Here's my first "Huge" project, a Science Fiction inspired rifle. Designed from scratch and having a size inspired by the Barrett M107. This is the longest project I've ever attempted, and the first one that took more than 6 hours to design.
I had originally designed it to accept an HPA airsoft unit such as a wolverine SMP or a similar system, but some design quirks caused that attempt to end in failure. I'll probably re-attempt that when I get more time to tinker, but for now I figured it'd make a killer prop for anyone attempting a sci-fi costume or cosplay setup. Finished length is approximately 45 in, or 1.14 meters.
This will take a couple spools of PLA if all parts are printed at 10-15% fill density. Many of the parts require a large amount of support material (the receiver pieces, magwell, and grip), so unfortunately there will be a lot of waste. The end result weighs around 1.1kg.
All pieces were sliced to fit a kossel mini's 180x180x230mm build area, so the unsliced full assembly files are included in case you wish to chop the model into larger pieces for printers with a larger work area. There is also an unsliced pistol version of this model, so you can slice and attempt that if a gigantic pistol works better for your costume than a rifle.
The Reflex sight model is an accessory sized to fit on the top rail, you can either leave it hollow or use the included template piece to cut out a piece of clear plastic to act as a lens, there is also room in the base to allow for some small electronics, along with a small hole to let the light from an LED shine onto the lens. So you should be able to cram a watch battery and an LED into position in the hollow base to make a functional dot sight.
Assembly instructions: Print all parts out of PLA at 10-15% fill density, print the trigger in its two halves and glue them together, Print the stock recoil/butt pad out of TPU at a 30% fill density (or 10% density PLA, if you don't want the squish). There are two forms of the magazine, one extended and one standard length, and two forms of the magazine well (one branded with a radiation symbol on the left side, and the text "XR-11, cal. 0.230 SN#0001 on the right, and the other being plain, in case you want to do your own custom text or symbols).
After printing all parts, prepare the surfaces and adhere them using either superglue, gorilla glue (the "white" expanding type), or two-part epoxy. I personally used a glob of gorilla glue in the center of each piece, surrounded by dabs of superglue to make sure that everything held firm. The trigger is held in the body using a 1/8" pin, and there is room to add a spring inside the body if you want the trigger to function.
