Huntindog wrote:
wnjj wrote:
Huntindog wrote:
The crows foot is just a lever that acts as a torgue multiplier as it's input side is attached to the output of the TQ wrench. The TQ wrench output normally would rotate on the center axis of the bolt. When a crows foot of any length is used between the TQ wrench and the bolt, the output of the TQ wrench is multiplies as it can no longer rotate on the bolts center axis. It now orbits the bolt covering a much larger path as it outputs the original force to the input end of the crows foot, which will ALWAYS mutiply whatever force is on the input end to the output end.
Incorrect. It will NOT always multiply the torque and that is exactly the point. Depending upon the angle of the crowfoot compared to the angle you apply the force to the wrench it will multiply, divide or not change the torque.
Try installing the crowfoot directly backwards so that it points back under the torque wrench. Now imagine that same thing but with a crowfoot that is the same length as the torque wrench. The wrench handle now ends up directly over the bolt and you will be applying 0 torque to the bolt.
I use this same principle to turn lug nuts on a wheel that is jacked up. If you attach a wrench so the handle extends back across the center of the wheel it takes much less resistance against the tire to stop it from rotating. It this case the wheel (from center to the lug nut) acts like a crowfoot installed backward.
The only distance that matters when creating torque is the one perpendicular to the direction you apply the force.
I can make some statics force diagrams if you'd like.
The original question was a 90 degree angle.
If you maintain that angle as in a dial type wrench, or not using the rachet function... What happens?
If you push directly perpendicular to the handle of the wrench, the torque registering on the gauge will match the torque applied to the bolt. Now in practice you probably cannot
perfectly apply the force without a little side force but the amount will be so small and is applied to such a small crowfoot distance that it won't change the torque enough to matter.
