Cessna Skymaster

Intro:

This scratch build is based off of the Cessna O-2 Skymaster. I kept it as scale as possible, but I also made some changes and liberties. Mainly I made the control surfaces bigger.

This plane is designed to be a twin engine, two power pods making it a swappable, but I have only tested it as a pusher. I think the pusher set up will be the most popular and will make this plane a great FPV plane. Without the front power pod, there is plenty of room for FPV gear and a battery.

This plane is designed around an 8 inch propellor. There is no room for anything bigger. However, the height of the fuselage makes it completely safe (maybe not "completely") to hand launch and you can belly land the plane without any worry about breaking the rear propellor.

Video:

This video ended up longer than I would have liked, but I got a lot of great footage that I wanted to share. I thought about adding music, but that's debatable. The audio doesn't always line up and I probably should have tried to fix it, but it's close enough. I was nice and lowered the volume for the on board footage.

(All flying was done Line Of Sight.)

Specs:

- 41.75" wingspan

- 30" length

- Made with less than 3 sheets of foam board, 4 bamboo skewer, etc. 

- 1300kv Hobby King motor

- 8x4 GWS style prop

- 25amp Hobby King ESC

- 2200mah 3S battery

Plan Preview:

Sketchup File with Printable Plans: Skymaster

PDF Version of Printable Plans: Skymaster.pdf

***(note: Printable Plans are different than the Preview. I condensed the Printable versions.)

Build Tips:

The majority of the plans are self explainitory. However, there are two things that I think I have to point out. One is because I do not have the standard colored lines on the plans. The other is an unusual building technique.

Tip 1:  Just like the FT Spitfire, the wings have a spacer. Unlike the FT Spitfire, the spacer is attached to the wings and is folded over. On the plans, it should be a dashed red line because the score cut is on the opposite side of the score cuts that create the airfoil.

Tip 2: The booms are three sheets of foam board thick and are hot glued together. However, there are also bamboo skewers inserted into score cuts to make the booms even stronger, in a very inexpensive way. The skewers should extend out onto the vertical stabilizers to brace them. The booms should also have some packing tape wrapped around them, but not completely. This works so well that I can actually carry the plane around by a boom without it feeling weak, as long as the battery isn't mounted. With the weight of the battery it does feel like I'm pushing it's limits.

Conclusion:

This plane flies more "scale" than "trainer" or "fun flyer". I probably should have made the wing tips undercambered, but you can easily alter the plans so they are. It does have some bad stall characteristics, but nothing out of the ordinary. Undercambered wingtips should fix most of the stalling.

I don't fly FPV, but this should be a great plane for it.

This isn't a good first plane, but should be a great first 4 channel with the pusher set up. If you keep the speed up it flies great. The prop is protected and the plane can withstand some abuse. And it looks great.