Description
Laylax Prometheus Non-Linear AEG Upgrade Spring MS120 (Emerald)
This is the Prometheus Non-Linear upgrade spring in the MS120 rating, finished in emerald. It is one of the stronger options in the Non-Linear range and suits upgraded AEGs where the rest of the gearbox has been built to take the extra load.
LayLax is a long-established Japanese maker of airsoft parts, with sub-brands including Prometheus for internal upgrades, Nine Ball for gas pistol parts and First Factory for external and replacement parts.
The Non-Linear design
Prometheus Non-Linear springs have an irregular pitch: the coils are not evenly spaced along the length of the spring. Laylax says this design eases wear on the gearbox, compresses more easily and is heat-treated for strength and consistent compression. Like any main spring, it sets the replica’s power and affects the rate of fire and the load on the motor.
A retailer listing for the MS120 describes an anodised coating that reduces wear and flaking, and gives a length of about 175mm. The emerald colour makes the spring easy to identify when the gearbox is open.
Choosing a rating
Laylax grades its springs with an MS number, and a higher number means a stronger spring. The actual result always depends on the rest of the build, including the cylinder, the air seal, the barrel and the hop-up, so treat the rating as a guide and confirm the outcome on a chronograph.
Check your site’s limits before choosing a spring this strong.
Fitting
Changing the main spring means opening the gearbox on most AEGs, although some designs have a quick-change spring guide. Take photos as you strip the gearbox, keep the shims and small parts in order, and lightly grease the spring guide before reassembly. After fitting, test with no BBs loaded, then have the replica chronographed to make sure it is within your site’s limits.
Key features
- Prometheus Non-Linear main spring
- MS120 rating
- Emerald finish
- Irregular pitch design, per Laylax
- Designed to ease wear on the gearbox
- Heat-treated for strength and consistent compression
- Listed for standard AEGs
What’s in the box
- 1 x Non-Linear spring MS120
Compatibility
Laylax lists the Non-Linear spring for standard AEGs. Some gearboxes, such as Tokyo Marui’s Next Generation recoil models and certain makers’ own designs, use different springs or spring guides, so check your replica’s manual or contact us if you are unsure. A stronger spring puts more load on the motor, gears and battery, so make sure the rest of the build is suitable.
Care and maintenance
Leave the replica uncocked when it is stored, so the spring is not held compressed for long periods. Store spare springs dry, and replace a spring that has noticeably shortened or lost power. Always chronograph after any change to the internals.
Who is it for?
The MS120 suits experienced technicians building a higher-powered AEG, such as a support or long-range build, where the gearbox, motor and battery are up to the task.
Please note: Spring guide and tools are not included. Always have your replica chronographed after fitting and before play.
