??? QUESTIONS ???

The mast of your Gyrobee tilts forward slightly, while that of most gyros is tilted back. When you revised the Gyrobee drawings for distribution on the net, you made the mast vertical - why?

Most gyro masts are tilted back between 7-10 degrees to align the axis of the head with the rotor thrust line. When Martin designed the Bumblebee, he tilted the mast forward to accommodate the special head he designed for that machine. When we built the first Gyrobee, we kept the forward-tilted mast but compensated in the use of a standard head by altering the angle of the head to the mast. Obviously everything worked just fine. Since you can fly a gyro with the mast tilted either way, I made the mast vertical in the revised Gyrobee drawings because it is much easier to build it that way.

Can the fuel tank be mounted above the engine, thus improving fuel flow?

I seriously considered that option. The primary advantage is that you would not need a fuel pump, since fuel would gravity-feed into the carb. No fuel pump is one less thing that can fail, which is good. The high mounting would also raise the vertical CG, which can't hurt. There are negatives however.

You will need a fuel shut-off valve. The present Gyrobee doesn't need a fuel valve and thus you can't forget to turn it on! You may think you would never do something so stupid, but I have taken off with a closed valve twice in fixed-wing ultralights! Not Good!

The high position of the fuel tank would make it more difficult to fuel the aircraft. I spent many years horsing up 5 gallon fuel cans to fuel our old Quicksilver and I really like the more convenient position of the present Gyrobee tank.
Any leaks that might occur will drop gas on a hot engine (or you) in flight - Not Good!

The bottom line was that I left the tank where it was, but it is a judgement call.

Ralph E. Taggart (gyrobee@aol.com)