growingSTEMS Combat Robotics at the St. Mary’s County Fair
Get ready for sparks, crashes, and buzzing excitement! growingSTEMS is bringing combat robotics to the St. Mary’s County Fair this year with a full day of thrilling robot battles.
Date: Saturday, September 20th, 2025
Time: 9:00 AM – 5:00 PM
Location: St. Mary’s County Fairgrounds
Builders from across the region will compete in two buzzing divisions in a double elimination bracket:
-
Beetleweights (3 lb robots)
-
Plastic Antweights (1 lb “plants”)
This event is hosted by growingSTEMS, a local nonprofit dedicated to inspiring students and the community through hands-on STEM education. With a custom-built arena, high-energy matches, and teams of all ages, this competition is sure to entertain fair goers of all ages.
Stop by, cheer for your favorite bots, and see what happens when innovation meets destruction!
6’x6′ cage with wooden floors.
The cage and event will be outside.
Competitors will be provided with a folding table, but are asked to bring their own extension cords / power strips and chairs for use at the event.
All competitors under the age of 18 will be required to have a parent or guardian in attendance.
Robots will be required to meet a modified set of SPARC Robot Construction Specifications – More information here – https://sparc.tools/.
Plastic Class
The spirit of these classes is to have an easy entry point for new
builders and to encourage creative designs by limiting materials to plastics that are
easy to work with, commonly used in 3D printers and don’t have strength
characteristics common in the standard classes. Components used for structure,
armor, and weapons must be 3D printed.
16.3.1. PET, PETG, ABS, PLA, PLA+, and ASA are the only materials that can be used
for the chassis and weapons. No other types of plastics or materials allowed (ie.
metal, carbon fiber, UHMW, etc). At their discretion, event organizers may allow
additional plastics that meet the spirit of the rules. Materials that are
functionally identical to PLA+ but have a different name for marketing purposes
will be considered PLA+ when determining legality.
16.3.2. Composite and blended materials that use legal materials as a base are not
permitted. Examples include but are not limited to: Carbon Fiber PLA, Glass
Filled ABS, and Flex PLA.
16.3.3. Non-plastic parts such as motors, electronics, axles, fasteners and adhesives
can be any material, but cannot be used in such a way to enhance the
structural integrity, armor the robot, or enhance any weapon. Magnets to
enhance traction or downforce are prohibited. Foam and rubber or rubber like
materials including silicone, urethane, and TPU are allowed for wheels and
padding of electronics provided they meet the requirements of this section.
Additionally custom cast wheels are permitted provided they meet the
requirements of this section.
All approved modifications to the SPARC ruleset are below:
- Due to facility regulations, this event will be enforcing SPARC rules 14.4 – Heat and fire are forbidden as weapons. No special weapons will be allowed.
- We will be providing a weight bonus for multi-bot configurations following a 50/50 rule set for the 3lb weight class.
- Two 2lb robots in the 3lb class
Event will be held at the St.Mary’s County Fair | 42455 Fairgrounds Road, Leonardtown, MD 20650
Registration will close for both weight classes on September 17th
If you have any questions / comments, please feel free to reach out – zlambert@growingstems.org