CNC Upper gearbox ICS AR15 (EBB) - RetroArms

CNC Upper (upper part) gearbox ICS intended for airsoft guns of type AR15 (M4), M16 and other types of guns with V2 gearbox from Taiwanese manufacturer ICS, made from a block of the strongest aircraft duralumin EN AW 7075 T651, which has higher tensile strength (590MPa) than ordinary structural steel (390MPa). Thanks to the material used, the gearbox has a several times higher lifespan than a normal zinc-alloy gearbox. The Gearbox is manufactured on precise CNC machining centers.

The CNC Upper gearbox ICS AR15 (EBB) has a surface treatment with protective anodizing, because due to the properties of duralumin EN AW 7075 T651 it is practically unanodizable, due to its high hardness and strength compared to commonly anodizable aluminum, normal anodizing will not penetrate the material. If this duralumin were not protected by surface treatment, there is a high risk of aluminum corrosion (large grey spots, sometimes with a moldy appearance).

The CNC gearbox can be installed in airsoft guns from ICS manufacturer. This also applies to internal parts. When installing internal parts or the gearbox itself, never use excessive force. When tightening screws, use a tightening torque of max 1Nm, otherwise the wrench will slip in the screw head. It is not necessary to tighten screws "to the limit"; if you want to be sure that the screws will not loosen, use a removable threadlocker or paint.

New Generation Modifications:

• The spring holder of the feeder arm has a notch to prevent the spring from falling out.
• All threads are now rolled, compared to a cut thread, they have higher strength.
• Both halves of the gearbox are centered by milled protrusions and grooves.
• For even greater durability, we have further strengthened the very critical point on the outer side of the gearbox near the cylinder head, where there is now a large radius and 100% more material in this area.
• The outer edges are machine chamfered.