Re: Is it worth buying the parts for a 049 tee dee rather than try finding one?

balogh Wed Mar 07, 2018 12:52 am

xtal_01 wrote:Just want to keep learning ....

Kim explained why I want to use a wedge tank for U-control flight ... makes sense.

So why do I see some people using a balloon tanks?

And why / when do you the pressure port on the tee dee?

And why do some people drill / tap a pressure port in the back of the engine? Do you then need a check valve?

Just all kinds of questions.

Mike

Mike,

I can only speak for R/C applications and about my experience, others may chime in with similar R/C and C/L advice.

The balloon tanks I use are not pressurized, I actually select a party balloon the size of which is just a bit larger than the volume of fuel I want it to carry....typically 1...2 oz for 049....09 COX engines, and smaller for the 010...020 size TeeDee-s. With a 2 oz syringe I fill up the balloon only to such a point when fuel starts to flow by itself into the engine with the plane in horizontal position, indicating that the fuel has just occupied the full volume in the balloon before it gets pressurized. Pressurization would make the mixture too rich at take-off and NV setting therefore problematic.

A balloon tank only takes 2 lines, one filler, and one supply line, no need for venting, no foaming due to engine vibration, good supply of fuel in inverted flights even without a heavy clunk, etc. The photo shows the tank of my LilRoughneck R/C bird (driven by a Killer Bee clone I assembled from parts, that I call TeeDeeReedie owing to its cylinder), removed from the tank compartment in the nose of the fuselage. I added a small plastic filter between the tank and the engine.

Is it worth buying the parts for a 049 tee dee rather than try finding one? - Page 3 Lilrou10

Or, another arrangement for the SIG Wonder R/C I built recently for TD09 engines:

Is it worth buying the parts for a 049 tee dee rather than try finding one? - Page 3 20171027

Reedie and TD engines both have enough suction power to draw the fuel if the diameter of the fuel line is not too small, the distance between the tank outlet and engine fuel nipple is max, say, 10 cm or 4 inches, and the tank bottom is not more than 1 inch below the carburetor level.

xtal_01 Wed Mar 07, 2018 12:25 pm

Thanks for the explination! I made the bad assumption (thus I know enough to ask) that a balloon tank meant a pressurized system. Obviously not the case!

Makes more sense to me now.

Still not sure why then people use the pressure port or they tap the back of the case for pressure if it is not needed? Is this only if you use too small of line ... or drill out the carb too big (so there is little suction) ... or have the tank too far away ... or ?

Mike

fredvon4 Wed Mar 07, 2018 12:29 pm

For combat and speed events ( that allow pressure) one great way to get a lot of power/rpm is to run as big a venturi as possible... when you do that to many engines, they will not run on suction...so pressure supplied from crank case or Bladder is needed

xtal_01 Wed Mar 07, 2018 12:44 pm

I love it that I no longer have to guess at answers!

Thanks for the explanation!

What did people do before the internet to find answers?

Mike

fredvon4 Wed Mar 07, 2018 4:13 pm

WE Tried hard to trust our friends were not BSing us...grin

Most of us read EVERY magazine we could find as did you---- and a lot was passed from dad to son or old guy to neophyte

BUT still there were many many guys who held their secrets secret....

BUT a lot of it was just us kids tinkering around and finding what did or did not work

Then there was the hobby shop guy most of the time super helpful with "you need this" to do that...OR have you thought about this new fuel or glue or whatever...Hey Fred I just got in a few of the New "whatevers" want to try one out? How I got my first Black Widow...that I though was wicked fast with a new can of Missile Mist....

Kim Wed Mar 07, 2018 4:25 pm

fredvon4 wrote:

BUT a lot of it was just us kids tinkering around and finding what did or did not work

THAT was the fun part !!!!

xtal_01 Fri Mar 09, 2018 7:32 pm

Just wanted to give a huge thanks to Kim!

He gave me my first Tee Dee and I just got it in the mail today.

Man this is truly a piece of beauty!

I can't wait to hear it run!!!!!!!!!!!!!!

Thanks again Kim !!!!!!!!!!!!!!!!!!!!!!!!!!!!

Mike

PS .... now can someone send some warm weather ... still snowing here in Vermont

xtal_01 Fri Mar 09, 2018 7:49 pm

I usually see pictures showing the needle sticking out to the left (if looking at the front of the engine).

However, I just saw a picture saying this is for free flight and it shows the needle sticking out of the right (again looking at the front of the engine) for u-control.

First, is this true? Does it matter?

Second, if it is true, do you "flip" the needle so that you have the black metal spring piece on top (putting the needle between the venturi and the cylinder) or do you put it in front of the venturi? And if this is true, do you use spacers so the carb does not hit the body nut?

Thanks again ...... Mike

Mark Boesen Fri Mar 09, 2018 10:31 pm

the needle can be flipped and/or rotated front to back or left to right, it depends on where your fuel line is coming out and if it might come in contact with ground on hard landing.

Kim Sat Mar 10, 2018 3:30 am

xtal_01 wrote:Just wanted to give a huge thanks to Kim!

Glad to hear it made it through all the weather that's stacking up on that side of the country!

Hope it works great for you!

Kim

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Is it worth buying the parts for a 049 tee dee rather than try finding one?