SALMONBUG

My Feedback: (1)

I am curently building a SIG tristar (discontinued canard)
due to the particular design of that plane, I need to bend one of the tank brass tube 180 °

I filled the tube with salt before bending it to avoid it crush
didn't work well.....

How should I do ?

mulligan

Unless you are bending larger diameter tubes, sand/salt will not work. Your best option is to purchase a tube bender at your LHS.

You might also consider a different fuel tank that outputs the fuel nipple at a different angle.

- George

SALMONBUG

My Feedback: (1)

the tube who need to be bend is the feeding brass tube
the plane is a pusher, the DUBRO 4OZ tank is located behind the engine.
in order to have the clunk working in the correct direction regarding the plane line of flight
I need to extend the brass tube till the end of the tank and make a 180, then I conect the clunk.

I hope you understand what I mean, because my english is less than perfect.

I went to the only LHS available in the vicinity and the magic tool is out of stock.

JimTrainor

If you can find a spring that fits snugly over the tube it will work.

smchale

My Feedback: (67)

I use a piece of weedwacker line. it's nylon and fits nicely in the tube...then you bend as desired and pull out the weedeater line. works like a charm.

SALMONBUG

My Feedback: (1)

after I had broken 3 ball pen to try to find a spring of the good size, I readed the tip of the weedwacker line. THIS ONE WORK GREAT !!!!!!!

My biggest problem was to translate weedwacker in my langage


thanks a lot

beto9

My Feedback: (1)

There are those 1" wheels (aprox.) that you can get to replace the ones running in your screen doors.... They are grooved and accomodate the fuel tubing very nicely. The mounting of the wheel provides a holding point... and you bend with your fingers... very nicely...
Not too costly either!
Albert

FalconWings10

My Feedback: (4)

Yep, I've found this to be the easiest!

monocoupe

My Feedback: (40)

Salmonbug,
Not to diminish Sean's weedwacker line trick...cause it's brilliant, but....Have you considered turning the tank around so that it points forward as usual? That's what I did with my pusher flying wing. Then I simply ran fuel lines back to brass tubes epoxied in the firewall. It works great.

Cheers, Nigel

SALMONBUG

My Feedback: (1)

my post concerning my setup was not very clear, I explain again.
my tank positioning regarding the engine is exactly the same than for a conventional airplane. brass tubing go trough the firewall also.
BUT inside the tank, the feeding brass tube go till the end off the tank, make a 180 and then is connect to the clunk.
I do that in order to have the clunck in the "normal" positioning regarding the flight direction

mulligan

Oh, that's what you meant...

in that case, why don't you just face the tank forward and run the fuel line from the front of the tank back to the engine?

With the 180 inside the tank, it sounds like it could bind up easily.

- George

SALMONBUG

My Feedback: (1)

I do like that for 4 reasons.

1) that's what SIG ask for
2) the engine is small (.15), and I would like to keep the fuel tubing lenght as short as possible
3) this setup allow to make the fuel feeding line exiting the firewall exactly the correct position to conect to the carb
4) The plane is very small and I simply don't have enough clearance around the tank to run my fuel lines (just enough for a thin gas control)

robb_h

My Feedback: (1)

Salmonbug,

I had a Sig Tristar about eight (8) years ago, and I had the same dilemma. My instructions said very little, if anything about the fuel tank setup. I did exactly like "Mulligan" said, ie. I faced the tank forward and ran the fuel line from the front of the tank back to the engine.

I was using an O.S. .15 FP, and the extra tubing length didn't seem to hurt it at all. I just made sure to set it a little on the rich side. I had a sullivan 2 oz. tank in mine and it was still a very tight fit. What brand/make of .15 are you using? I'm sure the 2 oz. tank would work fine.

Since the fuel tank is behind the C.G., I made sure it was full when I balanced mine. This seemed to be the most conservative thing to me. A 4 oz. tank would make a potential tail-heavy situation much worse.

I liked my Tristar, and it flew rather well. The only thing is that orientation is somewhat difficult. You can't tell if it's coming or going!


Regards,

Robb

SALMONBUG

My Feedback: (1)

my plan was like this

os .15 LA
DUBRO 4OZ
balance the plane tank full
use the above mentioned setup for fuel

because of the remote needle valve on the .15 LA my fuel lines must exit at the center of the engine mount (no place on sides or on top because of the needle valve).
So it's impossible to route the fuel line around the tank (in the case of a 4OZ

The 4OZ DUBRO can be insert in the plane and I always like to make long flights

I don't have a big experience with small .15, so my question is :"what flight time my I expect if I decide to go with a 2OZ ?

monocoupe

My Feedback: (40)

I guess I wasn't very clear in my first post, because turning the tank around is what I meant....in fact, that's what I said....

Cheers, Nigel

SALMONBUG

My Feedback: (1)

I found the idea of the 180° feeding brass tub good, why the hell doesn't you like it?

monocoupe

My Feedback: (40)

I never thought, or said that it wasn't a good idea. I was only trying to clarify my suggestion, which seemed to me to have been mis-understood...that's all. I certainly didn't mean to upset you.

Regards, Nigel

SALMONBUG

My Feedback: (1)

I think there are a lot of misunderstanding in this post due to my bad knowledge of english

I will analyse al your suggestions and go for the most reliable fuel feeding

thanks everibody

Charlie P.

I use multi-strand electrical wire. I keep a few lengths with the insulation stripped off and soldered at each end to keep them from unraveling. For smaller tubes I pull out a few strands before soldering the ends. Don't solder the whole length or it will be too hard to bend inside the tube.

The solder itself isn't bad to feed into a tube to keep it from collapsing if you're not putting too much of a bend in. The hollow resin core variety will crush, so it is best to test first on scrap tubing.

SALMONBUG

My Feedback: (1)

I understand now why SIG discontinued this kit. It's not really dificult to build, but instructions are not very clear, some technical choice are strange, there are mistakes on the plans, and so on...
You need to think a lot before gluing something and somethime you don't no anymore where is the nose and where is the back of the fuse (I swear).

Just to give you an idea, I give you one of the most flagrant strange thing.
the plane is design to have a removable wing, the receiver is located in the fuselage, but the antena is routed in a tube in the leading edge of the wing.....

robb_h

My Feedback: (1)

The thing I hated the most was the foam wing, as it wasn't entirely sheeted. It had leading and trailing edge sheeting, with cap strips. One wrong touch with the iron, and you stick the covering to the foam between the sheeting.

Th steerable nosegear is worthless. Actually, any landing gear is worthless. You'll never get it to take off from a grass field, especially with the .15 FP I had in mine.

All in all, it flew rather well. Just keep track of the orientation, as it gets confusing. Slow the plane, and hold full up elevator. The front canard will stall first, and lower the nose. This keeps the main wing from stalling. If you keep holding up elevator, it will do a neat up and down bobbing motion.

Cheers,

Robb

SALMONBUG

My Feedback: (1)

Robb,

Seems you builded the first release of the kit, in mine there are some upgrades, the wing is completly sheeted and I have a stronger landing gear

Small Fry

In one of my physics classes, we had to bend a piece of pipe 180 degrees. We heated the part we wanted to bend (kept the flame off of the pipe itself, just let the heat make it warm) and SLOWLY bent the pipe. You must keep the heat on it or else it'll kink and look stupid. Takes some practice though.

Prboz-RCU-delete

Why could you not put brass tube in the tank that will reach 1/2 to 2/3 of the way in and the put enough tube on to turn around and go backe to the front ot the tank where the clunk is. have the fueline bend rather than the brass?

my 2c worth

big max 1935

My Feedback: (9)

No doubt you have this done by now but mounting tank normally in the direction of flight will work , use long fuel lines the engine won`t know it. You could have used 1/8" copper tubing from auto parts store, that bends easily "once". Higley also makes a Biso bender that works quite well. Hope you got it OK! >>>>>>>>>>>>>>>>>>big max 1935>>>>>>>>>>>>>>>>>>>