2021-09-09 Meeting Minutes - Drivetrain

17 Days until Prototyping Conclusion!

Goals

• Finish all of the essential mechanical fixes this weekend
• Finish field testing the following weekend
• Look over the new rules: https://urc.marssociety.org/home/requirements-guidelines 

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

• Controls
  • Wireless communication and basic movement are done!
  • To do (Sahil Kale):

• • • Debug existing code (spazzing drivetrain, bug in inverse kinematics, safety stop)
    • Collecting current sensor outputs

Update & Action Items

General Notes 

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