Oh yes, there will be supports.
This is a bullpup nerf blaster that is big, comfortable, and shoots 2 rounds at a time. Based off the XR2 from Black Ops 3 (which I didn't play, just love the design) this is a fully ground up build, with a special geared pusher that has an extra long throw. That means you can shoot full lengths, half lengths out of any mag and adapter, and even 2 half darts at a time loaded into the normal size nerf magazine. It uses a standard nerf stryfe size cage, but can only fit 130 motors without modifying it. It's also made from the outset to take an ultrasonic setup, and it works quite well that way.
The two round burst is less reliable, and if you short stroke the trigger it can cause jams. That said, it does work, and it can work very well.
This is an intensive build, and I don't have a guide or anything of the sort for putting it together as of now. I found that it took me about a whole roll of filament total, and many, many hours. I'm offering this essentially "as is" because I've put it together, love mine, and think it's finally time to share the files.
You'll need to use pretty much every file, and there are nearly 50 to print. Many are small, and don't necessarily serve a huge purpose, but they all do something. The only optional part is if you use a solenoid pusher, you'll use the "trigger microswitch" file and leave out all of the geared pusher parts.
Might fit a prusa mk3, might not. I know it will fit a cr10.
THE BIGGEST known weakness is the trigger pivot on the "lower". I've put a hole that goes all the way through so that this can be reinforced with either a long m2.6 screw or with a pin of the same size (.1"). It may be possible to up the walls/infill to accommodate this weakness as well.
Trigger is updated with one that has a screw hole rather than a hook for the extension spring
I've added a build guild guide image to help everyone figure out how to put this damn thing together. Enjoy.
This is uncut footage from the second prototype, which broke during this event. I've since attempted to remedy the problem.