Noblarf tank solution

I now have about 20 flights on my Noblarf since changing the engine to a Double Starr 40. The tank is a Hayes 4 ounce.

The thing I did that is different is to use a tube punched through the front wall of the tank to be the Uniflo vent. This vent tube was punched through at a level with the engine's needle valve, even though it isn't nearly on the tank centerline.

I put a slight curve in the tube, and by simply rotating it I can change the vertical position of the tube's outlet in the tank.

This setup is working perfectly. I just needed to rotate the tube slightly to raise the outlet inside the tank after the first few flights to even out the engine run upright and inverted.

Ain't science wonderful! Just goes to prove that the shape of the tank and pickup position matter not at all. ONLY the Uniflo vent outlet position affects the upright/inverted run.

Since I am running a clunk, I need to be cautious of how much fuel is in the tank. It quits with NO warning.

BTW, I am running 15/11/11 fuel and a reworked Zinger 11x4 ( thinned, undercambered blade with the high-point around 25%). 60' of .012 solid line. I use about 3 ounces of fuel to do the pattern. Lap times are around 5.2 sec.

Larry:
Neat idea. How did you seal the tank after punching the tube through?

LAST EDITED ON Jul-28-04 AT 08:30 PM (CDT)
 
>Larry:
>Neat idea. How did you seal the tank after punching the
>tube through?

I'll take a guess at this one: plastic tank with rubber stopper type plug. Self sealing around any tube punched through the stopper.

LAST EDITED ON Jul-28-04 AT 06:17 PM (CDT)
 
Unfortunately, not a good guess. I punched the tube straight through the front wall of the tank near the outboard wall. The tank material seals perfectly well by itself if you leave the hole undersize. Not even glued in. If I was to experience problems, I would use Goop adhesive on it.

Metal tubing, (rigid) plastic tubing, or silicone tubing? I remember your articles about making tanks out of plastic containers where you simply run silicone tubing through holes.

And it's a plastic tank, right?

I'd read about varying the uniflo vent position by rotating the bent tubing before, just can't remember where.. it's somewhere in the pile of magazines in the boxes over in the spare room..

I have tried the Hayes 4 oz. tank with muffler pressure to standard vent in my Nobler ARF. The tank fits beautifully, and worked great, with perfect engine runs. The only problem was, with my Os 40 LA, It just wasn't large enough.

In this case, metal tubing run through the wall of the tank. No apparent leakage with just the interference fit.

I don't come close to filling the tank with the Double Starr 40 and an 11x4 prop. It runs mostly "fat 2". I could see that if you ran a 6" pitch prop, you would need to richen up the run, and that burns a lot more fuel.

Larry, I take it "simply rotating" involves melting a solder joint where the tube enters the tank?

No. Plastic tank, metal tube.

Larry's trick is a good one.

Right on Sir Dirt! I don't know how else to say "hole through plastic" and "interference fit" and "could glue it if needed".

Mr. S.M.A.L.L.,

Since Dirt, our laudable linguist isn't helping out, how about: "premeditated penetration of the polymer plane...," and "forced, shared dislocation of the molecules with resultant residual strain energy," and finally, "pucky it up, dude!"

Dave
LA_Flyer

PS-Still looking for the "perfect" size bottle to build a tank for my BabyClown. Gotta find one soon, 'cause the paint on the fuse is almost dry!

PPS-I drank a carton of milk the other day and noticed it might be a good size for the igNoblarf.... The moral of the story might be that if you can't buy control line fuel tanks at the LHS, go to the donut shop?