What multi axis hitch do you prefer?

[Martyn]

OK, due to popular demand "Max Coupler" the movie is now available at http://www.adventuretrailers.com/coupler.html

Shows full articulation of the coupler.

 

[go4aryd]

...Shows full articulation of the coupler.

Simple AND lovely!

 

[Martyn]

I'm not seeing how that's possible. Any pics of the situation? I'm pretty good with visualizing these things, I can see the bind in the LnR, but not the ball coupler. Must have been something unusual happened, because I go 90° on my trailers often and never had a problem.

Edit: Was it a heavy tandem axle? I could maybe see that.

This was a lightweight pressed steel coupler, you don't see this deformation occurring with heavy weight or cast couplers. The thing to understand from this picture is that the forces involved in a jack knife are large, the fact that it happens slowly is irrelevant. While the heavy couplers mask this, the light weigh coupler does not. Evidenced in the bending.

Most people who bend their coupler don't even know they did it because in their minds they were, going slowly, they didn't hit the trailer with their vehicle, and there was no noise.

No pictures of this particular situation. Happened at a small grocery store in Molepolole, Botswana, 1999, light weight off-road trailer.

 

[Martyn]

I would think the test was a straight on pull? The LnR coupler is bending with much less than 18k lbs in this case. When it binds, the forces are being applied in a way the manufacturer didn't intend.

Rob coupler testing is divided up in five sections
1. Longitudinal tension,
2. Longitudinal compression,
3. Tranverse thrust,
4. Vertical tension
5. Vertical compression.

Testing is done to a minimum of three times the certified rating or to destruction.

 

[Hilldweller]

Martyn,
Did we ever, as a group, say "thank you" for your patience, insights, and experience?


It ain't easy being a vendor... ...it really is different than being just a smart consumer.

 

[Martyn]

Martyn,
Did we ever, as a group, say "thank you" for your patience, insights, and experience?


It ain't easy being a vendor... ...it really is different than being just a smart consumer.

Thanks for your kind words, does that mean I'm buying the next round ?
:beer:

 

[Tucson T4R]

Thanks for your kind words, does that mean I'm buying the next round ?
:beer:

You know the answer to that is always, Yes you are. :elkgrin:

 

[Borrego60]

OK, due to popular demand "Max Coupler" the movie is now available at http://www.adventuretrailers.com/coupler.html

Shows full articulation of the coupler.

For some reason I could only see pictures and not a movie. I must be missing something. I thank everyone who has chimed in on this thread. Some very smart people here had some good information I did not even think about. It would be interesting to see some engineer from nasa to analyze this for areo dynamics and flight charateristics. Just kidding but great info,and again thanks to everyone again.

 

[BigDaveZJ]

OK, due to popular demand "Max Coupler" the movie is now available at http://www.adventuretrailers.com/coupler.html

Shows full articulation of the coupler.

I think the vid really helps. From the pics it's not entirely clear how the trailer would turn behind the vehicle. Are there any bearings or anything there?

 

[R_Lefebvre]

This was a lightweight pressed steel coupler, you don't see this deformation occurring with heavy weight or cast couplers. The thing to understand from this picture is that the forces involved in a jack knife are large, the fact that it happens slowly is irrelevant. While the heavy couplers mask this, the light weigh coupler does not. Evidenced in the bending.

Most people who bend their coupler don't even know they did it because in their minds they were, going slowly, they didn't hit the trailer with their vehicle, and there was no noise.

No pictures of this particular situation. Happened at a small grocery store in Molepolole, Botswana, 1999, light weight off-road trailer.

I'm sorry, but I cannot agree. The forces involved when you have not actually jacknifed are basically zero. A ball coupler is has three rotational degrees of freedom. Where are the forces you are suggesting coming from?

I'm not saying that a ball coupler is better than a LnR, or stronger, or perfect. It obviously has serious limitations in it's ability to allow the trailer to pitch and roll relative the TV. But without reaching those limits, there is no other way to bend them unless you really jacknife.

The LnR I'm sure is stronger, and much much more flexible. But that flexibility leads to an ability to get out of alignment and bind when backing up, without a jacknife, or the trailer doing something funny.

Rob coupler testing is divided up in five sections
1. Longitudinal tension,
2. Longitudinal compression,
3. Tranverse thrust,
4. Vertical tension
5. Vertical compression.

Ok, but not out of axis twisting, which is what happens in this situation.

 

[Martyn]

For some reason I could only see pictures and not a movie. I must be missing something. I thank everyone who has chimed in on this thread. Some very smart people here had some good information I did not even think about. It would be interesting to see some engineer from nasa to analyze this for areo dynamics and flight charateristics. Just kidding but great info,and again thanks to everyone again.

You may have to refresh the page on your browser or empty the cache to see the video. I placed the video where a picture of the coupler used to be so you could be seeing the old picture.

 

[Martyn]

I'm sorry, but I cannot agree. The forces involved when you have not actually jacknifed are basically zero. A ball coupler is has three rotational degrees of freedom. Where are the forces you are suggesting coming from?

I'm not saying that a ball coupler is better than a LnR, or stronger, or perfect. It obviously has serious limitations in it's ability to allow the trailer to pitch and roll relative the TV. But without reaching those limits, there is no other way to bend them unless you really jacknife.

The LnR I'm sure is stronger, and much much more flexible. But that flexibility leads to an ability to get out of alignment and bind when backing up, without a jacknife, or the trailer doing something funny.




Ok, but not out of axis twisting, which is what happens in this situation.

Rob

I'll leave the analysis up to you.

As far as I'm concerned if you jack knife your trailer, or put the trailer and vehicle at extreme angles the chances you are going to damage the coupler are high.

So try not to do it.

 

[R_Lefebvre]

As far as I'm concerned if you jack knife your trailer, or put the trailer and vehicle at extreme angles the chances you are going to damage the coupler are high.

So try not to do it.

I can agree with that. I just think something happened to that ball coupler that the driver wasn't aware of or hasn't admitted.

 

[ntsqd]

Something that just ocurred to me, what are the US rules governing trailer hitches and couplers?

Say that I wanted one of the OZ made couplers, could they even sell it to me?

 

[R_Lefebvre]

I don't think that's entirely clear as far as a private citizen is concerned. It might differ by jurisdiction, but I don't think it's an abolute that it be "DOT certified". In fact... I don't know that any couplers are DOT certified? I just surveyed all my balls, draw bars and couplers, not a single DOT marking amongst ~10 pieces. The more reputable parts (bought from a big retail store, or couplers on professional trailers) have manufacturers markings at least. The stuff I got from cheaper places like TSC have little.