It's Alive!

The new motor arrived today. It's an SHS High Torque and it is great. I also got a new SHS polycarbonate piston so I would not need to use the aluminium one which gave me so much trouble already.

I wasted no time in installing the new motor, even though it took me a while to figure out how exactly the motor cage is opened. Before that, however, the wires had to come off.

I began by taking a picture of the wires connecting to the motor so that I'd know which wire goes to which terminal when I was putting them back on the new motor. I then soldered the wires off (again there was the mystical Chinese nuclear waste solder which took forever to melt).

Now I know what goes where

The next step was to unscrew the screws holding the cage together. The cage was still held together by an L-shaped bracket on the side. The motor has a spring on the top which forces the motor towards the bottom of the motor cage but also holds the cage parts from separating. After a bit of fiddling, I figured out how to pull the the cage parts in different directions so as to disengage the two pieces.

There is a small metal plate on the bottom of the motor cage which connects with the motor base to raise or lower the motor height according to how the height adjustment screw on the bottom is turned. The plate naturally flew away as the cage parts separated and I lifted out the old motor. It took a bit of time to actually find the plate from the floor since it (naturally) rolled away as if running for its life.

Putting the motor plate back in, I took the new motor and started fitting it into the cage. It was pretty intuitive how to now reattach the cage pieces, but the motor spring didn't want to co-operate and jumped out of its place a couple of times. After a while it was over and the motor sat where it should and the screw was back on.

Then I simply soldered the wires onto their new terminals. The motor terminals on the SHS High Torque are nicely marked with a + and - and the positive terminal is also coloured red, which is a very nice addition. Then it was time to work on the gearbox itself.

Since I had a new motor in, and also because my previous attempt was obviously not up to spec, I decided to re-shim the whole gearbox. Shimming is time consuming, but really only takes patience. I first took out all the gears and shimmed each one separately to see how many shims I needed on each gear. Then I shimmed starting from the bevel gear and moved shims from top to bottom or vice versa depending on which way the gear should be moved. Then the spur gear followed, adjusted based on the bevel, and finally the sector adjusted based on the spur. It was all pretty intuitive once I knew what I was doing.

The new piston fit in without a problem, and the only issue I had was (again) the trigger pieces. I cannot for the life of me figure out why they are made the way they are. If they just were somehow connected, it would make it all so much easier. Perhaps I can in the future modify them to be somehow at least a bit more sensible. The annoyance of trying to get these small parts into place while a strong spring is trying to wrest the gearbox shell open and the gears are not quite fitting into their holes is just simply infuriating. I did finally get it all back together, though.

Since I still had the chronograph on loan, I set it up like last time, loaded up with 0.20g BBs and fired away. What a joy it was to see the AUG finally shooting so much better. I averaged 126 m/s (413 fps) across around 20 shots. Everything seems to work great, although I should maybe be getting a bit more power out of it still. Most likely the air nozzle is not mating properly with hop-up. But that's a small issue to fix compared to all of what I've done up until this point.

The AUG is mostly finished at this point, although I have some visual modification still in mind.

If there is one thing to learn from my trials and tribulations regarding this particular gun, it would be to upgrade as many parts in one go as you can. I've been working on this thing for over two months now and it has been incredibly frustrating to have to order one piece after another and then wait for them to arrive before I can get back to the project. Had I bought the air nozzle, cylinder, cylinder head, piston, piston head, spring, spring guide and motor all in one go, this whole project would have been done in a week or so. Instead I've done battle with it for so long and never managed to field it in all that time. I'm now definitely looking forward to taking this gun out and actually playing a proper game.