Fall 2024 - SRR ...

todo:

• upload pictures from pre-SRR mech meetings - parameterization

• upload jacob lecture audio #1 tilting

• upload jacob lecture audio #2 (dynamics room)

• upload conversations from robert audio

other resources todo:

• meeting w IC suspension members

• meeting with robert about shock selection

• check electric design sharepoint

https://pdfs.semanticscholar.org/b86d/bc4f5f60a10c107c5f4fb3c9c61a513426e4.pdf

https://www.reddit.com/r/solarracing/comments/141vkvf/3_vs_4_wheels/

https://www.reddit.com/r/solarracing/comments/asgzr8/suspension_design/

https://www.reddit.com/r/bajasae/comments/wx3ohc/which_of_these_is_trailing_arm_and_semi_trailing/

https://engineerdog.com/wp-content/uploads/2015/09/delta-vs-tadpole-steering.jpg

https://www.notion.so/8-30-square-1-5261c037b4604d5085155e8138966d66?pvs=4 (notes from discussions with lhr leads)

https://www.notion.so/updated-suspension-parts-fa0b0c813f1b41c993cdce7381d99bb2?pvs=4 (notes from budgeting, updating purchases, repairing daybreak/new car)

https://msumcmaster.ca/app/uploads/2021/11/2021-2022-Solar-Car-Presentation.pdf (trailing arm resource)

1. overall 3 v 4

   1. understeer vs tipping - tradeoffs in trying to redistribute weight to the front suspension, correcting understeering vs oversteering in 3 wheels

   2. “tadpole design has to incorporate extra linkages to approximate ‘Ackermann’ steering geometry to prevent wheel slippage”

   3. winning solar car prefers 3 wheel: lighter, less complex to design/manufacture, simpler rear align, gen > energy efficient

      1. BUT easy for car to go into spin if traction lost in rear - 60-70% of weight should be allocated to front of car to combat risk of a blowout and for braking purposes

   4. LHR discussions

      1. tanu, robert, jacob, nathan,

2. What is the difference between swing arm, trailing arm, and semi-trailing arm?

   2. trailing swing arm

      1. torsional rigidity in main arm

      2. main arm like trailing

      3. side arm for supporting lateral loads

      4. not that good at adjusting / tuning to be vertical - would need a trial

   3. trailing - only travels vertically so conserves most energy

      1. careful of bending stresses in the main vs swing because they need to retain rigidity and vertical wheel to chassis under lltd

         1. spring placements

      2. llt capacity >>

      3. less bending stress

      4. rr >, possible assembly weight >, but generally less unsprung weight

   4. semi - two pivot points ^

      1. generally same notes as trailing

      2. roll center can be modified

      3. ^ seems to be more stable than trailing (less info on three wheel / solar applications)

3. What are constraints from regs?

   1. 000 vs dynamics test - how much more can we theoretically increase our trackwidth / wheelbase - overall current shell and frame by regs? bulkhead space? '

4. changes to overall car based on 3 wheel - dynamics testing constraints

5. Frame and aeroshell constraints - to determine how much we can change overall trackwidth and wheelbase - what determined the space in space frame?

   1. noah’s notes

   2. suspension and wheel turnout cutouts

   3. array surface area

   4. overall aerodynamics sims → packaging

6. Hardpoints?

   1. ^

   2. vsusp - lower ride height - check at garage

7. shocks

   1. change the rear to a coil shock - but based on what parameters - shock discussion TBA

      1. minimize angle to vertical

      2. closer to the rear wheel and rod ends

8. MEOWWWWWWWWWW