High performance/speed gear box builds
There are many reasons wht people want to upgrade the internal parts of their airsoft gun. Some do it for overall performance, some people are looking to increase speed and trigger response, and some are looking to make a DMR (designated marksman rifle). This page will show you what I did to make my high performance/speed build. Hopefully giving you some ideas along the way. My goal for this upgrade was to achieve better trigger response and more realistic RoF. These upgrades where performed on an SRC SR36E2 gen 3 gearbox. The stock RoF on a 9.6 battery was quite decent for a stock gun. However, I decided to upgrade the gun to achieve a RoF closer to the actual G36. I also, wanted to increase my trigger response for smoother more practical semi auto fire. Last but not least, I wanted to achieve a higher muzzle velocity. My aim is about 420-440 fps on an M120 spring.
Gears
To increase the RoF and trigger response I decided to swap my stock standard ratio SRC steel gear set (18:1 ratio), for a Lonex high speed steel gear set (16:1 ratio). I was originally going to get a 13:1 gear set but decided against it after doing some research and finding that 13:1 gears would give me about 30rps, about 15rps over my rps goal. My aim is about 15-25rps.
Motor
Generally, for a build like this people will upgrade there motor to a high torque or high speed motor. I will be keeping my stock SRC high torque motor for this build because it is actually a very good motor. I always prefer high torque motors over high speed because a good high torque motor can power anything you want. High speed motors generally can only be used with M110 springs tops. You may be able to pull slightly more powerful springs if you use high torque gears, but that will decrease your RoF making it almost pointless. I may install a Lonex A1 motor later on. Also I replaces the pinion gear with an SHS pinion because they mesh better with Lonex gears.
Piston
In order to decrease the gear noise from the gun, and to help things run more smoothly, I chose a Lonex extreme toughness piston. This piston should mesh perfectly with the Lonex sector gear. Also, because of it's reinforced nature,
it should be able to stand up to the high RoF and hard impact of the spring.
it should be able to stand up to the high RoF and hard impact of the spring.
Piston head
For the piston head I chose a Magic Box ultra seal double O-ring. I've heard great things about this piston head and hope that it will help give me the desired fps. It's made from aluminum so it will increase the wait a bit. However it shouldn't break easily and for me that's a good thing in a high RoF gun. This piston head has ball bearings on the back that will also help to keep things running smoothly.
Spring and spring guide
I'm going to use the stock SRC spring guide for this setup. It's made from aluminum and has ball bearings. So it already does everything I need it to do. The spring will be a magic box non linier irregular pitch M120. I avoid using anything other than non linear springs for any setup. I believe the best spring guide is the Madbull ultimate spring guide as the entire shaft rotates on bearings. However that can wait until later to be installed as it's not really necessary.
Cylinder and cylinder head
I'm going to install a Lonex type 0 cylinder to help improve the air seal and heat dissipation. As for the cylinder head, I'm keeping the stock SRC aluminum one. It has double O-rings as well as an impact pad. However, I am also going to rap the cylinder head in Teflon tape. This will maximise the air seal and help increase efficiency and fps. For more information on maximising compression and air seal, click here.
AOE adjustment and Sorbo pad
As should be done with all AEG's I have installed a 70 hardness sorbo pad, and taken all the steps to adjust the angle of engagement. For more information on AOE adjustments, click here. This will help decrease the chances of anything breaking inside the gun. Especially because of the increased RoF.
Wiring
To help with RoF, trigger response, and efficiency, I will be replacing my stock wiring with low resistance wiring. The wire I will be using is 16awg Milspec silver coated copper wire. This should help with almost every aspect of the guns electrical system. I will also replace the regular Tamiya connectors with deans connectors. Deans connectors have far less resistance than Tamiya connectors. I also find them to be easier to use and much more durable. At the same time, I will clean off the carbon deposits on the trigger contacts and wedge. I also plan on installing a basic Mosfet later on.
Tappet plate, air nozzle, and Sector gear delay clip
As a final touch I will install a Core double O-ring air nozzle and an SHS V3 tappet plate. As a precautionary measure I will also add a Lonex sector gear delay clip.
Results
After many hours of work, I assembled the gun with all the new parts inside. I shimmed the gears as nicely as possible in order to be absolutely sure everything would work smoothly. I haven't measured it but I estimate I am getting about 430fps-440fps possibly even 450fps on the magic box m120. I intend to install an m110 later once I get my moneys worth out of the Magic box spring. Because the fps is a little high right now and it doesn't make the gun much better. As for the RoF I am getting about 15-20rps. Once again I haven't actually measured it. The trigger response is much better and the gun seem much more realistic as desired. The gear noise went down as the Lonex gears mesh together really well and I have had no miss feeding issues at all, probably thanks to the delay clip.
Some pictures taken after it was finished and tested:
Some pictures taken after it was finished and tested: