CF-1 Build Instructions (Red Bull Challenge)

by CptCrazyFingers | August 22, 2018 | (4) Posted in How To

I am terribly sorry it has taken me so long to provide build instructions for my Red Bull Air Race Inspired build. I found out that filming a build video was a lot more work than I first thought and that I just didn't have the proper camera angles to accurately show you how to build this plane. So I created a set of build instructions (the attached pdf at the bottom of this article) with lots of images to give you a good idea of how to build it. I also made significant changes to my original build plans because there were some significant flaws. I apologize if you attempted to build this using a previous version of my plans. In the body of this article I will outline the major changes I made to the build plans.

While trying to build the nose, I came across a big problem with my motor mount. It seems that I had it stopping about 1/2 inch away from the front edge of the nose and the side plates were too far apart to accommodate an FT firewall. I adjusted this and now the bottom plate of the motor mount is flush with the front edge of the nose and the side plates are the right distance apart. I also had to shorten them a little bit so the firewall could rest on top of the front edge of the bottom plate. 

Motor mount placement marks (where paper is removed) too far from front of nose.
Correct motor mount placement marks. 
With the correct placement of the motor mount, the firewall should be flush with the front of the nose.


While getting ready to rebuild the nose, I decided to make another change to the way the nose piece comes together. In my first design, I had the top of the nose join with the corner plate. This made it difficult to glue the nose together without it appearing a little deformed. It also required a bevel on one of the edges to ensure they came together flush. So I decided to move this joint to the middle of the top plate. Now, one half of the top plate is on either side of the nose piece. With the nose going together this way, you don't need to bevel any edges and you can push the plate against the table while gluing the pieces together. If there is some deformity, at least it won't be lopsided. 

First iteration where the nose piece joined at a corner.
Nose piece now joins at the middle of the top plate for an easier assembly.


One of the things I was unhappy with in the original design was how I held the canopy on the body. I used large popsicles sticks that stuck out of the front of the canopy to catch on a dowel across the nose. I didn't like this because it required two more popsicles sticks inside the front of the canopy to add strength. I left the popsicle sticks that go through the back of the canopy and act as supports through which a barbecue skewer can go through. I saw no need to redesign this, although I do get frustrated with trying to pass the barbecue skewer through the two popsicle sticks.  The new design has doubled over pieces cut out of foam board that catch on a foam board plate attached to the front of the fuselage section. These pieces glue to the sides of the canopy section and pass through holes in the front of it. The plate in the fuselage slides through slots cut out of the fuselage and has four small foam board wedges that provide vertical support to the area where the canopy pieces apply pressure. 

First design with popsicle sticks protruding from front of canopy.A long dowel was installed to catch the popsicle sticks.
New design uses pieces cut out of foam board to hold down the front of the canopy.A long thin plate, instead of a dowel, that glues to the front of the fuselage section acts as a catch.Small foam board wedges provide strength where the canopy pieces apply pressure.

 

The last thing I added were pieces that help you fold the wings. They keep the bottom of the leading edge at the proper angle when folding the wings. In the first design, I didn't use any kind of guide to hold the wings or provide a reference while folding them. Being that this has a symmetric airfoil, it is too easy to fold the wings and end up with a non-symmetric airfoil. Also, the wing root decreases in thickness. Because of this, you cannot just lay the wing pieces on a flat surface when joining them. Luckily, I discovered that the difference in thickness from the wing root to the tip is barely bigger than the thickness of a piece of foam board. 




Build Instructions

CF1buildinstrsmall.pdf

Updated build plans

CF1TiledPlansUpdate5.pdf

COMMENTS

Damorc on August 27, 2018
Nice write up and pics. Plane looks great. To maintain the clean lines you could change the nose piece so that the seam is at the bottom.
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MiniacRC on September 5, 2018
The awesomeness level of this design is off the charts!
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CptCrazyFingers on September 5, 2018
Thank you MiniacRC! I made a lot of mistakes and I’m still improving it. One thing I really like about it is how easy it is to land. It floats so effortlessly during landing flares (most likely due to the high aspect ratio). I just finished building an experimental wing for it and I can’t wait to test it. The wing has forward swept wing tips.
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CptCrazyFingers on August 27, 2018
Thanks Damorc, that’s not a bad idea.
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Scottmclam1 on September 9, 2018
The tiled plans seem like it might require foam sheets larger than 20x30”?
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CptCrazyFingers on September 10, 2018
The fuselage piece is the largest part and it barely fits on a 20x30 sheet of foam board. Unfortunately, the plans are organized in a way that reduces the amount of pages you will need to print and not in the order they fit on a sheet of foam board. You will have to tape the tiles together, cut out the pieces, and manually arrange them on a sheet of foam board. I ended up using 7 sheets for this build. Sorry for the inconvenience.
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Scottmclam1 on September 13, 2018
No worries. I have been taking my time and going slow. Hopefully it will fly when finished. Will the landing gear from the edge540 adapt to the CF1?
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CptCrazyFingers on September 13, 2018
Thank you for giving it a try. My favorite thing about this plane is it’s amazing glide slope. It makes landing smoother. As for the edge 540 landging gear, there is a ton of empty space inside the fuselage and it should fit. The only thing I can’t speak for is the flight performance with the landing gear. Let me know how it everything goes and please make any recommendations you may have on improving the plane.
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CF-1 Build Instructions (Red Bull Challenge)