Re-profiling my cam followers.

[The_Flying_Doctor]

Spent yesterday making a grinding attachment for my lathe using a die grinder and a jig to enable re-profiling of my cam followers as per Bill William's  specification.
Here is a video of how it was done.

[Renaud]

Hi,
Details of that attachment would be welcome!

[Bob Culver]

Very simple arrangements using an electric drill clamped somehow to the toolpost suffice. The careful part is clamping the follower to faceplate such that the centre is in exactly the desired position. A jig to locate every time would be handy but not essential. Better to remove too little than too much. Other folowers or an old ball race ring make convenient packing pieces. Finish on an a fine oil stone .

[Robert Foreman]

Hello Bob, 
It sounds like you are talking from experience, can you supply us with a drawing or photograph of the set up on your lathe please?

[Bob Culver]

The centre position carefully marked. The follower is simply clamped to the faceplate, and placed to match the tailstock centre. (ideally should be be checked with a dial gauge that centre is on follower centre line but I did not bother)

A rod of desired radius in chuck serves to establish the stop for feed. The grinding wheel can be at any height and need not be precisely square, or with good bearings! I originally used a B and D drill sparked out. On another occasion used a small bench grinder mounted as a toolpost grinder. Faceplate just rocked back and forth by hand.
A piece of large round with a trench milled exactly across the centre line and held in a 3j chuck would make for quick mounting.

Have to be careful with the hand oilstone as removes considerable material.

The camshaft is slightly more difficult but not much.

[Robert Foreman]

Thank you Bob for your rather vague reply. 
I would have thought if you were using a grinding head it's bearings must be in excellent order otherwise you would have a massive chatter every time you grind. 
  Likewise if the head is not perfectly square then you would end up with a tappet foot that isn't square.

[Bob Culver]

If you feed it across repeatedly until it sparks out any wheel produces a fine finish eventually, and does not have to be exactly square to work. An oilstone quickly smooths.
I just marked the required centre on a smear of paint. Any error does shift the timing somewhat.
A myriad arrangemnt to avoid setting up each time present. A channel section with grubscrews thru the side to locate the follower could be attached to the faceplate and manipulated once into the correct positon.
Can remove some metal initially on a hand grinder.

[Rogerfrench]

My father must have reground hundreds and hundreds of tappets. He used an old lathe with a grindstone mounted in a chuck and a simple hinged bracket with a tappet guide pivoting on it from one of 3 holes, for the different radii he used.
Somewhat similar to his cam-grinding method.

[Austin in the Shed]

How did he regrind his cams .Roger.Have you any pictures ?

[Ian Williams]

I have made pivoted jigs to re-profile followers on a linisher much as Roger described his father did on a lathe, keep then square and finish the surface on an oil stone.