Show me your self centering chuck !

[mmcmdl]

45 years as a journeyman machinist . Show me your self centering chuck please because this is a mythical creature . A self centering chuck would indicate to me that it would after chucking part you could hit a magic button to center to true your work piece . I've never seen one to this day , but if you come up with one , I'm in . There are 2 types of chucks . A set true and a regular scroll chuck . They both can be dialed in to zero TIR . They both need to be adjusted by the operator using the lathe . A " self centering " doesn't exist that I know of to this point . If it does , show it to me/us and we'll all buy a few !

 

[mmcmdl]

Hmmm..........................no takers yet .

 

[Aukai]

Mount to a lathe's spindle to hold round workpieces. Also known as scroll chucks, these are self centering—all three jaws move in unison, centering the workpiece as they close. Use the included lathe chuck wrench to open and close the jaws.

 

[markba633csi]

Sounds like a Captain Beefheart lyric:

Show me a chuck that'l run so true
Show me a chuck that'l know what to do
Throw us a party and we'll run in the dew
Give us a chuck and we'll go home, we're threw
(sax solo here)
Wild life, Chuck's got my wife

 

[MrWhoopee]

Since there is no absolute in our world, I believe you may need to define what qualifies as "centered". Is .0003" close enough or does it have to be .0000"?

 

[benmychree]

Three tenths? In my world, three thou is more like it!

 

[RJSakowski]

Pu another way, there is no such animal as absolutely zero runout, just close enough. Anything made by man or machine will have some runout. It may be measured in microns or microinches but it exists.

When we dial in a workpiece we use an indicator. The limitation is the sensitivity of the indicator and our visual acuity. Throw in our patience at trying to dial out that last bit of wobble. The three jaw that came with my G0602 (intermittently, not a precision chuck) has 2.5 thou TIR which is fine for 99% of the work I do and I would call it self centering.

 

[pontiac428]

A scroll chuck is a universal chuck, a self-centering chuck is a... collet.

 

[Eyerelief]

Unless of course the set tru manufacturers mean self (me) must adjust the runout to eliminate as much wobble as possible.
Kind of like self pump gas stations. When I pull up to the pump, the gas doesn’t pump itself, I must pump the gas myself. Grocery stores, airlines, garbage service (think sorting out recycling). I have become an uncompensated employee of just about every entity I do business with.

 

[markba633csi]

And you can add beta tester to that list