New Andersen WD hitch

[JBarca]

A fellow camper bud showed me this. It's new and different.

Anyone using one?

Andersen WD hitches

A U-tube video with the factory guy explaining it. You have to get past MR Truck doing his intro. Interesting 5th wheel hitch too.

http://www.youtube.com/watch?v=xvM7mCnqmwo&feature=related

It looks like this



I'll hold my comments for a short while to not cloud your thoughts. Ideally we can find someone here using one to quiz them on it.

John

[tim_and_amy]

To Ben and the other engineers. What is the durometer of the urathane that andersen is using? Do you know the specifics? A modeling program without those factors are bogus in my opinion.

[tim_and_amy]

I agree with Atlee,
Yes, I returned my Andersen, but when I took my brackets off it "self" drilled the set screw. The set screw is Pointed, not Flat.
The only thing the brackets did was Tilt, so did my Reese E2 I just put on. Which I also just took back and got an entire new set up with Triangle plates.
Any bracket held on by one bolt on top, and one bolt on bottom is going to move. At least Andersen figured this out and put set screws on it so it wouldn't move.

[BenK]

Thanks Barney and just realized that didn't get back to the tongue !?!

The simulation will take that gouge/dent produced by the set screw/bolt and
run the simulation based on some other attributes

Where it is in reference to the whole member and where between the ball/box, etc

If dead centered the forces are less than if off center. There will be bending
moments on any trailer tongue and there will be tension/compression cycles statically and dynamically.

There would also be some kind or level of 'dent' of 'bowing' in of that member
that would affect the moments of that tongue

Whether it will matter will take some deep DB info and math. I can do that, but
it would take a computer fractions of the time it would take me to look every
thing up and then dig out the calculator

Plus the computer can also compare and simulate it against the whole trailer
I can too, but it would take me orders of magnitude in time to do that.

Anyway, that is what I see when anything like this comes up. Ends up gut feelings
that generally are pretty close or in the general direction of a simulated results

The big 'factor' is the dialed in longevity required. Safety margin to most.
That would be in years and/or 100's of K miles, or some such level dialed in
and there would be a +/- to it.

[BarneyS]

Ya see why I never argue with these engineers we have around here? :b. :b. 😛
Barney

[BenK]

Oh...okay not clear...

The above is the process and the results of that simulation is a report telling
where there are issues.

Like the gouged mating union and the stresses on the set screw/bolt, tongue
member and the bracket would have an okay or that something was overly stressed

Along with that is the dialed in longevity required, plus some margin.

That is for the static conditions and the real benefit of simulation is for the
dynamic simulation where the computer runs it through the road conditions dialed
in (the road ambient/terrain/etc and the weights, speeds, etc, etc)

[BenK]

Got a few PM's asking what the heck is simulation...so here goes and won't write the
book that is necessary to truly do it justice...

First must say that modifications are re-engineering. Some so minor to not make
much of a difference. Others can change the thing too much to manifest other areas
that are marginal to become weak links in the food chain (it is a system, not just
anyone component)

Understand that most can not visualize deep and far enough to replicate simulation

Here is a quickie on what a 'good' simulation program will do, or can do...but...
always remember the old axiom..."garbage in, garbage out"

There will be a stress raiser with any pointed set screw/bolt

It will gouge into the tongue member and the point will blunt during the process

The tongue material will work harden.

The paint will become a lube, initially till it is scraped away, but there will
be some left in the mating surface between the tongue material and the set screw/
bolt blunted point. That will then become lube (it is both slippery and compliant
compared to steel) that will allow the set screw/bolt to loosen

Need to know the alloy of the tongue member (and the tolerance of that alloy),
whether hot or CRS, whether there was/is any secondary/tertiary work (not likely)
that would change that spot's temper.

By drilling a pilot (either through, or partial)...question is will
the end mating surface and force be enough to hold in dynamic situations
or did the engineers even consider that when they spelled out these
procedures?

Now to the screw/bolt (back to the tongue in a bit). What is the alloy/grade,
what dia, the pointed end (how sharp, etc), how far from the bracket with the
threads to the tongue member, cut or rolled threads, plated/not, etc

The grade and dia will tell how much torque it is rated for. The program must
be dialed in with the safety margin for that screw/bolt. Assume keeping it in
the elastic range and not into the plastic range (yield)

There is a calculated torque and penetration into the tongue member. The program
will look up in it's tables that tongue member alloy, temper, etc vs the screw/bolt
alloy/grade/dia/torque.

That will be what the designer/engineer wanted in the amount of penetration into
the tongue member. That will also tell how much the point will be blunted and it
that is okay

Not all simulation programs will go so far as to tell the new work hardened level
of both the tongue member and the point of the screw/bolt. Ditto not all CAD
programs will know enough about the paint (lube quality, plasticity, etc after
fully torqued)

Then the program will look at the bracket with the thread that the screw/bolt
used to gouge into the tongue member. This has a bearing on the actual torque
vs the wrench torque. The alloy, temper, etc is important as it is the thread
that, that set screw/bolt bases it penetration into the tongue member...unless
there is a high grade nut or some sort of threaded insert that is hardened pressed
into that bracket. There will be some level of bow and dependent on the thickness
(gauge), width, alloy, temper, etc of that bracket. Also how tight it is to the
tongue member.

Note here that you folks who used wrench extensions may have over torqued the
set screw/bolt. My 1/2" drive socket wrench is about 12" long. I can torque max
about 100 ft/lbs with that thing. A cheater bar that has a 2' length will have
3 times to become 300 ft/lbs as an example. A 1/2" bolt, grade 5 will take about 75 ft/lbs
at some percentage proof. Yield would be around 100 ft/lbs (there abouts, IIRC)
Hope that set screw/bolt is over 1/2" and grade 8 for you folks who used those
cheater bars

That is just in prep for the bushing forces that has a moment (lever arm) from
the point center line of the set screw/bolt to center line of the bushing screw

Back many pages, both John and Ron calculated an approximate force those plastic
bushings imparted. That would then be factored by the above moment to the point
center

This is just a fraction of the 'static' calculations or as I view it in my mind

It gets a bit more complicated when 'dynamic' loading is factored

Hope this gives a glimpse into how a simulation program functions. That the
DB (data base) and programer critical. If the DB does NOT have information on
a pointed setscrew gouging into a steel member...then either they have to go out
and buy an update (if there is one), or write the mini-program to handle that.
Both from a static and dynamic point.

And yes, this is what I see (and more) when I noodle this one, as do
on other designs. If you can't, don't assume everyone can't...

[Atlee]

Using the set screws is but one of 3 suggested ways to mount the brackets. The other two suggested ways are to 1) weld the brackets on the frame and 2) drill through the frame and bolt them on.

We're over thinking this thing. To me, common sense says that a dimple that is drilled into the frame is better than no dimple. With out drilling a dimple, one is betting on the small fine point of the set screw making enough of a dimple on it's on in the metal frame from the heavy torquing needed.

With drilling a dimple, the point on the set screw has a much larger, deeper dimple to set itself into.

[Lady_Fitzgerald]

BenK wrote:

BarneyS wrote:

Atlee wrote:
Snip...
One thing I have thought about doing is marking where the set screws go, and then drilling a dimple in the A-frame for the set screw to settle into.

Wouldn't this work?

That is what I would do. In fact, I would probably put a small hole all the way through.
Barney

To be devils advocate...

This is where simulation is needed, as this is a stress raiser of the
highest order. Snip...

Simulation?

[BenK]

BarneyS wrote:

Atlee wrote:
Snip...
One thing I have thought about doing is marking where the set screws go, and then drilling a dimple in the A-frame for the set screw to settle into.

Wouldn't this work?

That is what I would do. In fact, I would probably put a small hole all the way through.
Barney

To be devils advocate...

This is where simulation is needed, as this is a stress raiser of the
highest order.

ALL of the bushing/spring forces are concentrated on this small gouged
section of the tongue

There is some level of rocking of the brackets till they bottom out
on the tongue during that tilt. The brackets pivot on these screw points
till the rest of the bracket bottoms

There has been one reported instance of these brackets sliding. Both
that the screw points were NOT fully seated as per the manual and that
the brackets were too large for that trailer tongue

The reason simulation is needed for 'this' is that there are dynamic
forces on that point

Assume that the designers have a level of contact pressure to hold that
set screw in place, preventing it from backing out

If a hole is drilled...question is will it hold it from backing out
over time?

If not fully torqued (3 full turns), will have enough holding force
to keep it from backing out over time?

If not fully torqued (3 full turns), will it then have the metal of
the tongue 'work' itself into a oval, to then finally work itself both
out and/or slide down towards the ball?

Some of the attributes needed to simulate: the alloy/temper of the
bracket. The tolerance (how tight to the tongue), therefore how much
will the bracket/tongue/set-screw move during the trip(s)? etc, etc, etc

[BarneyS]

Atlee wrote:
Snip...
One thing I have thought about doing is marking where the set screws go, and then drilling a dimple in the A-frame for the set screw to settle into.

Wouldn't this work?

That is what I would do. In fact, I would probably put a small hole all the way through.
Barney

[Atlee]

I started on the install of my Andersen today. Couldn't finish though. Darkness drove me indoors.

It took a while to get the trailer parallel with the drive. Had to get on the ground, and partially get under the trailer to measure fore and aft. Then lift or lower the tongue.

I will say this. Thank heaven for the Barker I installed last week. Would hate to think about having to hand crank the tongue all the time.

I got as far as getting the rear brackets snug before losing daylight.

Shouldn't take much more to finish tomorrow. My biggest problem will be tightening the set screws enough to hold the brackets.

I may have to go buy an Allen wrench large enough tighten the screws.

One thing I have thought about doing is marking where the set screws go, and then drilling a dimple in the A-frame for the set screw to settle into.

Wouldn't this work?

[PHS79]

I was able to get the full three turns when I setup my hitch. But I used a allen wrench driver on my 1/2" ratchet, I started with just a regular allen wrench but when it got hard to turn after only 1 full turn of the screw I got out the drivers for the ratchet and it went pretty easy.

[logistic]

I used a 2' cheater bar on the allen wrench to install the set screws and I used red lock-tite. The downside to doing it this way is that the screws really pushed in the sides of the rails noticably. I have some regrets about that...

If I were to install it again. I'd drill the rails first using the alternate instructions in the manual. Then you could apply less torque on the set screws. I'd also consider just thru-bolting it and be done for good.

Goodluck on the install!

[mrad]

logistic wrote:
I just want to clear the air on some of the misconceptions this thread is generating.

1. Regarding the assuption that the brackets can slide on the frame: that's a WAG at best. In 3000 miles towing cross-country the Andersen setpoints haven't moved at all - none, nada, ziltch. I simply followed the intall instructions and the attachment is rock solid. The belt and suspender guys can certainly through-bolt the brackets for an added sense of security.



Only time and experience will measure if this new hitch has merit. The uninformed WAG game has run a bit far in this thread.

Logistics,
How deep did you set the set screw? The directions state to give three full turns after contact. I was only able to get 1 1/4-1 1/2 turns. Any more and I would have bent my allen wrench.

[logistic]

I just want to clear the air on some of the misconceptions this thread is generating.

1. Regarding the assuption that the brackets can slide on the frame: that's a WAG at best. In 3000 miles towing cross-country the Andersen setpoints haven't moved at all - none, nada, ziltch. I simply followed the intall instructions and the attachment is rock solid. The belt and suspender guys can certainly through-bolt the brackets for an added sense of security.

2. Regarding the pressure on the hitch latch mechanism, I can see the wear marks on the ball clearly. They are from the hemisphical hitch socket dome, not the latch. The only time the latch is touching the ball is when I lift the tongue up high to set the chain tension. This is exactly the same as on my old traditional WD hitch.

3. Folks who envision the ball slamming around inside the hitch socket are far from the mark. The ball is firmly clamped into the dome of the hitch. There is no slop in this connection.

Only time and experience will measure if this new hitch has merit. The uninformed WAG game has run a bit far in this thread.