Fulcrum question

[Brad_Blazer]

I am thinking of making a manual press, for a non tractor related idea.

My thinking is that if I use a 48" long lever, with the pivot point within 1" from the end and pressure point about 8" from same end, leaving 40" of actual lever, and with me weighing 170lbs, how much pressure would that create? It will be pressing on an object 3/8" in diameter (.375") or at least very close to that.

The PRESSURE will be about 10331 PSI based on your 3/8" target.

 

[LD1]

I think I understand now. With 1st class levers, I would always just compare one side of the fulcrum to the other to get the ratio. With 2nd class levers, I was trying to compare the distance from the Fulcrum to the Load with the distance from the Load to the Effort. As far as I can tell, this will give the same answer as your method, except when the load is right in the middle. Your method works for all classes of levers as far as I understand. I will have to switch.

Thank you Sir!

no problem

 

[SPYDERLK]

The PRESSURE will be about 10331 PSI based on your 3/8" target.

......:thumbsup:

 

[Den1952]

scanned an old physics book of mine, dont know if this will turn out right, info about a class 2 lever-fulcrum.

 

[Den1952]

and a scan with a class 1 lever fulcrum

 

[Den1952]

clicking on the above thumbnails brings them to an almost readable view.