Richard and I again met at the airport on Saturday the 30th. He brought along the things he had worked on to hopefully get the hand throttle to work. The modified control lever fit very well on the control bar, although it wasn’t very tight. We found that that would probably be better because I could adjust it in flight to be comfortable.
He also produced the bell-crank lever and we put it on the carriage throttle so that the both the hand throttle and the carriage throttle would pull out the throttle cable. We tested the bell-crank and it seemed to work perfectly if only we could find the cable to attach to it. The control bar throttle would override the carriage throttle control, but the carriage control with its lock knob would be used in cruise flight.
The bad news was that 8’ cable that I had which seemed like it was plenty long was not long enough. The cable housing was long enough, but the cable itself was too short. So by trying all possible combinations using the cable we had, we finally gave up for the day and I had my marching orders to find a longer cable. The problem with just getting 11’ of raw cable was that on the control lever end, there had to be the right kind of button (or whatever it is called) to fit into the lever.
So for lack of an 11’ cable, so we couldn’t finish the job. We gave up for the day and I went home discouraged that something this seemingly simple should be such a stumbling block. But later, I found in the LEAF catalog a list of parts for a brake system that allowed for special orders of cable by the foot. I e-mailed Richard and sent a scan of the catalog page. He encouraged me to order the parts, since they didn’t amount to much cash-wise, which I did.
Saturday, June 30, 2012
Monday, June 18, 2012
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.
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.
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