Gel Blaster/Airsoft Printable AR（M4） Receiver

This is a 3D printable upper and lower receiver model that is optimized for water bullet guns. It is recommended to print with PETG or other advanced carbon fiber materials. The model consists of an upper and lower receiver and 11 accessories.

The receiver supports standard type 2 gearboxes, and it has been tested with LDX data gearboxes (Lùdàn Táng 1.0 and 2.0 gearboxes, QS gearbox, SP gearbox), Jingji SLR gearbox, and Jinming 9 gearbox.

Recently I have been obsessed with Wargame and SpeedQB, and I have damaged many launchers. With my wallet being empty, I thought hard and worked on this for a few weeks so that everyone can get or make a useful lower receiver at a low cost.
Sharp-eyed friends should have noticed that the model has some desensitization and simplification designs (the dust cover, ejection rod, and empty magazine indicator are removed). On the one hand, it minimizes sensitive features, and on the other hand, it simplifies most accessories that are not related to the main function.
The receiver consists of two main parts, GU_Upper and GU_Lower, and 11 smaller parts. The hardware requires two 1.2 * 5 mm self-tapping screws (one for the rear pin and one for the rate of fire), and one 0.7 * 8 mm * 15 mm spring (magazine release lever). Of course, the universal AR gold parts can be used, as shown in the picture.
Currently, the receiver is compatible with gearboxes with the same data as LDX, IFP, Rock, etc. It is also compatible with the Jingji SLR and Jinming 9 gearboxes. The magazine is compatible with Jingji, Jinming (slightly loose), and Lùdàn Táng (slightly tight).

To ensure the strength of the z and y axes, both parts need to be printed at 45 degrees. The print file has been added with an inclined support base. After printing, the base needs to be cut off by yourself. Prepare a pair of water-mouth pliers and you are good to go.
The project is currently open-source on MakerWorld. If you need it, please feel free to take it. Welcome to like, collect, and reward. Thank you everyone.

*The project is still ongoing, and some of the content will be updated later.