Clean and lube a 3 jaw chuck possibly need to remachine?

[Brento]

I bought a mini 3 jaw chuck this weekend that was torn apart to be cleaned most likely. I am going to clean it but what can i use to lubricate it and oil it up that is safe and not going to sling everywhere when i use it.

EDIT: may need to remachine?

 

[andrewgr]

I recommend Stefan Gotteswinter's excellent youtube videos on tearing down, cleaning, deburring, and improving inexpensive chucks. See for example

 

[mikey]

Use grease behind the scroll, oil on and in front of the scroll. Use minimal oil on the scroll and jaws and stand to the side when you first start the lathe up after oiling the chuck. It helps to put some newspaper in front and behind the chuck to catch residual oil until it stops throwing it out. Just a fact of life with chucks.

 

[brino]

I recently used a card-board box set on the ways to catch the flung oil on first start-up of a newly cleaned and lubed chuck.
I think that tip was from a Keith Rucker video I had playing in the shop as I did mine.

One step Stefan didn't show is trying to push the jaws thru the slots without the scroll installed.
For me that showed just how tight and uneven the jaws were due to some machining burrs in the t-slots.

-brino

 

[Masterjuggler]

Last time I tore down my own chuck, I used way oil, just lightly brushed it on. For the slinging, I taped a paper towel around it and ran it at my lathe's max speed for a few minutes.

 

[Brento]

This is my issue i am seeing on why it was taken apart. Looks like the meshing of the worm gears is grinding through the plate and into the back plate. Fixes for this?

 

[brino]

@Brento ,

Ouch! I did NOT notice that in your original photo!

It looks like either
1) someone tried to clean-up the back surface of that chuck and cut way too deep, or
2) the pinions are not properly installed or retained, and it's been heavily used since about 1600
or perhaps
3) it was quite poorly made

The only true "fix" I see is making a new back plate. A peek inside will show how difficult it might be for this chuck.

-brino

 

[pacifica]

The question is if it will accurately(.002 or less runout) hold your parts, and if you can get it to be accurate.
A scroll chuck tends to be less accurate, I believe because of the difficulty in making an accurate archimedean spiral.
I've adjusted my 3 jaw chuck so it is less than .0005" run out at .75 " but then it is out .001 " at .25" and so on.

 

[Brento]

@brino i didnt posted the picture originally. Im not sure what to do exactly. It was used pretty good im sure. The backing plate that bolts to it has a collect for like a 8mm spindle so it may have been machined for it once idk. I dont have the means to make a new back casting though