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Fuel Tank on CG

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Old 11-30-2005, 07:45 AM
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aerospot
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Default Fuel Tank on CG

I've read posts here that have tweaked my interest for positioning the fuel tank at the CG.
Has anyone done this and what, if any problems would I encounter?
Will it have any effect on how the engine runs? Will I need a fuel pump?

I'm building a Sr. Telemaster and have a 12 oz tank for it. It's proposed to be a sailplane tug amung other duties.
Is this worth pursuing in this project? What about aerobatic builds??

Thanks in advance for the insight!

Dave
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Old 11-30-2005, 07:49 AM
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exeter_acres
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Default RE: Fuel Tank on CG

I did it with my Showtime... I run it with an Iron Bay regulator
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Old 11-30-2005, 07:52 AM
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Default RE: Fuel Tank on CG

Yes, for most glow engine you will need some sort of pump. O.S. Engines makes a few 4 strokes with built in pumps and ALL YS engines are either pressure or pumped. All gas engines have a built in pump.

Placing the tank on CG has one major benefit. The CG of the airplane does not change during flight so you will not have to change your trim settings during the flight
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Old 11-30-2005, 10:21 AM
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BillS
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Default RE: Fuel Tank on CG

Putting the tank on CG in a Sr. Telemaster … probably gains nothing and adds complexity. Why?

Bill
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Old 11-30-2005, 10:22 AM
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exeter_acres
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Default RE: Fuel Tank on CG

agreed...forgot that part... for a pattern or aerobatic plane...sure... but really no need for a Telemaster IMHO
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Old 11-30-2005, 11:37 AM
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Default RE: Fuel Tank on CG

Most models are designed for the fuel tank to be right behind the fire wall, and the aircraft is designed to balance with the fuel tank empty. Then when fuel is added it increases the nose weight which makes for a much more controlled flight. Ever try to fly a aircraft that is tail heavy?Very difficult to handle and get it back on the ground in one piece. Vern Washington R/C Flyers - President
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Old 11-30-2005, 11:59 AM
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Default RE: Fuel Tank on CG

Perry pump, Cline regulator, or Iron bay.

Cline reg is my favorite.
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Old 12-01-2005, 12:10 AM
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Default RE: Fuel Tank on CG

I'm with the guys who said "Don't bother"

With a Telemaster, you'll go through a lot of work and never notice the difference
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Old 12-01-2005, 12:42 AM
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Default RE: Fuel Tank on CG


ORIGINAL: MinnFlyer

I'm with the guys who said "Don't bother"

With a Telemaster, you'll go through a lot of work and never notice the difference
I agree. Especially for a tug plane. You tug the gliders up and pop them loose. Who cares if it's a touch nose heavy on take off. That just makes it stable.
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Old 12-01-2005, 01:58 AM
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Default RE: Fuel Tank on CG

A senior telemaster IS a glider !!
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Old 12-01-2005, 03:39 PM
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aerospot
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Default RE: Fuel Tank on CG

Ok, I get the point for the Telemaster but, what about an airplane that I want to do aerobatics with like an Extra.
Is it worth the extra effort and trouble to locate the fuel tank on the CG and would I need to pump it to say a 2 cycle .60 -.90 ??
I havent ventured into the 4 cycles as of yet. Just cant justify the extra cash for em. I'd rather go into a larger scale 2 cycle spark ignition when the time comes... Do they have built in pumps that eliminate the need to worry about tank placment?[&:]

Thanks !!
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Old 12-01-2005, 06:34 PM
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Rcpilot
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Default RE: Fuel Tank on CG

Any gasoline engine is going to have a pump built into the carb. Put the tank in the tail if you want too. They will pull fuel 3 or 4 feet straight up.

For a glow engine--with the tank on the CG--you'll need an engine with a pump (not many of those) or you'll need a Cline Regulator or Iron Bay Regulator.

IMO--it's worth putting the tank on the CG on just about ANY aerobatic plane. I put the tank on the CG in my little 40 size 3D planes, and I use a Cline Regulator for them.

For a 60 or 90 size Extra--absolutely it's worth the effort to put the tank on the CG. Just run a Cline Regulator on it and you'll be happy.
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