Increasing Rate of Fire (RoF) For AEG Airsoft Guns

Increasing Rate of Fire (RoF)

How do I increase my rate of fire?

This is a fairly easy question to answer, so I will go over some basic ways to increase your AEG’s rate of fire. Rate of Fire hinges upon several aspects: Motor, gear ratio, battery, gearbox efficiency, and your gearbox load (how much it is pulling back).

So depending on what kind of rate of fire you are looking for your set up will vary. If you would just like 25 BPS, for example you may only need a high speed/ high torque motor and a Lipo.

Airsoft has evolved to an era in which the high 20s a second is considered slow or ‘the norm’ amongst most techs. Many users are boasting guns up to 60 plus BBs per second.

So let’s start off by going over the basics.

MOTOR: AEG motors are classified into three basic types: High Torque, High Speed, and a mixture of Speed and Torque which I do prefer on most of my guns. Getting a quality aftermarket motor will most certainly be necessary when building your high speed gun. (Some exceptions apply ex. JG Blue Motor) Torque motors are usually used on specialty high speed builds, usually guns that are pulling springs above 120 M/S or Dual Sector Gear builds. Torque motors utilize strong magnets and will gain speed much quicker than ‘high speed motors’ will. Not to mention they are overall more powerful motors. High Speed motors have their benefits as well; they are to be used with springs of a lower rating, usually no greater than M110 or equivalent. Speed take a longer time to achieve their maximum speed, however in the end they will spin quicker than torque motors given they are not under the load of a heavy spring. Remember they are best suited to be used with less strenuous springs.

GEARS & RATIOS: Most Marui spec AEGs come with a gear ratio of or right around 18:1. This is a standard ratio. Anything less than 18 is considered high speed anything over is considered to be torque. If you are looking to build a high speed gun, with a rate of fire of 25 RPS more or less. Your gears may not need changed. But on the subject of high RoF builds, it is wise to shoot for a gear ratio of 14:1 or less. Why? Because 16.:1 is hardly any different than standard (18:1). Combining both higher speed gears with a high torque/speed motor will get you very noticeable results by themselves.

Specially Built Sector Gears: Ultimately some users prefer to have mega-high speed. This calls for a dramatic change in gear operation. I am talking about the Dual Sector gear. The Dual Sector gear is exactly what it sounds like. Assuming the reader has some basic knowledge of gearboxes, the dual sector gear takes place of the traditional sector gear that has 16 piston contact teeth, and divides the teeth up putting them on opposite sides of each other. Resulting in two piston cycles for each sector revolution, as a result the DSG can double your rate of fire. The Dual Sector gear is not intended for inexperienced techs or users lacking tech experience simply can’t handle the demands and modifications to make the Dual Sector Gear work properly.

BATTERY: Higher voltage increases motor speed and torque. Most widely used battery for high speed builds is an 11.1 v LiPo. 15 C + -- A Higher discharge rate is usually necessary in high speed builds pulling back a ‘heavy load’. As the author mentioned in the Batteries 101 article, it is wise to utilize a MOSFET switch to protect your AEG from higher voltage batteries such as 11.1 Volts or higher.

GEARBOX EFFICIENCY: To achieve the full advantage of your AEGs RoF. Or to Maximize its potential. You will need to make sure your mechbox is in tip top condition so it will not be slowed down. You will want to make sure your gearbox is shimmed to the best it can be with the shim space you have available. A bad shim job will put more stress on your motor and your gears, RoF and trigger response will suffer, and make your AEG ‘short lived’ especially if you are throwing in high speed components.  This is a user error that is unacceptable in AEG builds of any sort. Don’t be lazy, take your time shimming. Do a good job.

If the AEG does not have decent Bushings or Ball Bearings you will need to purchase some. Ball Bearing bushings are the preferred method for high speed builds because there is less friction on the gear axels, however the bearings can explode during super high speed possibly leading to more serious issues in your gearbox. Solid steel bushings will be more stable, but will usually not spin as well as ball bearings.

Lightening the piston A.K.A. Swiss cheesing is highly recommended, along with utilizing a light weight piston head (POM) is also recommended to keep weight down.

Correction of the Angle of Engagement (AoE) most all experienced users are familiar with this if you are not then refer back to the article titled “Angle Of Engagement.” The author’s preferred method is through use of a Sorbothane Pad with protective pad(s).

GEARBOX LOAD: This is more of a sub category of the previous category. This correlates with the previous category, so it is more of a subcategory. The heavier the spring used in your AEG, the harder your motor has to work to pull it back, which draws more Amps. Generally, the less load the better the motor can do its job and spin. Think of it aspects of automotive mechanics. You have two identical cars, both engines produce 500 horsepower and the exact same torque figures. However one car is carrying an additional load of 800 pounds. It is not rocket science, the car that weighs less will accelerate quicker and have a higher top speed. The same principles apply with spring weight; the heavier the spring, the slower the rate of fire. Some short stroked builds and all Dual Sector Gear builds require a heavy spring or buffered spring to compensate for the FPS loss as the piston is not being pulled back as far.