3D printed fin jig and epoxy fillets on a Goblin build

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OG1959

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Building a Goblin and decided to make a fin jig. I came up with this design in Sketchup which printed relatively quickly. (two hours) It works quite well.
You set the first fin in the part with two sides that hold it, CA glue that in place then us it as a guide for the next fin. Of course I marked four lines on the BT-55 tube before hand.

Once I had all four fins set in place with CA glue, I taped the body and tubes in prep for laying down the fillets. I used some Devcon 5 minute epoxy gel which I first applied with small a wooden dowel then stroked it with a small popsicle stick which had the perfect radius. I like the results! Planning to launch this one this weekend with double streamer recovery on a D motor.

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OverTheTop

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Just make sure you check you jig for square each time you use it as the 3D printed parts can creep and deform, especially in the warmer environments.
 

OG1959

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That worked out well enough. I followed up with a little PlasticWood-X. It's pink out of the can, turns tan within 10 minutes ready to sand. I like it. Easy to just smear in on with your finger. Follow up with a wet finger and it's 80% done. A bit of sanding and it looks smooth. Easy to sand too.

Launching this one tomorrow on a D12-3 or 5. Wheeeee!

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bjphoenix

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Those fillets look good. Good fillets are one of the holy grails of model rockets. You're at another level when you can do good fillets with epoxy.
 
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