2021-06-08 Meeting Minutes - Arm

Owned by Mathieu Harter (Deactivated)
Last updated: Aug 21, 2021 by Ethan Cronier
2 min read

Goals

  • CAD updates
  • Design Reviews
  • Next Steps


Update & Action Items

MemberUpdateAction Items
Caleb
  • Link part properties to templates (author, material, revision, etc.) → Templates done and linked to properties
  • Continue work on end effector
  • Create part templates with mass property

Austin

  • made an Am-0915 curve and put it in prototype 1 page, it seems very weak although I may be misinterpreting values
  • FRC hardware hasn't changed, (bag + 300:1 versa + 3.33:1 belt drive)
  • joint CAD halfway done, will have it done for thursday for sure. 
  • Joint 2 CAD

Medina

  • A5A6 CAD
  • continue CAD for joints 5 and 6
Ali
  • Select motor, gearbox and reduction
  • CAD joint
  • Continue CAD for joints 3 and 4 
Jasmine
  • Help Ali with joint 3 and 4
  • Create a testing procedure for the prototype
Keyon
  • Select motor, gearbox and reduction
  • CAD joint
  • CAD for joint 1
Ethan
  • 95% cad finished for end effector
  • Clean up end effector CAD
  • Prepare slides for end effector design review
  • Create cost document
  • Other documentation
Mathieu
  • Control Scheme in progress
  • buy nylon 3D printer material
  • Continue work on joint 1
  • Contact electrical, fw and sw to see if we need to integrate a gimbal
Haseeb
  • Custom arm controller
  • Custom 


New Tasks

  • Science mechanism?
  • Motor testing jig for fw/sw

General Notes

Design Review

A1:

  • motor versa planetary gearbox needs fasteners - fasteners missing from model.
  • heavy weight to tie down the base of the arm prototype
  • point of failure - the bearing, high moment on the bearing
  • point of failure - the plate on the bearing - thicker plate?
  • put bearing to support other side of versa planetary gearbox shaft
  • add encoder features
  • Add belt
  • figure out weight issues
  • make the turntables able to rotate
  • hex shaft collars?

A2:

  • figure out absurd weight
  • kerf correction
  • reduce shaft size
  • connect the gearbox standoffs to make 1 part not 2
  • servicing of motor will be tricky/rotate gearbox orientation

A3 and A4:

  • hex shaft collar for small pulley?
  • Change large pulley attachment method - ideally using a wheel hub
  • Add a way to secure bearings in the main block
  • Evaluate maximum thrust on bearings and spec out proper bearings
  • Add all fasteners
  • Separate middle block in 3D printed parts
  • Determine if circlips can withstand the thrust load seen by the arm
  • Evaluate if we can use shaft collars
  • Switch 3D printed shafts for metal shafts
  • Load, stress and deflection analysis on the aluminum tubing
  • check belt spacing
  • Add encoders
  • kerf correction
  • Check weight

A5 and A6:

  • Extend the shaft to the other end of the box tube and add a bushing
  • Add a shaft collar on axis 6
  • Add standoffs between plates
  • Add encoders
  • Add spacers between box tube and bevel gears
  • Adjust sheet inside bend radius for the 2 L plates to equal to sheet thickness
  • Add fasteners
  • Specify materials for all components
  • Switch flatheads to counterbores on end-effector attachment plate
  • Move end effector attachment plate closer to box tube
  • Check if gears can withstand the load of the end effector when lifting 5 kg
  • Check belt spacing
  • kerf correction
  • Check weight