Monday, September 16, 2013

Semroc SPEV Build Part 4, Stronger Screw Eye Attachment TIP


I usually sand down and square up the bases of nose cones and adapters.
The wide BT-70 end of the big balsa adapter is the screw eye connection.
After sanding, there was a recess with some broken up balsa. This wouldn't make a good place for the small screw eye threads to grab onto.

This is based on the nose cones you get from BMS.
BMS will send you a drilled dowel to glue into the hole left in the nose cone shoulder. This dowel is a much stronger than balsa  and give you a better hold on the screw eye threads.
I "drilled" out a wedge shaped hole with the tip of a small diamond file.


Three toothpicks are glued in a triangle shape in the hole.
Press them in but not too far, maybe 1/2" - Don't split the balsa! 



More glue was applied around the toothpicks at the base of the adapter.
A rubber band was wrapped around the toothpicks while the glue dried.
After the glue dried, the toothpicks were cut off and the ends sanded flush.

A pin is pushed in the middle of the three toothpicks as a starter hole for the screw eye.
Push the pin in straight and the screw eye should go in straight also.

Using this reinforcement the screw eye should not pull out at ejection.

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