I've finished a couple of projects since Haven went down and figured I'd post them:
This one I've actually had for a few months now, but I recently got the chance to take it out to a war a few weeks ago. Back around Apoc I adapted Ryan and Kane's Pullscrt design to pump-action in an attempt to create a viable 3D printed springer. The design worked, but I was unhappy with a lot of the design choices, so I sat down and redesigned just about every part and this was the result. It's powered by a full [k26] and a good 7" of draw and it shoots nice and hard.
One of the biggest changes was how I designed the bushing. I found that a solid bushing was imprecise and tended to leak air around the barrel. My new design has both and outer and an inner o-ring to seal the bushing to the body and the barrel. I still want to play a little with the tolerances, but the result is a bushing that provides a decent air seal without any adhesives.
The other major design change is the trigger, which is printed in one piece instead of two. I found that this allows the trigger to slot in better straight off the plate. Eventually I plan to design a "cap" that will fit over the end for a more comfortable pull. I also use a more slimmed-down plunger head with an x-ring seal. The x-ring has performed well for me so far, though it's hard to tell just how much extra range I'm really getting with it.
My RAPAH design would have only been possible with the technical help of NerfoMania, but I don't want to have to rely on him every time I want to build a new homemade, so I've been practicing with these:
This RABAH design uses most of the same parts as the RAPAH design, but with a free-flowing bolt-action prime rather than a pump-action prime. I started by emulating an Aeromech-style pullback and ended up making some design changes for safety reasons. I used a [k25] for priming reasons and they have about 7" of draw, which might be a little too much.
They prime by pulling the bolt back, which in turn pushes on a back plate to pull back the plunger rod. The bolt then returns forward on its own with the help of a return spring, which helps to reduce the chance of face-diddle and looks damn cool if I do say so myself. The prime is a little awkward but will be somewhat familiar to anyone who has used a snapbow or plusbow extensively. I've built two of these things so far and I'm relatively happy with the design; in the future, I plan on designing some kind of bracket to mount a handle or grip to and some way to mount a scope on it for the lulz. They take about 3-4 hours to build once all the parts are printed, which is a fantastic turn-around time for a homemade.