1. ## Re: Torque Amp

Originally Posted by William McCormick
I know what happened there Dave, your wife came into the room and whispered Y over X on the square mattress, haha.

Sincerely,

William McCormick
She is a distraction to be sure

I used substitution of:
Lt = Lc + Lw

Where Lt is combined length therefore:
Lc = length of crows foot
Lw = length of torque wrench

My distraction

Last edited by MinnesotaDave; 1 Week Ago at 09:46 AM.

2. ## Re: Torque Amp

She is a distraction to be sure

I used substitution of:
Lt = Lc + Lw

Where Lt is combined length therefore:
Lc = length of crows foot
Lw = length of torque wrench

My distraction

Certianly an understandable distraction, I wish I had.

I only started fiddling with the torque wrenches tonight. And I have to be up at 4:00am so I am already past my bedtime. All I was able to prove is that torque is one to one when you use an extension between the torque wrench and a crows foot. Angle of torque wrench does not matter at all.

My own personal observation of a quick attempt is that our formulas is it. I tried a torque I could easily develop and hold and at first I thought the standard formula might be right or pretty close. But when I ran the numbers through our formula darn it was dead on. The problem is that the difference is only like two pounds so I cannot call it. When I finish building my lever with multiple places to try out the wrench it should be very obvious. With the lever I can also measure with a scale at one foot out to get foot pounds. I can also check the calibration of the torque wrenches against the scale I think it well prove worthwhile. Hopefully I can get in and get out tomorrow and get home early and build my test lever.

Sincerely,

William McCormick

3. ## Re: Torque Amp

I was up at 4:00 am yesterday, loaded up the truck and on the road by 5:00, drove for over two hours on the way up there and over two ours back, I got home just after 12:00 am today so I did not get a chance to build my lever. But I am working on it. It was a productive day though we decided to take on an extra project. I went to a plumbing supply house, and the Milwaukee truck was there. He gave out \$15 meal vouchers to a local restaurant so we had a free lunch. My friend bought the big Milwaukee Impact Wrench and that big extension light and got a free battery. We could have just got the free meal vouchers, but we love tools.

Sincerely,

William McCormick

4. ## Re: Torque Amp

I only have one steel lever to work with, and I don't want to mess it up. I found some 3/4" stainless steel nuts I couldn't find any 3/4' steel nuts. I have one hex socket and one 12 point socket that size, I can use the 12 point socket on the delivery torque wrench. I might Everdure them to the steel lever if I cannot find steel ones today in my travels. They should be more than big enough to take the force. Even half-inch bolts shear off when we use the Milwaukee Fuel impact wrench, and they stretch when tightening so I figured 3/4" would be perfect. I am going to put a shaft onto the cantilever point on the lever and overhang that point by one foot where I want to make a spot to attach the scale, so I can check the torque wrenches and measure higher torque. There will be a big nut over the cantilever point and then a couple of nuts mounted up and down the lever to see what the different sized levers cause. I kept changing my plan and getting too tired to start a project after dinner, mostly because I am not sure of my plan or available materials. But I am almost there. I should make short work of it once I get started.

I also have a really nice long solid aluminum bar but I do not have any sane way to mount steel nuts to the lever. I was thinking of a custom made steel rectangular box tubing that I could weld up out of quarter inch steel, and then weld a large nut to it and use that, and have a set screw to hold it in place. But then the torque wrench is sitting way above the bar and would cause it to twist. Then I was thinking maybe I could cut off a piece of aluminum by the cantilver and then weld it and bolt it back to the lever under that cantilever or folcrum point so that the wrench was more inline with the spot and nut over the fulcrum point. This way I could just adjust my single nut to any position up and down the bar. And the scale would pull at a point more inline with the wrench.

Sincerely,

William McCormick

5. WeldingWeb Artisan
Join Date
Dec 2018
Posts
3,480
Post Thanks / Like

## Re: Torque Amp

This is why the Chinese, and just about everyone else in the World, are kicking our butts

A straight line force creating potential rotational movement

The force imparted to the end of the beam..................Torque

https://www.school-for-champions.com...m#.X76R9emSnIU

You put your socket on the round thingy, and pull/push on the long bar thingy, and ya gots torque applied to the round thingy. The ultimate question, which is uppermost in our pointy lil' heads......................just how much torque can ya apply to the round thingy before it breaks..........or when it reaches maximum clamping force without breaking.

6. WeldingWeb Artisan
Join Date
Dec 2018
Posts
3,480
Post Thanks / Like

## Re: Torque Amp

I can apply torque to anything. It's virtually unlimited. Length of the lever thing.

The only question relevant to designers, is the value at which something radically changes the material to which the torque is applied. Torque is torque.

7. WeldingWeb Artisan
Join Date
Dec 2018
Posts
3,480
Post Thanks / Like

## Re: Torque Amp

Put a torque wrench on the crowsfoot, and you're messing with The Universe. The torque wrench only measures torque around ITS HEAD. Without taking direct readings at the fastener, I highly doubt that you can get a satisfactory conversion to apply to your observed torque wrench reading.

Simple thought would be to add the entire rig up, and come out with your beam length. But.........the calibration on the torque wrench is based on deflection when applying torque to the wrench head...............not straight line force applied though your now longer beam to the fastener.

BTW............the crowsfoot, and the torque wrench, have different characteristics when it comes to deflection.
Last edited by farmersammm; 5 Days Ago at 01:56 PM. Reason: added last sentence

8. WeldingWeb Artisan
Join Date
Dec 2018
Posts
3,480
Post Thanks / Like

## Re: Torque Amp

I'm really afraid that you're gonna have to bite the bullet, and get something made for higher torque application/measurement.

I don't like the readout on this one. It was a wasn't-anybody-looking auction buy. I guess it's handy for a backup, and to check the other wrench with.

This is the go-to. I like a Vernier scale..........more accurate with finer graduations.

9. WeldingWeb Artisan
Join Date
Dec 2018
Posts
3,480
Post Thanks / Like

## Re: Torque Amp

I know I'm late to the party, and math isn't my strong suit.........

Without comparing the torque wrench reading to a known standard, I don't see how you can extrapolate a linear relationship between the straight line force applied to the torque wrench, and the actual torque applied to the fastener. The torque wrench depends on deflection between the handle, and the fastener(the middle of your joined wrenches).

You can apply force to a lever to create torque, then take that torque and convert it into straight line force.......................gears. But the direction changes at the point of conversion

For some duration of time, and amplitude of force...............the torque wrench head is soaking up energy before it transfers your pull on the handle. It's attempting to rotate its head in the opposite direction of the direction you actually want the force applied. You're essentially working with a spring loaded hinge.

I just don't see how you can read that torque wrench with any degree of certainty. Anyways.........the shop ought to be warm by now, and my noodle is getting tired

10. WeldingWeb Artisan
Join Date
Dec 2018
Posts
3,480
Post Thanks / Like

## Re: Torque Amp

I was thinking about torque wrenches out in the shop................

This got me to wondering as I watched stuff spinning round and round........................I'm not sure where the second torque wrench came from. It might have been just a duplicate buy for some reason, not real sure. Goes back to somewhere around 2010-2012.

11. Master Welder
Join Date
May 2014
Location
Central Wa. state
Posts
3,826
Post Thanks / Like

## Re: Torque Amp

I have a couple of those Proto and an SK 3/4" drive wrenches, but I prefer this one. It's a bit longer than most of them.

12. ## Re: Torque Amp

Originally Posted by farmersammm
I know I'm late to the party, and math isn't my strong suit.........

Without comparing the torque wrench reading to a known standard, I don't see how you can extrapolate a linear relationship between the straight line force applied to the torque wrench, and the actual torque applied to the fastener. The torque wrench depends on deflection between the handle, and the fastener(the middle of your joined wrenches).

You can apply force to a lever to create torque, then take that torque and convert it into straight line force.......................gears. But the direction changes at the point of conversion

For some duration of time, and amplitude of force...............the torque wrench head is soaking up energy before it transfers your pull on the handle. It's attempting to rotate its head in the opposite direction of the direction you actually want the force applied. You're essentially working with a spring loaded hinge.

I just don't see how you can read that torque wrench with any degree of certainty. Anyways.........the shop ought to be warm by now, and my noodle is getting tired
For a week in math class back in the day when you just didn't run out and by a couple of torque wrenches we had this on the chalkboard. And every day we looked at all the forces and came to the conclusion that if you used a socket extension into a crow's foot from the torque wrench it becomes a one-to-one torque reading to the torque applied to the bolt. So without a torque wrench or a scale or two torque wrenches to test with, we could not swallow that the rotational force the reading on the torque wrench could be dismissed. The lever-action created by the added lever length of torque wrench when it was in line with the crow's foot and not separated by a 12" socket extension would seem to have to compound or add to the total torque applied to the bolt. I have still not been able to build anything because I really do not want to waste material and time just to get a larger mystery. I can say from just fiddling that there is a difference from the standard 50-year-old formula but not as much of a difference as I suspected and tried to calculate for. I have to finish a root canal today so I probably will not get around to it. But from fiddling first with no crow's foot, both wrenches on the bolt, the two wrenches check out and the scale confirms it. When I add the crow's foot the torque output is higher than what it should be but not as high as I suspected. So there must be some other ratio going on there.

Sincerely,

William McCormick

13. ## Re: Torque Amp

It is funny but the original poster's example shows that he should have 139 pounds of tangential force on the four-foot extension to turn it. The 50-year-old formula converts it into a single lever equation and says that you only need approximately 105 pounds on the torque wrench handle if it was a single lever 5.25 feet long. And then just calculates that the torque wrench will read 132 approximately to get that 139 pounds of tangential force at that 4-foot point on the 5.25-foot lever. It throws out any rotational torque applied at the joint. Which we know the rotational force is a one to one force.

Sincerely,

Wiliam McCormick

14. Master Welder
Join Date
Feb 2012
Posts
4,219
Post Thanks / Like

## Re: Torque Amp

MAC, thanks to you I've learned that remembering the formula isn't necessary. Again, multiply the displayed torque times the length (5.25') multiplied times 0.8. Somewhere back in this post you did some math showing 0.8xxxxxx. I don't know how you came up with it but it works.

When I needed this torque amp, I needed close to 600 lbs of torque. As I mentioned, I broke my previous tool using at max of 150 ft/lbs so backed the replacement off to near mid range witch was 132ft/lbs. I did the math and got around 556ft/lbs. I then increased the rotational force a couple degrees ( tangenital haha) to get in the ballpark of 600 ft/lbs needed. In the original post I said I forgot the math and said I used 100 ft/lbs but as I said I forgot the math. All that was important to me was the 556ft/lbs.

Tool length of extension plus torque tool times 0.8 provides a good approximate torque.

5.25 feet times 132.38 ft/lbs times 0.80 = 556 ft/lbs.

#### Posting Permissions

• You may not post new threads
• You may not post replies
• You may not post attachments
• You may not edit your posts
•
Page generated in 1,606,778,130.01562 seconds with 14 queries