Need advice on building model airplane?

A homebuilt cessna 172:


i'm using a size 25 glow engine, and i built the wingspan at 52.7 inches the length of fuselage is 30 inches.....





how much weight would the airplane hav to be to be flyable for that engine?





and wat are the odds of using a 4 channel control wit no rudder control?Need advice on building model airplane?
That should be enough power, just dont expect a speed demon or anything.





I would try to keep in between 45 to 60 ounces.





Shouldnt be a problem. As long as you have alierons and a elevator you can steer the plane. You should have pleanty of channels though.


1 channel - Throttle


2 channel- Ailerons


3 channel- Elevator


4 channel- Not used thats fineNeed advice on building model airplane?
attach solid fuel to the wings for a turbo boost!
.25 is real small for the wing span you are working with. I you should be in the .50 range. .40 min. Once you raise the nose for takoff you are going to create induced drag which is a byproduct of lift. This is the point that without enough power you are going to get in to trouble. without the power to transition thru this very demanding portion of flight you will most likely stall the aircraft. To be that size and use that engine it eill have to be as light as you can possibly make it. What materials are you using. Foam? if not foam you need to go larger on the engine. Good luck.
Weight should be under 2lbs loaded. Be certain you have the CoG properly placed.


I would utilize the radio with throttle, rudder, elevator and leave the 4th blank. It's much more important to have rudder control than ailerons when you need to turn.
My first RC model was a 64'; three channel ARF (almost ready to fly) trainer powered by a Magnum Pro .28 producing 1 HP. The all up weight was 5.75 pounds and it flew quite well. The three channel radio controlled throttle, rudder and elevator. I had several hunded flights with only twelve major rebuilds.

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