Sarah

Hi Guys,


I would be grateful if anyone could let me know if there are any slightly larger fuel tanks which will fit in the nacelles of the Hobbico Twinstar.

The standard ones look like 4 oz tanks, there is space for probably 6 oz tanks but the ones I've seen are all too long.


Many thanks,

Sarah

Ed_Moorman

My Feedback: (1)

Good luck and I think they are closer to 3.5 oz. The world has been looking for larger tanks for the TwinStar for a long time. Please post the name if you do find one that fits.

Robby Newton, the moderator, builds longer nacelles for bigger tanks and fabricates longer fiberglass nacelle covers.

bass0matic

I put Sullivan 6oz tanks in mine. they are a 2" x 2" x 4", towerhobby.com has them. they are model number S403. you have to do a bit of grinding, reinforcing and move the servo back about half an inch, but it's worth it.

I'm puting two os 40la in it so I figure I'll get about 9 or 10 minutes flying time considering the superstar and avistar have 8oz tanks and you get about 15 minutes with those.

I just finished the grinding and reinforcing on one and the grinding on the other so if you want pictures let me know

Sarah

Hi,

Any pictures would be great thank you.

Sarah

jaka

Hi!
The best tanks you can get is Tettra "bubble-less" tanks. These are used by pylon racers all over the world! These tanks are long and slim.

bass0matic

I just checked out Tettra's tanks it looks like the biggest is 6oz. the problem with that tank is it's longer then the sullivan. by 3/8 inch. the nice thing about the sullivan I found is that it's 4 inches long which means more fits in the nacelle. the servo goes in the wing behind the nacelle and the more you cut out of the wing the less stable it is.

bass0matic

[img][/img]

ok, here we go. the first two pictures are the label for your ordering reference and the tank next[img] to the stock tank so you can see a difference.
[img]
The next picture is the nacelle ground out to fit the tank. a dremel comes in real handy.[/img]

the next two show the tank inserted in the nacelle

The next picture is the wing after I ground it out, but before I reinforced it.

the next picture the wing after I reinforced it.

then we have the nacelle inserted and the servo in place. please note the wall I built in the wing was done with popsicle sticks and epoxy to strenghen it and fuel proof it. it also seperates the servo from the tank.

take care in extending the servo tray as it only balsa. I also glued popsicle sticks under the top inside of the wing to screw the servo in as there is only balsa.

bass0matic

here are the first five

rcdude7

My Feedback: (264)

[:@] I don't know if that is going to work............ You removed the upper spar completly and half of the lower. These spars are the main load bearing structure in your wing. You have reenforced the area with posicle sticks, so you may be okay if you fly gently.........I don't know.
I scratch built new nacelles for my twinstar because I refuse to cut into the wing, and there is no other way to gain room for larger tanks otherwise.
I am using two OS FP .40's and two hayes 8 oz. tanks for my setup. I am also buiding larger ailerons and using a dual aileron servo config.
I would post pics, but my camera batts are kaput. Maybe later................

Mike

bass0matic

I think it will be ok, if it isn't...that's why it a hobby (what's a hundred for another). I finished it this weekend but it was to windy to fly.

I don't make it a point to be fly gently. I like fast.

I if all doesn't go well I will post a picture of the crash

Sarah

Good luck with the flight.

Sarah

jaka

Hi!
But why have the throttle servo behind the tank?? Removing that spar in the wing is not agood thing to do.

I would choose a .25 (4.0cc) engine and either use a 5, 5.1/2 or 6 OZ Tettra "Bubbleless" tank and just use one centrally placed throttle servo controlling the throttle via a Sullivan goldenrods.

bass0matic

Man, people put a lot of opinion into this.

before the modification the servos were behind the tanks, I just moveed them back half an inch. I am using golden rod for the throttle.

If anyone wants to see it fly can go to the Sepulveda Basin [>:] http://www.rcuniverse.com/forum/Sepu..._839955/tm.htm
and watch.

if I crash I'll post a picture and you can all laugh.

by the way I had an elephant stand on it and it held up nice

rcdude7

My Feedback: (264)

Ha ha, If it passes the elephant load test, it's cleared for pylon racing

MajorTomski

Umm I flew mine with .25 engines and the stock reccomended tanks. Flew quite well for about 12 minutes. Why do you need bigger tanks?

bass0matic

I put os.40las in mine

Sarah, What kind of engines are you using

Sarah

Hi,

I've got two OS25FX's for my Twinstar. The reason I wanted larger tanks was that one of the guys I know uses the OS 25FX in his Twin and he only get 6-7 minutes flying. If I allow a bit for reserve, in case someone is on the strip and taking a bit too much time taking off, then that would be 4-5 minutes flying time and I wanted more.

I would be interested to see how long other flyers get with two OS 25FX's.

bass0matic

my final exam of the twinstar proved good. The nacelles added strength to the spars that I had ground out. So all was good. I gave the wing a load test and they held up nice.

I fired it up...the engines were running a little rich (break in) I decided to run a couple of tanks on the ground. to avoid a dead stick in the air.

By the way, these are os .40 la with 10 X 6 APC props. I walked out to the runway and started them up (I didn't want to burn fuel when I was taxing) I lean them out and they were pulling 11000 RPMS (use a tach).

The take off was great I had good speed and brought it up high for the trim. end reult, it flew straight as an arrow without touching the controls.

did about 10 laps and brought it down although I landed it on the runway it ended up up on the grass. why? It needs brakes (fuel tubing on the axel) two engines have some pull.

when I walked up to it both engines were running. I was jazzed. so I got the dignity of being able to taxi it back to the pit area (instead of carrying it) when I was about 10 feet from parking it, one of the engines cut and I was able to taxi it with one engine.

It ran for about 10 minutes and flew about 80 to 90 MPH

Yahooo

Guy

bass0matic

by the way, one last comment. last week I time the engines at full throttle on the ground. I got 11 minutes. [sm=tongue_smile.gif]

Clay bartsch

My Feedback: (1)

all you did was cut the spars out. I bought a plane from a guy who did this and the effin wing flapped like a butterfly's wings the entire flight till the end when it collapsed in mid air.

Clay bartsch

My Feedback: (1)

he killed the wing structure.... no good now. I bought a plane from a guy who did this and the wing flapped like a butterfly's wings the entire flight till the end when it collapsed in mid air.

bass0matic

Remember, the nacelle reinforces the wing again. Mine flys fine.

Twin-star

Hi Guys
I added two extra 4 oz tanks attached side by side to the centre of the top surface of the wing of my twinstar plumbed them up using the tanks in the nacelles as if they were header tanks (ala helicopter set up) and ran all the piping through the wings. When the wing is attached the extra tanks sit inside the fuselage on the c of g point. I now have the equivalent of 2 x 8oz tanks running 2 x Supercustom 36 two stroke engines for 15 minutes going like STINK!!!!!!!!!!!
Works like a dream!

bass0matic

lets see some pictures

KI8FR

I put two 3 oz tanks in my fues side by side ran ran the clunk like from the fues to the vent line on the tank in the wing. then the klunk like to the carb. It works grate. Lots of line to run and to hook up and to un hook. but it did work and with my ervin 40 got a lot of flying time. I never timed it to see how long but it was more then I needed. I did not take it up more then 10 mi. at a time. The plane met its end when my X wife stomped on the fues. Now that why she is my X wife. the wing is still good so I am redoing the plane now with a new fues that is my own design. I hope that it will work and fly as good as it did before. I am putting retracts in it and making it a tail dragger. should be fun. I hope lol

Paul