.

Here you go.!

Simpler to show than type.

.

Yes they do. And yes I do. I should have mentioned that.

My bad.! ……….. I shall spank myself in punishment.

Nick

Thanks Nick, a great explanation. A couple of things (as a D1-5 user) I'd add are:

1/ Reference the original question, the cam pins are a 'loose' fit for a reason. If the pin was fitted rigidly to the chuck, the axis of the cut-out in the pin would need to be on exactly the same radial axis as the cam in lathe nose – if it was out by even a degree or two all the cam effort would be on one edge of the cutout with potential damage to the cam and galling to the pin. Having a degree or two of float in the pin allows the pin to self-orient itself to the cam when the first pressure is applied; also the threads are often tapped a little 'loose' to ensure the pins can move sideways a tiny bit to avoid fighting with the tapered-register alignment between the backplate and nose (in some ways analogous to a floating reamer holder).

2/ If anyone ever need to replace camlock pins, just be aware that whilst the visible part of the pin is standard, the threaded portion that mates with the backplate can have different threads (I once bought a pin-less chuck and found none of my existing pins would fit – metric vs. imperial)

3/ If changing pins, there's often a groove scribed around the pin, screw it in until that is level with the register face of the chuck, then pop the locking screw in – then, as Nick said, don't be surprised if you need to go in or out a turn.

4/ If, rather than a 3-cam, its a 6-cam chuck/nose, then recommended sequence for nipping/tightening is 1,3,5,2,4,6 to avoid risk of pulling chuck off-centre

5/ Especially if its a really heavy chuck, always try & bring each cam to the top before tightening to counteract gravity

6/ I'd always use a board between the chuck & bed just in case!

Dave

Edited By Dave Martin on 21/12/2015 08:56:48

Another D1-5 user here, these are a bit rare in the UK, tend to go from D1-4 to D1-6.

The D1-5 is a 6 pin camlock but I have cheated and removed 3 of the cams and replaced them with blanking plugs to speed up chuck changing which for me is a lot.

On a busy day i might swap chucks anything from 4 to 7 times per day.

Also gives you a shed load of spare pins for special projects

I agree with what Dave says two posts above #2 item.

When I had a lathe with Di-3 fitting I had pins with 3/8" BSF, 3/8" UNF, M10 x 1.0, M10 x1.25 and M10 x 1.5 threads