Re: Torque Wrench for SMA


On Tue, 18 Aug 2020 at 02:20, dbztuzujdhgtrjzthxh via <> wrote:
Hi Mike, Torque Wrenches are one of the easiest precision tools to validate (adjustment may be a different story)

You'll need a vice, a 5/16 (8mm) nut, a weight, a ruler and some sting or wire
Choose your weight for convenience - a 1 litre plastic bottle out of the fridge would be perfect (I say plastic because the weight of the contents is known and the packaging is negligible)

Unless I have mis-understood you, your method ignores the contribution to the torque of the mass of the handle, which will be distributed another its length.  Ít probably fairly insignificant on a torque wrench, which I would not consider a "precision tool" as you do, but I don't think calibration is not as easy as you stated.

I don't know for sure, but I suspect if you find the centre of mass of the handle, and the mass, you could consider that adding a torque equal to the mass * g * length_to_centre_of_mass, where g is the acceleration due to gravity. I don't understand how your method can be considered correct for what you consider a "precision tool".


Dave, G8WRB

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