2018:Cube Mechanism

Cube Subteam

Current Intake

• Prototype:
  • Side roller intake with 6 wheels per side, contacting the cube on the bottom, middle and top parts.
  • Rollers are on arms that can pivot outwards and are tensioned with surgical tubing attached to the frame.
  • Rollers are belted to motors mounted on the arms.
  • Arms are on hinges to help test lifting the cube once we have control of it.
  • 10.5" long arms.
  • Intake must grab the cube in a way that when it flips over to the other side the cube is in the right position for the exchange.

Current Cube Transport

• Rotating arm 21"x?" gear ration of about 300-1
• Conveyer Belt
• Elevator 

Meeting Notes

1/7 - Sunday:

• Intake:
  • Started work on roller intake prototype

1/9 - Tuesday

• Intake:
  • Put grooves in 4" compliance wheels to increase friction 
  • Arm tensioning moved to points on frame so they move independently

1/10 - Wednesday

• Intake:
  • Belted motors to frame, now driving the rollers with drills will not affect the movement of arms
  • Arm pivot point moved so they are 10.5" long, which makes sure we do not pick up multiple cubes at once.

1/11 - Thursday

• Intake
  • 6 wheels on each roller. Now that wheels are contacting almost everywhere on the cube, the intake is more consistent and cube doesn't tilt as much on entry.
  • Taped a lexan sheet to carpet to simulate something on the bottom of the intake.  This alleviated some of the friction from the carpet once the cube entered the intake
  • Almost finished mounting motors to arms so we don't have to drive it with drills.
  • Arms are mounted to a C-channel on a hinge so we can start to look at what happens after intaking the cube (like lifting it up).
  • Likely going to switch to 2" compliance wheels due to geometry inside the robot with the ramp.

1/13 - Saturday

• Intake:
  • General robot design decision: intake will be separate from transport mechanism
  • Motors mounted
  • Added a roller to each arm that touches the ground instead of the wheel shaft.
  • After playing with different amounts of wheels in different locations on the shaft, we determined that one wheel at the bottom is best because of how much lighter it is than having more wheels. This means it spins up quicker and also allows the arm to be more springy.
  • We realized that lifting the cubes straight up while it touches the wheels is near impossible so that will need to be figured out.
    • Could be as simple as actuating the arms outwards when we want to lift up the cube.
  • We also began prototyping a roller, which consists of rubber stretched over a plastic tube. This is extremely light and it initially seems to have a ton more grip than any wheels.
    • Matt D. is probably going to use these in a prototype of the arm/claw.