Friday, 9 January 2015

Of Triggers and Nozzles

I decided to finally grab the bull by the horns and get back to work on the AUG. I had a new air nozzle and wanted to get the gun back in working order for the weekend game.

The newest nozzle I bought is by Core, and it's somewhat different from both the stock piece as well as the SHS aluminium one I had installed before. The stock nozzle has no o-rings, so it's bound to leak quite a bit of air. The SHS nozzle has one o-ring, and is made from aluminium. Both of them have a step in their profile around halfway through, the purpose of which is unclear to me. The Core nozzle has a smooth profile, and uses a double o-ring system which catches grease between the two in order to remain well lubricated. What surprised me, though, was that the o-rings did not come preinstalled, but instead sat on their own in the package.

The nozzle also had some surprisingly bad burrs on both ends, but they were quickly dispatched with a round file and crafting knife.

Out of curiosity, I decided to measure the length of the three nozzles, and was rather surprised by the result.

Left to right: Stock JG nozzle, SHS nozzle, Core nozzle

The SHS nozzle is a good bit shorter than the stock or the Core one. I'm not surprised that I wasn't getting all the power I was expecting. Why, however, would they make the nozzle so out of spec compared to the stock one? The mind boggles. At least I'm better off now. I hope to be, at least.

I had dreaded opening the gearbox for a while because of the way the trigger mechanism is built. It is pretty nightmarish to put together, as I've explained in earlier posts.

The main trigger piece (on the left) has a metal contact plate on the rear face that connects two contacts on the gearbox body to enable full auto fire. That is covered here with duct tape to make the AUG semi-only. The separate claw-shaped piece (in the middle) actuates the normal V3 gearbox contacts which achieves the semi-auto fire using a cut-off lever. The return spring, rather unsurprisingly, returns the trigger to the forward position.

When assembled, the two metal pieces are only connected to each other by the tabs on the larger piece riding inside the cutout of the smaller piece. Said cutout is open on both ends, so there's precious little to stop the smaller piece from simply falling off when reassembling the gearbox. To alleviate this, I came up with a plan.

Using an empty beer can as material, I created a piece that would hold the two trigger parts together and allow me to use my limited number of hands for more pressing matters when putting the box back together.

The sides of the can are really thin, so I reasoned they would not interfere with the trigger's movement.

After I had a good sized piece cut off, I used a sharp punch to mark the locations of the holes on the shell, and later a larger one to cut out holes to match the trigger pieces.

With my brand new Keep-It-Together-Plate™, I was ready to once again organize my fingers like some meat origami so that every piece would stay put until I got at least one screw in place.

I suppose it was too much to ask. But hey, at least the two pieces stuck together! One more go, and I had it.

First screw was in, holding the spring in check, and all that I had to do now was to move the gears around enough to be able to get the top part of the shell to sit in place. It helps to push the nozzle in, as that moves the tappet plate back and in so doing, takes the pressure off the gears.

Once everything was in place, I quickly connected a battery to check everything works, and then stuck the box back into the gun. Everything works as it should, so here's one success for the history books.


  1. Hey, keep up the good work!

    I come to this site every few days hoping for updates. don't stop! I love the material and your writing style too.

    1. Whoo, my first comment! :D Thanks for the compliments. I'll definitely post more soon. Just been a bit busy lately. There's plenty of material to come, never you worry!

  2. good post .Thinks to your post.I think may be Of Triggers and Nozzles at will help you a lot