Spitfire Balance
 

I have built a Topflite gold edition spitfire. It has retracts, and flaps as per instructions. It is powered by a Saito 91. My problem now is, to balance the plane properly I need approximately 1 pound of weight in the nose. This brings the total weight to just under 11 pounds. The instructions say the plane should weigh 8.5 to 9.5 pounds. I know the instructions are not always accurate when it comes to weights and everyone I have talked to says a lot of weight is needed in the nose of a warbird. Does anyone have any experience with this particular plane and what is can weigh and still fly reasonably?

Re: Spitfire Balance
 

Hi

I am planning on building this kit , this winter . I have everything it takes , even Robart retracts , and fiberglass cowl . I have read extensively on this bird . IMHO , you are alightly under powered with youre 91 , when you will need that power , BUT , thats me . If you need weight , in the nose , add a bigger engine ,:D

1 ) Youre 11 lbs , is what many have comeout with ( TopFlite weighs down ALL there kits )

2 ) make dam sure its nose heavy

3 ) Practice , OVER THE RUNWAY PASSES / FLAPS , before you land an atempt ( never come in on idle ) ( unless you have that experience )

4 ) chose youre conditions as per weather

5 ) keep the control surfaces , SMALL , especially the elevator

http://www.rcuniverse.com/forum/m_14..._1/key_/tm.htm

Hope this helps

BTW , I love the Spit-Fire

Michel

Re: Spitfire Balance
 

I built this kit and had the same problem. I had to add 15 ounces of lead across the front of the engine. I had a Magnum .91 4 stroke engine in it. Mine crashed on the first takeoff.
You really have to nurse it off the ground because it is so heavy. I now have a Hangar 9 ARF spit with the same engine in it and it flies like a dream !

Re: Spitfire Balance
 

When building a scale bird, you always have to be conscientiously aware of any weight behind the CG. You must build light in the rear.
I know this advice comes too late for you but I just thought I would mention it.

Is there any way to move any of the weight from the rear to the front? Can you shift any servos around? Battery pack? Anything?

In the end, balance 'er up and make sure you have plenty of power. your 91 should do well, but make sure your engine is putting out the power. Up the nitro if you have to

I have flown all the Top-Flite gold edition kits at one time or another and I can tell you they are all excellent fliers. Some more finicky than others, but still fly well. The take-off shouldn't be a problem. Keep your speed up, and your power on, climb shallow to build up airspeed. Landing is another story. Like Michel says, you need to get a feel for the planes stall characteristics UP HIGH. Landing on the narrow undercarriage is going to be a trick. FLY it in under power. If you have flaps, you are going to need them.

Re: Spitfire Balance
 

Hi

I forgot to add : If you can conquer this bird , it is one of the most graceful you will ever fly , because of the wings .

Make sure youre well prepared , it,s better than GOOD LUCK .

All the best for the maiden

Michel

Re: Spitfire Balance
 

Thanks for the advice. Michel, you are right. If I had known that I would need that much ballast in the nose I would have bought a bigger motor. I even found out after the fact that the Saito .91 motor I bought was one of the lightest on the market! Doesn't help me any.
Max. I am working now on moving everthing forward. The battery is in front of the firewall and controls, reciever, and gear air tank have all been moved as far forward as I think I can get them. I moved the engine forward 1/8 of an inch and I am securing the ballast weight as far forward as I can. In fact it is this weight issue that has delayed the first flight. I am trying to be as careful as possible. Max, I was a member of the Aurora club a couple of years ago (Shane Thurston). If this is the same Max, you taught me how to fly! I moved to Vancouver 2 years ago, small world! Thanks for the tips, I'll do me best to follow you're advice, thanks.

Re: Spitfire Balance
 

Hi Shane.

Yes, its me :)

I am glad to hear you are still flying. I know your buiiding style, so I can assume that spitfire is gorgeous :)

Buddy, all I can say is if you can fly the heavier-than-normal Kavalier that you built (which I loved to fly and I said "it lands like and F-16"). If you can fly the crap out of that kavlaier, you should be OK.

You should have no problem with the spit. PLEASE have a spotter next to you. Sometimes on a maiden you have your hands so full flying the plane you cant take your hands off the sticks even to move the triims. A helper that can do that for you while you call out what you need is a real plus.

Tell us how you make out, and I would love to see photo's of that bird of yours

Cheers :TU:

Re: Spitfire Balance
 

I have a gold edition top-flite p-47 arf with a saito 100 i added about 3 oz to the nose and it still tail heavy...i am going to have to add another 3 for shure around the firewall.

Re: Spitfire Balance
 

Nick
I have been struggling with the balance issue for a while now. I have almost 1 pound of lead in the nose, I am trying to bring this down. My one question is "will it fly?" I don't think adding 6 oz to the front is excessive. If I only needed to add 6 oz I would not be worried. I don't care what I need to add to the nose, its the overall weight that concerns me. It is amazing how just moving stuff around will balance the plane and not add any extra weight. I moved my battery to the front of the firewall and my weight is bolted to the front engine bolts. The weight is as far forward as I can get it. I haven't finished making my modifications so I don't know what results I'll get but everything helps. Also, everyone says that warbirds are inherently tail heavy and weight in the nose is not uncommon. I also have 3 other planes of various designs and everyone of them needed some weight in the nose. I would check the overall weight and see what it is with the ballast. Good Luck

Re: Spitfire Balance
 

Shane- you got the right idea of putting your weight as far forward as you can- ie- attaching it to your engine bolts.

I am in the process of balancing my KMP Zero, and it is VERY tail heavy. I had to add about 5lb to the firewall, and that did not make me very happy.

The further from the CG you can get your weight, the less weight you will need to balance the plane. I am not satisfied with adding dead weight to the firewall like I did.

I am in the process of making a weight box that will be just behind the prop-hub. I should be able to halve the weight needed to balance the plane. The box has to be solidly secured to the fuselage. Mine bolts onto the motor mounts. I am documenting the process and will put up a thread on how I am doing it. Watch for it in the next few days.