Raiderbot X Meeting 4, 39 Days to Robot Ship
Meeting time: 15:00 to 21:00
We are two days behind schedule. I started a WOT (Weighted Objectives Table) discussion of the various lift concepts at 3:30. We started with seven concepts:
- Single-jointed arm
- Multi-jointed arm
- Telescope (elevator)
- Four-bar linkage
- Eight-bar linkage
- 60/40 scissor
We narrowed it down to the four-bar linkage and the elevator and chose the four-bar linkage after a qualitative analysis using a pros/cons list for each. But I still wonder if this was necessary, because it took another 30 minutes of our time and I ran 45 minutes past my proposed deadline of 4:30. Why couldn’t we have reconsidered the two options using the three factors we had rated most highly? Will says some people just need more stake in things? Anyway, my bad for not calling them on it. Areas of improvement:
- Do not let the loudest voices steer the discussion off-course.
- Constantly think back to previous discussions and decisions. People were putting the WOT factors under the pros/cons lists, which is nonsense.
- As always, be consistent, even when calling out for hands when rating the WOT factors. This is no time for jokes.
Will then separated us into four design groups for the lift, claw, base, and minibot.
Four-bar linkage: Mr. Groom found that making the shoulder pivot points’ distance shorter than that of the elbow pivot points allowed the claw to point down when the arm is down and point up when the arm is up. This should allow us to reach both the ground and the top peg as well as everything in between. This makes sense if we think about the four-bar linkage as a trapezoid and shifting the two bases—the linear displacement for the two lever arms is equal but the arm lengths are different, so angular displacements differ.
Minibot: make it as close as possible to a battery with motors glued on.
Preliminary design review planned for Saturday 17:00.