M39 EMR Airsoft Rifle w/ CYMA Version 7 Gearbox

Updated on 11/7/19, scroll down to that for better information!

I downloaded an existing M14 EBR model from an upload on sketchup. Original model credit to Rabid Beagles there.

https://3dwarehouse.sketchup.com/by/wujoberto

Then I used Blender to scale the model appropriately and looked up the difference between the M14 EBR and an M39 EMR. They both use Sage International's EBR chassis, but the M39 has a 22" barrel rather than an 18" barrel. I edited the model to make it 3D printable piece by piece to fit on my small bed and basically hollowed it out to make sure it can fit the gearbox. The whole process took me about a month with a total print time of about 90 hours. The whole rifle uses about 1100 grams of material depending on your print settings. I went through about a 1.2kg on test prints to make sure stuff fits together.

The most fickle part is the magwell. It's still not perfect and does require modification if you want it to feed properly into the hop up chamber. If you attempt to make this, the STL files need to be upscaled to 1000%. The holes are also not proper 1:1 sizes of an actual M39 model. I ended up using wood screws and tape because I got impatient and really wanted to finish this. This is NOT an easy print. It still requires a lot of work to fit it together with proper screws. Overall this was a really fun project. And also my very first airsoft gun (to own, use, make)!

Update 11/4/19 Assembly video, will update files soon. https://youtu.be/9sg_z99PBuI

Update 11/7/19 Updated STL files. These ones are good to print. Magwell feeding issue is also fixed. The stock, buffer tube, and pistol grip are not included in the STL files. I've used these ones here. I've edited the model so people can switch out whatever M4 airsoft grips they want and M4 style stocks. Total print time was about 63 hours for me not including the stock, buffer tube, and pistol grip. I used about 675g of filament. With the other parts included it will reach a little less than a kilogram. with the cost of filament and hardware, you can have a cosplay sniper for <$20!! Thingiverse is being stupid and not updating my publishing properly. I'm trying to delete the old photos and stl files but I can't so don't use those.

Please print responsibly! This is in no way meant for real firearms and only as a prop or for backyard airsoft. I don't recommend fielding this unless you print in something stronger like Nylon or ABS.

Stock: https://www.thingiverse.com/thing:3546860

Buffer Tube: https://www.thingiverse.com/thing:3717605

Pistol Grip: https://www.thingiverse.com/thing:3728030

Internal Airsoft parts purchased off Evike (~$135)

CYMA Version 7 Gearbox w/Motor

CYMA M14 Complete Hopup and Inner Barrel set (570mm)

Matrix midcap M14 magazine

1600mAh small tamiya butterfly type battery

Hardware required (~$15)

M3x0.5x6 - 11 screws (Gearbox cover plate, magwell, grip adapter, upper receiver)

M3x0.5x8 - 8 screws (Handguard, Trigger guard plate)

M3x0.5x10 - 3 screws (Rear sight, buffer tube attachment)

M3x0.5x12 - 12 screws/nuts (Picattiny rails)

M3x0.5x16 - 6 screws (Upper chassis)

100 grit Sandpaper (something coarse less than 220)

Superglue

My next project will probably be something like an L96 sniper or an HK416.

Print Settings

Printer Brand:

FlashForge

Printer:

Creator Pro

Rafts:

No

Supports:

Yes

Resolution:

0.20

Infill:

15

Filament: 3D Warhorse PLA

Black

Notes:

The magwell will require further modification for it work properly. I think I got lucky or something that my second magwell works because my 3rd one got messed up. The problem with it is that the cone i modeled to push down into the magazine will cause double feeding, or it won't push down at all if the part isn't properly printed.

Update: 11/7/19 Magwell feeding issue is fixed.

Post-Printing

Assembly may take 15~45 minutes depending on how patient you are with super glue