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R W
02-25-2008, 05:56 AM
I recently constructed a heavy puller using a 1.5", 8 threads per" bolt
& nut, would like to know what force could be applied per ft of leverage
using this set up.

joethemechanic
02-25-2008, 08:57 AM
Well a lot of that is going to depend on what you are using to lubricate the threads.

But with just straight up math, and figuring one foot from the center of rotation, you are going to move the handle 6.28 feet in order to move the puller 1/8"

so you are going to be moving the handle about 603 eights of an inch in order to get 1/8 of an inch of linear movement out of your puller.

So your mechanical advantage would be 603 to 1.

In a perfect frictionless world 1 pound of input force would produce 603 pounds of output force.

But in reality you are going to loose a lot to friction. What you are using for lubricant on the threads is going to be a big factor. So is the type of thread, and whether or not the bolt is plated with anything.

If you haven't done so already, get a thrust bearing for under the whatever it is that you are turning with the wrench. That will help alot.

R W
02-25-2008, 06:08 PM
Thank You Joe for your reply: The threads were well lubricated with anti sieze and the bolt slightly relieved.
Using a 5ft lever and allowing for friction, I feel aprox 100 ton force could be applied.
Not allowng for friction and applying 100lb at 5ft works out approx 134 ton (2240lb/ton)
Please correct me if this is incorrect.
R W

TozziWelding
02-25-2008, 06:56 PM
If it pulls what I (you) want it to pull, don't worry about the math. Homemade tools are the best, if it dosen't work the first time, re-engineere it.

steve45
02-25-2008, 07:17 PM
I don't think you'd get nearly that much before you tear up the threads. How long would the threaded section be?

joethemechanic
02-25-2008, 07:34 PM
Well if the tensile strenth of the bolt is 100,000 PSI it works out to 88 tons before you exceed the strength of the bolt.

If it won't pull what you want, try to get something with acme threads to replace the bolt.

joethemechanic
02-25-2008, 08:35 PM
Thank You Joe for your reply: The threads were well lubricated with anti sieze and the bolt slightly relieved.
Using a 5ft lever and allowing for friction, I feel aprox 100 ton force could be applied.
Not allowng for friction and applying 100lb at 5ft works out approx 134 ton (2240lb/ton)
Please correct me if this is incorrect.
R W

Yeah that 134 figure works out if you are going by the 2,240 "gross ton".

The 88 figure in my last post was based on a 2,000 pound ton

R W
02-25-2008, 09:27 PM
Thanks for your replys.
The puller was constructed to remove the rear hub from MH744D tractor, it consists of
an 18"dia x 5/8" plate, 6"x1.5", 8 threads/"(BSF)HTthreaded round,+ 2 nuts. The plate was centre drilled (1.5+) 1 nut welded centre, 1 to threaded round, 2flat bars, 2.5x.5 x12" were welded edge on just clear of the nut across the plate, which was attached to the hub by 2, 2.5x.75 UNC HT bolts. 4ft + of leverage and a sledge hammer to the forcing bolt were required to free the tapered hub.

joethemechanic
02-25-2008, 09:40 PM
A Massey Harris? I'm thinking 6 cylinder Perkins diesel right?

R W
02-26-2008, 02:08 AM
A Massey Harris? I'm thinking 6 cylinder Perkins diesel right?

Your thinking is right on.

William McCormick Jr
02-26-2008, 03:02 AM
I was using a big Bessemer adjustable clamp, and I read what it was rated for, I could not believe it. The adjustable three foot clamp was rated for 7,500 pounds. I thought that was pretty amazing. It only has about a 3/4" thread.

It explained how we were able to do some of the things we did with it though.

I also use their corner clamps for welding. They are pretty cool. They copper plate their threads. They make nice clamps. Probably an oxide of copper. Because it is very hard.

Sincerely,


William McCormick