New Andersen WD hitch

JBarca wrote:
It would be interesting to see if that somewhat linear relationship he has seen from 0 to 1,200# of urethane spring force held that constant on a tongue weight of 1000 or 1,400#.

John, I think that the load/compression relationship for Bruce's springs is not dependent on tongue weight.
The relationship which Bruce obtained simply says that it takes a load of about 1200# to cause 1/4" of compression.

I have no reason to question Bruce's results.
However, I do recall from the YouTube video that Ryan Andersen said 1/4" of compression would produce about 2000# of "pressure" and that both springs combined would pull the trailer forward with about 4000# of force.
So, the spring "stiffness" measured by Bruce is about one-half the value stated in the YouTube video.
Perhaps the video number is for a urethane formulation which is different from that in Bruce's springs.

IMO, the urethane spring "stiffness" value measured by Bruce is consistent with his scales data and also with the scaled load transfer data provided by Renojack.
Their scales data do not appear to be consistent with a "stiffness" corresponding to a compression of 1/4" for a load of 2000#.

For comparison, with a 1000# tongue weight and a typical TV/TT combination, a WDH would need to transfer almost 500# to the TV's front axle to give 100% load restoration.
The scales data presented by Bruce and Renojack suggest their hitches would transfer about 220-240# to the front axle at 1/4" of urethane spring compression.

Of course these estimates are based on some simplifying assumptions.
For example, it is assumed that the pitch-axis torque generated by friction forces between ball and coupler is negligible.
Given the uncertainty about the coupler-ball interface, it's difficult to know if that's a reasonable assumption.

Ron