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Old 09-12-2012, 05:11 PM   #589
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Originally Posted by idroba View Post
Gosh, a bumblebee can fly after all. Big grin.

I believe one other factor may come into the calculations. If you have a drop shank setup, I think the effective distance (I believe the calculations used 6.5 inches) is different depending on the bottom plate to hitch receiver distance, not the ball center. Thus, if you were pulling (twisting) from a longer drop you effectively have more lifting on the TV frame.

But, sitting here on the top of Marias pass, highway 2, just below Glacier National Park, towing with my Andersen, it all seems kinda academic. The hitch does work well. BTW, some white lube or grease on the frame tube ends does seem to help with the chain wear, but time will tell with that. You guys figure out how to solve that issue next please.

I will enjoy towing and camping while it is all worked out.
Well said , a 100 or so post of numbers that were wrong and a few more that are right, really seem enough for a supposedly users thread IMO. I'm glad everyone got their number fix now.

Back to the issue that needs to have some posts about it.. CHAIN WEAR.

It's been raining here for the last 2 days so I haven't had a chance to figure out my chain wear yet. hopefully tomorrow I will get a chance to look at it.

My plan is to move the brackets so the chain is in a direct line with the plate. We shall see how it looks. Then I have to decide what method I want to use to keep the bracket from moving. decisions, decisions...
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Old 09-12-2012, 05:34 PM   #590
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Originally Posted by Wazbro View Post
A WD hitch adds weight to the TV front axle and the TT axles so wouldn't it be a downward force on both?
To SHIFT weight, a downward force has to be countered by an upward force in order to keep the combined weight in equilibrium.

e.g. If your total rig weighs 4,000#, and you shift 300# to the front axle, the total rig will still weigh 4,000#. What is ADDED to one axle, must be taken off other axles.
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Old 09-12-2012, 05:58 PM   #591
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There are Threads on Weight distribution. PLEASE lets try and stay on topic. "The Andersen WD Hitch User Thread, I believe is the thread title.
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Old 09-12-2012, 06:09 PM   #592
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Here's how I used the calculations to see if this ANDERSON hitch would work for me.
My rig has an 800# tongue, and I need to shift about 300# to the front axle.
My measurements TV/TT measurements are:

W to shift = 300#
TV wheelbase = 132"
TV overhang = 60"
Ball to TV axle center (2 axles) = 192"
Ball center to chain plate = 6.5"

F = 300 x 132/252 = 157 lbs
S= 157 x 192/6.5/2 = 2,318 lbs on each chain. That's over the WLL of the standard 2000# chain on the ANDERSON HITCH. So, I could not safely get a 300# weight transfer using the standard chain.

If I cut back to a 250# transfer...
F= 250 x 132/252 = 130 lbs
S= 130 x 192/6.5/2 = 1,920 lbs on each chain. Under the 2,000# limit, but barely. Maybe I would want to limit the pull to say, 1,700# per chain.
That would give me an allowable weight shift of ~215 lbs onto the front axle.

For me, that simple pencil and paper exercise is a little easier as a rough evaluation than buying the ANDERSON HITCH, taking off my old unit, mounting the new ANDERSON HITCH, doing a lot of weigh-ins, and then possibly not knowing I was at the WLL of the chains. Knowing what I know from the pencil and paper, I would now inquire about heavier chains for the ANDERSON HITCH. Which, as a potential user of the ANDERSON HITCH, I will do.
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Old 09-12-2012, 06:24 PM   #593
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Originally Posted by mstephens View Post
Here's how I used the calculations to see if this ANDERSON hitch would work for me.
My rig has an 800# tongue, and I need to shift about 300# to the front axle.
My measurements TV/TT measurements are:

W to shift = 300#
TV wheelbase = 132"
TV overhang = 60"
Ball to TV axle center (2 axles) = 192"
Ball center to chain plate = 6.5"

F = 300 x 132/252 = 157 lbs
S= 157 x 192/6.5/2 = 2,318 lbs on each chain. That's over the WLL of the standard 2000# chain on the ANDERSON HITCH. So, I could not safely get a 300# weight transfer using the standard chain.

If I cut back to a 250# transfer...
F= 250 x 132/252 = 130 lbs
S= 130 x 192/6.5/2 = 1,920 lbs on each chain. Under the 2,000# limit, but barely. Maybe I would want to limit the pull to say, 1,700# per chain.
That would give me an allowable weight shift of ~215 lbs onto the front axle.

For me, that simple pencil and paper exercise is a little easier as a rough evaluation than buying the ANDERSON HITCH, taking off my old unit, mounting the new ANDERSON HITCH, doing a lot of weigh-ins, and then possibly not knowing I was at the WLL of the chains. Knowing what I know from the pencil and paper, I would now inquire about heavier chains for the ANDERSON HITCH. Which, as a potential user of the ANDERSON HITCH, I will do.
Just a note:
They are rated to 2000# but chains are rated at 1/3 of the braking strength. Which means they won't brake till they hit around 6000#

Reason: most people who use chains don't worry about the load they put on them. ie. Logging, trucking, ships, etc. But it would be interesting to see if Andersen will make them with heavier chains.

Another consideration is where the chain is welded to the bolt. I would think this weld would fail before the chain would? Or the clip and pin that hold the chain to the plate. IMO
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Old 09-12-2012, 06:26 PM   #594
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on the defensive now, please give us more theory. Seat of the pants experience trumps theory always no matter what the experts say. Jim
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Old 09-12-2012, 06:29 PM   #595
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Ok maybe not the weld that thing is beefy.
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Old 09-12-2012, 06:32 PM   #596
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on the defensive now, please give us more theory. Seat of the pants experience trumps theory always no matter what the experts say. Jim
Not sure what you are trying to say. But yes real world experience usually does trump theory from behind a desk.
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Old 09-12-2012, 06:34 PM   #597
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Originally Posted by mstephens View Post
To SHIFT weight, a downward force has to be countered by an upward force in order to keep the combined weight in equilibrium.

e.g. If your total rig weighs 4,000#, and you shift 300# to the front axle, the total rig will still weigh 4,000#. What is ADDED to one axle, must be taken off other axles.
Sorry fact is weight comes off rear axle to go to front axle and trailer axle check weight scale measurement threads.
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Old 09-12-2012, 06:38 PM   #598
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I believe the weak point will not be the chains or the welds, but the shackles that connect the chain to the plate.
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Old 09-12-2012, 06:42 PM   #599
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I believe the weak point will not be the chains or the welds, but the shackles that connect the chain to the plate.
This is my thought. It doesn't have a weight listed on it. ? When I go to the hardware store I will see what similar size ones are rated too. The Shackle I put in to extend my chain is rated to 2800#
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Old 09-12-2012, 07:36 PM   #600
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Originally Posted by mstephens View Post
EXPLANATION
Any downward force on the TV front axle must be countered by an upward force on the TT axle in order to have equilibrium. Using the TV rear axle as a fulcrum (noted in drawing), the ratio of the two distances determines how much upward force is needed at the TT axle to counter the downward force at the TV front axle. In the EXAMPLE a 200# weight shift to the front of the TV requires a 121# upward force at the TT rear axle.
Mark, the WDH causes load to be added to the TV's front axle and to the TT's axle pair. A load equal to the sum of these is removed from the TV's rear axle. This could be shown by downward forces acting on the front and TT axles and an upward force acting on the rear axle. Showing the front axle force and TT axle force acting in opposite directions is not correct.

Also, in the equations on your sketch, the product of a load or weight multiplied by a lever arm would be a torque rather than a force.

Ron
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Old 09-12-2012, 08:20 PM   #601
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Originally Posted by Ron Gratz View Post
Mark, the WDH causes load to be added to the TV's front axle and to the TT's axle pair. A load equal to the sum of these is removed from the TV's rear axle. This could be shown by downward forces acting on the front and TT axles and an upward force acting on the rear axle. Showing the front axle force and TT axle force acting in opposite directions is not correct.

Also, in the equations on your sketch, the product of a load or weight multiplied by a lever arm would be a torque rather than a force.

Ron
Excellent. Yes, the sketch is a bit crude. In retrospect I probably COULD have shown the upward force (or torque) splitting between the front TV and the TT axles. I puzzled on how to show it graphically and simply. Thanks for the clarification - much appreciated. I just want to keep drilling until I have it right!
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Old 09-12-2012, 08:21 PM   #602
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The chain is wearng at the bottom inside edge of the square tube. I am pretty sure grinding a champher on the bottom where the wear is taking place will fix it. If not, another solution it to cut the tube on the bottom side and bend the bottom downward matching the angle of the chain. Since, after 5,000 miles the wear isnt that bad, i am going to try the champher fist.
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