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Speed,Combat,Scale,Racing => Combat => Topic started by: kevin king on May 28, 2023, 12:50:07 AM
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I just started to build a Vintage Performance laser cut Winder 2. Power is to be a Fox 36 MK VI on bladder.
There is a gap between the bladder tank hole and the hole in the leading edge sheeting to take the bladder in and out. Should I fuel proof the entire bladder tank area inside the wing? And should I seal the gap between the leading edge sheeting and bladder tank hole?
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Should i epoxy fiberglass around this bladder tank to prevent it from splitting?
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The gap between the bladder tube hole and the hole in the sheeting should be filled with a wood spacer and then coated with epoxy to seal it. The tube itself should be sealed internally to prevent damage to the airframe if the bladder pops or leaks.
That airplane is quite a bit on the small side for the power of a MKVI. A 36X or Super Tiger 35 would be more realistic but suit yourself. Aircraft in that era tended to be around 325 sq. in. In contrast, common size for a competitive combat ship for a MKVI was more like 450 sq.in.
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I just started to build a Vintage Performance laser cut Winder 2. Power is to be a Fox 36 MK VI on bladder.
There is a gap between the bladder tank hole and the hole in the leading edge sheeting to take the bladder in and out. Should I fuel proof the entire bladder tank area inside the wing? And should I seal the gap between the leading edge sheeting and bladder tank hole?
Add some balsa where the hole will be to fill the gap. Glue it to the tube first, then sand it to match the airfoil shape.
Another option (if the gap is small) would be epoxy + micro balloons, added after the hole is cut.
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Thank you gents. These laser cut kits are the cats meow. I like the way the wing locks together in such good alignment without even any glue on it yet.😁
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The bladder compartment looks like a flourescent tube protector...?
If so...I never found just the right size of latex tubing that could be expanded to hold 3 ozs [or so] without squeezing against the bladder compartment.
The framework of that plane with all the intricate lightening holes and precise fits looks very nice.
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The bladder compartment looks like a flourescent tube protector...?
If so...I never found just the right size of latex tubing that could be expanded to hold 3 ozs [or so] without squeezing against the bladder compartment.
The framework of that plane with all the intricate lightening holes and precise fits looks very nice.
The tube is what came in the Kit, so i dont know if its a fluorescent light sleeve. I also found a fox 36X, which is an ounce lighter. Which ever engine breaks 120 mph i will use. Ive been wanting this for 40 years.
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Got the bladder tank window installed. First Winder with that option. Put the window on the bottom only.
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Also got 6 tanks through the mk 6 under some crazy conditions. 120 mph or bust.
https://youtu.be/AIMaUa4ptqY
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I would suggest getting a better bellcrank than the plastic one that comes in the kit if you're going for all out speed. Also, you're pushing your luck with the wooden test stand/plywood clamps for an engine that powerfull. Let us know how fast it goes.
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Whats wrong with using the Sig 3 inch bellcrank MM? Or is it the way its attached you dont like? Ps. Yes i was unprepared to break in the engine that day and it was a very sketchy last minute set up. The good break in stand was unavailable and i really wanted to push the break in process through.
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Just a plain nylon bellcrank, good for a sport plane. 3/16 garolite is good to make your own. You could copy the Sig design just leave a little more material on the inboard side of the pivot. https://www.mcmaster.com/products/garolite-sheet-stock/halogen-free-garolite-g-10-sheets-and-bars/ Tom Morris made some 3"x3/16 but you'd have to mount it different. Either way use a 6-32 shcs and nyloc nut, the bolt that comes with the Sig is soft. When that Fox mk6 gets to honkin' on you want to feel confidence.
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All my Vintage Combat planes have Tom Morris phenolic bellcranks. My concern was if they last 20-30 years I know the bellcrank would still be sound.
Tom
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Whats wrong with using the Sig 3 inch bellcrank MM? Or is it the way its attached you dont like? Ps. Yes i was unprepared to break in the engine that day and it was a very sketchy last minute set up. The good break in stand was unavailable and i really wanted to push the break in process through.
I broke a nylon bellcrank in half with a Clown racer powered by a OS 15. Perfect 3" bellcranks will not take the pull of a pre-Supertiger engine. I trust Fox, Veco, and my own work.
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Less than half way there i figure. Running up to 50 percent nitro should be interesting. But i got a fire extinguisher. 😄
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The leadouts are pictured in the forward position, and the stock position are the far right. The tip weight on the plans called for 1oz, I went with an ounce and a quarter. I was going to build a weight box but felt it was too much work.
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The leadouts are pictured in the forward position, and the stock position are the far right. The tip weight on the plans called for 1oz, I went with an ounce and a quarter. I was going to build a weight box but felt it was too much work.
Weight boxes movable leadouts are good for new untested designs. After building a few Voodoos, Flite Straks, and Noblers you know about leadouts and tip weight.
Lew McFarland pioneered the adjustable leadouts on his Shark 45 which was a radical new design. Unneeded adjustments are a failure point and added inboard weight that needs to be counter-balanced (double trouble).
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Hope you're going to use a better prop than the one pictured. Look up Eliminator prop or ZZ prop and get a CF 8x7. If that's the factory head you're going to want 5-6 head shims for 50% nitro or your crank will go bye bye.
MM
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MM,Thank you for the help. I have very limited experience with combat planes & engines. Where do i get the head shims from?
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Thank you Paul. Because i chose not to bury the engine in to the LE, and the motor is an oz heavier, I went for the adjustable leadouts, because i had no prior plane to use as a reference. I took a guess and added an 1/4 oz tip weight to make up for any added weight of the adjustable leadouts. It should be in the ballpark. I also talked to the designer of the plane, and his recommendation with 36 mk6 was a .25" forward of what is on the plans which I have. The mounting holes also fit the earlier fox 36 version which is lighter, so i have a choice of engines and leadout positions to keep everything going the same direction. Thats the goal.
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I woud just run it on 10%, it should hit about 20k on the ground with no venturi restricter. K&B HP glow plugs are good. You can get 120mph without the Panther @#$%. I wanted to ask you about the wood block between the motor bearers. Does the grain go up/down or front/back?
MM
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MM, the grain goes front to back. I know this is the wrong direction but i didnt feel like correcting it.
PS, Whats a panther @#$# ?
Kevin
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I will start at 10 % nitro and keep adding as required to get that 120
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MM, the grain goes front to back. I know this is the wrong direction but i didnt feel like correcting it.
PS, Whats a panther @#$# ?
Kevin
Al
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Kevin,
Order up some of these props for the MKVI. They have a stouter hub.
https://www.apcprop.com/product/8-75x5-0/
The earlier lighter Fox will want a 9X6ish prop is my guess.
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Kevin,
Order up some of these props for the MKVI. They have a stouter hub.
https://www.apcprop.com/product/8-75x5-0/
The earlier lighter Fox will want a 9X6ish prop is my guess.
Lane, thank you for the prop suggestion.
Kevin.