Day 13 – Prototype Voting (1/16/2020)

Authors: Andrew Georgioff, Ritik Mishra


  • Tomorrow, there is no open room due to inclement weather
  • On Saturday, 3 of the 4 FTC teams at the local middle school are competing at the Burnsville FTC qualifier.
  • It will be the birthday of Ryan the Scouting Lead on Monday. Since we don’t have open room that day, there probably will not be a blog post that day. Happy birthday, Ryan!
  • Stratasys is cool and we love them


Thank you to CEM who machined our driverails for us!

We riveted the drive rails together with the VexPro gussets. We ensured that the drop center was facing down, and that the counterbores were facing in the correct direction.

Once it was riveted together, we took the assembly back to CEM so that it can get welded in the near future.

Look at those rivets!

Single Flywheel Hood

We received the 3d printed single flywheel hood we from Stratasys today. We were fortunately able to attach it to the assembly before the prototype voting meeting, though it was decided we would give more time for further improvements before making a final decision.

We even shot a few balls. 

As it turns out, there is a lot of hood flex when the ball is about to exit the shooter (hood flex = no bueno). However, when we have someone pushing down on the hood to reduce flex (which is still imperfect), we are able to reach very good horizontal consistency.

Prototype Voting

Today, the team decided on which prototype designs we would be using on our final robot. We didn’t vote on the flywheel, since the two prototypes still have a lot of potential improvements left. We also didn’t vote on the wheel of fortune mover, since we have not been able to test that prototype yet. 

We decided on 

  • The Rotary OBA as our intake mechanism
  • The counterbalanced elevator as our climber mechanism
  • The conveyor as our ball manager

The meeting was a good opportunity to test and show off prototypes to the whole team.

Wheel Of Fortune Manipulator: CADded

Deployed State

Retracted State

Isometric View

Design Notes

  • Designed to use a NEO 550 Brushless Motor (aka a Baby Neo)
  • Compliance wheel is designed to be 2 inches but could probably be larger
  • Cylinder has 3.5” stroke

Potential Improvements

  • Hardstop on the deployment
  • Different plate shape that is more easily made
  • Put the cylinder in the middle of the two triangle plates

Quote of the day: “Every time I work with clear plastic, I sniff it to make sure that it’s actually polycarb and not acrylic” — Aedin Yu, Design Team Member