Jump to content



Recommended Posts

  • Replies 53
  • Created
  • Last Reply

I "see" a new hitch head mounting plate for the ET family of hitches to include the new " El Jefe" model!

Top brackets for mounting the hitch head.

Various holes to attach different air bag configurations.


Good observation, last two, three years all the hitch platforms were drilled with multiple hole patterns to accept different air bags, Hence Sr. and Super Sr.. These can be built as such from the start or retrofitted to Supers when heavier trailers are purchased. this project is to add a "third option"?

Link to comment
Share on other sites

Yes and no.

Eibach doesn't make what I needed but i found another manufacturer who does.

Looked seriously at hydraulic ones, form factor was all wrong, either redo the ET design altogether to fit one in or deign a hydraulic bump suitable for Mars landing and at a matching cost.

In low volume products "off the shelf rules".

Prototype proved (on the road) that the design performs well but also raised some "concerns", this "version" should take care of those.

You should like the "elegance" of it when you see the completed drawing.

Link to comment
Share on other sites

I didn't see the handle, I was there only a short time "on a mission", I'm interested because I have a new (extension) handle which i will make available. It should be finished in a week or so.

We will be at the ECR so wee can caucus some more.

I'm damping upwards (rebound) energy, there is plenty of airbag damping in the down direction, The problem is airbags don't shed energy like steel springs do particularly when you get close their natural oscillating frequency. It's almost like resonance and you can get several cycles before it dies down. The bump "disturbs" this happy situation on the first rebound. We are also experimenting with introducing various "pre-loads" and see what effect these will have.

It's not an issue with pin heavy rigs, like New Horizons, Spacecrafts, etc, It all started with DRV's "floaters" building 40' plus rigs and 5K pin weights. Long fifths, axles more to the middle (big rear overhang), light pin weight, etc.

Add to it an air hitch with substantial air bags and you get yourself a "happy combination", everyone happy and bouncing along.

Link to comment
Share on other sites

Still planning on using your bump stops similar to these?




Or hydraulic ones similar to these?



Wow. Those two options are the perfect example of simple vs complex solution. Not saying anything about quality or anything, it just struck me that way. Item 1--a piece of rubber. Item 2--about 50 highly machined parts that need tight tolerances, charge, etc.

Link to comment
Share on other sites

Here is the new handle deign that I came up with to solve a lot of the issues that I had. Number one was making an easy to use secondary lock on the hitch. In fact I made a second and third lock that can be used together or the hitch pin can be used on one side or the other. Looking at your trailer sitting on the ground after a hitch pin failure is only going to happen once to me.


It also makes the hitch a LOT easier to use, gets it out of the way of the pin release but does require the lock plate lower section to be welded to the hitch.




Close up up the lower plate that is welded to the hitch and match drilled to the new handle.




With the square hitch pins installed




Close up looking at the bottom of the handle with everything in place.



Link to comment
Share on other sites

Needs sort of an oleo on the upstroke, I'm really partial to the aftermarket moving vane shimmy dampers (these are not cylinders) for motorcycles because they have a needle valve for tuning the amount of bypass, this could be scaled up as a damper and using check valves and two needle valves it could even have different rates for up and down.

Here's what's inside, very simple: https://www.youtube.com/watch?v=rXYQRMb85Jw

Link to comment
Share on other sites

Wow. Those two options are the perfect example of simple vs complex solution. Not saying anything about quality or anything, it just struck me that way. Item 1--a piece of rubber. Item 2--about 50 highly machined parts that need tight tolerances, charge, etc.


Simple vs. complex is an age old conflict between engineers and business owners. Having been in both shoes I understand it perfectly. In my callow youth as a design engineer I would be crushed, crushed and severely disappointed when my elegant and complex design would be questioned or Lord forgive "criticized". Particularly when the criticism would come from some sales flunky pointing out some nonsense about preserving competitive price advantage in the marketplace. I would argue that it would certainly appeal to buyers since the competition didn't think about and it's unique and elegant.

When I was in the other shoes, I had to "disappoint" young and eager design engineers with an "idea" that very few people are willing to pay for unique and elegant when the competition has something that works and at a lower price.

An ET already has a lot of "elegant and unique" stuff in it that no other hitch on the marker incorporates and those who own one know what it costs. Adding another $500 or more in exotic dampeners might make it attractive only to "exotic" customers.

Note that the hydraulic dampeners that David and Chrissi mention are indeed unique and elegant but these are aftermarket products, attractive to people who already own the basic product and want to "make it better" or do things it was not designed to do in the first place. To those folks price an additional cost is no problem.


There were two other problems, there is absolutely no "free space" to add anything in that hitch and we are not talking about several hundred pounds of force, there are several thousands that need to be dampened. Finding something that would do all that and be available OFF THE SHELF, now that was unique and exotic.

Link to comment
Share on other sites


This topic is now archived and is closed to further replies.

  • Create New...