Rocketry Planet

One of my least favorite tasks of building a rocket was beveling the primary fin edges. It was always tedious and I always managed to mess it up, getting lop-sided tapers. I developed this simple little tool that anyone can make to help make the process much easier.

While I build only low and mid-power rockets with balsa wood fins at the moment, I think that this tool could be upscaled to work on larger G-10 and plywood fins.

To start, I cut two pieces of .080" aluminum to 3-3/4 inches by 5 inches and then rounded the corners. This tool uses common auto-body file sander sandpaper sheets, which are self-adhesive and can be purchased at most auto parts stores.

Since the sandpaper sheet is 2-3/4 inches wide, I marked the plates at 2-3/4 inches and then bent them approximately 10 degrees. This gives me a really nice taper on 1/4 inch thick balsa fins.

After that, I simply cut the sandpaper strip into 5" long pieces, stick them to the two plates and clamp the plates into my vise. Now I have a sturdy "V" groove of sandpaper and I can sand bevels into my fins quite easily.

I usually put the fin down into the "V" to start the two-sided bevel and then fine tune it by moving up on the "V" to sand one side at a time. What makes this easy is that the sandpaper is held on an angle and I can keep the fin vertical while moving it back and forth much easier than trying to hold the fin at an angle.

This has made building rockets not only more pleasurable for me, but I find that I build nicer rockets now!

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