Monday, February 6, 2012

Work on the formula 75 - nosecone



I have scuffed up most of the epoxy ready surfaces, other than airframe. These were all cleaned with soap and hot water, then carefully dried. Instead of purchasing a nosecone eye bolt as planned, I decided to use an extra Giant Leap 38mm anchor. This includes a strong eye bolt system as well as a 38mm aluminum tube. It is certainly overkill, but the plan is to just use the entire thing with the bulkhead at the center. I then made a small mix of 30 minute epoxy and locked the whole thing together. The application of epoxy was sloppy, but because this is an internal part I did not really worry about making it look perfect. The most important parts were all coated, including the nut, washers, threads, and the actual 38mm tube with vanes. This should help protect from off-center impacts on recovery, and will spread out vertical pull on the nosecone, but will ultimately not make a huge difference over a naked 1/4th inch eye bolt.


The bond strength of the bulkhead, or possibly the open eye bolt are now the weak points of this small component. This will be potted in place with a large epoxy pour of no less then 1/4th inch thickness at a later point. I expect that this will allow for an extremely strong nosecone assembly.

With the rest of this epoxy, the nosecone shoulder was installed in the base of the nosecone. This strikes me as a weak-point because the nosecone is so heavy. Therefore, it will be reinforced with epoxy, and later with a full volume of expanding foam.

No images of the nosecone shoulder were included because with black on black fiberglass, the contrast is too low.

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