Morning All,

is anyone building the US 120 and if you are would you glass the wing center section?I've just about got mine done waiting on a opto kill switch for it.I'm using a BCMA 26 sport engine for power and the Futaba T7C 2.4 for control.Was just wondering if the wing center needs to be glassed?

Thanks in advance Jim. Club Saito Member 509

I'm putting one together. I did not glass the wing. I did glass the backside of the firewall and the landing gear area.

The center section IMO does not need glass. I just lost my 120 flew it on a G26 gas for 6 months...............it lost radio control and went into straight into the ground form 300ft at 1/2 throttle......busted up the motor, fuse,almost every servo was a total loss.......but the wings center epoxy secton held together with no damage.

Hey Blade...I'm doing a 120 w/Saito 220 also...here are a couple of posts to check out!

http://www.rcuniverse.com/forum/m_6787119/tm.htm

http://www.rcuniverse.com/forum/m_44...tm.htm#4403673

I had this plane with a souped up Homelite 30cc on it, and a smoke system. Flew great. No problems with the wing center section. I flew it for about a year, then one day I thought I heard the engine falter on a fast inverted pass, and hauled back on the stick. You know the rest....

I replaced it with a Giant Big Stik, which is a nice plane, but the Ultra Stik seemed a little lighter and more aerobatic.

AV8TOR

I've had one of the old ones and two of the lites. The old one I bought from a guy and it had a TT 3000 on it. I went ahead and flew it that way. It didn't have enough ground clearance to use the proper prop and it never sounded just right. At half throttle it sounded like a dirt bike. Anyway, i bought a G26 and put on it and it flew great,,,, when it didn't dead stick. I put her in the trees but was able to get the motor. I put it on a new Lite and flew it into the trees on the maiden. I got another one and got a couple flights in on a Saturday and went back on Sunday and my son-in-law lost it in the trees when the elevator servo arm came loose. It was MG and I forgot to loctite it. I gave up on the US 120s and got a BigBoy. After many dead sticks and damage to the BB I sold the G26, got a YS 110 and never looked back. It has scary power for it's size and doesn't dead stick.

Sorry to hear that, I'd cut those trees down.

Hey Guys,
thanks for your replies I guess I won't worry about the wing to much then.I did do the firewall thing I cut the nose back 2.5 inches and used aluminum angle and 4-40 flathead screws and aircraft nuts.I don't think I'll have a problem with the firewall.Now I'm just waiting on a opto kill switch and I'll be able to go fly this badboy.

Thanks again.Jim

Sounds good Bladejunkie and the best of luck on your maiden. Be sure you get back with us to give us the details. some pics would be nice also...[8D]

Here is the progress I’m making towards my maiden. As you can see I've beefed-up the tail wheel areas. I have moved my rudder and elevator servos to the rear of my plane to offset some of the Saito 220's weight. I moved the top engine mount up 3/8" for the engine width and to help with the prop clearance.

I'm currently building one with an OS 1.60 with a 18x6 on it. I'm in the process of recovering the whole plane.
I could'nt handle the see through ultra cote. I've had two of the US 40's. Still have one with a OS.61 on it. I've
"Beefed Up" the firewall and landing gear on all of them, but always just epoxyed the wing halves together and
have never had an issue with it.

Rick

rccrippen,

what did you do to beefup the landing gear?I don't like the clear ultra cote either but, I got in a hurry to fly this plane so I'll just have to live with it,I did however recover the fuse.I wish these companies would offer ARC's as well as ARF's they would make a little more money off of us too!We would have to buy covering materials from them.Of course we would also see some of the lousy workmanship some of them have.
Anyway thanks for the reply.

Jim

Jim,
I use 1/2 in triangle stock and fiberglass cloth, I use the landing gear itself to mark the hole placement in
the cloth, cut those out about a 1/4 in. in dia. Cut your cloth to cover the entire area you want to strengthen,
plus about 1/2 in. extra. Take some 30 min. epoxy and coat the entire area with it. Not to thick, but thick enough
to soak into the cloth. Lay your cloth down in the area you have chosen, pushing into the corners and everywhere
till you have good contact throughout. Then apply some more epoxy on top of that, and work that in, soaking the
cloth thoroughly. Don't get to much epoxy, you'll know what looks about right. Then cut the triangle stock the
length of the sides and front and back. Place those in position, once again with the epoxy and glue them in place.
press them in nice and firm. Let it dry over nite and presto! your done!
I've NEVER had any area I've done this to fail. And out of the crashes I've seen when this was done to a plane, that
was the area that held together.

Rick

So your doing this work inside the plane, in the original landing gear area?
I'm just kind of unclear of where your actually doing this "beef-up". The landing gear on my US120 already has triangle stock in the landing gear area along the sides???

When glassing any cloth, only use enough epoxy to wet the cloth. You should plainly see and feel the texture of the cloth easily. Too much epoxy will greatly weaken the process. Another way to do it is to wet the cloth first then "squeegee" out the excess resin and lay the cloth into your work area. This is done easily with narrow strips and fingers!

Pappy's correct, I 'm a Material Bonder for Bell Helicopter here in Tx. I wrote that on the fly at 4 AM before work.
Use just enough to wet the material good. I use something called 956, But I've used the epoxy with the same results.
As for the stock, on this particular plane there is two small pieces on each side. I added more across the front
and back. I also have used square and rectangle stock when in a pinch. There are no hard and fast rules as
to what you have to use. I've even replaced the wood the gear mounts to with a piece of Oak, but if it's reinforced
enough/correctly, that should'nt be necessary. Wieght is only the real thing you have to watch, and in less your
one of the 3D guys that count every 1/2 ounce your really not going to make that much of a difference.

Rick

Thanx rccrippen...believe me weight is no problem. I'm running a Saito 220 on this plane and it has enought mussel to off-set any small amount of weight adjustments like that. I have re-enforced all the important areas already but will add a bit more to the landing gear support areas also! [8D]