I wanted a vintage look to the upscaled Alpha so that finger tab on the engine hook has got to go.
I can usually "score" both sides of the tab with my wire cutters.
With pliers, bend the tab along the scored line and it will break apart.
Follow with light filing to smooth out the edge and round the sharp corners.
Two 1/8" ply 50/60 centering rings were found in the spare parts box.The plywood is probably overkill, but it was handy.
The engine hook notches were made with my small diamond files.
The corners of the notches were a little round after the filing so the were sharpened up with some small notch cuts with my hobby knife.
In the picture a small notch in the upper ring is made for the Kevlar to pass through. At the right of the same ring is the notch for the upper part of the engine hook.
Here's all the engine mount parts for a 24mm engine.The split tube (at left center) will hold down the engine hook between the centering rings. It's simply a split piece of BT-50 and stronger than a wrap of tape.
The engine block is a 1/4" piece cut from an old D engine casing.
When I have a rocket where the outer tube is enough larger than the engine tube (as in this case), I sometimes install the engine hook "backwards," keeping the square end at the bottom and finagling the thumb-tabbed end through the slot and past the thrust ring. I have several rockets done that way right now with good results.
ReplyDeleteI also flip around the engine hook so the square end is at the bottom. Sometimes the square end has very sharp corners. Those are rounded off with a file.
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