What is this kind of collet called?

[Janger]

As usual swap lamp is making something (a tap holder) seemingly without effort. at 11:46 he has this kind of collet mounted in the 3 jaw to hold some material. Unlike 5c, R8, ER styles it does not use a drawbar or nut and a tapered surface - instead the collet is just clamped in the 3 jaw chuck. What kind of collet is this? The collet seems to be lightly tapered. I don't see how he gets it into the chuck straight. Also what is the point of doing this? Why not just hold the material in the 3 jaw?

 

[YotaBota]

Why not just hold the material in the 3 jaw?

Protects the part from jaw marks?

 

[Janger]

To keep it straight I think he is pushing the collet in until the chuck jaws hit the collet shoulder. ???

 

[YotaBota]

I think the taper in the collet is optics playing a trick, when the collet is going into the chuck it doesn't look tapered to me.

 

[a smile]

As usual swap lamp is making something (a tap holder) seemingly without effort. at 11:46 he has this kind of collet mounted in the 3 jaw to hold some material. Unlike 5c, R8, ER styles it does not use a drawbar or nut and a tapered surface - instead the collet is just clamped in the 3 jaw chuck. What kind of collet is this? The collet seems to be lightly tapered. I don't see how he gets it into the chuck straight. Also what is the point of doing this? Why not just hold the material in the 3 jaw?

View attachment 36376

In my opinion, 1. Protection from clamping injury is an important consideration. 2 Small taper requires clamping more precise dimensions of the workpiece, so the chuck jaw can be tightened to keep the chuck parallel and lock the workpiece (or roughly parallel). 3. This chuck is originally a high-precision chuck (the smaller the Angle, the easier it is to improve the clamping accuracy), but unless you are not ready to use it again on the special shaft head, this use method solves the urgency of the moment, but the resulting damage will destroy its accuracy, and may even lead to damage transmitted to the spindle head. 4. Unless you are very rich, please do not use this chuck in this way - this is a pity!

 

[Susquatch]

I make custom collets similar to this regularly. Not all collets require a drawbar or a nut. An internal button, an external sleeve, external jaws from a chuck, etc etc. will all work.

It's funny that @Dabbler and I were just talking about the definition of a collet. I define a collet as any device that can be expanded or collapsed to grip another part either internally or externally by means of a diameter change generally caused by expanding or collapsing slotted ears, but not necessarily so.

Although I am still open to other ideas, I am still planning to make a large collet to grip a 125mm OD dish that is graduated with individual degree marks all along its entire 360 degree diameter. The plan is for the collet to be tightened onto the disk using the internal jaws of a 3-jaw chuck - In other words, the 3jaw collapses the collet which then clamps the disk.

Post in thread 'Compound needs a better degree dial' https://canadianhobbymetalworkers.com/threads/compound-needs-a-better-degree-dial.7852/post-119402

 

[Dabbler]

What kind of collet is this? The collet seems to be lightly tapered.

The item isn't a collet (well not exactly) It is a 32mm adapter, for stepping a 32mm collet down to 25mm. The sides, are indeed, parallel.

 

[Rauce]

Looks like a bushing for a boring bar holder or maybe a lathe turret.