View Full Version : Camlock - Drawing, Specs, Diagram, ???

Paul Alciatore
06-07-2010, 10:54 PM
I have never seen a camlock spindle up close so I am wondering about the specifics of it's operation. Anyone have a drawing of this mechanism or some other form or explanation? Or a reference to a web site that explains them. Dimensions would be nice, but just a general understanding of how they operate is what I am most after.

Jim Shaper
06-07-2010, 10:59 PM

First hit on google.

Dr Stan
06-07-2010, 11:05 PM
I recommend picking up a copy of the "American Machinist's Handbook". I have one and it has all the data on many different spindle noses (and lots of other stuff). It is out of print, but there are copies available on Amazon.

I consider it to be a better machinist's reference than "Machinery's Handbook" published by Industrial Press.

Paul Alciatore
06-09-2010, 01:12 PM

First hit on google.

Jim, I'm not that stupid. I did do a web search. I would not waste anyone's time here with a question that I haven't at least tried to research myself first.

I have seen that page and others like it. It shows the hole pattern in the spindle and some turnable features on the OD near those holes. But gives absolutely no idea how the "locking" mechanism actually works.

And I have seen photos of chucks with studs sticking out. I believe these studs have notches in them. I suspect that there is some kind of rotating, offset feature that fits in these notches and is used to lock them. Or is it a tapered screw that engages them? Or what? And what prevents them from loosening with the vibration of cutting?

daryl bane
06-09-2010, 01:44 PM
Although I don't have a pic, you have answered your question. The studs on the back of the chuck have smooth cutouts. The rotating cams in the spindle end have a cutout as well that allows insertion of the stud. When the cams are turned(usually clockwise), the edge of the cam pulls against the cutout on the stud and pulls the stud in. The cams are a simple cylinder with a cutout for the studs to pass. This action pulls the short mating tapers ( integral to the design) together to form a hopefully nice fit. The fitting of the matching tapers is paramount to the accuracy of the system. Hope this helps.

06-09-2010, 01:59 PM
Paul, it looks like Daryl already explained how cams work. I only want to add that cams are designed in such a way that they are self-locking. They rely on friction to stay engaged - similar to Morse taper.

Also the chuck taper is designed to have a small interference fit to a spindle taper and at the same time to sit on the spindle face. Actually on my 12 x36 lathe I had to cut the spindle taper down a little bit to make sure there is a 100% contact on the face. This makes the whole setup more accurate and easy to replace with another chuck.

Jim Shaper
06-09-2010, 03:12 PM

I'll give you this one - these are a whore to find if you don't know where to look. I had to replace two of them on my lathe.

The left side is what's exposed out the spindle OD. The pin on the backing plate comes through the radius in the side and then the whole works is rotated about 90 degrees CW to draw the pin in.