Thanks for the kind words Dave
I bought the commando primary castings on eBay and a Bob Newby belt drive and clutch.
I guess you're aware the crank to clutch centres are closer (by about an inch if I remember correctly) so a shorter belt is needed
I'll post photos below and discuss the process...
I made new rear engine plates to suit the new gearbox position - also needs "modesty" plates on both sides now to cover gap behind gearbox
started with craft wood as it's easy to work with
A friend machined the area of the inner casting to remove the area which mounts on the commando crankcase
Then machined a piece of plate - inside diameter matches single crankcase - outside diameter matched the hole machined in the casting
You can see the plate if you look
Had engine plates water jet cut from 8mm alloy plate. First traced the wood templates onto paper, then scanned and turned them into AutoCad files which the cutting people need
Important to have bolt holes undersize then ream them to suit bolts - don't want sloppy joints
Shows the tight clearance for the pulley as I had worked out the alternator would be a tight fit
Shows the assembled alternator. Had to machine a recess in the rotor to get full nut engagement
Also had to make longer studs then play with spacers for the stator - Tricky getting clearance all the way around
You will also note you can just see where I had to grind a hole through the inner to allow clearance for the engine mount bolt that the centre stand would normally fit to
It had to remain even though I would have no centre stand
The hole I ground was later covered with a section of alloy tube (welded in place)
A shot showing the front mating - can't see the "adaptor" plate if you're careful
What isn't shown in photos is the grinding of inside the outer necessary to give clearance for the stator - I took of about 1/3 of thickness in a couple of places
A couple more shots below of the assembly
Shows how tight it is between engine and gearbox - hence no centre stand. I put some bobbins on the low shock bolts and use a paddock stand
This last photo shows the four stitch welds (TIG) used to hold the plate to the casting
Preparation was key, repeatedly heating the casting in the oven then cleaning with solvent until no more oil was evident - very porous!
Even then had to wipe with solvent during the welding - a two person job
Well Dave, I hope the info above helps you. Let me know if you want more
Cheers
Rob