Crayon Fins

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Well-Known Member
Mar 18, 2009
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I was wanting to build a Crayon rocket, but I want clear fins so that it looks finless from a distance. What type of material can I use for these clear fins?
I no this is probably a bad ideo, but some of the clear fins i have seen look kinda like the clear clipboards, probably not cheep and probably wont work but...
Originally posted by rabidsheeep
plexi would work right?

Plexiglass is NOT a good idea. I've heard that they break almost everytime on impact from landing. :(

Lexan is the way to go. Much easier to cut than plexiglass & can withstand hard impacts.

They are often found together in home improvement stores but they are definitely not the same!
An alternative to clear fins is to use flat black and make the butt end of the crayon completely above the fin can area. Especially with brighter colors on the main body, the fins tend to be demphasized. One could take this a step further and play with camoflage patterns - further demphasizing the outline of the fin area.

I'm doing a crayon rocket right now (a small BT-55 LPR version, not the typical big version) and plan to use the above approach to make the fins less prominent.
I used Lexan from Home Depot. The fins hang way below the tail and are still good after several flights on two different Crayons. I mounted them through the wall to a BT 80 that I used as a quick switch motor mount. To make the slots in the plastic tail cone I used a Dremel with doubled up abrasive blades. I also drilled holes in the fins' root edge and roughed up the root area and a the inside of the tail near the slots with sandpaper. I used epoxy fillets at the root and at the the tail cone. I drilled several larger holes near the root but inside the tail cone and used expanding foam to lock it all together. The epoxy only forms a mechanical bond to Lexan and the plastic used for the tail, so I wanted to be sure. I also made the tail cone removable with a couple of small screws, in case I ever had to replace/reattach a fin. I made an extra fin for this eventuallity, but haven't used it yet.
See this thread:
Yaeh lexan is awsome it is definately the best you can proobly get what you need with 6 dollers