The humid summer weather didn’t stop a thousand 3D printing fanatics from gathering at a county fairground in Amish Country for the 13th Annual Midwest RepRap Festival in Goshen, IN. Hobbyists showed off hand-built mods, businesses showcased their new innovations, pallets of filament were for sale, and in the back room, builders bashed 3D-printed robots.
MRRF is a one-of-a-kind event: part high-tech swap meet, part networking, and all kinds of fun. The event started 13 years ago when a local 3D printing manufacturer decided to host a gathering to celebrate 3D printing in its hometown. The festival is named after the open-source RepRap movement that liberated 3D printing from the corporate additive manufacturing industry. MRRF has successfully spun off sister festivals in Maryland, Colorado, England, and Japan. Each festival is independently hosted, but the purpose is the same: to celebrate homegrown 3D printing technology.
Anyone who’s been 3D printing for a while can appreciate Cody Bean’s open source Printventory STL file organizer. Bean, also known as “TechJeeper,” said he created the program because he would often forget where he had saved files and grew tired of having to redownload them. The community-supported software can organize files by name or designer and let you tag them how you like.
You can further curate your files by providing URLs, or even plug in an AI to sort things out for you. Once sorted, the system will help you find duplicates clogging up your system. Available for free at Printventory.com.
MRRF hosted two very different “combat robotics” events: the Death Racers and the Midwest Robot Combat Association (MRCA). Death Racers are shoebox-sized RC cars armed with whackers, plows and an “anything goes mentality” started by YouTuber Sam Prentice at the 2022 MRRF. The MRCA is a more regulated tournament league for Ant Weight (under one pound) and Beetle Weight (under three pounds) combat robots. Both involve very serious applications of 3D printing and are extremely fun to watch and drive. Each contest awarded the winners prizes such as 3D printers and filament.
I chatted with one of the younger competitors and found out his bot is made of metal parts and 3D-printed TPU. He said that TPU is extremely tough, which is important when your competition might be armed with a saw. His “ant weight” robot build had no size limitations and could use almost anything for parts, so long as it weighed under a pound.
There was also plenty of new tech on display, such as Creality’s Raptor Pro scanner, demonstrated by enthusiast Yuriy Melnik. The portable device can scan items both large and small and is touted as perfect for scanning anything from car parts to people to turn them into 3D models for printing. The Raptor Pro uses laser line scanning and infrared structured light to scan objects as small as a quarter inch and up to 13 feet. We got a few tips from Melnik on scanning techniques to apply to our upcoming review of the Raptor Pro.
The Midwest RepRap Festival is both fun and informative. It’s held annually in June in Goshen, IN. The next festival is 3D Printopia (formerly the East Coast RepRap) in Bel Air, Maryland in September, followed by SMRRF (the Sanjay Mortimer RepRap Festival) in Manchester, England in March 2026. The Rocky Mountain RepRap Festival will be held in either April or May of 2026.
