well... workin on my used trainer... getting it ready for flight... had a couple of questions about it... first of all... its a sig kadet senior, with a magnum .61xl.

question #1 gas tank... i bought a new one... its a dubro 20 ounce, when i started getting in to flying in the late 90's the gas tank in my then trainer had a very thin walled flexible fuel line that did not kink when bent inside the tank... the new dubro i just bought does not... it is standard fuel line... physics and logical reasoning tell me that the this flexy line will (and did) allow the clunk to always drop via gravity the the lowest point in the tank... also where the fuel would be... to always have fuel (untill you run out of course).. but my new tank does not have the ability to do so... i went back to my LHS and looked at a veriety of other tanks (all brands) and they all come with relativly stiff standard fuel line... i talked to the hobby shop owner who has been flying for years and he told me what i thoughts were correct and that it should be thin and flexy at least he has always used tanks with the flexy lines wasnt aware that they had changed the tanks, anyway... there is no way that my current tank would be able to supply fuel in a nose down attitude.. and i cant seem to find any tanks with the thinner flexier tubing, nor can i find the flexy tubing to modify it at three LHS's, what should i do... is the tank correct and im worrying about nothing .. or should i try harder to find right set up... kinda lost on this...

second question, my sig was modified by the PO to have ailerons and flaps... i have been told to keep the ailerons and dump the flaps .. ailerons are about 3"x10" and at the wingtips and the flaps are about 3"x the rest of the wingspan.. should i take them off or secure in place to make trailing edge the same all the way across... i dont think there would be anything wrong with taking them off as they were only adding to the stock wing area.. anyway...

thanks in advance to any feedback and sorry for being so long winded... i appriciate your opinions and insight... thanks again

I use "normal" fuel tubing for the clunk lines on all my tanks with no problems. You don't need extra-flexible tubing at all. It's true that if you are very nose-down for a long enough time, you can get the engine to die, but usually the engine gets stopped by something else (the ground) before it becomes a problem. Actually, because of the forces on the plane and the fuel acutally in the lines, you'll find it really hard to actually get the engine to even sputter in normal flying and even with "extended" downlines.

As for the flaps, they won't hurt anything, but on that plane, you won't really need them either. If it was me, I'd set them up if you can afford the extra servo and have a channel for them, but don't even think about using them until you're well past soloing. Then you can take it up high, hit the flaps, and see what they do. A guy at my field has a setup simular to what you describe. He can take off from extremly high grass/rough ground, it almost looks like the wheels don't even turn on the ground. And he can land almost vertically with out much of a breeze. Kinda cool for goofing around. Anyway, if you don't have hte servo and spare channel, then just fix them in the up possition and don't sweat them.

Leave the flaps on... flaps on a Kadet are interresting, even if unnecessary. Its kind of fun to put on full flaps, point the nose relatively high, add a bit of power and "hover" in place in a 5 mph wind. (not quite the same as a 3D hover... but same effect...)
Just a little bit of flap defelction goes a long way toward eliminating any chance of tip-stall on landing approach. The 2-ft ground roll of a Kadet Sr with flaps is great.

The Magnum .61 is a bit more than the plane needs... It can fly on a .35 from the mid 1970's. (less power than most modern .25's...) With the large engine, the thing is a heavy payload lifting model... you can easilly drop 4 GI-Joes with parachutes. (the old 12 inch tall ones) Most of the time it will be very happy at 1/4 throttle. (it will take off at as low as 1/3 throttle)

The fuel tank... yes you want to have the clunk make it to the bttom of the tank.... you dn't need it to make it to the front. (they tend to get stuck there if they do make it.) one of the heavier sintered bronze filering clunks may be what you need.

The lighter fuel tubing is made... It comes in the Goldberg ARF fuel tanks, among others. Sorry, but I don't know where to get it. (might e-mail Carl Golberg Co....)

Don't worry about the tank, use it as is. I even use a piece of brass tubing in the middle of my clunk line to PREVENT it from bending forward (where they have a habit of getting stuck).

Flaps are certainly not needed, but if you have the servo and channel, leave them there for later on.

And yes, that 61 is extreme overkill for the plane. You could probably add at least an extra 10 pounds to the plane, and it would still fly quite well.

Welcome, and good luck!
Dennis-

right on... thank you all for the replies... think ill quit worrying about tank... keep flaps.. i have a brand new 6xas pcm... and a gazzilion spare servos... so yeah ill keep em.... thank you all... still interested in varying apinions though...

I agree with all of the above. I would strongly advise ditching the 61. That would be serious overkill. And I think a 20 oz tank is just too big. It will work but you really do not need that big a tank. I would say a 12 to 14 oz would be fine. Especially if you go wiyh a 40. That big of a tank will make it very nose heavy when taking off with all that fuel in there. I am only making suggestions. Mine is NOT the voice of doom. I just feel with the smaller tank and engine you will enjoy it more. Brst of luck with your new plane.

Mark Shuman

BTW mine has a Saito 50 4 stroker on it and I never need more than 3/4 throttle.

actually, with a trainer the line can be flexible or stiff. it doesn't matter. however, once you get past a trainer, you want it to be stiff. here's why.
what happens when you go down a steep dive on a roller coaster? you want to fly upward. so when you are going a dive or pointing downward steep enough to drain all the fuel to the front of the tank, it is already being pushed against the back. i had the same question wehen i had to replace the tank on my trainer. i thought all the other tanks were defective because the line couldn't drop down line they could in the instruction manual.

hmm... would anyone like to trade me my .61 mag for a .40... cus i dont have the money to spend on a new one... i do have three radio systems and two mag .61's and the plane came with the mag... i wasnt aware that the tank would be too big ... it also came with a 24 ounce and i went to a 20 ounce thinking the 24 was too big... hmm... what to do... do you think that the 61 and 20 ounce will hinder my learning that much... i mean... will i just learn to use my left thumb and/or take longer to learn... or will i really run a risk of crashing or learning bad flying habits... thanks for all input...

Don't worry about it. While the 61 is overkill, it certainly won't hurt to use it (especially if the cost of replacing it is a concern). And if the tank is too big, you'll just have to remember not to stay up so long that you're hogging the frequency pin.

I have a .61 on a Kadet Sr with flaps... leave it on.

As I said... it just makes it capable of heavy payloads. Stick a 13X4 prop on it and go fly. (and you can darn near take off in the airplane's wingspan with no wind)