can I build a torque multiplier 3000 ft lbs

Take it to a hydraulics shop. Problem solved.

Torque multipiers are stackable, rent a couple of them eg drive a 1 1/2 " multipier with a 1" multiplier and that should do the trick.

Pete

What diameter of pipe will he need with a 10 foot cheater?

Ya tried the lever idea, I guess i need thicker wall pipe as the .125 thick pipe would bend. shop wants 75 to take the nut off and 75 to put it back on. I am cheap and that seems like a lot. I am thinking of a jig with a bottle jack.

For 10' length 2" pipe is more than big enough for average use. Bigger is needed when you go 15-20' especially if you use a come along on the end and have two heavy guys hanging off it (been there done that).

Actually the biggest problem is holding the other end of the rod without tearing anything up. Fortunately I've got a really big vise attached to a very solid column. Even then I used a shaft clamped in the vise sticking up, the rod end was slipped on the shaft and then the top of the shaft was chained to the column.

Of course after doing all of that the nut ended up galling to the threads and I had to cut it off to prevent ruining the threads on the rod (metric of course and me without a lathe that can cut metric).

As far as the strength of the pipe is concerned, length doesn't matter. The stress two inches out will be about the same whether the pipe is three feet long or thirty feet long. It doesn't matter if the pipe bows some, so long as it doesn't buckle. And the longer the wrench (or whatever) you have inside the pipe, the less the tendency to buckle.

Jerry

Yes, but you can apply much more force if it's 30 feet long, so the size does matter.

Not really, if it bends at the end of the wrench inside the cheater (most likely spot) it won't matter what's beyond that. Either 3' or 30' the longer just makes it easier for you to bend it.

Sounds like money well spent if your time is worth anything. (and broken stuff, and huge pipes you do not need, and jigs you would need to make). I would call a few more shops to see if it can be done a little cheaper. Plus, what will you use to hold the other side (as Wayne mentioned).

Are you saying that I can't apply more force with a 30 foot pipe than I could a 2" one?

if it bends at the end of the wrench inside the cheater (most

Which is exactly my point. If we need a 30 foot cheater to do a certain amount of work, the cheater will need to be larger to support the increased work.

Let's say I can apply 400 lbs of force to a lever. It the lever is 1 foot long, I might not be able to remove the stubborn nut. If it's 5 foot long, I can produce more pressure at the nut end while still only applying 400 pounds of force to the end, so the lever better be able to withstand it.

I use 2 1/8" Range One for long cheaters. Still light enough to man handle..still stiff enough to use for a cheater over 5' long

But then..thats what Ive got a lot of ..chuckle

Gunner

Rule #35 "That which does not kill you, has made a huge tactical error"

================================== FWIW --

The reason for the high torque is to provide adequate pre-load/stetch on the screw.

While it won't do you any good on the removal, I have seen large nuts with a number of high strength set-screws parallel to the threaded hole.

In use, the large nut was hand threaded on the shaft and seated. The smaller set screws were then torqued to provide the required pre-load or stretch/elongation. A little calculation shows how many set screws you will need. Because of the smaller helix angle, you get more force for a given torque with the set screws. These also may have been fine thread. You may have to fabricate a larger "nut" to provide room for the required number of set-screws. IIRC there were little copper caps that went under the setscrews.

Slick idea with easy on/off using only hand tools, even for large [huge?] nuts and [for me] extreme torque/pre-load/elongation specs.

Unka' George (George McDuffee) .............................. Only in Britain could it be thought a defect to be "too clever by half." The probability is that too many people are too stupid by three-quarters.

John Major (b. 1943), British Conservative politician, prime minister. Quoted in: Observer (London, 7 July 1991).

Commonly found on load frames used for testing materials and components....tapered nuts are also used to take up clearance after the load train is put in tension.

if you can mount the rod very rigid , and the bolt is the type that goes thru the piston into a female threaded hole in the piston end of the rod , sort of like caterpillar outrigger cylinders off of backhoes , case does this as well , then email me and i will tell you how to do it in less than 20 minutes without a multiplier.

oh and if it was tightend to 2800 , it will take between 32 and 3500 to break it loose .

email williamhenry at bellsouth.net

gm wrote:

I have seen the other responses and have this to add. I do know that if you press a hammer on a nail it will not go very far in a piece of wood. If you rare back and hit it the force is multiplied many times. The same will work for this application. If you can make a hammer wrench it will move with a good enough lick. I use this quite regularly. Get a wrench at least 3 ft long and get a fat man to stand on the wrench and hit the wrench with a sledge hammer about 1 ft from the problem area. It will come off. Putting it back with the right torque is another problem.

This is an interesting topic to me. I have this tool called a Powerwrench made by ken-tool. It is basicaly a long socket with a gear reduction at the wrench end. You slip a pair of bars on the gear end and reef on it. The triples your force and makes it easier to loosen/tighten the inners lugs on big rigs and buses or bookmobiles. Anyone need this thing?

I would definitely be interested.