Retroarms CNC gearbox V2.2 HK417 (8mm) - QSC

CNC Upper gearbox part V2 designed for airsoft replicas AR15 (M4), M16 made by manufacturer ICS from Taiwan in EBB (Electronic Blow Back) version. This gearbox is manufactured from one solid block of aircraft aluminum (Dural) EN AW 7075 T651, which has higher strength (590MPa), than common construction steel (390MPa). Because of used material, our gearboxes have the best durability and resilience than common zinc-aluminum gearboxes. We are manufacturing these gearboxes on our precise CNC milling machines in our factory.

Package includes: CNC Upper Gearbox ICS AR15 (EBB), set of screws.

We made some useful improvements into our CNC gearboxes V2:

• Spring holders have grooves, so the springs for tapped plate and trigger switch will not jump off.
• All threads are now shaped instead of cutted for better strength.
• Both of the gearbox parts are centered by milled grooves and edges.
• For better durability, we added more material around cylinder head part of the gearbox, this was the most critical part and we added 100% more material where is huge radius.
• Outer edges are now cutted off.

CNC gearbox can be installed only in airsoft replicas made by Umarex. That means even the inner parts. Do not use rude force during installation. Use only 1Nm tightening moment on screws, otherwise the screws will overturn in heads. There is no need of tightening screws with rude force, if you want to be sure that screws will sit perfectly, use thread glue or thread color.

You can use in our CNC gearbox any spring of your choice, but be aware that stronger springs will result in lower durability.

!! do not use MAXX cylinder head !!

Installation of the inner parts and gearbox requires professional knowledge, experience and skills. There are a lot of airsoft manufacturers on the market and every one of them create their own sizes, there are no standards like engineering ISO in airsoft. This is the main problem with a lot of inner and outer parts from different manufacturers which can be same product, but with different dimensions. We recommend using only parts from manufacturers with Tokyo Marui compatible parts, where should not be a problem with compatibility with our CNC gearbox.