Video: Making a pressureless bladder tank and using it to fuel my Medallion

I'm that good! It always blows the clip off when it starts if I don't hold it. I've had it since forever. Maybe a new one is in order.
And yes, the video was corrected to 1080i. For the first half hour it was only 480p

Na, keep the clip, sometimes older things work the best and just "feel" right. Again thanks for taking the time.

Very nice! It runs smooth and steady. I think I'll mod one of my Tee Dee venturis for better fuel draw and try it and a balloon tank on the Brodak Baby Lightning Streak I'm planning to build this winter.

tubebass wrote:Very nice! It runs smooth and steady. I think I'll mod one of my Tee Dee venturis for better fuel draw and try it and a balloon tank on the Brodak Baby Lightning Streak I'm planning to build this winter.

Mine has a stock venturi. I would recommend waiting until you actually fly it once and see how it performs first. Also I like the way it runs with the old style dual bypass cylinder, you might want to try one, especially if yours still has the original single bypass cylinder. Just my thoughts.

I should also tell you what went wrong before you make a bladder tank; I flew my prototype bladder on the Stuntman23 with a Tee Dee last weekend. It wasn't perfect, but I think I have all the problems worked out.
What happened is, looking back I did a poor job of mounting it on the plane. I put it under the plane like in this picture:


When I flew, it was farther forward, all the way to the end of the firewall. The closer the better.
Notice I didn't use a container to secure the bladder, I just tied it to the fuse in the rear. That was a mistake. Then I accidentally pinched the fuel tube in front with a rubber band and restricted the flow, so it gave me a hard time evacuating the air and some probably remained. That's The most important part of fueling it. Since I was worried about balance, I only filled it half full, so I wouldn't have to hang on to a wild pig for 7 minutes. (That's how long a full balloon will run with a TD). It gave me hell getting it running. After I straightened out the rubber band, it ran fine when it finally cranked. But while it was flying I could see the balloon fluttering wildly. It was secure, but it should have been in a container to hold it still.
While flying, I did some level laps and it ran steady and fast. When I flipped it inverted i did about 5 laps and it ran exactly the same as when it was right side up. But when I did loops it stuttered and slowed. I finally crashed it when it cut out on the downside of a loop. I tried another and for unknown reasons had trouble evacuating it again and the same thing happened. Except this time after it cut off while pointed at the ground, the lines went really slack and the damn thing started again. A full power nose in created a spectacular blast of fuel spray, the tank was ruptured and that was that.

I think if you watch out for all those mistakes, it will run fine. I go again Saturday or Sunday. Better weather forecast for Sunday. Just fair warning, mine is still unproven. But if I put it into a container and secure it more carefully, I think it will work well.

Awesome video! Thank you for taking the time to share that with us. I found that it is just as frustrating to watch somebody else have their engine "POP" but not fully start. You have that little bad boy running beautifully.

Bob

I had to give that cylinder back to Microflitedude so I put my new SPI set from Bernie on it. It sounds different, not quite as throaty but it runs smoother. I can't tell a speed difference. I still haven't gotten the hang of cranking it in the first few flips. I might need a better glow driver. I just use two alkaline D cells in parallel.

BTw guys you know you can post a video like this.

Mine always show up like that on RCG, but not here. Maybe it's because I add a link to the 720p HD video. I see you used a "Flash" tag in yours.

NO here you must copy the link and then paste it in the thing from the toolbar that looks like film then click "ok"

I see. That works as long as you clip the URL from the browser address. It won't accept the "Share" link I was using for HD or SD.

I just copy the URL of the video and it always works fine for me.

nitroairplane wrote:I just copy the URL of the video and it always works fine for me.

That's what I've been doing wrong. I copy the link from the "Share" button which I think takes you to the same video, but on my channel page.

Oh yeah that wont work for sure.

nitroairplane wrote:Oh yeah that wont work for sure.

I wonder if you know that the great Roger Freihheit of Microflite in Tacoma Washington (www.micro-flite.com), the developer of the PET Thermal Exhaust Throttle muffler for 010-s used to sell similar balloon tanks not long ago. I bought couple of them and used them in my 010 powered RC birds and they really worked fine. The great thing about these balloons is they are so easy to fill, prevent foaming of the fuel and as the engine sucks in the fuel they gradually collapse until the last drop is consumed.

Unfortunately it is not easy to get a response from Roger on my emails but I keep trying to get some more of his great stuff for 010-s that he may still have on stock.

balogh wrote:

nitroairplane wrote:Oh yeah that wont work for sure.

I wonder if you know that the great Roger Freihheit of Microflite in Tacoma Washington (www.micro-flite.com), the developer of the PET Thermal Exhaust Throttle muffler for 010-s used to sell similar balloon tanks not long ago. I bought couple of them and used them in my 010 powered RC birds and they really worked fine. The great thing about these balloons is they are so easy to fill, prevent foaming of the fuel and as the engine sucks in the fuel they gradually collapse until the last drop is consumed.

Unfortunately it is not easy to get a response from Roger on my emails but I keep trying to get some more of his great stuff for 010-s that he may still have on stock.

Ahaaah I did know that!
I was in contact with him about it last year and way going to order 2 and 2 engines.

RknRusty wrote:

tubebass wrote:Very nice! It runs smooth and steady. I think I'll mod one of my Tee Dee venturis for better fuel draw and try it and a balloon tank on the Brodak Baby Lightning Streak I'm planning to build this winter.

Mine has a stock venturi. I would recommend waiting until you actually fly it once and see how it performs first. Also I like the way it runs with the old style dual bypass cylinder, you might want to try one, especially if yours still has the original single bypass cylinder. Just my thoughts.

Well I've got lots of venturis. The other reason I want a restricted venturi and non-SPI set-up is that I want to try a throttle sleeve on it. Milton Dickey, dickeybird on the forums, recommends that as a way to get a tee dee to idle reliably. It does reduce the power output though.

I had a throttle sleeve on a tee dee .020 and it ran great!

balogh wrote:

nitroairplane wrote:Oh yeah that wont work for sure.

I wonder if you know that the great Roger Freihheit of Microflite in Tacoma Washington (www.micro-flite.com), the developer of the PET Thermal Exhaust Throttle muffler for 010-s used to sell similar balloon tanks not long ago. I bought couple of them and used them in my 010 powered RC birds and they really worked fine. The great thing about these balloons is they are so easy to fill, prevent foaming of the fuel and as the engine sucks in the fuel they gradually collapse until the last drop is consumed.

Unfortunately it is not easy to get a response from Roger on my emails but I keep trying to get some more of his great stuff for 010-s that he may still have on stock.

Do you remember anything about them that I'm missing or could do better? Like, compared to mine, what his pickup tubes looked like, or his bladders, were they balloons or something similar?

I never made it to the shop today. I was going to make some spare bladder tanks and get them mounted properly on a couple of planes so I can fly tomorrow. But I spent all day doing house work and raking leaves.

here ya go rusty,

Looks about like mine. Can't see the pickup tube but I think my version is okay. I made a much better one with more uniform and larger holes. And after pushing a 1000 grit sandpaper plug through it to get out the large burrs, I came up with an idea; I waved the flame from my butane soldering torch , one of the Mini torches, over the holes and all the tiny stray plastic pieces disappeared and it looks like a factory made tube now. I will fly today. Bladder tank version 2.0. It's in a proper container this time.