- #1
lortech
- 11
- 0
I do mobile mechanical work on customers cars. If the car needs under car work, I always ask "Is the car on a slopped grade?". It is very unsafe to jack up a car on a sloped grade and rest it on jack stands with the possibility of the jack stands tipping over if the grade is to slopped.
I was thinking, why not design and build a jack stand that works on uneven grade driveways and roads. I am not sure how safe a stand like this could be. I imagine its base dimensions would be much larger. Also, the main support column would be on pivot at its base and it could be up righted so it pushes the vehicle strait up at 0 degrees, rather then road grade angle which could make it topple.
The slope side of the jack would be much further from the jack point. Or is that even necessary?
Gravity obviously would be pulling strait down on the jack. At the same time, the coefficient of friction would want to make the jack slide down hill. I would have a rubber pad riveted to the base of the jack so this does not happen.
Is there a way to mathematically calculate the brake away coefficient of friction on a rubber mat for given weight and angle ?
Thanks a bunch. Given the typical weight of a car, 2,500 bls. Road grade angle 10-15 degrees maximum.
Not sure what the typical road coefficient of friction number is.
Also, the jack head would pinch onto a part of the body so it does not slip off or, tie down with a tie strap.
I was thinking, why not design and build a jack stand that works on uneven grade driveways and roads. I am not sure how safe a stand like this could be. I imagine its base dimensions would be much larger. Also, the main support column would be on pivot at its base and it could be up righted so it pushes the vehicle strait up at 0 degrees, rather then road grade angle which could make it topple.
The slope side of the jack would be much further from the jack point. Or is that even necessary?
Gravity obviously would be pulling strait down on the jack. At the same time, the coefficient of friction would want to make the jack slide down hill. I would have a rubber pad riveted to the base of the jack so this does not happen.
Is there a way to mathematically calculate the brake away coefficient of friction on a rubber mat for given weight and angle ?
Thanks a bunch. Given the typical weight of a car, 2,500 bls. Road grade angle 10-15 degrees maximum.
Not sure what the typical road coefficient of friction number is.
Also, the jack head would pinch onto a part of the body so it does not slip off or, tie down with a tie strap.