Brian Taylor Cessna 120 build

Started by octagon, December 26, 2020, 07:21:55 PM

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octagon

I finished the Unionville Beaver I was building so today I started on a Brian Taylor designed Cessna 120. I have always had a soft spot for that plane even though I have never flown one or even been in one. I ordered a short kit from Sarik in England. After studying the plan and trying to make sure I understood how I wanted to build it and convert it to electric I started. The fuse is built in 2 parts, the front cabin area and the back of the plane behind the wing, and then they are joined together. So I started on the back end first. The formers for the fuse were not included in the kit, so they had to be constructed and then the fuse sides had to be cut out of 3/32 sheet. I was pleased with the way the sheeting came out, I soaked it on the outside with windex. I pinned it and then used thick CA while holding the sheeting to the formers. It was easy to get it done because at this point the bottom of the fuse is not in place. I finished up by using light weight spackeling and will build the front fuse tomorrow and if all goes well, join them.
What could possibly go wrong?

Frank v B

#1
Rob,

Interesting project.  Can you give the specs... the size, weight and motor size of the plane... but don't stop building to answer these questions. ; :)

F.

from Wiki:

Cessna 120 — The Cessna 120 was an economy version of the 140 produced at the same time. It had the same engine as the 140, but lacked wing flaps. The rear-cabin "D" side windows and electrical system (radios, lights, battery and starter) were optional.
Number built: 7,664
Produced: 1946-1951
First flight: June 28, 1945 (140); 1946 (120)
Manufacturer: Cessna Aircraft Company
"Never trade luck for skill"

octagon

The wingspan is 62 inches, but, at least Brian Taylor's prototype weighted 5 pounds. I feel a 25 1000kv would be just barely enough, so I have a 40 that will be way overpowered, but I have it and the motor mount for it so I will use it. I think 3s will work and I have a 60A ESC that will work nicely . Probably go with mini servos, but I don't have any that match so I will have to get those. The 120s were delivered with little paint and just in the silver of the metal they were covered in so I am going for something like that.
What could possibly go wrong?

octagon

I didn't get home until early afternoon and did not have batteries charged, so instead of going flying I went building in my workshop. The model is built in sections and then joined. Today I built the cabin area, the forward of the cabin area, and then joined them. I fashioned a servo tray out of basswood and mounted the motor. The next step will be joining the back and the front of the fuse. I need to fashion some sort of hatch to insert the battery, probably underneath, behind the landing gear. going to use pull pull for the rudder and a control horn inside the fuse to operate the elevator. I will fashion the control horn out of brass and piano wire.
What could possibly go wrong?

octagon

I spent today designing and making a hatch to make the insertion of the battery easier than taking of the wing each time. The model's plans are many years old and no information about a hatch is mentioned on the plans.There is no room between the cowl and the windshield for a hatch so it had to be underneath.I am quite happy with the way it came out, and although not perfect, good, good enough anyway. The next step will be finalizing the servo location. I want to use pull, pull for the rudder, but I think instead of nyrods for the elevator I am going to make a control rod out of 1/4 inch hardwood dowel. I will probably raise one servo higher than the other so that the cabling and rod do no interfere with each other.
What could possibly go wrong?

Andy Hoffer

Hey @octagon

Looks like a great kit Rob.  I really like your nostalgic choice of the Cessna 120.  Beautiful build so far.  And your amaryllis look fantastic!!

You are so lucky that you're allowed to build on the kitchen table!  The wide selection of knives and paper towels are really handy!!  It's also nice having a strainer handy for finding lost screws and washers in the balsa dust.   ;D

Andy

octagon

Thanks Andy. Worked on a tail wheel yesterday. I made it out of brass and wire and it turned out pretty well and I think will work. Joined the fuse today and it is finally starting to look like and airplane.
What could possibly go wrong?

Andy Hoffer

Quote from: octagon on December 30, 2020, 07:08:13 PM
Thanks Andy. Worked on a tail wheel yesterday. I made it out of brass and wire and it turned out pretty well and I think will work. Joined the fuse today and it is finally starting to look like and airplane.

Hey @octagon,

I am totally confused.  To my untrained eye that tail wheel looks like it's made of plastic and rubber (except for the axle, which does look like steel wire).  What am I missing here?!!  ;D

ANdy

octagon

It has been a while since I posted progress, but I have been working away. I spent the afternoon today doing a lot of covering. The plans included the panel lines so I covered in smaller pieces trying to emulate them. Think it came out ok. Next step will be to build the wings, the centre section is built, so I should be able to build them tomorrow and cover them later in the week. Then, detail the cowl and mount the engine. Have to paint the landing gear, but rustolium makes a perfect match for the cub yellow. Going to emulate a 120 that is still flying in Alaska. I think my yellow is different from the full sized, although there seems to be pictures of it closer to the colour I used to, so a bit of literary licence is in order. I will send to Callie for the graphics for it.
What could possibly go wrong?

octagon

I have been rather bad at posting pictures of the work on the Cessna. The plane is all but finished. Have to put the windows in and paint and detail the cowl. The 120 has quite distinctive air inlet grills on the front of the cowl. At first I tried cutting the fiberglass, but it looked like a dog's breakfast when I finished to I filled it in and make the grills out of 1/64th plywood. The next picture shows the hatch where I will be able to insert the battery. It took a while to figure that out because the kit was not designed for electric, but I didn't want to take the wing off every time to change batteries, and even if I could make a decent job of a door, it would still be pretty tight. I embedded the hinges deep into the flying surfaces so I was able to keep the gap small and at the same time hiding the hinges for the most part.The last picture is how I attached the struts to the fuse. I used the same method that my Hangar 9 Cub uses, with bolts that go through and cotter pins (ya, I know they are not cotter pins, but I don't know what they are called really) that will make the taking the wing off pretty easy. All up weight including a 4 s battery is 4.7 pounds. I am quite happy with the outcome and it is pretty strait. The graphics were ordered from Callie and should be here fairly soon. The model mimics a full sized plane that lives in Alaska. 
What could possibly go wrong?

Andy Hoffer

Hey @octagon

Photo 1957 on the kitchen table includes a Flowering Plants book, along with some magnificent Amaryllis on the stove.   (Do you steam them or sauté them?)  Will the Callie graphics be based on motifs from the book, e.g. amaryllis?  Gloxinia?  Sunflowers?

Looking great.  (Nice to have a break from the tiresome civil aviation and warbird graphics.  You have good taste Rob!

Andy

msatin

You never fail until you stop trying

octagon

Finished the 120 today. Put it on skis in the hope I will get to fly it some day. Plane turned out well. There were a few mistakes on the plans but overall it was quite an enjoyable build.
What could possibly go wrong?

Andy Hoffer

Quote from: octagon on January 27, 2021, 06:40:55 PM
Finished the 120 today. Put it on skis in the hope I will get to fly it some day. Plane turned out well. There were a few mistakes on the plans but overall it was quite an enjoyable build.

Hey @octagon ,

She's absolutely gorgeous Rob.  I really like the black glare shield on top of the cowling.  The black skis make a nice accompanying accent.  Interesting to see the depression in the snow.  You did a great job of preserving the snow surface when you placed the plane on stage for the photo.  Bravo!

Looking forward to a portrait shoot with you!

Congratulations on a beautiful build.  You have superb taste and wonderful craftsmanship!

Andy

Polecat

Looks great Rob, what's next on the building board?

Ken