Axle Placement When Benroy Body Overhangs Frame

[Can-O-Yeti]

Now that summer is here and I don't work again until August, I am busily working on a Benroy. I am working with a 4x8 HF 1740 bolt together trailer. My plan is to put a 5x9 Benroy on the trailer. I have experimented with the trailer balance Excel worksheet and have a number of options that all give me a tongue weight around 12.5% of the trailer weight. I am getting these options by varying the weight in the tongue box, in the galley and by how I position the body on the frame. Is there a reason why I might prefer one of the following?

A. Overhang body 6 inches in front and 6 inches in back
B. Overhang body 12 inches on back
C. Overhang body 12 inches on front

My reason for asking this is that hanging off the back has a huge affect of where I should place the axle. More overhang on the back makes the tongue weight fairly sensitive to the galley weight. If at all possible, I would rather overhang in front (where it could affect turning). In addition, I would like to keep the axle mounting bracket across the joint where the two 4 foot sections of the trailer come together to add some rigidity. Any suggestions before I start drilling?

[madjack]

....first, you need from the coupler to the body, at least a distance equal to half the tow vehicles width plus a couple r 3 inches +, to insure that you do not hit the body of the camper with the bumper of the TV...

...second, as you have noticed, the way you load the camper has a very definite effect on the balance...ordinarily, I would say to put the axle around 40 inches from the rear of the (9')camper body...how does this affect balance and placement of the body on the frame...

...third, 12.5% is an excellent tongue weight, you can go heavier on the tongue weight but be very wary of going much lighter(less than 8-10%)
madjack

[pathdoc2]

I'm basically doing the same project, a modified Benroy 5x9 on a HF 4x8 frame. I was planning on a 6 inch overhang in each direction. I was going to brace the frame such that it had extra support on the bottom to support the overhang. I'll take pics once construction begins in earnest. Frame arrives this weekend.

[bobhenry]

When I do mine over I will add a 2x2 sq tube the entire lenght of the trailer and tongue and even extend forward beyong the existing tongue 18" to 2 foot. I am getting some flex in the factory tongue and this concernes me. It looks like the tube would lay right over the diagionals after the overslung coupler was removed.

[SkipperSue]

I'm building about 6 inches over the frame myself. Here's how I moved my axle back. I too was concerned about the frame strength if I moved the axle bracket back too far. I was able to keep a small part of the bracket in the area where the frame halves meet. The origonal mounting hole is right behind the black mark I made on the frame.



A more detailed thread on this subject can be found here.

http://www.tnttt.com/viewtopic.php?t=11635

I hope this helps answer some of your questions.

[Alphacarina]

I'm building about 6 inches over the frame myself. Here's how I moved my axle back. I too was concerned about the frame strength if I moved the axle bracket back too far. I was able to keep a small part of the bracket in the area where the frame halves meet. The origonal mounting hole is right behind the black mark I made on the frame.



A more detailed thread on this subject can be found here.

http://www.tnttt.com/viewtopic.php?t=11635

I hope this helps answer some of your questions.

If you take one of those two siamesed cross members out and cut one in half, you can bolt/weld each half inside the frame where the two halves come together and that will do a fine job of strengthening everything

When I put mine together, I clamped the two frame halves to a piece of channel iron (to hold them perfectly straight) and butt welded them together before I even started bolting the trailer together - THAT will give you a much more rigid frame than what you show in your picture . . . . your little 2 inch overlap with only one bolt in the front half would scare me to DEATH - That looks very wobbly to me

Don

[gcollins]

That picture of two halves of your frame butt-joined together looks a little precarious to me. Here's what I'm doing for my 5x9 on a 4x8:

I stretched the 8' frame to 9' by using the center two crossmembers to bridge between the two halves of the frame. That way my floor will rest solidly on the ends of the frame, without hanging over. Actually, I stretched it 12 1/2 inches, because there were already holes pre drilled in each section of side rail, so I would be sure to get both sides the same length. Of course, I drilled a couple of extra bolt holes, just to make sure there wouldn't be any play in between the three pieces in the vertical, as well as horizontal plane.

After much deliberation, I had decided to place my axle at 38" from the rear (35% for maximum tounge weight, per the information linked from the top of this page). However, there was already a bolt hole which would place it at about 40", so I figured that would be ok. That kept me from another potential measuring mistake, resulting in possibly a misaligned axle.

Now, I am working out the details for my floor. I am trying now to decide whether with 1x2 framing (basic benroy plans) that it will be ok for the floor to have a "6-inch hangover" on the sides. I'm leaning toward letting it hang over, framing it with 1x2's, since the end walls will be fully supported by the metal frame.