Reinforcing The STU Sector Gear

Sector Gear
 

Parts manufacturers usually don’t recommend the use of super torque up (STU) gears with spring ratings higher than M/SP140. For those who tried usually resulted to shorter (than normal) gear lifespan. The truth is STU’s (Super Torque Up) can wind up spring ratings up to SP/M150 and can be reinforced for a more dependable set-up (been using mine for more than a year of regular use without any problems). This procedure requires access to an acetylene welding torch and some welding rods (ordinary welding rods will wear out quickly based on experience and would require you to use “Hard Facing” type welding rods which have a stronger/harder metal property).

Gear Sets: The Sector Gear And its Weak Point

The sector gear is the top most gear on an assembled AEG (air electric gun) gear set. It is the gear that meshes and winds the piston (or piston body). This gear usually fails when the last tooth wears out (the last tooth takes the most stress because this is the part that carries the load of a fully compressed spring (the last tooth of the piston which is the inserted metal tooth on most polycarbonate/plastic piston body, mates to this part). So by theory and logic…. The last tooth of the sector gear is the part that will surely wear out or break off first (either with a stock or a heavy rated spring). With this in mind we tried our hand in strengthening/reinforcing the last tooth to see how long will it hold out on a basic skirmish airsoft gun (aeg). An airsoft rifle that sees regular weekend usage and fires an average on 2 high capacity magazines, roughly around 850 rounds of BBs per gaming day.

Tool Requirements:

1. Acetylene Torch

2.”Hard Facing” Welding Rod

3. File Set

4. Table Vise Clamp

 5. Grinder with a thin grinding stone/blade

Procedure:

Given that you have the tools, the capability and the “know how” to use them….

Using a Vise Clamp, Securely position the sector gear so that you can “build up” the metal on the last tooth by welding the metal of the “Hard Facing” welding rod (be sure to remove the combustible coating of the electric welding rod by hammering it first).