Hello all, I'm typing this guide to not only share part of my teching knowledge with you, but to answer the most frequent question I receive from the community: "How do I build a high speed airsoft gun?" Well, hopefully this guide will teach you different ways to do just that. However, before we start, you must know a couple basic things: - If this is your first time upgrading a gun or opening your gearbox, close this thread. This is not a beginners guide or a walk-through of all the required modifications that need to be done. You must figure out how to do those on your own, through research on forums (especially this one, airsoftmechanics and airsoftforum), youtube, stickies, etc. It is not hard, all you need to do is have a willingness to learn and the audacity to do so. This is a good place to start: http://www.airsoftsociety.com/forum...nners-guide-opening-gearbox-first-time-32341/ - If you expect this to walk you through a clear cut way to make a high speed aeg, you're wrong. This guide will give you a tremendous amount of information, hints, tricks and tips for building a high speed airsoft gun. But it is not a step by step guide on what to do, because, for obvious and not so obvious reasons, that simply wouldn't work. This is a good explanation of what spoon feeding information does to the community [taken from Zardichar (slightly modified with some of my personal thoughts)] Why is research better than spoon feeding? 1. You don't waste other people's time. 2. In your research, you learn other related information in addition to the info originally sought, furthering your knowledge on the topic and enabling you to help others in your similar position. 3. With spoon feeding, you are rewarded for not doing any work. With research, you are rewarded for doing work. Which one do you think produces a more productive society? Also, in the words of Star_Folder: "By telling someone to do their own research, we are helping. If someone is willing to do the research they need to do, then they will be willing to do the mods they need to have a successful build. If they just expect to be spoon fed, they'll drop in parts, and nothing will work right. We tell people to research because we want the best from them." - If you are not willing to read, learn, expand your knowledge PAST THIS THREAD and continue researching/improving ideas, you should not be teching. I've been building airsoft guns for over 3 years now, and I still find myself learning new mods, techniques and ways to approach a problem. This thread does NOT hold all the answers to building a high speed gun, there will always be more. Now, onto the guide. It will take me a bit to write up, so please, bare with me everybody. *Note: This guide is not about upgrades in general, it's not about DMRs, hopups or how to tune and mod your aeg. It will cover different aspects of a topic, but only one topic. That being what is needed for high rps aegs. Therefore, I will put MOST of my attention on the drive train of the gearbox and disregarding some other aspects of the gun. (Don't worry, if its important I will include it, if its not, there will be plenty of information about it the stickies as well as these forums.) Here are some links (stickies on this forum) that will help newer techs grasp the idea of the gearbox and some of the modifications done to make it perform better, that may not be included in this guide: http://www.airsoftsociety.com/forums/f10/zardichars-collection-guides-airsoft-teching-80513/ http://www.airsoftsociety.com/forums/f10/guide-elite-mech-box-modifications-23385/ http://www.airsoftsociety.com/forums/f10/how-shim-like-true-mechanic-30461/ How does an AEG shoot? How can I make it shoot faster? First off, I will overview what makes the aeg shoot, and why certain parts make it shoot faster. Your battery sends power to your motor, which spins its pinion gear. This spins the bevel, which spins the spur, which spins the sector. On top of the sector gear there are teeth that contact the piston's teeth. As your sector gear is spinning the teeth on it meet the teeth of the piston and begin to pull it back, against the force of your spring, which is held in place by the spring guide. Once the sector gear pulls back the piston a certain ammount of length, the teeth disengage and the springs force is released, pushing the piston forward, through the cylinder, until it contacts the cylinder head. All of the air that was in the cylinder is pushed through the cylinder head, through the air nozzle, and through your hopup pushing your bb down the barrel. Now, your sector gear continues to spin, pulling back the tappet plate, which pulls back the air nozzle, which allows another bb to enter the hopup. This cycle continues (this is full automatic firing). Breaking that long, boring wall of text down. There are only certain parts of the gearbox where the speed at which they move can actually be changed. That being: -motor (the speed it spins) -gears (the amount of rotations the sector makes in a given time period) -piston (The speed that it returns back to the cylinder head) So, in essence, a high speed gun is trying to increase speed in these things: -The motor, because it dictates the possible max speed of fire. This is what turns the gears in your gearbox. This is done by installing motors with different TPA ratings and Neo magnets. -The gears, because they can contribute to how much time it takes to pull back the piston, which results in a shot. This is done by installing lower ratio gearsets. -The piston, because its return time controls when you can begin another shot. (if the gears are spinning faster than the piston can return, the piston will hit the gear teeth, you will hit pre-mature engagement, and your gearbox will make a very loud shrieking sound, which will ruin your day.) This is done by lightening the piston assembly and adding a stiffer spring. The Basics In any upgraded aeg, you want to make sure your gearbox is running as efficiently as possible with as little stress as possible. This is where DIY mods (such as shimming, aoe, grease, radius, sorbo, rewiring, etc.) come in handy. They increase the reliability, longevity, and performance of your parts. Motors are all made differently for different reasons (will discuss this more later). But to be brief, there are 3 main types: -HS (High Speed): low TPA, high RPM. Can spin the fastest, but has the least amount of torque. So it is strained easier. -HT (High Totque):High TPA, low RPM. Cant spin as fast, but has more torque to pull more stressful loads. -Balanced: Medium TPA/RPM. Balance between above two. *Motors work based on efficiency. So, even though a HS motor can spin the fastest, it can only pull a certain stressed load before it starts to slow down, which is where HT motors come in. (will refer to this in next section below) Gearsets come in different ratios. (18:1, 16:1, 13:1, 12:1, 10:1, etc.) The lower the ratio, the less rotations of the pinion (motor) it takes to spin your sector gear 360 degrees (one full shot), so the higher the rps of your gun (low ratio = shoot faster). However, the lower the ratio, the more stress is put on your motor. So, referring to above, not all HS motors can pull setups on low ratio (fast) gearsets. This means if a HT motor can pull a setup on 10:1, but the HS can only pull it on a 16:1, the HT might have a faster rps than the HS. Now lets use this information... There are different levels of high speed airsoft guns, and different ways to approach each level. I will do a rough categorization (Fps value at around 400 for estimations): -low stress build - <20 rps -medium stress build - 20-30 rps -upper stress build - 30-40rps -high stress build - 40-50+rps There are different ways to meet each goal listed above, I will start with a low stress build.