RCCOMBAT Forum

In the 50's and 60's, control line guys used a flexible liner in their home-made tanks that was filled up and then collapsed as the fuel was drawn out. Sort of like the no-burp baby bottle liners that you may have seen. If I remember right, they used latex balloons as the liner. The advantage of this is that there is absolutely no "foaming" in the fuel system and the fuel draw is consistant.

Is anyone using a bubble-free tank in RC Combat? If so, what are you using for a liner?

I have a lot of experience with bladders, and would be comfortable with them for Open B but what to try the various suction type of systems for SSC before I switch to bladders for SSC.

Gary,

There are actually a fair number of guys already using bladders for combat, just as there are using clunk tanks. If you want to try a bladder, you can place one inside the clunk tank.

In practice, I've never seen much advantage to be gained from using bladders, especially in SSC where max RPM is limited.

On the other hand, I have seen guys not get launched on time when their bladder enexpectedly bursts, or get sprayed with fuel when trying to fill them up. Another one of the other major bladder-turnoffs for me is the needle sensitivity. Although there are some guys that know what they're doing and can usually make the bladder setup run well, many guys spend more time futzing with the needle than they do flying and then suffer "lean runs" when it's not set correctly.

Bladder/Clunk is mostly a matter of personal preference, and since you have a lot of experience with bladders you may fair better than most. Can't hurt to try! [:)]

James,

There are a lot of guys flying bubbless tanks. Most use a clunk tank with a baby bottle liner inside. Captain America gave me some custom bubless tanks. They work very will!

Roid

I know some guys used old hair coloring bottles etc. and put the baby bottle liners in them. Using an old tank would work as well. the main thing is you put the fuel pick-up line in the liner and out the regular tank opening but the muffler pressure line must be outside of the liner. This usually requires the line not come out of the the original opening on a Sullivan style tank. A Hayes type tank would work better. The bottle liner must be fuel tight and the rest of the tank fed by the muffler pressure must be air tight. They really do the job but are more difficult to fill because you must empty the bladder of everything before re-filling it. Air can back-up into it after the engine quits. Another thing to look out for is the pick-up line for the fuel(clunk). It should be formed so the bladder can't fold over the end and shut off the fuel. Less energy is required to stop foaming in a regular clunk tank but the bubbless type tanks are the next best move before resorting to pressure bladders. I know, I have used all three types until the end of last season. I'm strictly a clunk guy now.

Alex usually when a bladder bursts is because it is used more than a few times, in a real competition I use new bladders on my open b makos and havent had this problem, also if you have a clear bladder cavity like clear tape or florecent light tube use a rag to cover the filled bladder from the suns rays (this is when your getting ready for the 90 seconds), this is a tip that Lee Liddle gave me last year , I have baby linner bubbles tanks on my ssc avengers and they work great

its purty simple and works good, any light 4oz bottle works, the stopper I found at ace hardware store, its aluminum tubing, I used welders contact cement(and no it doesnt atack the baby liner), and they been lighter than my 4 oz hayez clunk tanks, They last long, but just remember to empty them after a day of flying

Nice work Gil. Baby bottle liners appears to be the answer to my original question. Thanks. I'm just going to use clunk tanks for this weekend, but will bring some 1/2A size bladder tubing in case I start having problems with suction/foaming.

Dear GSJames,
Jett Engineering makes and sells bubbless tanks for Pylon. I used them in Bat Trick fuselages for quite awhile and was very happy with them. Try their web site: www.jettengineering.com

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Tetra also makes bubbleless tanks and they are distributed by Central Hobbies.

Anybody ever try a Fuel Magnet?

They are used in nitro helis and they have LOTS of vibration and foaming. In my nitro 50, will suck nothing but fuel down a mear skim of fuel in the tank.

http://www.readyheli.com/OMI_Fuel_Magne ... magnet.htm