HS Produkt VHS-K2 Airsoft Replica Build [Part 2: Upper Receiver]

Alright, with the barrel assembly done, now it's time to do the rest of the upper receiver.

I split the upper receiver into four parts due to the size - two for the top rail, two for the actual upper receiver body. 

The longest piece of this assembly is 300mm. This would unfortunately end up being slightly tool tall to print on the Ender 3, so I had to take... action:

I also have a Creality CR-10S5, which is an absolutely enormous printer - so enormous that it prints everything poorly unless I have it print at a snail's pace even after hundreds of dollars of upgrades, so it's mothballed. I decided to take the Z axis extrusions and lead screw off to put on the Ender 3. The E3 can't travel all the way up the new Z axis due to the cable loom length, but I'll make an extension later. It's long enough for this part, at least.

Printing the rear receiver half was much simpler, as it's only around 150mm long.

The extension to the chamber block is now serving part of its purpose - to affix the rear end of the barrel assembly to the upper receiver using two M3x8 screws. There is a slight protrusion on the back to lock the upper into the lower - more on that later.

And there it is, the upper receiver all printed. The gap between the two rail sections is an unfortunate result of stacking tolerances - luckily, these aren't critical, but I will probably end up replacing the top rail with an adjusted version later. I haven't started the charging handle yet because I may be having part of it machined out of aluminum for me, as 3D printed options for the "knuckle" will probably end up being too fragile long-term.

So yeah, upper receiver's all done. On to the grip and fire control group. Next time!

-Craig, ETW