Hey all

This is a quick trip through the classroom with Rich Delaney.  I had a few questions this week about properly determining any given mechanical advantage ratio.  We have some many great examples, so I pulled this video from the Rigging Lab Academy. course files.  Welcome to the T Method.

The T-System for calculating Mechanical Advantage always starts with the input (the effort end of the system) and assume that force of 1 unit of tension (or 1T) is applied.  If a rope is continuous and has no attachments then the tension is of the same magnitude throughout.

At any attachment to a rope (i.e. a rope grab) tensions are added. At any change in direction in the rope (i.e. a pulley) an opposing force is required to pull against the ropes going through that change.

So there is an Ideal vs Actual Mechanical Advantage, where Ideal is more of the perfect world and Actual is well… reality.  We can also refer to this as Practical and it comes with all the normal world of friction loss.  We can still predict through modeling, as seen in Richards Advance Physics 3 Friction.

Hope this was helpful.

Peace on your days




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