earlier post first, then resort to new chucks if I need to. Plus the home made collet thingany seems like it might be safer than chucks with jaws hanging out on a limb for someone like me, at least until I get better at things.

 

[Lons]

Hi Lostway
I'm not sure if I'm missing something obvious here but if it's just the insides of the rings you need to sand and polish the simple and cheap solution would be just a simple jam chuck to hold the ring.
A sacrificial recess cut in a lump of wood, mdf or ply held on a faceplate usually works well enough.

If you search on the internet there will be plenty of examples, it's a method that' been around a long time so tried and tested. If you still want to buy a chuck then you can use that instead of the faceplate which makes a quicker switch if you need different size recess.

 

[LostWay]

Lons: Yes indeed. I'm more than happy to go with a simple solution to get me going. I my head it seemed like it would be trivial to buy a simple chuck tailor made for the job, but the reality seems different. Plus the advantage of a simple jam style thing is that I get a smooth continuous surface near where I will be working, which is never a bad thing.

 

[Tanglefoot20]

"...over thinking..."? Possibly, yes, knowing me.

I think I need to try making some kind of jig as per an earlier post first, then resort to new chucks if I need to. Plus the home made collet thingany seems like it might be safer than chucks with jaws hanging out on a limb for someone like me, at least until I get better at things.

If you’d like to private message me I can help you out...I was a turner for 20 years....learnt most of the tricks etc...

 

[Tris]

Martin- this is the general idea

https://pin.it/4CPdH7u
Hope the link works. As for turning the taper I would mark off the required length, use a parting tool and calipers to cut down to the widest diameter then take it down to that with a skew or spindle gouge, part down to the narrowest diameter at the end then turn the taper a little oversize. Then just a case of sneaking up on it by test fitting, twisting it in the headstock, remove any shiny bits with light cuts until the whole thing fits nicely.
I'm pretty bad at turning spheres, more like eggs but I'd be tempted to use a blank on a small face plate for a cup chuck instead of over the live centre, or modify the collet idea. If you've an old fashioned spade bit the point of that might give you the right taper to go over the point of your live centre or they can be ground to a suitable profile easily.

Hope this might help
Tris

 

[Cooper]

Hope the link works.

Thank you Tris, the link is very interesting, and your method of turning the taper makes sense.
Re the wooden balls. I turned them to match a template down to a 10mm shaft, then parted off. I then turned them around so the equator was now on centre and fitted the balls between hollow supports to turn off the lumps. The support in the chuck was easy but the one that had to fit on the live centre was a bit of a struggle. In the end I drilled out the middle of it as I couldn't get right into it to fit the point, I never got a really tight fit. But as you said it was "just a case of sneaking up on it by test fitting".
Cheers
Martin

 

[LostWay]

Thanks for all the feedback people, much appreciated.

I'm going to try making a simple jam chuck style thing myself, then if that fails I'll check out a versachuck i think.

In the meantime I was at least inspired enough to re-do my push in spindle for inner holding the rings. Bad photo attached. Hopefully I'll send a photo of the outer gripper soon.

 

[Jonzjob]

I don't know if you have sorted your problem of holding the rings, but here's my method.

I had to turn 40 curtain rings for a 2" curtain pole and I couldn't get the rings big enough to fit. So I made a simple pinch chuck the fits on my Axminsnter K10 chuck with Odonnel jaws. It gives complete access to the inner surface and takes a few seconds to turn for the other face.

If I remember correctly they are 2 1/2" inner diameter, but you can make it to any size you need just from some scrap wood. I recessed the jubilee clip so stop the possibility of smacking you fingers at 2000rpm!

Make it along the grain as that way it pinches without cracking. The chuck and the Jubilee clip stop it flying apart so it's quite safe.

 

[Sachakins]

Hi,
Have a look at this idea


Cheers

 

[Jonzjob]

I'm confused? Now it's been turned what do you do with it?

It seems to be held in a Jacobs chuck by a small nail/

 

[Sachakins]

I'm confused? Now it's been turned what do you do with it?

It seems to be held in a Jacobs chuck by a small nail/

Forget the Jacobs chuck mounting, thats just that type of lathe. But u could use same idea, but mounted onto the wood taper you made, don't need the pin bit at all.
The ring pushes into end of pipe, acts like a compression ring, gives easy access to inside of ring to finish.