failing jack stand thread

RatLabGuy

RatLabGuy

You look like a monkey and smell like one too
Joined
May 18, 2005
Location
Churchville, MD
Am I crazy - what happened to the thread about the possibility of jackstands failing w/ the dude's video and the math everybody hated
 
it was nuked to the degree that Shawn or Cyd had to have done it.
Its not just user soft deleted its GONE
 
Ron said:
it was nuked to the degree that Shawn or Cyd had to have done it.
Its not just user soft deleted its GONE
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I didn't do shit.

Can't you permanently delete threads?
 
It's not even linked to my likes received list.

It's like it never happened. :eek:
 
Anyone know what sub forum it was in...this is like a scavenger hunt now.
 
I think Upnover posted it
 
I nominate @Paul new owner if this interwebs rig.

Atleast he doesn't wear Crocs.
 
Yes, I posted it.
Yes I deleted it. Permanent delete, it's gone.
Why because of instead of seeing the mechanics of how they are designed, and the safety feature that is supposed to be built in, every one wanted to attack the math, the way it was presented etc. Not one positive comment from all the know it all's on here. Often this place seems more like Pirate than NC4X4.
 
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What safety feature is supposed to be built in? Why would you want to use a pry bar to release the jack stand while it was under load?
 
I finally watched the video. I don't see anything safety related.

If you overcome the force that the jackstand is holding up by using the release lever, the jackstand will release. It takes a lot of force to do that, because that's the way jackstands are designed. So if you forcefully try to make the jackstand release, it will release.

I'm trying to figure out what part of those sentences isn't common sense.

My positive comment is to please remember your personal safety and never try to forcibly make the jackstand release while under the vehicle. Because, you know, I'm sure that had never occurred to you before.

FYI, very little math is involved to figure out the force to shear the roll pin. You look up your best guess for size and material of that Harbor Freight special, and the pin chart will tell you the rated double shear break strength. So McMaster Carr says a 1/8" generic steel slotted pin is rated for 1800lbs. So then you just need to calculate the torque it takes on the arm to get to 1800lbs (or whatever for the actual size pin) at the diameter of the release arm that the pin goes through. That really doesn't tell you anything about the safety of the jack stand though.

I'm pretty sure the roll pin is not really designed to be a safety feature, and is just a convenient press pin to assemble a cast component onto another component without having to have tight manufacturing tolerances so the jackstand can still be sold at Harbor Freight for $10. It would have to be a very small pin to use as a safety feature, like maybe a 1/16" pin. I'd have to do the math based on the 500 lbs from the example.


I didn't get a chance to reply to the original thread, sorry. :flipoff2:




:D
 
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shawn said:
What safety feature is supposed to be built in? Why would you want to use a pry bar to release the jack stand while it was under load?
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The roll pin and the design of the jack. The roll pin should shear before it will raise up the jack stand. The design it's self is the second "safety" feature(has to raise load before it can go down)

why would you use the pry bar? I have no clue. Can't think of a time I ever needed to. But the maker of the video was trying to show what would have to happen(lifting the load) to make it fail. From what I saw, he was trying to recreate what happen to the guy the car fell on, IMO he basically ruled out, that he simply hit it with his boot.
 
Disappointed Guy 10052017202309.jpg
 
Ron said:
Anyone know what sub forum it was in...this is like a scavenger hunt now.
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this one, GCC.

Was titled "Interesting"
 
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