Tip over Point/Angle
- Shane
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Tip over Point/Angle
I'm trying to figure out at what angle my vehicle would tip over (sideways).
https://www.omnicalculator.com/physics/car-mass-center
How accurate is this?
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https://www.omnicalculator.com/physics/car-mass-center
How accurate is this?
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- XJ Junkie
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Too many variables. Especially with the terrain & what speed you’re at. What I do know for sure is that it’s roll over angle is far greater than we think.
Disclaimer: Uninformed, no research, just very strong opinions
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... I think the vehicles specs reasonably reflect standard vehicles measured limits uder controlled tests
... then it modified by your added accessories and load etc be they roof racks, tents etc and whether loads are secured or slide at extreme angles etc
... and further modified by vehicles trail/terrain predicament & attitude ... typically one would think that two wheels defie pivoting points ahead of tipping though speed and momentum etc will further change the dynamics.
... one would have to make a few simplifying assumptions but ...
... ultimately resolveable to force vectors ...
... then it modified by your added accessories and load etc be they roof racks, tents etc and whether loads are secured or slide at extreme angles etc
... and further modified by vehicles trail/terrain predicament & attitude ... typically one would think that two wheels defie pivoting points ahead of tipping though speed and momentum etc will further change the dynamics.
... one would have to make a few simplifying assumptions but ...
... ultimately resolveable to force vectors ...
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And this is why no manufacturer wants you to buy a 4x4 - because of silly shit like above. Hell, you should be blacklisted on all insurance schemes for thatHunter4x2 wrote: ↑Thu Aug 22, 2019 12:37 amAs mentioned in posts, too many variables. What I would do is pack vehicle as if going on holiday, then Jack one side up till vehicle slowly wants to lift off Jack( just 7se ropes to prevent it rolling over, mark that angle and gently put vehicle back on ground. Sounds crude but then imho you would get a true roll over angle for that load at that time.
I remember watching some time back that at one of the 4x4 training schools they had a vehicle thingymajig that you drove your vehicle onto this equipment, it would then tip your vehicle until your one side of the vehicle wheels started to lift. They then measured this tip over angle.
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Ranger Mildtrak
Scorpio Curry Cruiser
A tos-lookin', lunchbox, lipstick and powder puff carryin' home-built trailer
Scorpio Curry Cruiser
A tos-lookin', lunchbox, lipstick and powder puff carryin' home-built trailer
This is my simple method.
Not 100% correct but gives a reasonable indication
When the COM dot crosses the vertical black line you are going over
Not 100% correct but gives a reasonable indication
When the COM dot crosses the vertical black line you are going over
- Shane
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How do you calculate COM?Wooky wrote:This is my simple method.
Not 100% correct but gives a reasonable indication
When the COM dot crosses the vertical black line you are going over
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It's not really calculated and hence not 100% accurate.
Basically the two red dashed lines drawn corner to corner in my photo.
As cars are somewhat "box" like laterally, where the two lines cross is approximately where the COM will be.
It just gives an idea on how well calibrated your "pucker factor" is on side slopes
Basically the two red dashed lines drawn corner to corner in my photo.
As cars are somewhat "box" like laterally, where the two lines cross is approximately where the COM will be.
It just gives an idea on how well calibrated your "pucker factor" is on side slopes
- Shane
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My "pucker factor" is the real issue here!Wooky wrote:It's not really calculated and hence not 100% accurate.
Basically the two red dashed lines drawn corner to corner in my photo.
As cars are somewhat "box" like laterally, where the two lines cross is approximately where the COM will be.
It just gives an idea on how well calibrated your "pucker factor" is on side slopes
Any excercises one can do to improve the "O-ring" strength?
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- Apocalypse
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Tip over angle is easy. just move the centre of gravity over either outside tyre edge.
it's not bad, it calculates the centroid of mass at a particular angle but it fails to take into account suspension compression - especially on long travel / low spring rate vehicles, and more so on high COG heavy vehicles. eg 4x4, especially lifted 'overlanders' with all the heavy kak and 140l of jerry cans on the roof.
As the actual slope angle increases , your body roll increases at a greater rate as the low side springs compress, which shifts the COG over the tip point sooner than this simple calculation will estimate.
to be very contrary to the above opinions, there are not enough variables. without spring rates and compression information, this lacks the detail to be really useful...
it's not bad, it calculates the centroid of mass at a particular angle but it fails to take into account suspension compression - especially on long travel / low spring rate vehicles, and more so on high COG heavy vehicles. eg 4x4, especially lifted 'overlanders' with all the heavy kak and 140l of jerry cans on the roof.
As the actual slope angle increases , your body roll increases at a greater rate as the low side springs compress, which shifts the COG over the tip point sooner than this simple calculation will estimate.
to be very contrary to the above opinions, there are not enough variables. without spring rates and compression information, this lacks the detail to be really useful...
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- Shane
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In other words lift it up until it nearly falls over...?Apocalypse wrote:Tip over angle is easy. just move the centre of gravity over either outside tyre edge.
it's not bad, it calculates the centroid of mass at a particular angle but it fails to take into account suspension compression - especially on long travel / low spring rate vehicles, and more so on high COG heavy vehicles. eg 4x4, especially lifted 'overlanders' with all the heavy kak and 140l of jerry cans on the roof.
As the actual slope angle increases , your body roll increases at a greater rate as the low side springs compress, which shifts the COG over the tip point sooner than this simple calculation will estimate.
to be very contrary to the above opinions, there are not enough variables. without spring rates and compression information, this lacks the detail to be really useful...
Not the best idea but an easy solution.
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- Apocalypse
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Shane wrote: ↑Fri Aug 23, 2019 2:07 pmIn other words lift it up until it nearly falls over...?Apocalypse wrote:Tip over angle is easy. just move the centre of gravity over either outside tyre edge.
it's not bad, it calculates the centroid of mass at a particular angle but it fails to take into account suspension compression - especially on long travel / low spring rate vehicles, and more so on high COG heavy vehicles. eg 4x4, especially lifted 'overlanders' with all the heavy kak and 140l of jerry cans on the roof.
As the actual slope angle increases , your body roll increases at a greater rate as the low side springs compress, which shifts the COG over the tip point sooner than this simple calculation will estimate.
to be very contrary to the above opinions, there are not enough variables. without spring rates and compression information, this lacks the detail to be really useful...
Not the best idea but an easy solution.
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that's fine, but you can't jack it up on the chassis - you need to lift the one side on it's suspension - because the high side springs unload as the centroid shifts to the low side. and then you still haven't worked in dynamic loads, like a bump/bouncee or braking or accelerating.
You can feel when a vehicle is reaching it's tipping point. small movements of your own body mass make for big movements in the body's posture at the tipping point. it 'feels' light.
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... unsprung mass , so often a criticised aspect in vehicle specs, probably a benefical stabilising component in tip-over logic...
... also, at the penultimate stage, the cars full rolling mass would increasingly load the sidewalls of the two pivoting tyres ...
... tubeless tyres would be prone to collapse and provide a final limit-breaker to tip-over ?
... also, at the penultimate stage, the cars full rolling mass would increasingly load the sidewalls of the two pivoting tyres ...
... tubeless tyres would be prone to collapse and provide a final limit-breaker to tip-over ?
... Famous Fiver VoorLoper ...
... Veni Vidi Vici ...
... Veni Vidi Vici ...