Saturday, June 18, 2012 Working on the Throttle Problem

After my abortive attempt to fly the Jetwing May 24th, on June 12th I e-mailed Richard Schmidt to ask for technical advice. He is the ex-racing car driver/mechanic that helped me get the Kawasaki engine to perform well. I explained the problem with the foot throttle and the basic need to find a way to control the power by 1) not using the foot-feed because of my physical limitation, and 2) keeping both hands on the control bar at all times during landing and take-off.
My thought was that I probably needed a hand control that was attached to the control bar, which is what the Jetwing had on it originally when they were first built back in 1982. In fact, Larry Miller’s Jetwing is still set up that way, except that his has the cable from the control connected directly to the carburetor. I rather like the idea that if I could get a hand control to connect to the existing control on the carriage, I could still use the control on the carriage during cruise flight and not have to have the control on the control bar effective all the time. Sort of like a Jetwing cruise control. I included some pictures with the e-mail of Larry’s plane. He thought that would work, and we agreed to meet at the airport the following Saturday, the 16th.
True to his word, Richard was at the airport waiting for me when I arrived. It was hot and muggy, and we worked most of the afternoon. I had gotten some bicycle brake control levers from a used bike shop, along with a cable, but not surprisingly we found that what we had in mind wouldn’t work. The throttle lever (bicycle brake lever) was too small and would not attach to the control bar, and even if it could be made to attach, the “travel”, which is the distance the cable has to move to apply full power, was longer than the control lever could move. Although this seems like a pretty obvious conclusion, it took several hours to determine what exactly needed to be done.
Richard wasn’t discouraged, though, and said that he could fabricate a 3:2 “bell-crank” lever that would solve the “travel” problem, and he also would modify the control lever so that it would attach to the control bar. After some e-mails back and forth, we agreed to meet again the first available Saturday.