1/4 Scale Bud Nosen Designed Citabria

[Joker 53150]

Slow progress from time off around Christmas, but back at it now. The main structure around the gear is all built, along with a couple small "hatches" which can be removed to let me pull the landing gear out in the future if needed. These will be covered separately to allow easy removal. I've also applied a layer of thinned balsa filler, sanded it, and then another layer to smooth out the surfaces, and am very happy with how smooth they're getting (compared to what I started with, at least).

 

[Joker 53150]

The fuselage is getting closer and closer to covering. Before I can do that I need to get the hinged surfaces done, so I'm pinning the hinges to make sure they'll never accidentally come loose. In this case I'm using 1/8" hardwood dowels and epoxy.

The rest of the fuselage sanding is done and it's SOOOO close! My punch list is getting short for the fuselage, and the only delay now is waiting for parts delivery.

Some damage was done to the original dash, and rebuilding it will never be easier to do than now! It just needs filler to dry so it can be sanded and painted black.

A different tailwheel was swapped in, which is a little longer than the original one. I've got to do a little checking to make sure it's strong enough to handle the weight of the plane. Hopefully it is, it looks much better than the original style.

 

[vhandon]

Where did you get that miniature diet coke bottle? haha, I love the size of this plane!

 

[Joker 53150]

Wing work is slowly progressing again - the innards are a bit rough, but it's solid. New rib caps are all on and the servo trays are all built in a way that spreads forces out among 3 full rib bays each. I'm spending more time trying to get the exterior as cleaned up as possible so the covering looks good, so the blue bits on the far wing are painter's tape marking areas that need either sanding or filling. The close wing hasn't gotten that far yet. Next step for it is getting the hinge slots cut.

 

[Joker 53150]

It appears all the work trying to get the ribs leveled out is paying off. When viewed across the assembled plane its far more even than before, with only minimal variation from rib to rib. Filling and sanding are still required, along with fitting the servos.

 

[Joker 53150]

Other than a little flying over the past few months, I've done a whole lot of nothing build related. Time to change that...! A few days ago I pulled the wings for the Citabria out and got the ailerons and flaps finished up. The wings still need some final sanding, but the control surfaces are done, so I decided to try out the pinking tape I picked up for the project. This is the narrow tape, applied across the tops of the ribs and the trailing edge of an aileron. After it sits for a couple days to (hopefully) stay shrunk and taught I'll give it a light coat of white paint. The color scheme will either be red & white or blue & white, and a layer of white will fill a little bit of the weave to (again hopefully) give me a cleaner edge for the second coat of paint. I thought about going the extra mile and adding the fake rib stitching under the pinking tape, but came to my senses and realized that'd be a TON of extra work!

 

[Chuppster]

What material are you using for covering?

 

[Joker 53150]

What material are you using for covering?

I believe it’s Solar Tex. I got it from an estate sale and there should be enough to do the wings. Not sure what the pinking strip is made from, but it goes on easily with heat.

 

[Joker 53150]

This is officially the longest it's ever taken me to cover one wing - approx 3 hours, not including the flap, aileron, or center section. The covering itself was fairly quick and easy, it was the detail work adding the pinking strips that took at lot of time. It's been a while since I worked with the Solar Tex type covering like this, and I really missed it.

The pinking strips are applied over the tops & bottoms of each rib, and around the front and outside edge of the wing. I've also painted the aileron with a light coat of Rustoleum Gloss White paint & primer to see how the pinking will look after painting. I was concerned that a few layers of paint would essentially hide all the detail I'm trying to hide. Happily for me, it still shows up nicely, and I expect it to still look good after another light coat of white, followed by the accent color(s).

 

[TooJung2Die]

That's one of those subtle details that will have people giving your airplane a longer look.

 

[Joker 53150]

That's one of those subtle details that will have people giving your airplane a longer look.

Agreed. Looks like I'll also need to order more of the pinking tape. The kit I ordered was supposed to be enough to do a full 1/4 scale plane, but I've gone through half of the narrow tape after just 1 wing and the center section. The fuselage will need quite a bit as well, so maybe I'm using far more than normal? Not a big deal, it's not expensive and should be here in a week, well before I really need it.

 

[Joker 53150]

Well, looks like I didn't have as much white Solar Tex as I had hoped, only enough to do the top of the wing in white. The bottom is getting some Solar Tex in Cub Yellow I had from my first giant scale plane, and the white paint will do a good job at hiding this little secret. Pinking strips are also going on, including reinforcement patches around the strut mounting holes. I believe these "patches" were used in either areas that needed reinforcement or to cover up access holes. These pinking strips are also made from Solar Tex in "Natural" (un-colored) finish. The guy who makes them ran out of Natural, so eventually I'll switch over to the White he's sending me. The fuselage will be covered with Natural Oratex, which replaces Solar Tex.

 

[Joker 53150]

Wing covering continues at a slow pace while I test out some different methods for painting. I let the paint on the first aileron cure for days and then gave it a second coat when I painted the first wing, center section, and first flap.

Now that it's been a few more days I got out a sanding sponge with fine paper and went over the surfaces lightly to remove any "fuzz" from the edges along with any dust in the paint. In theory this should give me a cleaner looking finish when I get to the last layers of paint. From what I've seen so far, I think it'll work better sanding after the first coat, followed by a tack cloth and then second coat of white.

A few edges of the pinking tape either lifted after the first coat of paint were applied or lifted and went unnoticed before painting, so after the sanding I'm taking time to use the trim iron to re-flatten all of the pinked edges. Between the adhesive backing on the pinking tape and the paint it's working well to flatten the edges.

 

[Joker 53150]

Gotta say, I'm happy with how the Rustoleum Paint & Primer covers the yellow. Granted, it's not a dark color, but it doesn't take much to make the yellow go away.

 

[Joker 53150]

Well, so much for the pinking kit being enough for a 1/4 scale plane. I got as far as doing the first elevator and ran out of the narrow tape. I still have a couple yards of the wide tape left, and the new order should be here any day now. The elevator was covered with yellow Solar Tex to try and use up the scrap pieces from previous builds, pinked, and then shot with the first coat of primer & paint. The painting really helps show where the pinking tape isn't stuck down well enough, and after a few days of curing I can simply go over it with the trim iron to fix the problem. I really can't wait for the finish color to go on, and this should look so much better than the original MonoKote shiny covering.

This is the first test-fit of the wings with the main mounting hardware. The big concern was if the pieces would fit too tightly for the bolts to go in once I added all the covering, pinking, and paint between the wing halves and the center section. Only one screw was a little tight, the rest fit perfectly.

Again, after a single coat of primer & paint there are numerous spots where the pinking needs some attention, but overall I really like how it's turning out.

On a different note, if you find yourself mixing epoxy regularly this is a handy "tool". In the past I laid down a wide piece of tape on the workbench and mixed it there, but that meant transferring from the tape to the project and risking drips while transferring it. I've also used small mixing cups, but they can be "tippy" when my mixing stick is sitting in the cup. My wife works in a dental office and she told me about these little mixing pads. Basically, they're like very heavy duty Post-It Note pads - mix on the pad, apply to the project, and then tear off & discard the used piece. They're fairly cheap and work great.

 

[Joker 53150]

I picked up some 1/4 scale instruments a while back and decided to finally use them. I wish they were colored a bit, but will look better than not having them. They’re paper behind a plastic bezel.

 

[Joker 53150]

Test-fitting of gauges. I don't know what order or how they should be arranged, and it's not real important. They'll simply give a little extra bling to the finished project. Doing the pinking tape is taking far longer than expected. With all covered surfaces painted I had to let it all cure for about a week so I could go back over the pinking to seal it down again, which was just finished this evening. When the winds are calm I'll take everything back out for sanding and another coat of paint.

 

[Joker 53150]

The wings are coming along nicely. They still need some trim color to bring them to life, but I'm much happier with how they look now compared to being covered with MonoKote. The down side so far is the extra weight, which is fairly noticeable. The servos, linkages, and servo mounting plates still need to go on. So far I've used about 3 full cans of white paint & primer doing two coats on the wings (with ailerons and flaps), wing center section, rudder, and elevators. You may remember that the covering I've used was a combination of White and Cub Yellow, and the pinking tape was White and Natural. At this time I can't tell any of it apart, the Rustoleum did a fine job masking the original colors.

 

[Joker 53150]

With the wings done and the paint curing, it's time to focus on the fuselage again. As with the wings, I'm using multiple colors so I can use up some of the scrap Cub Yellow and White, while large surfaces will be covered with a new roll of Natural. The two uncovered pieces by the landing gear (also sporting a new coat of white paint) are "hatches" that allow me to slide the landing gear in & out. When I started doing this re-hab I had to chop out quite a bit of material that was built around the gear, effectively trapping it in place. These pieces will be removable (with a little work) just in case the landing gear needs to be removed in the future. As is normally recommended, covering is going on bottom to top and back to front to help hide seams. In this case, many of the seams will also be hidden by the pinking tape. When the bottom is done and the plane can be flipped over I'll do one last check of wiring inside before covering the sides and top since access inside is still fairly easy.

 

[Joker 53150]

If I were smart I’d have done this last night after covering the bottom, but I wasn’t and now I wait. Windows. Many people install them after covering, but I’m not a fan of seeing the plastic glued to covering around the window opening. In this case the side windows are going in first and the covering will be installed up to and over the plastic windows. The plan is to mimic the window cutouts with covering for a clean look. Bathroom tiles are being used to force the plastic flat against the fuselage, and weighted bags give it a little more force.