2021-11-11 Meeting Minutes - Drivetrain

15 Days until Final Design Review...unless,..

Goals

• Review next steps post Ping's feedback
• Confirm Drivetrain design with the rest of the team, see if we're missing any requirements
• Touchbase with rest of Drivetrain team/stakeholders. Review timelines

Action Items

• Wheel integration!!!
  • To do ASAP!
    • Get more detail on the inner fillet of the wheel so that we have more information on the constraining area
    • Print the current wheel hub and test ASAP 
    • Consider alternative methods, such as adapting the original hub → Asha Mills Emmett
• Prototype bonding aluminum hubs to the carbon fibre
  
  • Verify choice of epoxy
  • Verify successful establishment of the bond gap between the aluminum and carbon fibre
  • Verify by testing the strength of the carbon fibre assembly after bonding using the Department's equipment
  • To do ASAP!: 
    • Buy bonding materials from Composites Canada
    • Get a cap machined
      • Add bonding step 
    • Develop a test plan and establish what we are specifically looking for (Instron?)
  • Questions:
    • How much material do we have left? → Chanpakorn Chaiklahan
    • Approximately 3 ft., enough for another test.
• FEA!!! → Andrew Tersigni (Deactivated)
• Smaller CAD updates
  • Refer to the review's meeting minutes for specific feedback on each sub-system
  • General feedback:
    • Reduce the amount of hardware needed → PEM nuts, flange bolts, reduce overkill of mounting locations, remove unnecessary 3D printed parts
    • Reduce areas of stress concentration!
    • Verify machinability with Demtool's guidelines

Lower Priority

• Bill of Materials!!! Confirm what components are getting sponsored, confirm that items don't have ridiculous lead times, pricing, etc.
  • Do in a separate excel file for now...need to touch base with Ethan about his doc
• CF assembly jig → Max Apitz-Grossman
  • Just come up with a plan for now. Design and a more detailed plan for this can be delayed till after exams
• Treads
  • Lower priority? Can also be delayed until after the design is finalized, just account for some space in height/width, etc.

Updates

Full Drivetrain Team Discussion -- Notes

1. Walk team through the Drivetrain CAD → can show slides
2. Current length, width, height values
   • Length: 1.5 m
     • When corrected, give numbers to Orson!!!!
   • Width: 1.18 m
   • Height: 0.92 m
3. Current mass = ~26.5 kg
   • Chassis = 8.07 kg
   • Suspension (1.78 kg) * 2 = 3.56 kg
   • Differential = 1.0 kg
   •  [ Wheels (1.32 kg) + Nanotec Motor (0.64 kg) + VersaPlanetary (0.34 kg) ] * 6 = 13.8 kg
4. Current distance from mounting to the ground = ~530mm
   • Arm was estimating 350mm → reconfirm that geometry matches the prototype
5. Current height of Gimbal stand = ~940mm
6. DIstance from plate to end of the rover = 0.4m

Questions...

• When does SW want to claim the prototype? How long do you plan to use it for?

Notes...

• Consider routing and separation of signal/power, shielding
  • Create two channels, specifically for encoder
• Confirm E-Box plan with Ethan → who's taking it over, do we know?
• Manufacturing timeline.........discuss
• Fear bushes (protect wires!)
• Revisit gearbox loading and bending
  • Backup suspension plan
• Moment calculations arm → statically will it tip? Moment at which it will tip?
  
  • Note: some missions are without mechanism
• Consider the fact that we need some slip with our front/rear wheels for turning
  • Tread on all wheels versus some
• Contact with less wheels (4 versus 6)

New Tasks

General Notes