Hensley Arrow: How does it REALLY work?

Stressor wrote:
I totally agree with you Mr. Whittaker. The linkage only works one way, and Mr. Gratz continues to want it to work 2 ways, and insists that it does, despite two great big steel bars.

Absolutely not true. You're sounding like one of the early day scientists who insisted that the world was flat or that the Sun orbited about the Earth. It would be helpful for yourself and others to put together your own model built with popsicle sticks and screws (make sure holes in "linkage" are clearance holes so pivoting resistance is negligible) or something similar before making such "authoritative" statements.

Stressor wrote:
All of the talk about the VPP is simply nice to know, and it only applies if the tow vehicle is turning.

This is absolutely not true. All forces - turning, lateral, and otherwise - must translate through the side links one way or another, making the projections of these side links (VPP) pertinent at ALL times.

Stressor wrote:
I spent a couple of hours playing with mine over the long weekend, and after getting all greasy, and suffering back strain, it looks like a simple explanation will suffice.

Your back strain was for naught if you didn't remove the effect of all the tires on the ground. You'd have to do that to isolate the behavior of the hitch itself. Again, it would be so much simpler to just build yourself a model of the linkage.

Stressor wrote:
It is not possible to describe how it works unless it is described dynamically, in short, do not remove any contact with the ground, but take the various loads and friction into account.

It takes a little mental calculus to do it, but heck, even a psychologist can do that.

Engineering school must've got the best of you when they got to free body diagrams. You must be able to isolate elements of a system in order to truly understand what they are doing. That's fundamental. Just go make a stick model of the linkage. Then we'll talk some more.

Tim