The Twimster: Foam dart blaster SCAR barrel

thingiverse

WIP SCAR barrel. Designed for 5/8" OD aluminum barrel, no other barrels planned yet. No STLs are provided until further testing completed. Step assembly only, for now. CAD assembly contains hardware from McMaster Carr. Hardware is still subject to change. Current hardware list: - Fishing line, unsure of length/size - (3*) 6-32 x 1/4" button head screws - (1) 6-32 x 1/2" button head screw - (3*) 6-32 square nuts - (1) 6-32 hex nuts * Only (2) required if strung continuously in a single run, if you're willing to put yourself through that process. The three square nuts will be switched to hex nuts in the final version, I am simply using the hardware I have for now. Known Issues: - Missing an awesome logo and styling. - Requires ballistic and gameplay testing. - Some portions may need to be thickened/strengthened for production. - Stringing process sucks. Definitely requires a stringing tool such as the one from the R-Scar (https://www.thingiverse.com/thing:4301520) - Threads might fight each other - trying to loosen the top thread might undo the bottom thread. Requires specific grip to work around this. - Locking/unlocking the string rotation adjustment will rotate the strings as well. This needs to be resolved with either a ratcheting mechanism, or the top thread needs to be removed and a different retention mechanism designed. - Cam lever tensioning needs more oomph. Designed and printed on Wanhao i3+ with ADVI3++ firmware and Inland ABS, sliced on S3D v4. NOT guaranteed to work with any given print setup due to how inconsistent different printer/slicer setups can be. If you have issues with tolerances/fit, please discuss in the comments and provide details. That said, my print setup isn't that great and I print with a 0.6mm nozzle, so the tolerances should be loose enough to work with most setups. There is one custom modeled support on the cam lever, modeled with a 0.65mm gap (just over 2 layers for my 0.32mm layer height). You may or may not need to adjust this. All other parts print without supports. Most overhangs are 45°, threads are 60°. Printed threads are 2mm per revolution, this will likely be changed to a coarser thread later.