Tony Hallo

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

Tony Hallo

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

Tony Hallo

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

Tony Hallo

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

Tony Hallo

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

Tony Hallo

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

selwyn

My Feedback: (19)

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

Selwyn.

Tony Hallo

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

Tony Hallo

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

Tony Hallo

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

Tony Hallo

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

Tony Hallo

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

rc-sport

My Feedback: (12)

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

MarksLHS

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

Tony Hallo

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

Tony Hallo

Here's a shot of the full scale back end.
Tony Hallo

Ryan Nau

My Feedback: (54)

I have the 1/3scale balsa usa cub on the building board. Great kit so far, having fun building it. I have the wing framed up, and most of the fuselage now. Im just wondering, will the wing support be strong enough with just the 2 bolts and struts holding it in place and giving it strength? Im thinking the wing will fold easy with no tube going through. Im really thinking about changing it around a little bit and putting a tube sucket through the wing and wing saddle with a tube going through for extra strength. Thats how its done with most big airplanes.

Tony Hallo

Ryan,
I don't think the wing tube will offer much help because the top of the fuselage isn't that strong without complete redesign, a couple of spruce sticks butt glued to the fuselage don't offer much strength. Study it and I think you will agree. Piper called the struts "lift struts" because that what they do, don't fly without them. Even the wing design is weak compared to normal model standards, i.e. no shear webs, if the top of the fuselage doesn't come off, the wing will fail without the struts. The struts carry the load of the plane into the landing gear plate.
Tony Hallo

Tony Hallo

Well the avionics package is complete and ready for final assembly. All wires are landed and waiting for paint. I did make one change on the aileron and flap serve wires. The plans show the wires running into the cabin area right in clear view through the top skylight. The original hole is shown is the first photo, they will get filled. I just couldn't see doing all this scale work and having four servo wires flopping around in clear view. I routed the wires through the wing stubs behind the skylight and dropped behind the rear panel to keep them out of sight. The wings will have Earnst charge jacks installed the make field assembly easier, just push the female plugs into the wings while assembling at the field.
Tony Hallo

Tony Hallo

Spent some time today on the door, I decided to inset the latch mechanism into the door out of the view. The plans show the linkage exposed on the inside of the door. I cut grooves with a router attachment on my Dremel tool, 1/8" by 3/16" deep groove for the control wire and a 5/16" by 1/16" that will be filled with balsa after the linkage is complete. I plan to install a handle on the inside of the door just like the real one.
Tony Hallo

Tony Hallo

Also covered the front fuselage area. The cowl over laps the fuselage by 4" or so, part of the sheeting will be cut away for carburetor access. I installed a former at the cut line shown on previous photos of the linkage.
I'm not getting much reponse here, I hope everyone is enjoying?
Tony Hallo

Edwin

My Feedback: (2)

I'm watching. I have a build thread on a busa 1/4 scale J-3 and an L-4 going on at rcsb. I'm just now on the wings. Have several changes to do to the ailerons and aileron hinges to make them scale.
Edwin

MarksLHS

Tony,
I think a lot of people are watching and enjoying, but the only response I/we can think of is WOW!!! Keep posting the progress please.

Mark

gumhead

Im still here [8D]

selwyn

My Feedback: (19)

I'm following your every move and enjoying the build....can't wait to see the end product...keep going!!

Selwyn.