FTmustang65

My Feedback: (6)

Hello,
I am new to this site and new to the hobby. I recently purchased a great planes piper 40. I know what you are all thinking why is he talking about a saito 72 or 82 thats way to much. Well I purchased the kit to learn on and experiment with. I really like the cub, but I really got into the hobby for military planes and such, but a guy at my local hobby store said dont go military right away. The reason I am trying to decide for the the two is because I want to be able to pull the motor later and put it in another plane, but i am also afraid of over powering the cub to. I believe on my Futaba 7C I can program it to not let the the throttle past a certain point which would also help, but I also read that not powering a engine to the max is bad for it. Can any of you please help me out I have read so many different posts and come up with different ideas all the time thank you.

Henry

Nathan King

You definitely don't want to go military for the first couple airplanes. I would take your airplanes to the club to get proper instruction. It will save you much grief. The .72 or .82 will work okay, especially with a Piper Cub that already has a very low wing loading. You'll probably have to cut out a little more cowl and add some ballast in the tail though, but there's nothing stating that you have to floor the throttle all the time.

About not powering the engine to max... Set the carb to open fully at full throttle, you just won't need to go wide open often. Engines don't need full throttle constantly to work properly.

Not powering an airplane to the max is definitely not bad for an airplane. For my sport models, I usually aim for the lower range. I've even taken grief from a few club members who said my airplane wouldn't get off the ground right before I successfully maidened it using half throttle. I think I do it because I'm into full scale flight, so even the lower power range seems ridiculous. I also like the look of a model flying how a larger (scaled up) version would. I for the life of me don't know why everybody thinks you need an engine with wings just to get off the ground. Every time I show up with a new model the first question, without fail, is "what 'ya got under the hood?" Drives me nuts. In my experience, even the manufacturers smallest recommended engine will fly the airplane well. I've even experimented going below the minimums and usually don't run into trouble, though I wouldn't recommend doing it unless you make some calculations first - after all, all bets are off outside of that specified range. Of course, If you are looking for blazing speeds or unlimited performance on a competitive aircraft then you'll want to use the largest displacement in the range, or possibly higher if you're very careful how you do it.

I personally value reliability over power. To each his own, I guess.

ChuckW

If I had those two choices, I would go for the .82. Yes, it will be a little much for a cub, especially if you want to fly it in a scale manner. It is the same size as a .72 though, not much more money and a little more powerful. Plus you're just choosing an .82 over a .72, not something ridiculous like a 1.25. You'll probably find that it'll fly the cub great around 1/2 throttle.

As for the cub itself, will it be your first plane? If so, it may not be the best choice. Sure it's slow and has a lot of lift but it has other characteristics that make it less than ideal as a trainer. If this is your first plane, get a trainer instead. If the cub is your 2nd or 3rd plane, it should be no problem.

FTmustang65

My Feedback: (6)

Hey thanks a lot guys I will probably just go with the .82 considering that its the same size as the 72. Yes this is my first plane and my one friend that I got into the hobby with bought a trainer and I bought the expensive controller so we are going to do a little sharing in order to earn our wings. I will have a few flights under my wings before I maiden the cub. Does anyone know on the cub If I should strengthen the tail or not and if so how should I do this. It is a kit and I have not finished yet I am working on the fuselage right now, so it would be a good time.

bassfisher

My Feedback: (21)

The Cub is not a first plane (and sometimes not even a 2nd-depending on the pilot)by any means. They can have nasty habits that a new pilot is just not ready for. Like getting into warbirds, experience is a great thing to have in your back pocket before you try to fly one. I would buy my own trainer in case your buddy's goes in while you are learning how to fly. Recievers are not that much and you can always transfer everything from the trainer to the Cub when you are ready. Since you already have the radio, you could just buy a flight pack, Tower has them (Rx Battery, RX, Servos, swithc) at a pretty good price, just make sure the Rx is ordered for your channel. I might get flamed for this, but IMO, an .82 4S on a .40 Cub is way too much engine. Yes, I know, throttle management, but it is still too much engine. I'm flying a H9 60 sized 90" Cub with a .70 4S, and it flies scale at 1/2 throttle or less with power to spare. I would just put on a .40 to .46 2S on the front end. You could even move the engine from your trainer (assuming a .40 size trainer) over to the Cub and still be happy.

khodges

My Feedback: (1)

Build the tail per the plans, and make tail braces for it like the full scale has; maybe the GP plans will show it. If you want to strengthen anything, go for the area around the windshield and side windows (what would be the "A" pillar in a car). If you've already decided you'll fly this plane as your second one (your buddy's trainer as the first), you may as well plan on some ground loops. When this plane ground loops, or tips over, the wingtips will catch the ground, and the torsional loads will break the front former. Add a strip of carbon fiber rod, or fiberglass it to add some strength. The extra weight (the model can afford it) will be very near the C/G, so no problem there. This is the weakest area on the Cub frame, and most likely to break from bad landings, and botched takeoffs.

FTmustang65

My Feedback: (6)

Awesome thanks a lot for the tips hodges I will do that.