High stress builds Require pretty specific aftermarket parts. They are very difficult to build and maintain. DIY mods must be perfected. A complete understanding of how to modify the gearbox is required.
If your goal is between 40-50rps or higher (with SSG), you will need to change even more parts and modify most of them to meet it.
To get this speed you can:
-upgrade your batteryI recommend a 11.1v LiPo with a pretty high amp discharge.
-rewire your gun to at least 16awg, deans and a 3034 MOSFET, lower resistance wiring and connectors increase the power that can be given to your motor from your battery, the mosfet protects your trigger contacts from carbon buildup wearing them down.
-upgrade your motor, a HS motor with low ratio high speed gears (13:1, 12:1, 10:1, etc.) will get 40rps+ with a 11.1v high amp discharge LiPo battery. Now this build gets increasingly more difficult, since you start to run out of HT motors as options. HS motors have the ability to run at a higher RPM, but cant handle the same load a HT motor can. You have to combine these motors with different gear ratios and modifications to overcome the high spring tension needed to avoid PME. These setups require a lot of modification and trial and erroe to build correctly. They will ALWAYS run at a high stress level.
Some High Speed motors include: SHS HS, DA HS
-Upgrade your spring(ESPECIALLY IMPORTANT IN THIS SETUP), as your rps increases your gears spin faster. Your piston needs to be fully returned and waiting for the sector gear to pick it up to start another shot. If it is not yet fully returned when the sector gear engages it, you will hit PME and have a big mess to clean up in your gearbox. That being said, generally an m130 equivalent rated spring (or higher) should be used. You can short stroke to reduce fps or lessen the load on your motor if needed.
-DIY mods to correctly run your new gearbox speed. These include (not limited to):
-Shim, Grease, AOE
-Swiss Cheese piston (if you need to increase its return speed)
-radius cylinder window
To reinforce your new gearbox you can:
-upgrade spring guide to metal ball bearing to help sustain the increased amount of times the spring will be compressed against it.
-upgrade to a metal toothed piston. A full metal racked piston will greatly increase the strength of the teeth, which makes it able to handle higher stress setups.
-upgrade to solid metal bushings. Bushings are a high stress part of the GB commonly overlooked, bearings can also be used in 8mm+ GB shells.
-install an STS.
-upgrade to a high durability* GB shell (Lonex, G&P, VFC, sometimes DBoys and JG shells are strong too)
-upgrade to a high durability* cutoff lever
-upgrade to a high durability* anti-reversal latch
-upgrade to a high durability* piston head
-upgrade to a high durability* cylinder head
-perfect all DIY mods.
You can keep:
-anything else not mentioned
*Certain stock parts are high durability, usually JG and DBoys. You will learn more specifics during research.
You might also run into feeding issues. It is unlikely, but the combination of your air nozzle, hopup, magazine and bucking can affect how the bbs feed in your aeg. You can modify your feeding by adding a sector clip (which delays tappet timing), trying different magazines, a new hopup or bucking, etc.
Tips and Tricks:
-No two builds are identical, and no two goals have only one way to achieve them. If you are building/upgrading a high speed (or any) airsoft aeg, it would help to keep track of your progress. Jot things down that work, things that don't work. Use a thread on a forum to communicate with others and keep track of your progress. This will serve as reference for future needs and help others figure out how to solve problems you come to face.
-However, don't start a thread saying "I want to upgrade a gun, what do I need to buy". It shows you have done little to no research and will not work in the end because you wont have the knowledge to successfully tune and modify the parts going into your gearbox. Instead, try to follow this format proposed by Zardichar, I like it a lot actually: http://www.airsoftsociety.com/forums...threads-70415/
-Before starting a build, plan it out. I can't tell you how many times people go into a build with no plan or under no research and have no idea what I'm talking about when I try to help them. It makes the process a lot longer and, quite frankly, annoys me. It is also very annoying when I go through a whole upgrade plan with somebody to meet their performance goals, then AFTER THE FACT I find out they have insufficient funds for their project. Plan out your build before hand, it makes the process a lot easier.
-Do not get discouraged. Teching requires a lot of patience. Things WILL go wrong, problems WILL occur. Its all part of teching unfortunately. Figuring out what needs to be done to overcome your challenge, well that's the fun part.
Specific Information and Recommended Parts
Buying parts for your high speed aeg can get annoying and confusing...not to mention expensive. Here is a recommendation of some strong, reliable and cost-effective parts to put into your aeg. (as of Nov. 2013)
-modify stainless tempered
-Modify Ceramics 8mm
-ZCI stainless bb
-Super shooter bb
-SHS blue 15t
-Lonex Red (swiss cheesed)
-SHS gen.III (18:1, 16:1, 13:1, 12:1, pinion)
-JG stock (18:1)
-DBoys/CYMA/XYT stock (18:1)
Now, as stated above, different motors have different TPA ratings and turn at different speeds. This is also further effected by the battery and wiring connecting the two. So, with an 11.1v 20c 1600mah battery, and upgraded wiring (16awg with mosfet on deans), here are some estimate rof outputs for certain motors on an m120 spring:
-18:1 = 18rps
-16:1 = 23rps
-13:1 = 30rps
Matrix Magnum HT
-18:1 = 19rps
-16:1 = 24rps
-13:1 = 32rps
SHS HT (2013)
-18:1 = 22rps
-16:1 = 29rps
-13:1 = 37rps
-18:1 = 20rps
-16:1 = 26rps
-13:1 = 35rps
-18:1 = 24rps
-16:1 = 32rps
-13:1 = 43rps
Common Problems, Troubleshoots and Fixes
Here I will list some common found problems you might encounter while building your high speed aeg, what might be causing them, and how to fix them.
After a long, hard days work of tinkering with your gearbox, you finally have it all back together. Only to find out that pulling the trigger just results in an unsatisfactory "click" sound rather than an impressive speed build. Instead of throwing your gearbox against a wall, check for these problems:
-motor height way too tight (high)
-battery is weak
-battery is dead
-bad electrical connection
-weak motor for setup
-piston too thick
-extra strain in gearbox (really stiff spring with bad shimming/greasing for example)
-physical block in gears (an object is jamming the gears)
-really bad shimming
-gearbox shell too tight
Or, better yet, if your gearbox makes no noise at all when you pull the trigger. You should look for:
-wire came unplugged
-contacts are fried
-contacts grounding/not touching
Now, if your build actually works, but it is not as fast as it should be (considering the parts you chose to use) you may need to retune it. Check:
-if there's any extra resistance/friction in gears or piston
When your gun shoots, but makes an earsplitting shrieking noise, check for:
-bevel to pinion height
-worn down gears
If your gun is shooting, but the bbs are dropping off prematurely, check for some of these problems:
-tappet timing is off, shorten your tappet return spring o cut 1mm off the tappet fin
-bad seal with hopup, shave the front of your tappet plate
-mags cant keep up with your new rof, try new midcaps with a stiffer spring (MAG brand are good)
-tappet not being pulled far enough back, add a brass ring or sector clip and then experiment with tappet timing
-slight PME, make our piston assembly as light as you can, counteract friction in your piston rails (grease and shaving), and buy a stiffer spring if needed.
If parts you bought aren't fitting together properly, there's no space for wires, adding one shim instantly makes your gearbox lock up, MODIFY THEM! You should have things such as:
-dremel tool with various bits
Put these tools to use! Cut, grind, shave, mold, modify your pieces to fit your needs.