Anybody into Commandos will tell you that the bike was apparently built around the horn. The stock location is deep in the center of the bike, difficult to get to - not the greatest place for a horn to make sound. My original horn ended up being bad, so I needed to replace it. Further the original Lucas horn was probably everything Lucas thought it should be, which as it turns out, is pretty much the same as how they designed and built everything. So I wanted to upgrade to a pair of Fiamm Freeway Blasters located in a more strategic position .I also needed a place to mount my new fuse block, the Fuzeblocks FZ-1.
I decided to mount all this stuff aft the air cleaner, but in front of the battery. My first goal was to model the space in Fusion 360, so I could design a way to get everything located. Once I had that, I designed a sheet metal mount. It took about 5 iterations to get it to work.
Once I had a design, I used Fusion's sheet metal tools to create an unfolded 1:1 plan of the part. I glued this to a piece of sheet metal, then cut and bent it along the lines. Once I had it bent up, I welded it together and painted it.
Everything pretty much fit as I hoped it would.
Here's the thing partially wired. In order to mount it, I welded a could of pieces of angle to the battery tray and then attached some captive nuts to be used with some horizontal bolts to secure the horn mount (you can see a couple of slots in the picture above - bottom of the front rail). So the horn mount slips down on top of the rails and 4 bolts are inserted horizontally to secure it.
And here it is mounted up. I'm pretty happy with the way everything ended up. The horn relay is a bit cramped, but normally not a service item. Now on the the next part of the project - the wiring harness!