balloon tank easy-stopper

RknRusty wrote:Hey Rod, thanks for the idea. I wish I'd started a folder of your ideas long ago. One of these days I'm going to try a balloon on a stunt ship. Maybe seal it in an exhaust pressure chamber. I wonder how much pressure comes from a muffler, it can't be much. I could try and see with a check valve if it'll budge my cheap old automotive manifold gauge.

:lol!:they haven't all been good ideas Rusty.. This particular application shows how the elasticity of silicone line can lend itself well to both; tension or compression sealing. In this case; it forms a sealed plug when a hard-tube is inserted.. eliminating the need to glue-in a hard-tube inside the stopper.

It does take having the right size drills though. The feed-line shown below has several perforations along its wall and one at the end.. made with a 1/8" hole-punch.




I'm brainstorming a set-up for my reed-speed T33. I need to run the balloon/stopper through a plastic test-tube capsule. I'm using a long balloon.. not a round one. It's un-inflated size fits perfectly in the tube. The neck is cut-off for the desired length. The neck is also too thick to fit inside the tube.. when stretched-over the spool.  



A small "bracelet" rubber-band secures the shortened balloon, and clears my tube.




These little balloons fit tight on this spool. I was able to inflate one without it blowing-off.  They might work well for a Tee Dee .010. I'm guessing it holds between 4-5cc's of fuel.

Some testing revealed that my "nifty" fitting.. leaks. I did a "draw-test" using a syringe.. and the balloon won't stay collapsed. A pressure-test in juice-glass filled with water, confirmed the leak-area.



Not that it needs to hold pressure.. but the introduction of air on suction.. will no-doubt cause trouble. Possibly running a small bead of silicone-adhesive around the tube on both sides may help.. or maybe installing it into the spool with sealant..    

The syringe is a CVS Pharmacy item found in the baby department. Its nose-tube is long.. and this fuel-tubing fits really well.



Drawing back on it when connected; should collapse the balloon more than this.. and it should stay collapsed, which it doesn't.  



My post isn't living up to it's name.. but I'll keep trying until I get it right!

I have little kids, I must have a dozen of those from prescriptions. I have even more of the 5ml from Tylenol.

I also have designated a couple of them for the fish tank. Wish I thought of that one years ago!

Several reside in the flight box as give-away fuelers too.

For our needs as fuel handling the ones that use a plastic plunger without a rubber part are superior since the rubber becomes gummy as it swells in the alcohol.

Phil

It's "Squeez-N-Caulk" time!






Once it sets-up.. I'll re-test.

one of my thoughts Roddie was the wood stopper was leaking and needed sealing....I would suggest epoxy coating on the entire piece of wood to be fuel proof

That should do the trick // so you are going to remove the carb. tube to refill ? I am planning on two hoses one with a one way valve from Texas Timers to fill through and the other for feed , I am thinking rubber stopper for a plastic clunk tank ( got that from Andres ) he uses them and I am sure in all this STUFF I have some extras My main concern is that I don't know how much fuel I will need and is the balloon big enough ? I got another small long balloon and blew it to max and clipped off to let stretch over night I think it will do need to measure how much fuel it will hold and find a stopper !! getback

fredvon4 wrote:one of my thoughts Roddie was the wood stopper was leaking and needed sealing....I would suggest epoxy coating on the entire piece of wood to be fuel proof

Was thinking that too Fred cause wood is poises .

fredvon4 wrote:one of my thoughts Roddie was the wood stopper was leaking and needed sealing....I would suggest epoxy coating on the entire piece of wood to be fuel proof

Hi Fred, yea.. that definitely wouldn't hurt. Maybe dipping the bare spool in polyurethane sealer would do the job?

Checking back this morning, my hard-tube is sealed, but the balloon-seal is leaking. Even though the wooden spool seems smooth.. it's still too rough, allowing seepage.

This hasn't been easy so far.. The designing part anyway. My focus has been to keep a low-profile shape that will fit in a small streamlined tube. The long-shaped balloon seems to collapse very evenly along its length.. which might provide a more even-flow to the pick-up, as compared to a round balloon. I'm hoping it will work well with control-line in particular.

If I can get the sealing issue solved, it won't be hard to make one.. and its probably the lightest-weight of any other stopper material; short of a cork. I do have an idea for a cork-stopper, where the balloon is inserted into the tube.. and it's neck is stretched around the tube's opening. The cork-stopper with its plumbing pre-installed; would then be pressed into the tube to complete the assembly. Better craft-stores usually have a good assortment of small corks. Rubber-stoppers are too heavy.. even small ones. So far.. weight is down as compared to a wedge-tank.

Here is the weight in grams, of a #15 Perfect 1/8oz./4cc wedge.



and my balloon type of almost twice the fuel capacity.

Just rubber band directly to the silicone line where it is stiffened with the brass and be done already.

This wheel has been invented before.

Phil

(I've rewritten this a half a dozen times and it still sounds angry and rude to me... I don't mean it that way.)

getback wrote:That should do the trick // so you are going to remove the carb. tube to refill ? I am planning on two hoses one with a one way valve from Texas Timers to fill through and the other for feed , I am thinking rubber stopper for a plastic clunk tank ( got that from Andres ) he uses them and I am sure in all this STUFF I have some extras My main concern is that I don't know how much fuel I will need and is the balloon big enough ? I got another small long balloon and blew it to max and clipped off to let stretch over night I think it will do need to measure how much fuel it will hold and find a stopper !! getback  

I'll be fueling through a tee-fitting in my single feed-line. I'd save your one-way valve for use with a pressure-bladder Eric. Placing it on a fill-hose won't allow you to suck the air out of the balloon. You want to purge the entire system of air if possible. Pinching my carb-hose (upstream of the tee) with my fingers, allows the balloon to be collapsed and fuel to then be pumped-in. Releasing the pinch when full, will fill the carb-hose.. as long as the needle-valve is not closed. The tee is then capped-off.

I'm assuming that 7-8cc's of fuel is enough to complete 10 laps, running a TD .049 on 35' lines.

pkrankow wrote:Just rubber band directly to the silicone line where it is stiffened with the brass and be done already.

This wheel has been invented before.

Phil

(I've rewritten this a half a dozen times and it still sounds angry and rude to me...  I don't mean it that way.)

No worries Phil. The issue is.. my hard tube doesn't pass through the spool. It was part of my compression-fit design.

I gotta go to a future in-law meet and greet this afternoon.. but I'll get back on this soon.

Roddie I am with Phil on this...you get fixated some times and that is cool but the reality is You have already made good balloon tanks with OUT the spool

So just use the flower tube as a neat way to hold the balloon inside a wing or along the fuse and forget the complication of the stopper method you are trying to engineer

I don't have convenient access to those small flower tubes so I make fuel proof cavities, use 35mm canisters, or Rusty's Chinese finger sock to keep the balloon tank where in need it to stay

fredvon4 wrote:Roddie I am with Phil on this...you get fixated some times and that is cool but the reality is You have already made good balloon tanks with OUT the spool

So just use the flower tube as a neat way to hold the balloon inside a  wing or along the fuse and forget the complication of the stopper method you are trying to engineer

I don't have convenient access to those small flower tubes so I make fuel proof cavities, use 35mm canisters, or Rusty's Chinese finger sock to keep the balloon tank where in need it to stay

Yes Fred, you and Phil are right. The stopper isn't needed.. and I didn't realize that. Have either of you used a small zip-tie rather than a rubber-band around the neck of the balloon?

I just tried one.. and it's working pretty well.





This also increases the capacity of my balloon, which I was a little concerned about.

Those tiny silicone bracelet rubber bands are what I used. Put them on a small, short tube that the balloon can fit through (1/2 inch PEX or similar about an inch long). Loop the band onto itself about 4 or 5 times, put the balloon and brass through the tube and roll the band into place. Extra easy.

Take apart with clippers or a knife.

I used a filed brass tube, it punctured the balloon on the 2rd run. I only benched an engine on it. I never flew anything on non-pressure bladder.

This hole punch into silicone with the brass only at the neck is genius!

Phil

Don't remember where I got them but I have several packets of 100 rubber bands intended for orthodontic braces. They are a bit easier on my fingers than the O rings I was using. I did not have much success with the red caps using the very small zip ties...they always left a leak point right at the tightening pass through of the nylon zip tie

pkrankow wrote:Those tiny silicone bracelet rubber bands are what I used.  Put them on a small, short tube that the balloon can fit through (1/2 inch PEX or similar about an inch long).  Loop the band onto itself about 4 or 5 times, put the balloon and brass through the tube and roll the band into place.  Extra easy.

Take apart with clippers or a knife.

I used a filed brass tube, it punctured the balloon on the 2rd run.  I only benched an engine on it.  I never flew anything on non-pressure bladder.  

This hole punch into silicone with the brass only at the neck is genius!

Phil

I like that idea Phil! Thanks! I was picturing myself trying to loop the band enough times to be tight around such a small diameter. Your method would make it a lot easier. I would guess that the rubber-band(s) would clamp better all the way around than a zip-tie would too.

The syringe I'm using holds 10cc's.. but it also needs to suck all the air out of the balloon. Since you can't disconnect it during the air-evacuation/fuel-filling process.. the syringe would need to be twice the capacity of the balloon.. wouldn't it? Maybe Andras (Balough) will check-in and offer some advice. His balloon tanks work really well.

I invested in a 1/8" hole-punch a while back. It's what I used to nibble through the walls and tip of the silicone fuel pick-up tubing.



Here's an example of what can be used as a capsule for a small long-type balloon.



I think this will work well on my profile T33. I've got an idea on a mount system that I'm going to try this afternoon.

Tool holder. That label had me confused a moment. Good idea.

Phil

I also use aluminum cigar tubes to support balloon tanks as well as forming my own tubes from two layers of MonoCoat sticky side out and sticky side in as the outer colored layer formed about a dowel mandrill of the diameter I desire

I bought a bag of 7" round balloons today at Walmart for 98 cents.

Here is a size comparison between the tubular balloon I've been messing with.



The blue one has about a 6cc capacity with it's pick-up tube installed.. and the 7" (round) red one would have an approximate 11cc capacity after installing a pick-up tube.

The blue balloon came in a package labelled "assorted shapes/colors" but did not specify an inflated diameter. I would guess that to be 6" or less. The other shape in that assortment is round.. and very small.

The "animal/twisty" type balloons are too small and narrow to use for this app. They're roughly the diameter of a typical drinking-straw when un-inflated.

For someone who hasn't used balloon tanks before, what is the drill for filling and connecting to the engine without squirting fuel all over the place?
Thanks -

The balloon tank acts a lot like a hard tank and has some (but not as critical) need to be mounted to not force the fuel to flow up hill or gravity feed and flood the engine,,,,basically they prefer to be centered on the same plane as the NVA/Venturi

The simplest way is to remove the fuel line from the NVA and with a syringe (a bulb can be used) suck all the air out first then fill the balloon but not expand it making pressure.

If the feed tube inside has enough holes the typical reed or Medallion engine will be happy just sucking it out by venturi action and usually the entire fuel load will be consumed before going briefly lean and shutting off

My TeeDees all prefer pressure systems to needle properly, and in those cases I substitute a Red cap or Tubing bladder,,,this method requires the fuel line to be pinched off and the engine started off prime then release the pinch to let pressure fuel flow...a bit of a learning curve but after than real easy to do three handed...grin

Quote ; My TeeDees all prefer pressure systems to needle properly, and in those cases I substitute a Red cap or Tubing bladder,,,this method requires the fuel line to be pinched off and the engine started off prime then release the pinch to let pressure fuel flow...a bit of a learning curve but after than real easy to do three handed...grin
. Thanks Fred I needed a good laugh !! Eric