Author Topic: the old harley drip (Read 727 times)

roger · « **on:** August 02, 2008, 06:21:38 AM »

any body have a drawing diagram of how to make a fuel tank from an old 35mm plastic film can? every time i try it drips. also the brass tubes, whats the configureation of those ?
??

need drawings

minnesotamodeler · « **Reply #1 on:** August 02, 2008, 06:55:11 AM »

Pick your canister carefully...some lids fit tighter than others, I guess the quality control is kinda lax. If all else fails, "goop" the lid on. (That's the product name, "Super Goop", some kind of silicone sealant I believe.)

Pickup tube should be halfway up the outboard side, maybe 1/8" from the back. Uniflow vent 1/2" ahead of that. Actually, a clunk line of small surgical tubing works really well, put a short piece of metal tubing on the end with a wheel collar attached for the clunk.

Simpler yet, put a floppy balloon tank in the canister.

roger · « **Reply #2 on:** August 02, 2008, 09:03:54 PM »

ahhhhh i think i know what ya mean

watya mean outboard side? i wish we could draw with this thing!

HB~>so theres gonna be 2 tubes in the cap right? 1 is longer and 1 is shorter right? 1 goes almost to the bottom and shoot ! im lost

roger

minnesotamodeler · « **Reply #3 on:** August 02, 2008, 10:17:21 PM »

You got it, Roger...2 tubes in the cap, one runs to the back (nominal bottom of canister) about 1/8" or so away from the end, along the outboard side, meaning the portion of the cylinder farthest toward the outside of the circle (canister is lying on its side when mounted on the airplane). Other tube (vent) runs along the same place, just stops 1/2" shorter. Bend the outer end of this tube up, above the top of the tank so fuel won't siphon out. Once the engine's running, it's drawing air thru this line so fuel won't siphon out even inverted.

Bootlegger · « **Reply #4 on:** August 03, 2008, 06:34:24 AM »

Something else to consider is using copper tubing instead of brass as the brass will deterioate in the fuel and give you some engine run grief...

minnesotamodeler · « **Reply #5 on:** August 03, 2008, 06:41:30 AM »

With the plastic canisters I actually use aluminum tubing. Rough it up a little and the "Goop" sticks to it very well.

But I use the floppy balloons (so called because they are left "slack", no stretch at all) even more.

roger · « **Reply #6 on:** August 03, 2008, 03:48:39 PM »

then why is it that on cutting open a tank i found that brass tubing was used and not copper or aluminium and also that some tanks are in fact made entirely from brass?

Marvin Denny · « **Reply #7 on:** August 03, 2008, 05:31:11 PM »

Main reason was cost. Brass is (was) somewhat cheaper. It (brass) when annealed, bends a little easier than copper, and lastly Brass is a little easier to solder than copper.
There was a well written article some time back in the PAMPA Stunt News . I still have a copy of that article I think. It even had some pictures of brass tubing that was removed fron some tanks that had started giving run problems.

Bigiron

roger · « **Reply #8 on:** August 03, 2008, 06:36:26 PM »

H^^oh