Hey all you Jet Jockeys out there in with hysol and kerosene on your hands, need some help with a tank for a recent Roo 2 project. So far I have found that the typical 2 liter soda pop bottle is a bit too long for the space between the foam Herax formers. I have seen a Windex refill bottle that looks like it might work but, having no experience with this I thought it better to ask the "experts". Also, the small 3 1/2 " hole in the aft former does not seem to accept the bottom of the typical 2 liter bottle that would help stabilize the tank anyway. Would like to keep it at 2 liters rather than go to something smaller that surely fits but won't supply a JetCat P80 enough jet juice for more than 5 minutes.
Any suggestions for a different kind of soda bottle besides those we find at the store???

John

http://www.angelfire.com/wi/jettech/page2.html

jet-tech makes kevlar fuel tanks,

for the roo I have the 105 oz oval plus a BVM UAT

Crazy,-- thanks for the imput. I am aware of the Jet-tech line of tanks and their custom fit but I'd rather fit something more simple and less costly if possible. The majority of the Roos and Rookies that I've seen appear to be using the soda bottle tank if I'm not mistaken.

Hey guys, give me some feedback!!! There must be some kind of bottle that will work within the space of 9 1/4 ". There must be one or more of you Jet Jockeys that have used it successfully in the Roo. BTW Crazy4Flight, I have a 105 oz Jet-Tech tank that is too large for me to also add a smoke tank to the bird.

jpor22

Why not just open up the hole in the rear former until the 2 litre bottle fit's ???

John

I just enlarged the hole in the rear former. I slid the 2 litter bottle back until the cap just sat on the front former. This also helps to support the rear of the tank. I then just use a few rubber bands around the necks and down to some hook eyes to hold it all in place. It works great!!!

Bill

Thanks Countryboy and Bill. I'd do just what you recommend, but the amount of the rear herex foam bulkhead seems too meager to do it. Don't know if your Roo's were of the same type but on mine, compared to some, the hole leaves about 1/4" of material at the top and the bottom of the former and beyond that I'm right at the skin of the fuselage. I think I would have to remove all of the material to fit the standard 2 liter bottle and I'm concerned that since the foam is so weak I'd have a problem with bulkhead strength.
If I'm not mistaken, it seems that the typical 2 liter bottles now used for soft drinks are shaped with a longer neck than those I've seem used before and that seems to extend it too much for this application. Hey, I could be worrying more than neccessary about it but those of you who know --clue me in.

John

Take out whatever you need to take out, there is not much you can do to mess up a roo. I've taken out the complete forward former in one of mine to put in a custom tank. No issues. Just secure the tank in there and move on to the next step. It's scary first time building a turbine jet, but you'll look back on it later and laugh.

Sean

If you read the manual, it says remove whatever is necessary to fit the tank.
Not much left of my former, over 300 flights and it's still OK.
The former is very soft and weak anyway.
I used a 2 ltr Pepsi bottle if I remember correctly

Very simple. Just cut the bottle in 2 pieces and remove a 1/2inchs or whatever it takes to make it the correct lenght, use aeropoxy (hysol) to put it back together. Aeropoxy is kero proof. That's what i did on mine. I have a coke bottle cut down to 1.850litres. I can post you a pics if you want....

Interesting solution. For that matter, you could wrap the fuse with 6 ounce and resin probably.

Sean, Pete and "Mon Ami", thanks for your collective imput. I knew that I could get the answer from my fellow "Jetsters"!! It has been several years since I built a jet, a BVM Sabre, and my builders' intuition is rusty!! Now I can move on with the build with some confidence that I'm not screwing up. I'll do as you two suggest, Sean and Pete, which will be to auger out the aft opening until it accepts the bottle. If it still doesn't I'll modify the forward bulkhead to fit and get on with it.
The "French" solution could also work or one could go to a smaller 1.89 litre bottle (eg. Aquavina), if a smaller turbine was the powerplant, and avoid the extra work.

Thanks again guys, I hope to be laughing about it soon.

John

Yup i didnt mention that i'm using a Wren MW54, so it take less fuel, only 6oz min at full throttle. 1.85l is about 62oz...I get an easy 10 min of flying...At wich rate a P80 is eating fuell at full throttle??

My P-80 eats 8.7 oz/min 17lbs thrust

new 19 lb thrust P-80 9 oz/min at full throttle

John,

If you haven't moved along with this already, I snapped a few pics to confirm that it can be done. You will also notice in the first pic that the front former has been removed. I did this in order too get at the wing roots so that I could glass them where the fuse had split open at the seam.

Countryboy,
Good pics, they are helpful, thanks. My Roo has the foam herex formers that are very weak compared to the balsa in yours. I guess ripping them out if needed won't matter in the big picture but, I will start with augering out the rear former opening and if it won't fit then I'll R/R the front one and continue. BTW I also need to glass the seam at the front of the fuse inboard of the root attachment point for the wing. I hear it can separate and that could be catastrophic in flight.

Thanks again for all of your help, I've enjoyed the "back 'n forth" I've had with fellow builders and pilots.