Well, today I made my tool for undoing the cam follower guides on BSA M and B series engines.
I cut down a 1/2" drive socket so that I just had the square drive section left. I then filed the square from the std. 1/2" size to fit the square on the cam follower guide. That is about .585" across the flats.
Next I drilled through a piece of suitably sized hexagonal bar....375"(3/8") diameter all the way through and .875 (7/8") diameter, just deep enough to accept the cut down socket with approx. 1/16" protruding when in place..
Then the socket was welded in place around the outside of the protrusion.
The tool fits neatly over the square of the follower guide and the shank of the follower protrudes through the top, so the tool can be held firmly in place with a 5/16" cycle thread nut screwed to the follower thread where the tappet adjusters fit. Then it's just a case of using a spanner or socket on the hexagon.
I 'road tested' it this afternoon removing a couple of guides and it worked a treat..Once the guide is moving the whole tool can be removed and the guide can be undone using an ordinary spanner, leaving the follower behind to be extracted from below...
Thanks to everyone for the replies to my posting on this subject...and to Neale Gentner who suggested holding the tool in place using the follower thread and a nut...very obvious really, but I didn't think of it ....Ian

email (option): ian@wright52.plus.com

I did mention to the guy that's doing the spindles about making a spanner up to remove them and he seems to think it's no problem and has put it on his to-do list. He has been looking for BSA parts to make that people want, but aren't available at the moment. It may be a longer term project, but I'll keep everyone posted when he gets round to it

email (option): davmax@ntlworld.com

What about the engine shaft extraction tool?

Just cannot seem to get around my other project(s) to make one...

email (option): unpob@yahoo.com

Thats one I didn't think of!

email (option): davmax@ntlworld.com

It would be nice to have a correctly made pinion extractor, but I always manage with my off the shelf two leg small pullers. I find that with most of these pinions there is never much room to get the puller behind

I've sometimes had to grind the puller and even keep the legs pressed together with a G clamp. It usually works to put as much tension on the pinion as you can then give the puller a sharp tap. Ron

email (option): ronpier@talk21.com

There are also extractors for the cam spindles and intermediate gear spindle...Ian

email (option): ian@wright52.plus.com

The way I took it off on my cut away engine, was to remove the left side case and then support the right side case while smashing the shaft with the rawhide mallet. Did insert a brass plug on the end to make sure the threads would not be affected. Clumsy but it worked. Weight of suspended flywheel helped. If I would have had a hydraulic press, it would have been easier.

email (option): unpob@yahoo.com