Hensley Arrow: How does it REALLY work?

Stressor wrote:
Ed,

Mr. Gratz does not understand the linkage. I have read his remarks for some time, and his understanding of the hitch is imperfect. Some of it he has down very well, but he is unable to visualize the operation in use. He still thinks the hitch pivots on the ball.

Here is a quote from him:

,..." The rear link, which actually is the upper (rear) housing, does move side to side and the ball is securely attached to it. When the rear link moves, the ball also must move. It makes no difference whether the ball moves about 5" to one side or moves precisely 4.768" to one side. The point is – the ball does move side to side. The figure of 4.768" derives from the assumption that the front pins are 7.125" center to center, the rear pins are 7.875" center to center, and it is 5.000" center to center from a front pin to a rear pin. If you prefer to use different numbers and different tolerances, I can provide the corresponding maximum side to side movement.

This statement can only be true if the rear struts are very, very loose.

As for my students, to their credit several of them are in doctor school at this time, so my understanding could not have hurt them appreciably.

I believe that the correct expression is "head up and locked."

Now, Ed, would you kindly add to the discussion rather than poke holes? Do you own a Hensley? How do you think it works?

I think you may be misinterpreting Ron's remarks. While the ball does NOT move RELATIVE TO THE Orange part of the hitch, it surely does move (initially in translation) every time you turn - even a little.

Please remember my comment about the bird flying directly over the hitch looking down. He has to fly a serpentine path to stay over the hitch as the TV turns from side to side. From the birdeye view, the ball can and does translate as far as the links will allow it to - some 11 inches by my reckoning.

I suggest you have someone else drive (S L O W L Y) your vehicle in a parking lot, make some small turns while you walk along side. Watch the hitch at work. It's really quite interesting, not to say 'magic'.

As for the airplane analogy, one can either be fixated on the scenery or on the instruments, but neither is healthy for very long. You must do both - continuously and for as long as you are flying. Gear down, gear up. Makes no difference until you need them (or don't). Same goes for the eyes and the human processor.

Yup I have a HA, and I knew pretty much how it worked before I bought it. Actually, I did the above exercise with a friend's rig before I bought the hitch. Of course, I know a lot more about it now..

One thing I do know is that the linkage only locks at about 80 degrees to one side or the other. But that's enough for me...

Ed B