Vimana89
Legendary member
I've been flying for the better part of a year now, a lot of the planes I fly are custom home builds that are a bit crude by some standards. I've been building mostly planes in the mighty mini size range, small park flyer sized, and have used only 1806 radials, 2205 radials, and Graupner 2806 Ultra 1900 KV, which is similar in performance to the 2205. I have experimented with these motors on 2 and 3s with different prop combos, generally knowing what was within the safe and effective range, but I never got too deep into the specifics of selecting the right motor for a build or building the right plane around a motor. I'm really taking educated guesses and going off recommended or compatible with lists on the products I'm using. I'm going to have to do a little research into this and ask around.
What prompted me to really want to polish up my knowledge at this point was building a larger version of my V Sliver RET slender delta design. The original park flyer size model with the 2205 Radial or 2806 has tons of power to spare with a 3 bladed 5x5.5 Hulky prop on 3s. It can tail stand and float around and even maneuver and turn while maintaining a ridiculous high alpha, it can stay very steady in slow flight, and really pick up some rocket speed on full throttle. It had about a 16-17" wing span by about 30" chord. I have attempted a larger version twice, and both came out about the same as each other, but not as well as the small version.
My most recent one flew decent, but suffered from some structural integrity issues and random bad luck. It was not optimal though. It had a very low aspect ratio of 18" span by 40" chord with a custom style KFM wing, which is actually perfectly functional with all the vortex lift and wing area, and it flew nicely, but the 2205 and 2806 are my biggest motors, and on the larger model they are underpowered. I get a very turbulent wing rock if I fly it excessively slow or try high alpha stuff like the smaller model. The only time the smaller model got such violent wing rock was when I rode the battery too long and it lost power in the air. That's telling me the motor just isn't making enough extra thrust to keep this thing up and steady at low speeds.
I can post pics of both the larger and smaller slender deltas if necessary, but what motor and prop combo would be best for a 42-45" long slender delta, with a stipulation that it uses a high mounted pusher and the best clearance is for a 5" prop, what motor, prop, and battery combo would be best to give me some stability on high alpha and at low speed, and why? What makes it the appropriate choice? I think generally I want higher KV for a smaller diameter prop if I'm not mistaken, that's all I know.
What prompted me to really want to polish up my knowledge at this point was building a larger version of my V Sliver RET slender delta design. The original park flyer size model with the 2205 Radial or 2806 has tons of power to spare with a 3 bladed 5x5.5 Hulky prop on 3s. It can tail stand and float around and even maneuver and turn while maintaining a ridiculous high alpha, it can stay very steady in slow flight, and really pick up some rocket speed on full throttle. It had about a 16-17" wing span by about 30" chord. I have attempted a larger version twice, and both came out about the same as each other, but not as well as the small version.
My most recent one flew decent, but suffered from some structural integrity issues and random bad luck. It was not optimal though. It had a very low aspect ratio of 18" span by 40" chord with a custom style KFM wing, which is actually perfectly functional with all the vortex lift and wing area, and it flew nicely, but the 2205 and 2806 are my biggest motors, and on the larger model they are underpowered. I get a very turbulent wing rock if I fly it excessively slow or try high alpha stuff like the smaller model. The only time the smaller model got such violent wing rock was when I rode the battery too long and it lost power in the air. That's telling me the motor just isn't making enough extra thrust to keep this thing up and steady at low speeds.
I can post pics of both the larger and smaller slender deltas if necessary, but what motor and prop combo would be best for a 42-45" long slender delta, with a stipulation that it uses a high mounted pusher and the best clearance is for a 5" prop, what motor, prop, and battery combo would be best to give me some stability on high alpha and at low speed, and why? What makes it the appropriate choice? I think generally I want higher KV for a smaller diameter prop if I'm not mistaken, that's all I know.