Temporary tank mount on a Profile

[Joe Ed Pederson]

I've got a Sig Akromaster profile model completed except for mounting the fuel tank.  I made the longest uniflow metal tank that would fit between the Leading Edge and the back of the engine so there's no room to put the tank on plywood or solder on tabs to utilize threaded inserts to be able to adjust the height of the tank.
 
Having never guessed correctly the exact tank height on a profile, I'm asking for ideas on how to temporarily mount the tank until the correct height is determined by flying.

Thanks,

Joe Ed Pederson

[bill bischoff]

Brodak BH-778 tank brackets solder to the top and bottom of the tank instead of the ends of the tank. Perhaps they will work.

[Dan McEntee]

    1) Put some kind of thin, rubber pad on the back of the tank, the same dimensions as the tank.

    2) Get an approximate idea of where the tank will sit and mark the fuselage. .

    3) With the engine off the fuselage, slide some small rubber bands down to the tank area and put as many as it takes to securely hold it in place. Something that is even better is an old bicycle inner tube cut up into wide rubber band. Stuff wadded up paper towels or what ever above and below the tank to get it to hold position.

    4) Reinstall the engine and test fly. You should still be able to move the tank up and down a little bit until you get a decent idea of where it should be and then mark the fuselage again.

   5) The brackets from Brodak that have already been mentioned can be used, or "U" shaped wire hooks can be made and installed where one arm is above and below the tank, then bend into a hook and use rubber bands to retain the tank, used with the same rubber pad as in step #3. You can slide some small fuel line over the U shaped pied before you install it and it will help to keep the wire from chaffing away at the finish on the model.

  Type at you later,
  Dan McEntee

[Joe Ed Pederson]

Brodak BH-778 tank brackets solder to the top and bottom of the tank instead of the ends of the tank. Perhaps they will work.

Thanks for the suggestion Bill, it would be a good idea (and I'll remember it) on some models, but because of the shape of the fuselage on the Akromaster in the nose and where the motor is mounted there is no room above the tank to put a threaded insert.  The tank will be very close to the top of the fuselage.  and on the Akromaster the top of the nose is the maple motor mount.

Joe Ed

[Joe Ed Pederson]

    1) Put some kind of thin, rubber pad on the back of the tank, the same dimensions as the tank.

    2) Get an approximate idea of where the tank will sit and mark the fuselage. .

    3) With the engine off the fuselage, slide some small rubber bands down to the tank area and put as many as it takes to securely hold it in place. Something that is even better is an old bicycle inner tube cut up into wide rubber band. Stuff wadded up paper towels or what ever above and below the tank to get it to hold position.

    4) Reinstall the engine and test fly. You should still be able to move the tank up and down a little bit until you get a decent idea of where it should be and then mark the fuselage again.

   5) The brackets from Brodak that have already been mentioned can be used, or "U" shaped wire hooks can be made and installed where one arm is above and below the tank, then bend into a hook and use rubber bands to retain the tank, used with the same rubber pad as in step #3. You can slide some small fuel line over the U shaped pied before you install it and it will help to keep the wire from chaffing away at the finish on the model.

  Type at you later,
  Dan McEntee

Thanks Dan, that's a great suggestion.  I'll do what you suggested.  Don't have a bicycle inner tube so it will be a lot of rubber bands.

I was planning on using "U" shaped wire hooks when the correct position is determined.

Joe Ed

[BillP]

#11 size rubber bands work. Its the same size used on rc ships with wings that mount with rubber bands. You can get a bag of 100 at the local office depot for a couple bucks. They melt over the long term but work fine for finding tank height...or change them out when needed.