I've completed the composite reinforcement on the Tomach fins. Previously, I did two layers of fiberglass, as detailed
here. This resulted in some lifting and uneven epoxy saturation due to a lack of proper equipment.
In order to have confidence flying this rocket well above Mach 1, I wanted to ensure the fins were stiff and and mounted securely. Recently, I added a small patch of carbon fiber, followed by 2 layers of light tip-to-tip fiberglass. This was done with vacuum bagging, which helps squeeze out extra epoxy, and promotes tight, proper adhesion of the composites.
Unfortunately, one of the fins developed a warp. I'm not sure if this was before or a result of the recent composites work. It has the potential to cause significant spin. Despite the warp, the fins are now extremely stiff and strong. I have stood on this rocket and the fins barely deflect. My plan is to fly it on a smaller motor to get a feel for how severe the spin is, prior to launching it on anything that could break Mach. If it causes a wobble instead of a spin on its axis, it may shred during a high performance flight. (This rocket sims to 1300 mph on some 54mm motors).
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New Composites
(The fiberglass is transparent until sanded, like at the points above the fins.) |
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| The Warped Fin (It's off by about 1/8" at the tip.) |
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Warped Fin
(Note that it curls to the left at the root as viewed in this picture.) |
I also designed and 3D printed a GPS mount that fits in the nose cone. It features a base that slides into the nose cone coupler, which mounts the lipo battery and Featherweight GPS tracker. The cap slides in over the base to retain the battery, and features an undercut flange which the nose cone retention screws capture to secure the entire assembly.
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| Base with Lipo and Featherweight GPS |
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| Cap |
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| Base Installed in Nose Cone Coupler |
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| Cap Installed |
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| Nose Cone Coupler Installed in Nose Cone |
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| Hardware in Place, Securing the Tracker |
