L2 Certification, Rocket Building

Fin Slots in Airframe

I’ve discovered that the fins are not exactly (or even close) to 120 degrees apart. The distance between two sets of fins is the same, while the other Fin/fin distance is greater than the other two by 5mm. Not terribly good. What this means is that the Jig that I made to hold the Fins in place ONLY has perfect alignment in ONE position. i.e. I cannot rotate the rocket and have the fins line up in the slots of the wood.

This has meant that I need to change my fin install procedure, by allowing me to rotate the WHOLE Jig into position, so that each fin that is being glued is vertical. I’ve done it as follows

Wooden stand
Wooden stand

 

Stand in action. Left hand side is raised 30 degrees
Stand in action. Left hand side is raised 30 degrees
Fin inserted into slot
Fin inserted into slot

 

Checking slot with a Square to make sure it is close to vertical
Checking slot with a Square to make sure it is close to vertical

 

We can take the wood stand off and attach it to the Jig, pointing out the other side. This allows us to install the other fin pointing down to the wooden base.