New Way Lunar Jumper Build, Part 3, Engine Mount & Shock Cords

The engine mount assembly is standard. A slip over coupler holds down the middle of the engine hook.

Here, the Kevlar line is tied beneath the upper plywood centering ring.

There isn't much space between the outer BT-50 and BT-20 engine mount tube. A larger square knot could bulge out the BT-50 tube wall.

I used an overhand knot, but rolled the Kevlar over and under the wrap 4 times. This still allows the wrap to be pulled tight and keeps the line close to the engine tube.

The wrap is set into the wet glue centering ring fillet. The loose tail is cut off and also set into the glue fillet.

The picture to the right shows the heat shrink tube slip down to the top of the ring, protecting the Kevlar line. 

The short shrink wrap is slid over the tied knot joining the elastic and Kevlar line.

Near the elastic, be careful with your heat gun - 

TIP: Using the low setting on my heat gun, the elastic started to melt!

I had to cut off the old knot and re-tie the elastic and Kevlar. I might tie an additional piece of elastic to the shorter line joined to the Kevlar.

The second time, I kept more distance between the heat gun and the heat shrink tube.

Second try was good! (Maybe that's why two pieces of tubing were included.)