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Topic ClosedActual Weights as measured

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GlueGuy View Drop Down
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Direct Link To This Post Topic: Actual Weights as measured
    Posted: 05 Oct 2019 at 7:58pm
Originally posted by Jeepinator

Given all the smart people on this thread, I’d like to add another element. What is the underlying risk of exceeding tongue weight and will air bags reduce it?  I’ve not determined my exact tongue weight yet but I suspect I exceed the 350# even with the WDH. 

I am aware that sway and receiver/coupler damage are potential risk factors but I assume there are others. 

The TV and trailer are level when the WDH is engaged.
The WDH does not reduce the tongue weight, it distributes the weight. Effectively it will reduce the amount of the tongue weight applied to the rear axle of the TV, and distributes it to the front axle of the TV and back to the trailer axle. The amount that goes to each axle depends on the torque plus the length of the moment arms.

Also, air bags will not reduce the tongue weight. Air bags will increase the weight that your rear suspension can handle, but will not increase the weight the axle/bearings can handle or the weight the frame of the vehicle will handle.
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Direct Link To This Post Posted: 06 Oct 2019 at 8:33am
Originally posted by GlueGuy

 The WDH does not reduce the tongue weight, it distributes the weight. Effectively it will reduce the amount of the tongue weight applied to the rear axle of the TV, and distributes it to the front axle of the TV and back to the trailer axle. The amount that goes to each axle depends on the torque plus the length of the moment arms.

I watched yet another pretty good explanation of how WDH's work. To me there is still a bit of magic in this thing..

Even he states the weight on the ball remains, yet transfers/distributes the weight/torque. Magic I tell ya! It's gone, yet still there..
I like how he explains the action of torque the WDH does to compensate (?) the effect. So it's easier to understand why the weight remains, but the effect changes. Still say there's a bit of magic there..

Now he talked of the ball using most of this effect. I tend to wonder how much of this torque is also placed upon our hitch frame. Those of us that have, know how much pressure is on the WDH bars. For example only; if 200#'s are sent forward and 100#'s sent aft, then is the torque applied to the ball/tongue frame equal to that distribution? Or in order for the magic to happen, is it indeed greater..

Here's the video. He's informative and quite a kick to watch! http://www.youtube.com/watch?v=kCgRiVNaXFc
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Direct Link To This Post Posted: 06 Oct 2019 at 12:42pm
  The way the WDH was explained to me which made sense to me is that the WDH works like a bridge. The camper axle as one shoreline and the tow vehicle front axle being the other shoreline. The tongue weight is supported at the center of the bridge. Does that make sense.
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Direct Link To This Post Posted: 06 Oct 2019 at 3:32pm
Originally posted by David and Danette

  The way the WDH was explained to me which made sense to me is that the WDH works like a bridge. The camper axle as one shoreline and the tow vehicle front axle being the other shoreline. The tongue weight is supported at the center of the bridge. Does that make sense.

Still think there's magic involved! LOL

I've come to a point of understanding the basic principles involved. Torque is something I get. The video and the way he does it, helped quite bit. To me it's how much force is being applied on on tongue frames to accomplish the feat (magic). 

The video is worth a watch and at one point he talks about what 'we' drive through and the added torque/force (?) that is applied. My questions are not if WDH (which he calls Load leveling and like that better) is good or bad.. It's what effect and how to compensate for. 
When my trailer comes back, I will re-enforce the tongue frame. I do believe there's more happening there then 'we' believe there is and worth the expense/effort.
At least the conversation of..

I'm always open to learning.



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Direct Link To This Post Posted: 08 Oct 2019 at 5:47am
Originally posted by David and Danette

  The way the WDH was explained to me which made sense to me is that the WDH works like a bridge. The camper axle as one shoreline and the tow vehicle front axle being the other shoreline. The tongue weight is supported at the center of the bridge. Does that make sense.

That's a good start, except that both TV axles are on the shoreline and we're trying to get more weight on the front axle and less on the rear because the rear one is on the edge of the cliff. Now, let's say the bridge contractor bought his bridge beams too short but still wants to use them so he puts a bolt through them and connects them at a center pivot point. Then to keep the whole thing from falling down he adds a spring between the two beams in the center holding them up. That's pretty close to what a wdh does. 
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Direct Link To This Post Posted: 08 Oct 2019 at 5:57am
Originally posted by Olddawgsrule

When my trailer comes back, I will re-enforce the tongue frame. I do believe there's more happening there then 'we' believe there is and worth the expense/effort.
At least the conversation of..

I'm always open to learning.


There is for sure more load being applied there by the wdh spring bars pulling down. Not to mention the dual batteries etc.  Even without the wdh and batts, there is a high load stress location on the trailer frame a bit under the front of the box. Its not as high as the spot just behind the axle but it's there. So reinforcement in that general area isn't a bad idea. It would probably be better not to lose too much clearance at that point so a 2 inch tube might work better than a 4 inch one which would be the way I think I'd go in the axle area. 
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Direct Link To This Post Posted: 08 Oct 2019 at 8:04am
I understand what Offgrid is saying. We have a 4x8 utility trailer that had a failure where the tongue met the body. It was a single 3x3 beam and not an A frame, so it had only a single point of connection.  Welding a reinforcement beam under the original beam and adding triangle gussets took care of the issue.
with the RPods A frame, at least there are 2 connection points.
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Direct Link To This Post Posted: 08 Oct 2019 at 1:50pm
Originally posted by Pod People

I understand what Offgrid is saying. We have a 4x8 utility trailer that had a failure where the tongue met the body. It was a single 3x3 beam and not an A frame, so it had only a single point of connection.  Welding a reinforcement beam under the original beam and adding triangle gussets took care of the issue.
with the RPods A frame, at least there are 2 connection points.
Vann

I'm certain Offgrid can explain better, yet what we have, I don't consider a true 'A' frame. The way it is done, I consider it a 'V' frame. Maybe even with the way it's done (and the welds being very good) it should be better than a true straight tongue. Yet I wonder..

Speaking for myself, and what I hope to see done to my trailer (in for warranty frame repair),I figure a 2x2x? will be added under the tongue 'A' frame to stiffen it. Under meaning it would travel past the existing frame cross member and be attached (welded) to the side frame member. That would make it a true 'A' tongue frame.

Here's where I go to Offgrid and ask of what percentage of strength is a weld compared to a through section of frame? My assumption, if the welds are good, 80-90% of original. 

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Direct Link To This Post Posted: 08 Oct 2019 at 2:32pm
Originally posted by GlueGuy

Originally posted by Jeepinator

Given all the smart people on this thread, I’d like to add another element. What is the underlying risk of exceeding tongue weight and will air bags reduce it?  I’ve not determined my exact tongue weight yet but I suspect I exceed the 350# even with the WDH. 

I am aware that sway and receiver/coupler damage are potential risk factors but I assume there are others. 

The TV and trailer are level when the WDH is engaged.
The WDH does not reduce the tongue weight, it distributes the weight. Effectively it will reduce the amount of the tongue weight applied to the rear axle of the TV, and distributes it to the front axle of the TV and back to the trailer axle. The amount that goes to each axle depends on the torque plus the length of the moment arms.

Also, air bags will not reduce the tongue weight. Air bags will increase the weight that your rear suspension can handle, but will not increase the weight the axle/bearings can handle or the weight the frame of the vehicle will handle.

Here's where I now sit dis-mystifying the magic. And only 'my understanding' of the magic!

Offgrid explained the torque I see as actually being moments of the action introduced by the WDH. I get what he's saying now mostly from watching the video I offered. The magic is being explained.

The down force on the ball from the trailer is not removed. The force (moment/torque) is being displaced by the WDH through it's action. Thus sending X forward and X backwards. Then again that amount being determined by the axle length of the TV (I think I've learned). That again becomes a question of why if the weight of the ball is not removed, then where do we get the addition weight on both the TT & TV? My assumption is because of the action of the WDH. My concern is what is happening on our tongue frame for all this to happen. It's only 2x4x.10 steel and is it capable to compensate? 

That to me is a lot going on on our frame.

I do see by the program Offgrid offered, I need to go back to the scales for some accurate readings for it to work correctly. Which I will do.

Does a WDH work? No doubt it does. More to learn and understand.


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Direct Link To This Post Posted: 08 Oct 2019 at 6:08pm
Originally posted by Olddawgsrule


I'm certain Offgrid can explain better, yet what we have, I don't consider a true 'A' frame. The way it is done, I consider it a 'V' frame. Maybe even with the way it's done (and the welds being very good) it should be better than a true straight tongue. Yet I wonder..

Speaking for myself, and what I hope to see done to my trailer (in for warranty frame repair),I figure a 2x2x? will be added under the tongue 'A' frame to stiffen it. Under meaning it would travel past the existing frame cross member and be attached (welded) to the side frame member. That would make it a true 'A' tongue frame.

Here's where I go to Offgrid and ask of what percentage of strength is a weld compared to a through section of frame? My assumption, if the welds are good, 80-90% of original. 


I can't explain the detailed design of the rpod tongue attachment, I really haven't gone under there and looked at it. What I am saying is simpler:  if you just assume that the trailer frame was made up of two continuous 2x4 beams running from the hitch to the rear of the trailer, and supported by the hitch and the rear axle, what you would have is a simply supported single ended cantilever. If you then loaded those beams uniformly from end to end (not true for an rPod but a reasonable starting point) you would have the standard structural case of a simply supported uniformly loaded single ended cantilever. For that case you can look up the moments and deflections, no need to do some kind of complex analysis. 

That's this case:


If you look at the moment diagram, there are two points where the moments reach maximum (which is where the frame will bend if the stresses there exceed the yield strength of the steel). One point is partway between the hitch and the axle, trying to bend the frame down, and the other is at the axle itself, trying to bend the frame up. That's why I'm saying that there is a high bending load location near the front of the trailer, but probably under the box a little bit. Not sure without doing the calcs how the two bending moments compare and exactly where and I'm travelling (without my pod unfortunately) so I can't take the measurements right now. 

Re the strength of a weld, a good welder can make a weldment just as strong as the steel he or she is welding (emphasis on good welder using the proper technique for that weld). If we're talking about adding a doubler tube under the existing tube that is a pretty benign thing to weld because the mating surfaces of the two parts will be at or near the neutral axis of the weldment. The neutral axis is the cross section where there will be no stress (in other words, the location where the parts transition from being in compression to tension when placed under load). 
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