Set-Tru Chucks?

[Splat]

What are Set-Tru chucks? I've seen them in 3 and 6-jaw but not in 4-jaw. Are they preferable to an independent 4-jaw chuck? Thanks.

 

[pdentrem]

An independent 4 jaw chuck is a set true automatically. Set true chucks are usually self centering chucks like the 3 jaw and others that use a scroll to move the jaws all at the same time.
Pierre

 

[Halligan142]

https://www.youtube.com/watch?v=yXub0kvRyZ8 Video of me taking mine apart for cleaning and lubing. You can see the make up of how it works. Basically a set-tru ir adjust-tru chuck is a chuck that the backplate register is smaller than the chuck register. In four spots on this register collar are screws that when tightened or loosened will move the entire chuck around on its backplate to be able to adjust a part into true alignment. It does not have the adjustment capabilities of a 4 jaw. They work real well and I use mine all the time. When not using it to dial in a specific part I throw a 1" diameter piece of stock in there and dial that in. That seems to give me about the same accuracy of a high quality chuck through all of its range.