2021-09-09 Meeting Minutes - Drivetrain

17 Days until Prototyping Conclusion!

Goals

Current State of Progress & Action Items

Prototype

  • Mechanical assembly
    • It's actually.....working?? (for the most part)
    • Mechanical assembly needs to be made more robust
    • Prepare for testing
    • To do still:
      • Add horizontal support beams to stiffen pegboard
      • Add jam nuts to differential linkages. Prevents it from unthreading
      • Cut new bearing plates with more mounting holes, reattach
      • Replace short screws with longer ones
      • Add Loctite to joints
      • Bring all wheels to an equal pressure, see if we can get them thinner?
      • Print battery and weight holders, add to bottom layer of chassis
      • Cut and add wheel treads
      • Create & fabricate attachments to keep differential bar in place?

    • Learnings so far:
      • Flexing in EVERY joint
        • Should minimize wiggle by having press-fit bearings/bushings secured with Loctite or glue
        • Research other rover designs or other methods in general for stiff – but still flexible – rocker-bogies
      • Weight of motors in the current position is also causing some bending of the legs
      • Definitely use metal spacers or more robust plastic spacers for the final drivetrain
  • Wiring
    • All but sensor connections are completed
    • To do still:
      • Wire up the current sensors to the ADC and Raspberry Pi
      • Mount electronics board to the chassis via hinges
      • Debug existing code (spazzing drivetrain, bug in inverse kinematics, safety stop)
      • Collecting current sensor outputs

Update & Action Items

MemberUpdateAction Items

Emily Adam (Differential bar)


  • Work on mechanical fixes to prototype, this Saturday and Sunday
  • Redesign → order and drop off plates for machining
  • Locate weights
  • Pick out motors (during the week), follow-up with Austin
  • Reach out to Fraser and Nathan about current chassis design
Former user (Deleted) (Wheel connections)
  • Set up ANSYS for Karan
  • Do some connection research, early CAD
  • Confirm motors, figure out motor integration


  •  Produce chassis mounting dimensions and (rough) layout drawings → by end of the Sept 19th
  • Confirm with Farris about antenna plan 

Former user (Deleted) (Stress calculations)

  •  First look at FEA
  • TBD about commitment...by next week?
  • Download ANSYS
  • Dive deeper into FEA

Former user (Deleted) (Frame/structure)

  • Spent a lot of time in the machine shop for arm team
  • cad for frame & joints
  • fix + print mounting for battery and weights


General Notes 

  • Add cross members/stiffening in chassis
  • Get feedback from past drivetrain members? 
  • Want to test carbon fibre → mounting piece bonding (TBD)