Lathe Jaw Protectors

Er, aren't they called 'collets'?

Collets (collars) are normally round inside, tapered outside, and must be pulled into a sleeve by a threaded assembly. 3 and 4 jaw chucks can grip hexagonal (3) and square (4) work pieces.

Yes, but I don't have a collet chuck at work so it's not an option unless I spend lots of money.

Look for soft jaws.

Jaws & Jaw Caps

That's the sort of thing, I've obviously been using the wrong search terms.

These guys have some...

http://www.e-jaws.com/

Soft drink cans make great workpiece protectors. Just cut off what you need with a pair of scissors.

The problem with truly soft jaws is you don't get a firm grip and probably not well-centered either.

Hello, what you want is a bit dangerous and tricky to use, so it is not common. And it is if I remember also prohibited as the contact to the work piece is no longer good enough.

We used cardboard wrapped around the parts as protector. But what you want is a bit dangerous and tricky to use, so it is not common.

I myself in some cases have fragile plastic parts in the lathe which will not survive the 3 prongs of the jaw. So I used a hole saw and the lathe to make a plywood ring with the inner diameter equal of the outer diameter of the plastic part and using a saw I made a slot into the ring. This is sufficient to fix the part secure in the lathe and to allow the forces during turning. Changing the part is quick and efficient.

Greetings

I often have to make some sort of mandrel to hold parts as you describe, usually from Delrin.

I understand about the lack of holding power but counter that by taking suitably light cuts.

Hi,

You use what is known as soft jaws. The chuck has jaws that have tee slots in them and the face has serrations and to this you bolt mild steel jaws. You then hold the jaws tight by inserting a ring, either on the outside or inside depending on whether you wish to hold your item internally or externally. Then you turn the jaws to match the diameter of the item to be held. This means two things(1) the item runs totally true (2) and it is not damaged.

Regards

Oliver Dunthorne

PS. I suggest you look at a web site of a well known chuck manufacturer for details

We have aluminium soft jaws but it can sometimes take longer to machine the jaws than to modify the component.

When jobs come to me it is often something that is needed immediately so time is of the essence. It may just be facing a small amount off of one end so I don't mind if the component runs a bit eccentrically.

You can buy safe jaws they have aluminium pads to hold the work piece attached to each jaw.

Bazzer

When I was in the shop I used to wrap trimmed copper sheet around the jaws, or just small shim pieces between the jaws and workpiece (the shim style can be tricky to hold in place while chucking up the job so double backed tape can help with that).

The copper was soft enough to grasp the workpiece firmly but not mar the surface. I suppose some would say this method is dangerous but I was in a research, not a production, shop.

Hooker

An old leather belt.