2021-10-24 Meeting Minutes - Drivetrain
CDR (Final Design) Meeting November 18th → 25 DAYS
Goals
Review subsystem designs
Talk about the next steps
CAD integration plan, best approaches?
Do it in stages?
Mentor feedback meeting
CAD Spins
Chassis
Notes:
Current mass: 5.7 kg**
Missing mounting plates
Increase strength of 3d printed shelf connector
Currently looks like it would snap from side to side movement
Consider mounting to upper clamping block (around rocker beam), then extending the block's width to mount elsewhere
Or consider switching 3d printed system to: 3d printed part as the easy mounting interface, then having aluminum gussets/blocks to handle the fastening load
Reference Austin's prototype arm joint
Go with single connector for tubes as used in last week's iteration
Consider adding a divider to locate the beams for assembly? Or verify that boring bar on lathe is deep enough to bore through
Increase elevation of rocker beam
Consider switching current clamping set-up of rocker beam to clamping downwards, pillow block style
Verify CF tube will fit with a bearing, check out SKF
Consider an aluminum sleeve to interface from CF to bearing
To discuss with Austin: mounting scheme
Suspension/Legs
Notes:
Current mass: 1.6 kg per suspension
For connector pieces, add clearance between outer faces so that locating step and locating stud are the only surfaces making contact
Undercut radius of male to get rid of the edge
Swap rocker bushing to bearing
Can keep bogie bushings. Avoid machining down the flange, lmao
Call out bogie connector for a smooth surface finish since rubbing against bushing
Swap shaft collars for something more sturdy, like retaining rings or thread the shaft and secure with a nut
Add differential mounting surface
Wheel connections
Notes:
Current mass: ~1.3 kg for designed components
Avoid cutting the motor...
Change inner ridge of the wheel hub close to the gearbox end. 3D print prototype and test on wheel
Add bearing after the gearbox to increase wheel support and load-bearing
Remove additional flange underneath corner brackets
Verify encoder height → swap to 22mm encoder
Differential bar
Notes:
Current mass: 1.0 kg
Preload fasteners, swap socket head on C-Channel to cap or hex head
Make sure blocks can slip over lol
Delrin can be picked up from EMS
Consider easy adjusting of length of eye joint
Will require different pieces
Remove locating dowels
Add anti-canterlever
Consider twisting and digging of plates into acetal, increase it's width
Thread eye joints into a mill component rather than have a nut
Increase thickness around bushings
Add spacer between bushings
Update & Action Items
Member | Update | Action Items |
---|---|---|
Unknown User (a4tersig@uwaterloo.ca) (Chassis) | ||
Unknown User (amillsem@uwaterloo.ca) (Wheel connections) | ||
Unknown User (e2adam@uwaterloo.ca) (Differential bar) |
|
|
Unknown User (mapitzgr@uwaterloo.ca) (Frame/structure) |
| |
Unknown User (tvaler@uwaterloo.ca)
|
New Tasks
CF tube analysis
Verify if tube has tolerance from 32 mm diameter with its surface finish
Check 2019 drivetrain for chassis-suspension weight ratio