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Make sure we create a list of which order of parts in susp bottoms out first
Order of bottoming out parts:
Shocks
Control Arms
@Kayla Lee Help me out with this one
Force bottom out parts so that shell or other parts don’t get damaged (easier to replace CA’s than middle shell)
Tolerancing and degrees of freedom
You can define tolerancing by components + things that will just be off if they aren’t met. Somethings we can look into are welding tolerancing and how far off things get and then also tolerncing of bolts & bearings.
There is also a website for tolerencing of parts that we can use
Compressive loads will cause more things than just buckling like the tearing of composite fibers causing the inserts to come out – need to emperically test our pushrods in compressive loads as well
Shocks:
Look into if we can do rot pots cheeper (not a super important thing in scale but just something to be aware of)
What is the purpose of sensors and what do we want out of each sensor?
Think about what we want out of each sensor like we should def get data on the G forces we expect to see from contact patch (I think the IMU’s do that)
Bellcranks:
Axle for bearings has super tight tolerance, see if you can just buy it from somewhere or get it outsourced because the amount of time to product is a LOT
Def preload the thrust bearings
Depending on the bolt you choose is going to be relatively soft seal, you are going to very quickly bolt past the yield of the bearings (not sure what this means compleatly but might want some clarity on this)
For snap rings we need ultra low tolerance snap rings (can machine bell crank in house with CNC but other things might need to be outsourced)
Control Arms:
Handcalc the truss solver values and hand calc the bending stress on the CA’s
Don’t 3D print jigs
Look into laser cutting or water jetting the parts instead of manufacturing in house because of timelines
Everything should be in the z-x plane for bending, unsure about the setup
Talk to Robert about CA sims
Look into staking bearings can be significantly faster
Used Arora in the past for bearings and can make it faster and decrease uncertainty
Might have to China some parts because precision because you need 1/10th precision for housing
Staking is overall going to be much faster and won't take many weeks of man hours to get it done
Look into HDPT locationtional constraints instead of angles
Suspension
GREECE THE BEARINGS
Overall Suspension:
Make sure we create a list of which order of parts in susp bottoms out first
Order of bottoming out parts:
Shocks
Control Arms
@Kayla Lee Help me out with this one
Force bottom out parts so that shell or other parts don’t get damaged (easier to replace CA’s than middle shell)
Tolerancing and degrees of freedom
You can define tolerancing by components + things that will just be off if they aren’t met. Somethings we can look into are welding tolerancing and how far off things get and then also tolerncing of bolts & bearings.
There is also a website for tolerencing of parts that we can use
Compressive loads will cause more things than just buckling like the tearing of composite fibers causing the inserts to come out – need to emperically test our pushrods in compressive loads as well
Shocks:
Look into if we can do rot pots cheeper (not a super important thing in scale but just something to be aware of)
What is the purpose of sensors and what do we want out of each sensor?
Think about what we want out of each sensor like we should def get data on the G forces we expect to see from contact patch (I think the IMU’s do that)
Bellcranks:
Axle for bearings has super tight tolerance, see if you can just buy it from somewhere or get it outsourced because the amount of time to product is a LOT
Def preload the thrust bearings
Depending on the bolt you choose is going to be relatively soft seal, you are going to very quickly bolt past the yield of the bearings (not sure what this means compleatly but might want some clarity on this)
For snap rings we need ultra low tolerance snap rings (can machine bell crank in house with CNC but other things might need to be outsourced)
Control Arms:
Handcalc the truss solver values and hand calc the bending stress on the CA’s
Don’t 3D print jigs
Look into laser cutting or water jetting the parts instead of manufacturing in house because of timelines
Everything should be in the z-x plane for bending, unsure about the setup
Talk to Robert about CA sims
Look into staking bearings can be significantly faster
Used Arora in the past for bearings and can make it faster and decrease uncertainty
Might have to China some parts because precision because you need 1/10th precision for housing
Staking is overall going to be much faster and won't take many weeks of man hours to get it done
Look into HDPT locationtional constraints instead of angles
Steering
Lower Steering:
Putting too much emphasis on rack removal, just use the existing mounting design since the belly pan should be much easier to remove.
constrain rack from tilting with a wedge or smth on the belly pan
For rack failing in bending, should change geometry before changing materials; suggest design rack extenders such that they fit over the rack itself to prevent bending and use one bolt to go all the way through. Alternatively,
Helicoil aluminum threads
Change flex lock nuts to jam nuts
Upper Steering:
Aluminum sleeve on upper steering will get torn through by bearings; change to hardened steel or look at Misumi sleeves for this purpose
bearing contacts must be lubed and look into shaft seals
consider AL or steel assembly for weight savings
consider plastic bushings instead of retaining rings
Goals:
Emperically test steering column by end of the year
Jig
Buy Steering Stock and Narrco Rack
Buy Bearings – Ask Gerard if it is bad to buy it this early
Also idk how but learn how to fix unsprung assembly
SIMS
Stiffness? Using Tubes/CM to sim? Using 3 ________ ? Suspension force?
Hubs:
Profile looks good, rim-to-hub is beneficial we should use through holes for rotor to hub, but make sure we have enough clearance for tooling behind
FEA is not enough to tell if our important connection (hub to rotor and hub to rim) will not fail so we need to hand calc those,
luckily Jacob sent me some materials on those
lowkey i have been leaving the hand calcs for yall so I will be stepping up and doing my fair share of those we chose grade 8 bolts for easiness but for weight saving i think we should do the shear calcs for those to find smaller diameters of holes and spec them like grade 5 or whatever we determine meets our criteria w a fos
Hub to Rims bolting can be done with either a hex bolt or a threaded rod and shear pins (email B&B)
Make a hub bolting reference sketch for rim bolts.
If only doing like 6 rim to hub, don't need to have cad for all 9 connections
Axle:
All hand calcs
Multi axial loading (Von Mises) and stress constrantation calcs. Shigleys.
Steel (bored out and heat treated) vs Aluminum
Shoulder on axle (one though upright)
Between bearings Tapered vs Straight
Bolting through upright or shoulder though inboard side?
Brake:
Keep current circuit but disregard line lock
Need to change MC size and balance bar to have more forward biased brakes
Although my sims have FOS lower on a .15" thicnkess rotor if Chris's team can have a 1/8" rotor (4130) with such an aggressive lightening pattern w/ through holes and have it be fine for them, then I think my sim setup is too simple and I am doing something wrong
Also trailing arm caliper placement can be optimized
Not threading the rotor (mb yall i was dumb on this one) we need a sholder bolt thats unthreaded but bc our length is very small it will be hard to find so need to work this out
Make our own!
Goals for end of year:
Figure out hand calcs by end of year
Stress Concentration
Axle
Bolted Areas
Von-Mises
Axle
Bolt Joint Analysis
General for every bolt
Finalize Axle
Timeline:
Start a calc that davies can look at by EOD Saturday (4/12)
Talk to Davies about our situation of axle load case and how would we go about figuring out the von Mises throughout the week (4/14 - 4/18)