Cole Jaws

[niall Y]

I've just encountered a rather annoying limitation of my Cole Jaw, set up. I was trying to hold a bowl with them, only to find that it wouldn't grip . The extent of travel on my Nova chuck jaws, from open to closed is about 20mm, which gives a range of 116 mm to 136mm for one particular button position, and 140mm to 160mm for an adjacent one. So, there is a shortfall of 4mm.

I realise that this is probably because the Charnwood Jaws I have, (although they fit) are not compatible with my Nova chuck. What a pain in the butt.

Looks like my only option to get the bowls finished is to buy some of those larger squarish buttons that are sold for Record or Nova, Cole jaws.

 

[Katomi woodsmith]

Oh no that’s a pain esp when you are trying to finish a project
I ran into the reverse my jaws were to small for my project, and I can not afford to buy the larger set

 

[Duncan A]

Put some short lengths of garden hose over the buttons to pack them out?

 

[ChaiLatte]

Is this a representative picture of what you have?

https://www.oliverswoodturning.co.uk/product/nova-cole-jaws/

And the parts that are too small are the round things that look like rubber doorstops?

In an emergency, buy a roll of insulation tape and wind 2mm-worth around each button to reduce the gripping diameter by 4mm.

You could make a wooden or delrin ring 2mm thick that slips over the button to cater for in-between sizes.

You could make a set of buttons that are 2mm diameter greater than what you already have.

The smart money would put the fixing hole eccentric to the outside diameter, so by rotating the button 180 degrees every diameter would be covered.

 

[kinverkid]

You could use actual rubber door stops but taper down.

 

[Vulcan]

Once you’ve finished your current bowl consider making a donut chuck. Cheap and easy to make, they hold things far more securely than Cole Jaws.

 

[Vulcan]

I should have added. I first made a Longworth chuck out of plywood. It worked as intended but I wasn’t impressed with the amount of grip. I eventually binned it and bought some Cole Jaws which I still have. I wasn’t that impressed with the security of the Cole Jaws either. Fine if you use tailstock support, but you have to remove it at some point to finish the foot. I then came across the Donut Chuck. Easy enough to make, just don’t use a wooden foot for it, use a faceplate. It’s much more accurate and consistent. You can make rings of any size up to the capacity of your lathe to suit any job, including modest size vases. No tailstock support required. Do a google and look at some of the videos. I used plywood but you could also use MDF, some folks do. I used Stainless M8 threaded rod for mine from Screwfix.

 

[Orraloon]

I made a Longworth chuck and true its best to get support from the tailstock as much as possible but thats just good safe working practice. The last center nub does need care to take off but unless you have a big dig in its fine. I guess you could even power sand it off if you want to be extra safe.

I have not yet used a donut chuck and I made the longhworth as a less expensive option to cole jaws.
Regards
John

 

[Richard_C]

Rather than suggest lots of other chucks, to get what you need with your current set up you can try rubbers. For the benefit of readers from the USA, rubbers=erasers. The stiff white ones that you get in many places including supermarkets. You might need 4, cut each in half so you have 8 rectangles, drill for your Cole jaw screws. Then orientate to where they best grip your workpiece.

An aside. I have a piece of paper pinned up behind the lathe with max and min of my various chucks and jaws, and any “blind spots” that I can’t easily grip. That helps plan each thing I make.

 

[HamsterJam]

I just use a plywood friction plate - fits any sized bowl (up to the size of the plate) without adjustment.
You could probably do the same with your cole jaws.

 

[Vulcan]

A common issue with removing a tenon or reshaping the foot of a bowl is ensuring it’s centred as much as possible. I wrongly assumed that both a Longworth Chuck and Cole Jaws would achieve this automatically. They don’t - but you can always get lucky. I found the most important thing to do was to accurately mark the centre of the bowl before turning it round to hollow it. You can then use this mark to help centre the bowl on your Donut Chuck or Cole Jaws to remove the tenon. You may need some additional packing to achieve this though. Exact centering, whilst desirable, is not absolutely essential on larger bowls with a large foot but becomes much more noticeable if you don’t achieve it on smaller projects.

 

[Richard_C]

A common issue with removing a tenon or reshaping the foot of a bowl is ensuring it’s centred as much as possible.

A good point. Coles jaws have "springy pegs" so don't always mount accurately. As long as the centre is well marked you can mount the bowl snug but not tight, bring the tailstock/live centre up and put some pressure on, tighten the chuck and then take the tailstock away to clean up the base.

 

[Vulcan]

A good point. Coles jaws have "springy pegs" so don't always mount accurately. As long as the centre is well marked you can mount the bowl snug but not tight, bring the tailstock/live centre up and put some pressure on, tighten the chuck and then take the tailstock away to clean up the base.

I have tried that but when tightening the Cole Jaws fully it pulled the piece slightly off centre again. Router mat between the bowl and the jaw plates helps to some degree.

For me the best option has been the Donut Chuck as it applies pressure down through the work piece rather than trying to just grip the edges. It can still move off centre again when tightening but I found it less likely and quite easy to correct with foam packing.

 

[Paul Hannaby]

I just use a mandrel to reverse the bowl to finish the bottom. It works for any size/shape of bowl without the need for expensive chuck jaws. For a more complete description take a look at this video on bowl turning (mandrel is at 1:04)

 

[kinverkid]

There is also the camping mat method but you will still need tall support. Early Andy Phillip videos show examples of how to use them.