Have a look at my tool... For torquing nuts.

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Dean

Dean

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After seeing a couple of posts regarding torquing base and head nuts and bolts, thought I would post some pics of the adaptor I have made up for this job.

I couldn't get W/worth spanners here so bought a cheap set of A/F spanners and carefully filed it out to fit.
The 3/8 square drive was a cheap 3/8 socket cut to keep the drive piece, then welded together.

It is 3" between centres so I can use it straight on torque wrench using the conversion maths.

Cheers all.
 

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Nortoniggy said:
This is one I made that can be used with any spanner. Just need to sacrifice a 3/8" drive socket.

Have a look at my tool... For torquing nuts.
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Ian
Click to expand...

Nice simple solution. Wish I had seen that before I started....
 
Nice simple solution. Wish I had seen that before I started....
Click to expand...

suppressing beer out nose on insightful remark. That may show up on a red neck problem solving series that go around time to time.
 
I think Snap-On had something like L.A.B.'s diagrams.
They have shed loads of crow's feet/offset sockets.
May have been in the old paper ones.
May still be on their website.
 
midnightlamp said:
http://www.motionpro.com/motorcycle/partno/08-0380/

I use this guy all the time, same idea, different implementation, also wonderful for spoke wrenches and other custom tools. Also useful when adapted to hold factory tools!
Click to expand...

US supply only, anyone got a supplier in UK or who will deliver to UK?
 
ludwig said:
L.A.B. said:
If the adapter is set at right angles to the wrench then the torque figure doesn't change.
Click to expand...

??.
I would think the lever length is the red line :
Have a look at my tool... For torquing nuts.

Imagine his adaptor was 1m long ..
Click to expand...

http://www.dmctools.com/Products/torque ... harts.html

Have a look at my tool... For torquing nuts.

When an adapter or extension is used on a torque wrench it increases the torque range of the wrench. The formulae for computing torque when using an adapter or extension is explained below.

A = (Length) Distance from center of torque wrench square drive to center of the puller’s hand grip.

B = Distance from center of torque wrench square drive to center of drive at end of extension.

C = (Torque) Torque wrench setting.

D = Torque desired at drive on end of extension.

P = (Force) Pull applied.

To determine torque wrench setting: C = (D*A) / (A+B)

NOTE: After computing “C” and setting wrench to computation, measure and mark “A” where pull is applied.

It is recommended that the axis of the extension always be used in line with axis of the torque wrench as shown above.

Have a look at my tool... For torquing nuts.


Should it be necessary, due to obstructions, to have an angle between the two axes, then the above formula is modified as follows. Due to increasing rounding errors, keep the angle as small as possible.

A, B, C, D, & P are the same as above.

E = Effective moment arm of the extension.

Ø = Angle between extension axis and torque wrench axis.

E = (B)(COS Ø)

Therefore:

C = (D*A) / (A+(B*COS Ø))

When Ø = 0, COS Ø = 1, then equation is reduced to C = (D*A) / (A+B)

When Ø = 90°, COS Ø = 0 then C = D (Regardless of the length B)
Click to expand...
 
ludwig said:
In our case , the lever length is the distance of the nut to the grip of the wrench .
a 90° extention makes for a longer lever , = increased torque .
Click to expand...

I think you've oversimplified it. I don't think it works like that, nevertheless for all intents and purposes, no torque adjustment is required when using a 90 degree extension.
 
If an adapter is being used for torquing and is set a a given angle be it straight, 45 degrees, 90 degrees or indeed any other angle then if at all possible it should be used on all fasteners being torqued at the same angle. This way even if the amount of force applied is not correct due to difficulty in calculating it or incorrectly calculating it then at least all fasteners should have equal force applied. Most home mechanics would not have access to a highly accurate calibrated torque wrench so the results would be questionable at best. Plus I am sure we are all guilty at some time of not believing the wrench and pulling a bit more.
 
ludwig said:
simply repeating your original statement is not enough to prove me wrong ..
Click to expand...

I don't think I need to prove you wrong, it's already been done.
 
Sorry ludwig you're off on this one. Torque is the force multiplied by the normal distance to the moment arm ONLY or the normal component of the force to the moment arm itself (which comes from torque being a cross product of force and distance).

On a 12" lever arm with a 100 lb force applied perpendicularly at the end, you get 100 ft-lbs of torque.

On a 12" lever arm with a 3" extension in line with the arm with a 100 lb force applied perpendicularly at the end, you get 125 ft-lbs of torque

On a 12" lever arm with a 3" extension perpendicular to the arm, with 100 lb force applied perpendicularly at the end, you get 100 ft-lbs of torque and a 100lb shear load on the bolt. You also get a 100lb force at the vertical moment arm of the height of the extension (if it's small like a wrench style it's not a lot), producing a bending moment on the head of the bolt.

The key is that the force is applied perpendicular to the arm, and in plane with it's axis of rotation. This is why it is not suggested to use extensions (they make it much harder to do the second) and why you are always suggested to pull on a torque wrench at 90 degrees to it's orientation.

You can also use the real janky way to get the cylinder base nuts which is to use a fishing scale or luggage scale hooked inside the boxed end of a double box end wrench and pull perpendicular to the wrench to torque the base nuts.
 
Help me out on this guys. It seems like there is a difference between straight line force and rotational force. If you apply the same force on different parts of a lever, the farther out you go the more force you apply to the pivot end.
If you apply a rotational force (head of the torque wrench) directly over the bolt/ nut that force is the torque setting. If you extent with a wrench in a straight line then you decrease the torque setting to allow for the mechanical advantage of the extension. When a angle is introduced at the wrench head/ extension, the way the rotational force is applied the the bolt/nut is changed. Instead of pivoting on the bolt head directly you are turning the wrench and pushing the extension at the same time in order to rotate the bolt. I think this is where the issue is.
I'm just guessing at all of this, but it seems that as the angle approaches 90 degrees the mechanical advantage of the extension goes away. Once past 90 degrees I bet you cant turn the bolt at all. The caveat to this whole thing is IMO if you have an extension that is 1" will a 8" extension react the same way at 90 degrees. I think that is Ludwig is getting at.

I love this forum. The more I read the more confused I get. Ignorance might be bliss...........
 
How fascinating funny, no wonder Norton factory hardly used T-wrenches. Fact of the matter is the pivot point is the fastener and torque wrench's guts are calibrated to read torque applied at the fastener [not the handle] - when the spring gizmo attachment is a known lever length from the pivot point. So just arrange your adapters so the fastener and the spring gizmo are the same distance as if no adapter in the way. Any force not applied 90'/tangent to the fastener axis is not being applied to turn the fastener, just pinch skin more to get click to occur at same correct torque value as square on hand pressure. A simple vector addition/subtraction problem but as fasteners are not boats or space ships any miss directed thrust just doesn't apply.
 
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