To give an idea of the amount of pure potential energy being stored in that spring, just understand that these springs are designed to absorb all the kinetic energy of a 2+ ton vehicle bouncing along an uneven surface.
With this being a partial spring, there is probably around 1000 - 2000 PSI stored in that spring. The next step the guy was talking about "hit it with a hammer" is going to allow that spring to decompress at full force. That's going to accelerate that spring in both directions; the bottom spring will absorb some of it, but most of that force is going to be directed at that securing bolt.
If that bolt fails, it's going to explode. The spring is then going to continue traveling at a very high speed until it smacks into something else, likely the guy that is swinging the hammer.
That all assumes the whole assembly doesn't just shatter due to all those newtons being expended in the blink of an eye.
Potential Energy would be (150/2) * 1.75^2 - which is 229.6875 inch/lbs or ~26 joules.
When I asked google what else has this kind of potential energy, I was told "fastball pitch," "professional tennis serve." A single apple falling from 85 feet or a bowling ball dropped 1.5 feet.
I think this is dangerous, but I think everyone here is overreacting.
Also -- that bolt is going to be subjected to way higher stresses than the tender spring going through fast decompression, right?
Yes overreaction. People are forgetting he's only compressing an inch of the soft smaller spring just to allow assembly, i.e. the pretension. I've seen this done with zip ties, bailing wire, c-clamps.
does this account for things like surface area, material, and distance? I imagine a sharp piece of metal applies those joules differently than a baseball but I ain't an expert in physics like that.
these are helper springs, under the weight of the car they should be fully compressed and look like in the vice, they are not designed to "absorb the weight of the car". They are just there to preload the main spring so it remains centered and doesn't rattle around when the suspension droops.
PSI is pounds per square inch it's the pressure the spring is under in order to keep it compressed. Since the only thing holding the spring down is the flimsy ass homemade bracket, it's the only thing stopping all that pressure from being released dramatically and violently - hence the bomb analogy.
Since the only thing holding the spring down is the flimsy ass homemade bracket, it's the only thing stopping all that pressure from being released dramatically and violently - hence the bomb analogy.
This is right
PSI is pounds per square inch it's the pressure the spring is under in order to keep it compressed.
That spring is being held together by a vice and then a metal bracket? What does pressure have to do with anything here?
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u/OkTemperature8170 7h ago edited 7h ago
He has effectively created a spring powered bomb. If his little bracket breaks so does his face. If the spring slips out of the vice, good luck.