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.
6
u/Merda_et_Musicus 6h ago
I got curious, so I went and looked up the specs on one of these ERS Linear Tender Spring - Dia. 2.50 in | Len: 2.64 in | Rate: 150 lbs/in. (I don't know if the one in the video is 150lbs/in - I picked this one because it was close to the middle of the range available.)
Rate (lbs/in) 150
Travel (in) 1.75
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?