2018:Mechanical

Overall Robot Dimensional Restraints as of 1/11/2018

After a coordination session with mechancial subteams we reached the following dimensional guidelines for all subteams to keep in mind.  Sketches (hopefully) to be added Thursday:

• Drive Base: 
  • We will be a narrow bot with our CUBE intake side(s) being 27.75" and our ramp deploy side(s) being 32.75".
  • We may be a "U" or "H" or solid rectangular drive base frame.  We will have a decision on this by Saturday night.  In the meantime, drive base is focusing on the side rail design.
• CUBE Mechanism:  Please note, this section breaks the CUBE mechanism into FOUR parts: Intake ("touch it own it"), Stabilizer (holds the CUBE firmly in an orthogonal orientation), and Arm (moves the CUBE), and Outtake (CUBE exits the mechanism). 
  • Following bumper rules, we have 15.75" of width for all parts of the CUBE mechanism that rests against the drive base frame.  All other parts must deploy over the bumpers.
  • CUBE mechanism must comply with 16" extension rule (be careful with pivots!).
  • "Going Thru the Robot" with the CUBE creates three possible pinch points:
    • A CUBE mechanism with a fixed Arm rotating 180 degrees from robot front to robot back creates an arched ceiling underneath it that the ramp storage must fit under.
    • A CUBE mechanism with any Arm design rotating 180 degrees from robot front to robot back creates a path through the center that nothing else can occupy.
    • A CUBE mechanism with any parts that extend outside the drive base require space to store those parts in the Start Configuration that could impact ramp storage.
  • If the CUBE Arm has 1 pivot point (at the base), in order to rotate 180 degrees with Intake and Outtake of the CUBE at the floor (13" CUBE orientation is min on the floor front and back, 11" CUBE orientation is min on the floor front and min. 1" off the floor back) then the centerline of the Arm is approximately 6.5" off the ground.
    • If the Arm has 2 pivot points (at the base and one creating two segments) this constraint may not apply.
    • If the Arm has 2 pivot points and the Intake/Outtake/stabilizer articulates at the end of the Arm, this constraint may not apply.
    • If the Arm has 1 pivot point and the Intake/Outtake/Stabilizer articulates at the end of the Arm, this constraint may not apply.
    • If the Intake/Outtake is attached only to the drive base and the Stabilizer is on the Arm, this constraint does apply. Please note in this instance the ability to Outtake into the SWITCH may be compromised.  It also implys that we are duplicating the Outtake or designing a second Outtake to deploy the CUBE at the front and back of the robot.

Time Trials

On 1/10/2018 time trials were conducted using past years' robots to determine how much driver control affected timings for picking up a CUBE and getting it to the EXCHANGE.  Picking up, driving backwards and delivering the CUBE to the EXCHANGE was compared to picking up a CUBE, turning 180 degrees, abd delivering the CUBE to the EXCHANGE.

	2016	2017	AVERAGE	16" FP Extensions
180 Degree Turn	53	47	50	42
Back & Forth	35	33	34	27

Drive Base Subteam

Leads: Ben S, Jordan S, Julia P

Drive Base Size

• 27 3/4" x 32 3/4"
  • 34 3/4" x 39 3/4" (with bumpers)

6 wheels

• 4 omni wheels with 2 colsen center wheels
  • 6 Colson wheels will be tested

Gear Actuated 

• gear ratio: 14-64

Frame 

• TBD:  See discussion above on robot constraints.  Based on CUBE mechanism design this could be a U, an H, a rectangle, or a rectangle with notch in the preimeter angle/channel.

Current

• Working on gearing and rail design, getting items on the shopping list and CAD.

Cube Subteam

Pickup: 

current 

• intake
  • working on prototyping an intake with side rollers 
  • put grooves in compliance wheels to increase friction 
  • moved tensioning points on the frame so the movement of one arm doesnt move others
  • working on a belt system to move wheels 
  • testing on changing the length of arms to be shorter to make them stabler 
• possible Cube transport 
  • Rotating arm 22"x?" gear ration of about 300-1
  • Conveyer Belt
  • Elevator 

End Game Subteam

Leads: Mark M, Tai L, Rachel B

Go to the End Game Mechanism  Page for detailed concept, prototyping, design and much more of the 1511 End Game Mechanism:>)