Our team recently completed a robot that we built entirely from scratch. Designed to be modular, we included a double-barrelled t-shirt cannon and used it to educate our freshmen, who make up over half of the team.
Will try to get some pictures up soon.
Yes please post pictures. Sounds like a great off season project. Also perhaps you could include a summary of what you learned.
Is it two barrels or TWO GATLING GUNS? Never mind, don’t answer that question. (One of my many dreams is to have a dual gatling t-shirt cannon.)
When you post pics, will you show off the modular function? We built a WCD base that we plan to attach prototypes, t-shirt cannons, and other things to; is that what you have, or is it completely modular, including the drivetrain?
Our main goal, and one that we met somewhat, was to prep our freshmen for build season. We had a large influx of newbies this year, and we wanted to help our team, which is over half new people, get ready for build. We now have members who know how to solder, construct, design, use CAD, and program. There are some issues, though. For example, our mechanical subteam was very large, and basic training was somewhat lacking.
The modularity has been accomplished by having all the motors separated from the controllers by Anderson connectors that are sort of slotted together to make a unified connector. The entire electronics board can be unscrewed and removed, and connected (hypothetically) to another drive base without any use of solder or disconnecting wires from the PDB. The end effector, in this case a cannon, can be removed easily from the frame on which it rests, and is connected to the electronics board by the same sort of connectors as the drive system. The board itself has an excess of controllers, outputs, and has room to put on more. Overall, it will provide a solid prototyping platform and a good basis for future electronics boards.
Will get the pictures soon. Our team media person is being slow 
can’t wait to see some picture I bet that it is pretty cool to see them.