balloon tank easy-stopper

I need to watch those vids again. They're real good.

Thanks Phil I was wondering were I could pick up one of those am still thinking local surgical supply or something in that category. The plastic hemostats I have but are just to much time involved in getting to it and releasing in time for the engine to get fuel before it cuts off . getback

akjgardner wrote:I'm Starting to stock up on pill bottles from when I got My knee replaced, I was wondering if this balloon Idea would work in a small pill bottle? The bottle is approximately the size of a 1 once fuel tank. any Ideas ?

Sure it would Joe. It's only a "capsule" to keep the balloon from flopping-around during flight. I bought a bagful of "assorted-shapes" party balloons. Look for them in the greeting-card/toy-aisles at the markets that you frequent. They're generally 6" diameter balloons when inflated with air. Some are the "long-type".. which I like.. because they'll fit into a more streamlined capsule.. and give you a little more length to your fuel pick-up line.



This helps to keep fuel flowing as the balloon collapses..



Your pill-bottle should work fine. I'd cut the bottom off for streamlining if your mounting it outside in the airstream. In that case; secure the bottle with rubber-bands.

akjgardner wrote:I'v got several Guillows 400 series airplane kits and plan to use this idea when building them. The pill bottle would fit in a former right behind the firewall helping to prevent fuel from leaking over the inside of the frame.Plus I'm cheap and these 1 ounce fuel tanks are pretty expensive for what they are. Thanks for the help Roddie

Glad to help Joe. Andras (balogh) has a lot of experience actually "running" balloon-tanks in his RC airplanes. I do not. His have built-up fuse-construction and the balloon-tanks are enclosed.. which sounds like what you're planning. Andras runs them exclusively.. so he can give you tips on the best way to arrange the plumbing for ease of fueling, reliability.. etc.

One of the last times I traveled to the USA, I was fortunate to have my hotel shampoos in nice little bottles with metal lids and a seal. A couple pieces of brass tubing, a dab of JR WELD, and wheel collar, I have a nice homemade clunk tank. Of course tank style is dependant on the application.

roddie wrote:

akjgardner wrote:I'v got several Guillows 400 series airplane kits and plan to use this idea when building them. The pill bottle would fit in a former right behind the firewall helping to prevent fuel from leaking over the inside of the frame.Plus I'm cheap and these 1 ounce fuel tanks are pretty expensive for what they are. Thanks for the help Roddie

Glad to help Joe. Andras (balogh) has a lot of experience actually "running" balloon-tanks in his RC airplanes. I do not. His have built-up fuse-construction and the balloon-tanks are enclosed.. which sounds like what you're planning. Andras runs them exclusively.. so he can give you tips on the best way to arrange the plumbing for ease of fueling, reliability.. etc.

Thanks Roddie for your referral.

akjgardner, please see my typical ballon tank arrangement below. Hobbyshops sell the rubber stopper with 2 or 3 holes on it.



You may want to plug one out of the 3 with e.g. the stem of a plastic earbud. The 2 others lend themselves for a fill line (1) and supply line (2). The tank itself is a normal rubber party balloon that kids play with/carry to school events. The rubber stopper fits snugly in the neck of the balloon, no need to tie a wire or anything foreign around the neck.



For better utilization of the space in the nose of the plane I use L-shaped plastic tubes (these are plastic conduits sold with servo pushrods also made of plastic, that I heat with a hairdryer and bend with the plastic pushroad kept inside to prevent the tube from buckling when shaping the L, then pull out the plastic pushrod.)  for the fuel line intersection with the stopper, so that the bent tubes should reduce to overall lenght of the tank setup and allow the placement of the tank as forward as possible.

The balloon tank makes an air-vent unnecessary, no heavy clunk to keep the supply line end under fuel level in wing-overs is needed, keeps the fuel foam-free, and fills the plane nose whatever shape it has, very efficiently. And the whole setup is very cheap. I cover the free ends of engine mount bolts occassionally  protruding into the tank compartment of the fuselage  nose with a short silicone fuel tube just in case the balloon rams into the firewall on an unplanned landing. The silicone sleeve on the bolt ends will prevent the balloon from getting punctured. Of course this assumes the bolt ends are accessible from the tank compartment to apply the sleeves on them every time you replace the engine on the firewall.

Texas Timers carries a lot of fittings for both balloon and bladder tanks. Rubber balloons have a tendency to deteriorate quickly with glow fuel. Another option for balloon (non-pressure) tanks is to use the fingers from nitrile gloves. Many places sell nitrile gloves for pennies each.

Resurrecting this thread; there's some enjoyable reading. Merry Christmas one and all!  

I've been saving the capsules that "end-mills" are supplied in. I use the end-mills on the CNC router at work. These particular capsules consist of a seamless transparent plastic tube with rubber caps on both ends. The end-mill size is 1/2" dia. X 3" length. The tube itself is 3" long, its outer diameter is .570" and the tubes' wall-thickness is .022". Without its two rubber caps, the tube weighs 2 grams.

It'll ultimately be tested on one of my many 1/2A U-Control profile models. The plan is; to have the tube straddle the models' C of G and mount to the outboard-side fuse/wing junction using hook & loop (Velcro) strips. Once the tube is positioned/attached; the balloon assembly is then inserted.




I've done very little with the hobby over the last few years.. but I'm gradually "getting back" ( Eric) to it. There's a fellow that I met this past Fall; through our CEF member Bill Steklenski. A while back.. Bill had visited the fella; who actually lives in nearby Chepachet, RI; less than 5 miles from me. Bill had told me during our phone calls, that this fella (Rob T.) has built several marine "outboard-drives" using .049 FRV/glow-engines. Well I saw them on my visit.. and let me tell you; they're nothing short of amazing. Rob is a master-modeler who has built his own model engines from castings.. using an old lathe/milling-machine in his basement-workshop. There was also a myriad of models that he's built (Aero and Marine mostly..) but he has amassed a HUGE amount of building-stock IE: balsa, plywood, hardwood.. spare-parts for vintage model-engines.. hardware of all sorts.... that I found most impressive. I hope to visit with Rob again, after the hustle and bustle of the holidays has passed. It's getting increasingly harder to find people who share this wonderful hobby.

Good job, and great idea roddie! They look like it will work just fine.