Mounting a cam-lock chuck

[AlfromNH]

I’m reinstalling the chuck on my Asian 1340 lathe. The Grizzly manual says “ideally the cam lock mark will fall between the two pointed arrows on the spindle nose“. This is the closest I’ve been able to get by trial and error. I assume when they use the word “ideally” it’s not a critical thing, so this is fine?

 

[Firstram]

Not really, that stud should be screwed in one more turn.

 

[tweinke]

Yes, turn the studs to adjust, if they go over center it can be tough to get the chuck off, and more importantly the chuck may come loose. All you need to do is remove the Allen screw beside the stud and turn the stud. then try again.

 

[extropic]

^^ What they said. ^^

Plus, I have put an "index" mark on my spindle OD as well as each chuck, so each stud mates with the same cam at each installation.

 

[Dabbler]

-- what they said

...and...

[after you studs are properly adjusted]
A very good way to treat your taper is to slightly snug your cams very slightly, then snug them about half way, then tighten completely. This prevents the taper from misaligning, which wears the taper, sometimes wearing it out of round. I have only encountered one lathe like this, but it is the best guess as to how it got egg shaped. With D1-5 and D1-6, it is also good to cross tighten, just like wheels studs: 1 then 4, 2 then 5, 3 then 6 in the above 3 steps.,.

 

[AlfromNH]

Thanks for the responses. This is an older Bison chuck, and doesn’t have the Allen head screws that lock the studs from turning.
the studs won’t go another full turn it seems, but I’ll spend a little more time on it.

 

[mksj]

You want the cam mark to land between the two locking spindle marks, if the stud is not going in far enough it may be that the thread is bottoming out or the recess for the pin is not deep enough. In either case you should be able to correct either so the locking pin can go in one more revolution. You might post a picture of the back plate and locking pin if you need further recommendations. If you have no allen screw to lock the pins, you could use some low strength Loctite or glue to keep them from turning once they are adjusted properly. Also per what Dabbler has mentioned, I always tighten my the camlocks sequentially in 2 or 3 passes to make sure that the chuck is evenly mounted.

 

[Provincial]

It is possible that the pins will fit better if swapped into different holes. Mark the pins and the holes to keep track, then try switching them around. A spreadsheet could be a useful tool to keep track of the positions tried, and a guide for which ones to try next. 3 pins and 3 holes is doable. 4x4 more difficult.

 

[Dabbler]

@AlfromNH If you have another chuck, you can take out the cam studs and 'shave' the face of the stud the depth of one turn. Allowing it to turn in one full turn is the goal. It should be done fairly accurately, but that will allow the cams to operate in the proper range. rinse, repeat on other studs...

 

[Beckerkumm]

A bison backplate would have the studs. Do you think you might have a home made plate ? If so, you can buy a Shars type and complete the finishing yourself. They aren't that expensive considering you are getting the cams and studs with it. Dave