Here’s an easy mod for those of you who fly with the tail fin removed because it requires heatshrink where the tail fin normally sits. The goal is to prevent the tail motor holder from sliding up the boom and severing your tail motor wires. Securing the tail motor holder is important on the 9958 because the tab molded into the tail motor mount isn’t very strong. On hard impact, this stopper tab will break away and the motor holder will slide up the tail boom and nick or severe the motor wires. It is one of the biggest weakness to the 9958. The resulting cut wire is obvious, but when it’s only nicked through the insulation, the bare wires can short and cause the RX to reboot or weird tail behavior during flight. It can be hard to see the nick wires.
This is one of the first things I do to my 9958. Desolder the tail motor wires so I can remove the boom. Then slip on a 3/16″ heatshrink tube in my choice of color. On one end of the heatshrink tube, I use a pair of tweezer to prestretch the heatshink tube to the max it will allow without tearing. This allows me to fit over the plastic motor mount.
Then slide the heatshrink tube as far as you can get it on and use a hair dryer on high settings to shrink the tube. You can put a tinsy amount of glue at one end of the heatshrink tube if you so desire to strengthen this mod even more. The final result is a highly decrease risk of nicking or cutting the tail motor wire while still allowing easy future repair should the boom become damage.