Maruzen M870 - Improved Shell Set - Airsoft - Free Download

*Will not work with the M1100! (It will rip the shells apart)

Unlock the potential of your Maruzen M870 by using 3D printed shells, while at the same time reducing wear of your "almost museum piece of an airsoft". 
In testing I found it to be more efficient, to have extra models for lower BB loads, than to "underload" a shell that could fit more BBs.
So I made them available in different sizes, 1 BB up to 9 BBs.
Recommended BB-count and BB weights are writen on the shells itself.
Just choose the shell size of your liking and get to printing. 

I found a seal design, that will retain your BBs in the shell, while not reducing your energy.
Gloss TPU (95a) is needed for the seals. If you follow my Print Settings, the seals will provide consistent power, not distinguishable from OEM shells.

Print Settings:

Shell Body:

I recommend PETG or PLA.
Feel free to go crazy with the colors.
Models are already orientated for optimal printing.

Layer height: 0,2mm
Perimeters: 3
Massive Layers (bottom): 20
Infill: 15%
No supports needed.

Seals:

You need to use a TPU (95a) with a gloss finnish, to ensure a good seals.

Layer height: 0,2mm
Seam position: Random
Avoid crossing parameters: Active
Print parts one after the other: Active (only when printing more than one top seal at a time)
Perimeters: 3
Infill: 15%
No supports needed.