TIP: I don't use masking tape for engine lock retention. Paper masking tape breaks down over time. If you've ever cut open an older rocket, that tape turns to dust!
Electrical tape will last much longer, is more flexible and wont tear.
Notice the upper picture -
This is how I start the wrap to get 1 1/2 wraps, two thicknesses of tape are over the engine hook. Start with the end 1/4 turn below the hook. Go all the way around and finish off with 1/4 turn over and past the hook. In the lower picture the engine mount is flipped. Notice the direction of the engine hook.
I'm using an Odd'l Rockets heavy wall BT-20H. The "H" stands for Heavy. These heavy wall tubes are only available from jonrocket.com.
The inside diameter of the BT-20H is the same as a standard tube. The outside diameter is a bit wider because of the thicker tube wall.
The inside of the 20/50 centering rings require a slight peel to fit over the BT-20H tube. It's easier than you think. After the thin peel is removed, test fit and sand the inside for a good fit over the tube.
The rear 20/50 ring is slotted. You can use some heavy duty scissors to cut out a 1/8" wide wedge piece.
Sand the cut ends to square them up.
I appreciate that you take the time to show how you make your engine mounts. The engine mount in a rocket is like the foundation of a house; you'd better get it right whild you're building it because it's nearly impossible to fix once it's finished.
ReplyDeleteThanks Lonnie,
DeleteThis one took a little more work, sizing it to fit a heavy walled BT-20 and the notched rear ring.
I built a couple of mounts recently with BT-20H and I can attest to how easy it is to peel a layer out of the rings to fit. It is very much worth the effort.
ReplyDeleteYay!
DeleteThat's the feedback I like to hear!