Robot Annual Maintenance

Started in the 2023-2024 season, Tech Tips are segments released in the FIRST Tech Challenge Team E-mail Blast. Sometimes the Tech Tips are included in whole in the email blast, but sometimes there is more content than is reasonable in the email blast so partial content is included in the blast with the rest of the content here.

Robot Annual Maintenance Tips

Just like “spring cleaning,” an annual check-up for your robot’s electronics and software is essential to prevent common issues caused by aging components.

  • Secure XT30 Connections: If your power cables feel loose in the REV Control Hub or Expansion Hub’s XT30 connectors, avoid using glues like hot glue to keep the connection together. These only hide an unstable connection between the metal contacts, which can lead to intermittent power loss under shock. Instead, the metal pins on the device’s XT30 connectors likely need to be uncompressed. Refer to REV Robotics XT30 troubleshooting for proper maintenance of these pins.

  • Battery Rejuvenation (Charge Cycling): Older NiMH batteries can develop crystalline structures internal to the battery chemistry, increasing internal resistance and reducing power output. Charge cycling — discharging slowly to 10V (at between 500-600mA) then recharging — can break down these crystals and rejuvenate the battery. This should only be done with advanced chargers (e.g., Toolkit Q4AC, Hitec RDX2, Tektite Charge 2B) for batteries older than one season or those with an internal resistance exceeding 150% of their new value. Charge cycling shouldn’t be done often, remember batteries only have between 300-400 charge cycles before they naturally begin to deteriorate. However, draining a battery below 10V or charging a battery over 2A too often can greatly decrease the expected life of a battery by up to 40%!

  • Continuous Wiring Inspection: Make wiring inspection an ongoing task, not just an annual one. Regularly check for frayed insulation, loose connections, or bent pins. Specifically, ensure no exposed wire is visible where it meets XT30 connector housings to prevent potential shorts.

  • Software Updates Are Key: Always update your Control Hub OS to the latest version (e.g., 1.1.6 for Wi-Fi driver security) and your FIRST Tech Challenge SDK (e.g., SDK 11.0) for improved performance and better support from tournament staff.

Following these tips will help ensure your robot’s electronics and software are reliable and competition-ready.

Got any questions or want to discuss additional tips with others? Come start or join the conversation on the FTC Community Forums!