I'm trying to figure out how to calculate a value to set on my torque wrench. I'm having to use an extension on the wrench because I can't get the head of the wrench into the opening. I have seen a simple calculation T = L/(L+E) where L = the length of the wrench and E = the length of the extension. That seems to make sense, but does it work with a click-type wrench? Also, the website said to measure L from the middle of the handle. That seems a little bogus, but I don't have a better idea. Anyone?
Not exactly what your looking for but may be some use to someone here. For those of you who, like me, occasionally find themselves confronted with a fastener on a fuel line or a HVAC refrigerant hose armed with nowt but a torque spec and a regular torque-wrench. A socket can't be got on the thing, and you have a crowfoot adapter but, yikes, the Leaving Cert. physics nerd in you knows that this will screw up the torque setting. Well fear not, for this is how to correct it. The first thing to know is that if the wrench is fitted to the adapter at a 90-degree angle, there is no adjustment required. Zip. Nada. Bubkes. All well-and-fine until you need, for space/access reasons, to keep the whole tool straight, or maybe even at 45 degrees. So, the equation goes like this: TS == (TR x DW)/(DW+(DA*cos(Z))) ...where: TS == torque setting at the wrench TR == torque required, i.e. torque spec of the fastener DW == Distance from the wrench pivot-point to the centre of the handle DA == Distance from the centre of the adapter "jaw" to the wrench pivot-point Z == Angle made by the wrench and the adapter Say we have a fastener rated at 50 lb. ft. The distance from the centre of the square-drive on our wrench to the centre of the handle is 18 inches. The distance from the centre of the adapter "jaw" to the centre of the wrench square-drive is 6 inches. We want to keep the whole lot straight, i.e. the angle of the adapter to the wrench will be zero degress. So: cos(0) == 1 Torque setting to use == 50 x 18/(18+(6 x 1)) == 37.5 lb. ft. Now say we have the same set-up, but this time we want the adapter at a 90-degree angle to the wrench. So: cos(90) == 0 Torque setting to use == 50 x 18/(18+(6 x 0)) == 50 lb. ft. ...i.e. no adjustment from specified torque is necessary. As a speadsheet formula (as tested in OpenOffice Calc): =((TR*DW)/(DW+(DA*(COS(RADIANS(Z)))))) Happy nerding!
I think the equation you're using is for offset torque which isn't the same as using an extension. I can't imagine an axial extension effecting the torque value by any significant amount...but I'm not a Engineer.
So the center of the handle is a good measuring point? Thanks. I'm going to try to set up a 90 degree offset. If that doesn't work I'll go with 180 and do the math.
Yes, as this is typically the mid-point of the linear area where the force is being applied. In this case, the center of your palm/hand.
If its just a straight extension with no swivel than i believe you keep the same torque setting. This came up once before, and as long as it was a straight extension then the numbers stayed the same
what size drive extension and what is the ft/lbs of torque you want? extensions do twist but the torque has to be high enough for it to be enough of a factor to consider.
Center of the handle gives the average length so that would be correct. Most beam-type torque wrenches have a pivoting handle, the pivot is in the center of the handle. That math shouldn't make your head hurt. If the numbers are small, have Mongo help you. Just remember that for any numbers between ten and twenty, he will have to take his shoes off. If he says the answer is twenty-one, don't look in his direction.
Thanks for the advice, guys. I appreciate it. TC, I'm figuring out how to torque the transmission drain bolt on an R1100S. I'd love to meet the guy who designed that, and kick him in the balls.
I always thought that 90* from parallel was the same value, regardless of length (within respectable reason). And I just ran the calculator at 90*, so if you can keep everything at 90* you are golden. Otherwise use the link below (stolen from GixxerBlade): http://www.cncexpo.com/TorqueAdapter.aspx
90 degrees requires no correction. If you're going to do straight on with a torque adapter I always use http://www.engineersedge.com/manufacturing_spec/calculator/torque_adapter_extension.htm
Snap on guy told me the new digi-ones do that crap onboard, I told him Google was free and was quicker
In general I agree. But this is a HUGE thing. 55 nm of torque, and there is no way to get a torque wrench in there. Why? No fucking idea.
No shit. " Hey guys I'm about to build a fire. Can somebody help me figure the thermodynamic heat transfer on my chimney? The house leans left 4 degrees. Also, there is a wind from the east. Usually 15knots."
I've always wondered if guys at dealerships torque everything. I understand head bolts, etc. needing to be proper. The other 3/4 of the car is probably not near as important I would think.
