The other day I made the formers for the Height & Airspeed and tried a blank. While I have worked out the technique and the shaping, it didn't work out brilliantly.
I ended up cutting and filing the ridge too short. It covers the computor when inserted but does not go high enough above it. A good first test anyhow.
So decided tonight just to have a fiddle with a better depth holder. This time I used the shrinker much more extensively and worked with a half inch flange (a little too much as it turned out, probably go with 3/8 in future. A lot more attention to the hammer work and the overall curve this time and it paid off.
Using the sand bag as a base for hammering is great..first time I've done that. I can see what a useful tool they are now. They are fairly expensive and until now I have been wondering if I wasted the money. No, they are a nice pick up.
There is a lot of work to be done on cleaning up the finish and I suspect that, as I now have at least two more of these to do, I'll weaken and use the Dremel for a bit of that. I usually like to finish things by hand but looking at the hammer marks and shrinker marks in these, there is a lot of elbow grease to find!
I've also decided to clamp these into the milling machine to cut the rim absolutely evenly. There is still a little meat all the way around to allow this.
Once that is done the other few small pieces can be made and rivetted on. A good heavy piece of elastic fabric and some parachute clip studs complete the deal.