RE: Bob Cat Copy Falcon 120 Jet
Had three excellent flights yesterday, I made a few changes since my last flight. I fitted spring back struts on the mains, like the Jet-1A type. I saw someone on this site had fitted them but no info on what type. I also contacted Digitec to work out which ones would fit. No answer. I think they are crazy, because these models are going to be really popular. The field I am flying from is grass, so decided that to proplong the wing and fuse structure, I definatly needed better legs. I bought 2 legs from Motors and Rotors, they are made by AT, I had to mod them to fit. A lot of milling and cutting down.
They work great, they take a lot of punishment away from the undercarriage mounts, very impressed. Will post some pics later and try to upload some vid footage on youtube later.
My lipo batteries for ECU and radio are as far forward as possible, as my home made engine is heavier than your manufactured ones, to get the correct the CG. I had made up a rail system to hold them, but for ease of removal, I have now taped my carbon rail holders directly to the air tank, so I just pull the tank out, complete with batteries for charging and balancing. I also found a really easy way to hold the tank in, a simple spring and clip that clips around the air tank supply pipe. real easy.
Flights were @ 7.5 mins, so about 9 min run on the engine. I use just a 1320 ma lipo for the jet ( for weight reasons), so with starter motor giving the lipo a battering, I tried a different soloution. I soldered on another lead to the power lead just as it enters the ECU. When i start, I plug an old Nicad pack into this fly lead. I start the engine and as it acelerates through its idle rpm up to its calibrating speed, I quickly switch on the onboard lipo pack and imediatly unplug the nicad pack. After landing, after shut down , I plug the nicad in and imediatly switch off the lipo, so cooling runs are from the nicad. This way I fly many times without recharging.
My 1320 Lipo reciever pack was fine after 3 flights, the excellent Align regulator voltage LEDS had dropped just 1 indication, so hadly any consumption.
With the flaps, had a slight amount of up programed in with 20mm flap. This is not reqiuered and causes the model to ballon slightly. With no elevator input it is just right. Have to try the full 45 degrees yet.
For info, my Undercarriage and heavier wheels, have added a bit more weight. With a full UAT, dry weight is around 14.5 pounds. Engine puts out about 13 lbs thrust. Fuel is around 3.5 pounds. On the grass there is lots of drag. The model will accelerate to a set speed then will go no faster. Feed in a little up, and the model accelerates rapidly and smoothly lifts off on its own accord. On landing the stoping distance is really short due to the grass. No brakes required. Model is docile and rock steady, can be slowed up to unbelivablely slow speeds and yet you can throw it arouond. I am still getting aquanted with my model and love it.