Cam lock spindle issues

[funkyfazel]

Hey guys,
Im new to this group and new to cam lock spindles in general. I recently got a Central machinery 12x36 lathe. It was made in 1998 and is in pretty good condition.
It however did not come with the chuck or the cam lock hardware in the spindle. According to the manual it a D1-4 cam lock type.
I bought a new 6'' 3 jaw chuck from Grizzly with D1-4 cam locks in it. I got the locking cams that go into the spindle from MSC.

The problem is when i put the chuck on the cams on the spindle just turn freely and wont lock down in the lathe cam studs.
Ive adjusted the studs in the chuck from all the way threaded in to out as far as they can go and still get the locking alen in.
Not sure what else to try.Thanks in advance for in info yall can provide.

 

[Dabbler]

Can I please assume you haven't dealt with camlocks before? If you have, please accept my apologies up front.

Camlocks are designed to be adjustable. your chuck came with studs adjusted out to the 'loosest' degree. If you look carefully, you will find each cam lock stud on your chuck has a line machined into it. This is likely visible for each of the studs.


Here's what you do: you pick a stud and a cam. for the first time, you can make it easier by marking them in magic marker. try that stud only. If it acts like you say, then remove the cap head screw for that stud, and screw the stud on the chuck in one full turn. then try the cam. repeat until you get the cam lock starting to get resistance at about 90 degrees of turning - full lock up should be around 100-120 degrees. if it hits 180 degrees, it will just slip past the locking point. If you keep a count of the number of turns, then do all of the studs in by that number of turns as your starting point for them.

On both of my D1 spindles, the locking point is at '5 oclock' but I have used camlocks where this is different, hence the '90 degree' and '120 degree' references.

 

[funkyfazel]

Can I please assume you haven't dealt with camlocks before? If you have, please accept my apologies up front.

Camlocks are designed to be adjustable. your chuck came with studs adjusted out to the 'loosest' degree. If you look carefully, you will find each cam lock stud on your chuck has a line machined into it. This is likely visible for each of the studs.


Here's what you do: you pick a stud and a cam. for the first time, you can make it easier by marking them in magic marker. try that stud only. If it acts like you say, then remove the cap head screw for that stud, and screw the stud on the chuck in one full turn. then try the cam. repeat until you get the cam lock starting to get resistance at about 90 degrees of turning - full lock up should be around 100-120 degrees. if it hits 180 degrees, it will just slip past the locking point. If you keep a count of the number of turns, then do all of the studs in by that number of turns as your starting point for them.

On both of my D1 spindles, the locking point is at '5 oclock' but I have used camlocks where this is different, hence the '90 degree' and '120 degree' references.

Thanks for the quick response. I tried what you explained and I can get the stud to lock but in the locked position the stud has a lot of slop and play. It won't pull the chuck up tight. The chuck won't fall off but it's loose and moves around. I'm flying out of town today but when I get back I'll post some pictures. Thanks again.

 

[keeena]

Can you post measurements of the camlock stud? OAL, diameter, and ~length from the non-threaded end to the middle of the scallop?

Remove all the camlock studs and fit the chuck - does the short taper feel like it grabs or does the chuck bottom out on the camlock face and have wobble? Throw a plywood board on the ways - don't want to drop the chuck on those

 

[funkyfazel]

Can you post measurements of the camlock stud? OAL, diameter, and ~length from the non-threaded end to the middle of the scallop?

Remove all the camlock studs and fit the chuck - does the short taper feel like it grabs or does the chuck bottom out on the camlock face and have wobble? Throw a plywood board on the ways - don't want to drop the chuck on those

Update on my endevers. I readjusted the studs on the chuck back plate for the 30th time this morning. And wouldnt you know it it finally locked in good and tight. Next question, should there be a pin and spring in the cam lock bore on the lathe? The manual shows them but of mine only has the cap head screw. Its locked down tight and has no wobble,but i dont want to chance it if it needs those parts.

 

[Dabbler]

should there be a pin and spring in the cam lock bore on the lathe?

You will have to scan the picture, as words don't quite give me the picture of what ypu are talking apout. My cam lock spindles and chucks have no pins or springs, at least where I'm thinking.

 

[funkyfazel]

should there be a pin and spring in the cam lock bore on the lathe?

You will have to scan the picture, as words don't quite give me the picture of what ypu are talking apout. My cam lock spindles and chucks have no pins or springs, at least where I'm thinking.

In the picture it's number 175-176. Parts are cap head screw, spring, locking pin, and spindle locking cam.

 

[keeena]

The aren't absolutely mandatory, but yes - those springs under the cap screws are to keep some pressure on the cam detent plungers. The plungers are there to give you an audible & tactile click when the cam has reached the 12o'clock position.

 

[Dabbler]

Oh, I see what you are talking about.

My big lathe has a spring and a detent; When you reset the cam to the 'fully open' position to take the chuck off, it won't let the cam turn a little bit and prevent the chuck from being removed. It also has a set screw to hold the cam in place. Both are unnecessary to correct functioning of the spindle. When all the cams are tight, the backing plate of the chuck is locked onto the short taper, transferring all the power and centering the chuck. radial run out is accomplished by the backing plate being in 360 degree contact with the flat non-tapered part of the spindle.

It is usable as it is, but adding the spring and set screw helps make it more usable.

 

[Dabbler]

[Addenda] b To use a D-x spindle it has to lock strongly enough that when you want to remove the chuck, it takes a sharp 'rap' from a soft or deadblow hammer to 'knock it off' the taper. If the chuck doesn't lock onto the taper with the cams undone, there is something very wrong.