Mystery chuck jaws?

[crazylegs]

Anyone got any ideas about these jaws? They have a shallow square sided grove machined in the face. What do they hold and how?

[Derwent Woodturning club]

I think you are looking at the rear face of the jaws and the shallow groove is to locate them accurately on the carriers. Also most holes are countersunk on the top face. Could you post a pic of the other side?

[crazylegs]

No this is the front face the other side has the narrower locating slot.

[Twisted Trees]

Still need more photo's from more angles, that one picture isn't helpful!

[fuzzyturns]

This could be set of jaws to mount your own large custom jaws made of wood or similar material. In theory you could mount your custom jaws straight onto mounting jaws, but the contact surface is quite limited, and would therefore allow for a relatively large degree of flexibility or inaccuracy, whereas with these, there would be a much larger contact surface. Just a guess, though.

[burywoodturners]

If the four jaws in the picture are part of the set then you have engineering jaws. and will close up to take a small drill.
I have the Axminster version and apart from being knuckle bashers they also stir up a draught!
Great for really small jobs but just watch your knuckes
Ron

[The Bowler Hatted Turner]

I don't think they are accessory mounting jaws that fuzzy suggested as there are not enough holes in the plates neither do I think they are the engineering jaws that burywoodturners has mentioned as they will not close up enough. But as the holes are not counter sunk or counter drilled I would assume they are custom made. They may be for opening into a metal ring that fixes onto the bottom of a turning. Have a look at the ring to see if it is dovetailed.

[Sandy]

Hi crazylegs,

Yep, I can see where Fuzzyturns is coming from, potentially agree but also with Twisted Trees that additional images are needed. Do you know / are the jaws stamped with the manufacturer name and what is the overall diameter?

In other words, more info needed!

[crazylegs]

I know its been a while but here are some more pictures, both sides and edge. No markings, no countersinks.

[The Bowler Hatted Turner]

Looks like they may have been intended to grip a bowl ring.

[crazylegs]

not sure what that is. Any pictures?

[fuzzyturns]

The strange thing is that the circular recess on one side is in line with it's position on the jaws, i.e. it forms a ring. On the other side that recess is of a completely different diameter, and will only form segments of a ring if the jaws are wide, wide open. Doesn't make any sense to me.

[crazylegs]

yes the narrower and in my mind the most likely to be the recess that fits to the chuck would mean the chuck would have to be open. The circular recess would then not be circular? I can see no way these could be used. My logic is telling me they can not work.
They are well made and appear to be of good quality and came with a job lot of jaws for a nova chuck. All the others are 'normal' these are the weird ones.

[Woodcrafts]

Could they be adaptor plates to allow one make of jaws to be used on another manufacurers jaws, possibly to use Nova jaws, which have a raised fillet to fit in slots in the jaw carriers of a Nova chuck onto an Axminster chuck which has the raised fillet on the jaw carriers to engage in slots in the actual jaws? This would need the securing screw holes to be the same for each make of chuck so I may be completely wrong. But the shape and dept of the slot would not be sufficient to hold a piece of timber on their own.

[The Bowler Hatted Turner]

Is it the photograph or is the large groove dovetail shaped?