I went back up to Donnington tonight to check out Graham’s other engine. It wasn’t what I expected but it has potential. It also gave me chance to try out the new spanner. (Which fits the nuts but is too big, so a little adjustment is required).

It looks dry and with all the manifolds intact, so the internals may be OK. The manifolds will take a lot of time to remove, which is Saturday’s job. Another trip planned with Bob and Nick then! I’m lucky to have some good friends around to help out!

Mr Nick proudly showing the final item. I will research whether it’s worth hardening it before we head off to the airfield.

Cheers Nick!

Lining up a treat, you can see the dowels in action.

I went round to see my mate Nick today, armed with some 6mm steel plate left over from the workbench. The idea was to make a spanner by cutting the same profile as the prototype in steel.

The issue we had was the cutting depth of the small diameter cutters. We had to cut half way through, then turn the job over and do the same from the other side. We also had to make sure that the two sides lined up perfectly.

Nick made a jig to hold the job between two dowels along the centre line, so when we turned it over everything would line up. It worked perfectly! I’m really seeing the benefit of CNC machining and I think as I tool up that’s the way I’ll go.

Here’s the master at work.

Now to make one in steel……

So I rang my mate Nick on Saturday morning around 9. We chatted about the project and general stuff, including the possibility of turning my plasma cutter into a CNC plasma cutter – which I’m quite excited about.

Nick was keyed up to make a spanner and I’m taking the nut round tonight, but he asked for some basic measurements. Number of teeth, outside diameter and depth of the teeth. At 11 I received the picture below by email. Looks pretty good doesn’t it? Clever Lad!

So the plan is to make a few mock up spanners in plastic for a trial fit. Once we have the best version it’ll be cut in steel, hardened if necessary and ready to use in anger! A big leap forward for the project, thanks Nick!

I have in my hand, a very nice Bristol Hercules cylinder nut. Courtesy of Patrick Smart who has a pair of restored Hercules engines he runs up at charity events. I can get this to my friend Nick who recons he can make a spanner on his 3D machine. Thanks Patrick!

Patrick’s mate Pete was kind enough to weigh a piston, rings and gudgeon pin they have and send me the details. I needed these for Bob so he can work out the balance factors.

Two important pieces of the puzzle coming together, thanks very much guys.

Bob has finished drawing the plans full sized and a cracking job he’s made of them. I now have a couple of copies courtesy of work, so I can cut out one of the full sized projections and stick it on the wall. With a wheel either side it’ll give me some idea of scale and what the frame needs to do.

A friend and the drawing office have independently offered to try to transpose it into CAD, which will be really useful for 3d modelling. It might also lead to an alternate way to get the patterns made.

I’m still trying to find a special spanner, or even just a nut, so I can see what parts I can salvage from Graham’s engines. Looks good on paper though doesn’t it??