The SF5

The SF5 is a 3D printable MP5 receiver set. It is compatible with OEM HK parts, PTR parts, RCM parts, and most of the other clone or US-made MP5 parts.
Thanks to it's design, the SF5 is a cost-effective way to get MP5 performance at a discount - because many of the complex and expensive parts of the MP5 are replaced with printed or AR15 parts, 
the price to complete a build is rather cheap.

At the core of the SF5's design is its press-fit clambshell barrel mount - a simple, effective way to securely and rigidly attach the barrel and trunnion to the receiver.

Printed Parts Checklist:

REFER TO THE "BUILD CHECKLIST" FOLDER AFTER READING THROUGH THE "SHOPPING LIST" SECTION OF THE BUILD TUTORIAL PDF

Hardware Checklist:

Refer to the "Shopping List" section of the build tutorial pdf.

General Print Settings:

This receiver has been tested to work well in eSun PLA+. In any material similar or superior to PLA+, this receiver should work as well.

Note that all STL files are oriented and scaled properly, and changing their scale or orientation may result in your parts not fitting/working properly. Especially with parts like the barrel mount and receivers, orientation is important! Some cooling settings/filaments may cause some parts to warp slightly. This is generally acceptable, and will not negatively effect function. If warping seems extreme, refine cooling settings/print speed. Note that you should follow these print settings in order to get the best possible results - changing nozzle size or layer height may cause you to have to hand fit things!

My print settings for PLA+ were as follows:

Walls: 8 walls recommended
Nozzle: 0.4mm
Layer Height: 0.15mm
Temp: 230/60C
Infill: Ideally 100% - though if you use 8 walls you can use much lower infill - this has been tested at 20% infill and 8 walls, if you are trying to set a low weight record.
Supports: On/full (tree supports are ok)
No files or models Licensed for Commercial Use, Subscription, or Sale. Copyright 2023 Matt Larosiere.
Cooling fan: 20% normal, 50% on bridges. Off for the first 20 layers. Keep the fan low to prevent warp (this is a guideline, your settings may vary).
Bed Adhesion: gluestick or hairspray - since the big sections of this print have small footprints on the bed, using plenty of gluestick or hairspray is recommended.

All other settings can/should be left as default or whatever you know works best with your printing setup