Balsa USA Super Cub Build
 

I'm building two 1/3 scale Balsa USA Super Cubs this building season. I plan to post photos along the way. Shown here are some photos of the wing framing. Rather than mount the servos as shown on the plans I substituted 1/8" plywood for the ribs where the aileron and flap servos are located.
Tony Hallo

RE: Balsa USA Super Cub Build
 

The planes are being build with the J3 scale aileron option from Balsa USA. In the Super Cub case, this requires two optional kits to handle the ailerons and flaps. Here are details of the hinges and control horns.
Tony Hallo

RE: Balsa USA Super Cub Build
 

Here's a photo of the full scale aileron control horn. The full scale is a pull-pull arrangement, the model will have push rod on the under side of the wing.
Tony Hallo

RE: Balsa USA Super Cub Build
 

This wing takes up most of my 13' work bench.

RE: Balsa USA Super Cub Build
 

Does that have barn door ailerons? I have a thread started on a 60 size Great Planes 90" wingspan Cub and it's got barn door ailerons. You can see the indent in the wing where they go in my pictures I posted. So far yours looks like a good build!

Gibbs

RE: Balsa USA Super Cub Build
 

Here's a couple of pics of my Balsa USA Cub I've been working on......... I would like to make it as scale as possilbe,do you know of anywhere to find cockpit material?

RE: Balsa USA Super Cub Build
 

Here are some photos of the wing aileron and flap hinging. Hopefully the pace will pick up, the first one always the funnest and most difficult, once all the details are worked out, it's just cut and glue. To be honest I was a little worried about the scale hinging, but it looks as though all worked out well and I am pleased with the results.
Tony Hallo

RE: Balsa USA Super Cub Build
 

A few more. The leading edge drops below the bottom surface of the wing when deflected up to provide addition drag when banking which helps prevent adverse yaw, hope it works!

RE: Balsa USA Super Cub Build
 

Must be something in the air. J-3 builds seem to be falling from the sky. I have a build thread going at rcsb. Busa 1/4 J3 and the L4. Couldnt decide on which one so I'm building both.
Edwin

RE: Balsa USA Super Cub Build
 

The Super Cub will be powered by a 3W 56 Twin Competition verison, should be more than adaquate for this plane. It fits inside the cowl completely, even the plugs and spark plug wires fit without holes. Original plans called for a 64 CC four stoke conversion engine, however the cowl glass work was much to nice to hack up. So the search was on for something that would fit without cutting the cowl up. The 3W is a nice piece.
Tony Hallo

RE: Balsa USA Super Cub Build
 

The rear intake and small crankcase size provided a challange to get everthing just right. The firewall is two layers of 1/4" plywood beveled on a 45 degree angle to provide adaquate clearance for cooling. The cowl overlaps the fusalage by 4" so the carb will be accessable when the cowl is removed.
Tony Hallo

RE: Balsa USA Super Cub Build
 

The landing gear took about a week of evenings to complete. The assembed gear offered by Balsa USA is a bargain. I would recommend upgrading to the assembed gear option if anybody out there is considering building one these planes. It works great, just took some time to build. The bungee covers are held on with small sheet metal screws, the original design looked like it would be troublesome after the plane had a few flights on it.
Tony Hallo

RE: Balsa USA Super Cub Build
 

Here's another shot.

RE: Balsa USA Super Cub Build
 

Some photos of engine installation.
Tony Hallo

RE: Balsa USA Super Cub Build
 

Tony,

Here are some photos of my 1/3 scale Balsa USA Super Cub.
I flew this plane to 5th place at Top Gun in 2005.

It took me about 2 years to complete.
Lots of fun to build but takes a lot of time to add the scale details.

Larry

RE: Balsa USA Super Cub Build
 

Some more photos

RE: Balsa USA Super Cub Build
 

Tony, I'm enjoying this thread...keep up the good work and keep the pics coming....I've been looking at doing one of these, and this may just push me over the edge.;)

Selwyn.

RE: Balsa USA Super Cub Build
 

Larry...very nice looking bird....what motor did you use?

Thanks

Selwyn.

RE: Balsa USA Super Cub Build
 

Have you started to cover her yet tony?

RE: Balsa USA Super Cub Build
 

Here is one I saw fly this past weekend....

RE: Balsa USA Super Cub Build
 

No I'm still building, finishing the right wing now and then it's time fit everthing together. The plane will be covered with Stits covering, first time I have used this covering material, hopefully everthing goes OK.

RE: Balsa USA Super Cub Build
 

Here's a photo of the fuselage, fitting the cabin top on. Work will begin on the tailplane soon.
Tony Hallo

RE: Balsa USA Super Cub Build
 

The top is just about finished, tomorrow I hope to fit the stabilizer and rudder.
Tony Hallo

RE: Balsa USA Super Cub Build
 

One modification I did on the 5/32" front wires. The instructions have you hold the wire in place with epoxy. I soldered on a short piece of 3/16" bass tubing and formed an eye on the end, a 4-40 screw and blind nut secures the wire in place. The joint will be epoxied once the fuselage is moved.
Tony Hallo

RE: Balsa USA Super Cub Build
 

hey, just thoght id chime in here and say, nice work on the cub! ive been kinda sorta watching this thread, and some others b/c i might build a cub in the near future (just gotta get some other projects out of the way)
keep up the good work

RE: Balsa USA Super Cub Build
 

Here's some progress I made over the holiday weekend between party time. The tail plane is on and set. I made a couple modifications along the way, the trailing edges on the both horizontal and vertical stabilizers are two pieces of 1/4" x 3/8" balsa laminated together, I substituted spruce for the inner piece. I also inset the ribs about 1/8" on the leading and trailing edges. The leading and trailing edges are made up of balsa/lite ply/ balsa laminations, I just couldn't see getting a good surface to glue the ribs. Insetting is much stronger as the ribs are glued on three sides.
Tony Hallo

RE: Balsa USA Super Cub Build
 

The plans call for a nyrod on the elevator, personally I don't care using these on control surfaces so the elevator servo will be mounted inside the fuselage near the leading edge and connected with 4-40 ball links. Access to the servo will be under the aluminum cover for the jack-screw. The kit provided a 1/4" X .050" piece of steel for the elevator control horn that gets silver soldered onto the 13/32" tubing that the elevators plug into. I made up two horns that are more robust and provide a 360 degree solder joint. A 4-40 ball link will be captured between the horns. The original horn is laying near the trailing edge of the horizontal stabilizer for comparison.
Tony Hallo

RE: Balsa USA Super Cub Build
 

I had to fit the interior pieces as the back seat defines the space available for the radio, elevator servo, and battery pack. There's plenty of room, just wanted to be sure nothing interferes along the way. Speaking of servos Balsa USA recommends 80 oz. on the ailerons and flaps, 120 oz on the elevator and rudder. This plane will have Hitec 5985's on the ailerons and flaps. about 170 oz.. The rudder and elevator are treated to 5955TG's, about 330 oz. each.
Tony Hallo

RE: Balsa USA Super Cub Build
 

I had a question on IM regarding stabilizer connection details, the photos were too large for IM so I'm posting the photos here. Someone else may have the same question for those 1/4 scale builds looking to add scale detail.
Tony Hallo

RE: Balsa USA Super Cub Build
 

Spent some time working on the avionics package, installed the rudder pull-pull system and elevator servo and linkage. The parts supplied with the kit for the rudder pull-pull looks like a pile of scrap tubing, however after fitting everything together it works well. I did add several small servo screws to the spruce blocking just to make sure a glue joint failure doesn't cause any problems in the future. The rudder servo, battery, radio, voltage regulator and servo buss will all be mounted on the tray installed with Velcro and foam rubber isolation.
The cables on the rudder get soldered with a brass sleeves after covering and paint is complete. In the photo I have the calbles held in place with heat shrink tubing just to fit everything up.
For the bellcrank end the instructions had you bend the cable over itself and solder into a brass threaded connector, I either lost them (very possible) or they were not in the parts bag. I made my own using a 4-40 Dubro rod ends. The clearance hole on the rod end is drilled to 1/8", 1/8" brass tubing is tapped on the ID to 4-40 and cut just long enough to protect the cable when screwed onto the 1/4" 4-40 screw. A loop is fashioned on the end with a soldered brass sleeve.
Tony Hallo

RE: Balsa USA Super Cub Build
 

Here's a photo of the completed elevator linkage.
Now it's time to remount the engine and fit the throttle and choke controls before finishing the fuselage. Tomorrow is out on the town night, will not get much work done until the weekend. Till then.
Tony Hallo

RE: Balsa USA Super Cub Build
 

Vey nice work you're doing Tony.....will you have access to the elevator servo when covered?

Selwyn.

RE: Balsa USA Super Cub Build
 

selwyn,
The elevator servo access will be under a aluminum cover, the plans call them parts E and F, basically they are scale covers similar to the full scale Super Cub for access to the elevator jackshaft. Apparently the elevator on the full scale can be raised and lower on the ground to correct inflight trim problems. In my case the right side will be slightly larger to cover the access hole. The elevator is non-adjustable on the model. I hope this answers your question.
Tony Hallo

RE: Balsa USA Super Cub Build
 

Well Friday night party time started early on Friday, this is what greeted me as I turned onto my street. I was without power until Saturday morning therefore not much work was accomplished until Sunday. Without power my wife and I decided to visit the local saloon early and stay late which may have impacted my desire after the power was restored!
Tony Hallo

RE: Balsa USA Super Cub Build
 

On Sunday I resolved the throttle and choke linkage, maybe that had something to do with getting started on Saturday. I just can't understand how engine manufactures get away with selling engines designed specifically for R/C and throw on a carburetor right off the chain saw. It's nearly impossible to get everything just right. The linkage supplied with the engine was useless in my installation, to be honest I think it would be useless in most cases.
Just one example, most manufactures recommend eliminating the spring on the throttle, why do they provide the carburetor with spring closed function? Can't they finish the job?

Criteria used for locating the servos;
Hidden from view
As far away as possible from the engine
Straight stiff control rods
Accessable for future maintenance

The control rods are carbon fiber to mininize noise.

Tony Hallo

RE: Balsa USA Super Cub Build
 

Here are some photos of the tail brace wires and fittings. The fittings are made from 22 gage steel, 7/16" piece of 1/8" K&S tubing, two 2-56 nuts, and 3/32 SS tig wire turned downed and threaded for 2-56. It took me about two hours to get the follow rest adjusted on my lathe to turn the wire and another hour to get the K&S die adjusted just right. I can now thread one end of wire in 5 minutes or so.
After the plane is covered and the wires are adjusted I plan to solder the fittings to prevent vibration problems. This may cause problems if they need adjusted in the future, but hey I'm not owner, just the builder. I keep telling the owner this is the prototype, my cub will be the production model!

Tony Hallo

RE: Balsa USA Super Cub Build
 

Here's a photo of the full scale tailbrace rudder post connection.
Tony Hallo

RE: Balsa USA Super Cub Build
 

Wow Tony thread is great. In the first pics the Xacto knife next to the control horns really tells how big this plane really is. Impressive

RE: Balsa USA Super Cub Build
 

I don't know, this build is very impressive for a prototype! In fact I would go so far and say prototypes that come out of DEBTONE AIRCRAFT better than most production models. I know, who or what is DEBTONE AIRCRAFT? Here's a little hint. You already know the builder and head engineer's first name, can you guess what his wife's name is? (I think I know of a model aircraft manufacturer who used this method to form there company name!)

Mark

RE: Balsa USA Super Cub Build
 

I installed a servo wire tube for the elevator servo and antenna tube just to keep everything neat, also finished off the lower tail brace wires. I made some modifications to the landing gear plate, the plans have you glue in a 1/4" plywood plate between the 3/8" longerons, I decided to inset a 1/8" plywood plate into longerons along with the 1/4" plate. This provides gluing on two surfaces verse one in the original design. I've seen the owner rip more than one tailwheel off when built per plans, he will not rip this one off. A scale cast tailwheel is on the way from Texas, I can't wait to see it.
The bottom tail brace wires are shown along with the parts provided in the kit. The bottom tail brace bracket is also inset into the landing gear plate and will be installed before the covering goes on as is the full scale version.
It's Friday night party time, who knows what tomorrow will bring!
Tony Hallo