Semroc Snake Jumper Build, Part 3, Replaceable Kevlar Ties

Some Kevlar is stiff, other Kevlar is soft and can start to unravel.
TIPS: I'll usually tie off the end with an overhand knot to prevent unraveling.
Run a bead of wood glue (never use CA glue on Kevlar or any string) and rub it into the Kevlar. After it dries you can cut off the knot in the Kevlar (wire cutters are easiest for this) and the line won't fray.

Here's how the replaceable Kevlar is tied on.
On the left is the low end of the engine mount. A tight loop is tied around the back end, over the hook on the other side. Feed the Kevlar line through the tube and out the top. Don't glue the Kevlar loop to the centering ring!

On the right is the upper side of the engine mount. A loop is tied in the end of the Kevlar for attachment of the shock cord.

After a few flights you can slip the loop off the back of the engine tube, slide it through the tube and see if it needs replacement.

A forward fillet was applied using a Q-tip taped to a dowel. Put a drop of glue on the Q-tip and spread it around the ring / tube joint. It'll take a few applications of glue drops to get all the way around the outside of the ring edge.