Page 1 of 1

Side Wall Attachment Engineering

PostPosted: Tue Mar 22, 2005 11:36 am
by Syekick
I can see that by attaching the side wall exterior, frame. insulation and interior skin to the exterior of the trailer frame will provide approximately 2" more of interior width.

Will I lose any appreciable structural integrity as compared to mounting the exterior side wall skin to the trailer frame and allowing the frame, insulation, and interior side wall skin to rest on the floor?

I suspect that it makes little difference and is a matter of preference. But, as my training is in electronics and not mechanical engineering I have doubts. OK, lots of doubts!

----------------------
Remember. Computers are your friend. You wouldn't hit a friend would you?

PostPosted: Tue Mar 22, 2005 12:47 pm
by angib
I think some people will want to tell you that the side wall must sit on the frame, perhaps because they are thinking of sitting a house wall on its foundation....

But if you look at some people's old teardrop photos, you can see 50-year old teardrops whose walls hang past their floors.

So go right ahead and put all the wall 'outside' the floor, though you should make a good joint where they meet.

BUT, but, but, are you thinking of doing this because it will make your trailer body 48" wide inside? Because if so, what is the roof going to be made of? Are you going to be trying to buy 50" wide plywood? 'Cos it ain't made!

Once you go past 48" width, there isn't much of a good reason for not going to 60" or 64".

Andrew

PostPosted: Tue Mar 22, 2005 12:57 pm
by mikeschn
Here's some food for thought. If you are planning on painting your teardrop you could go with 48" on the inside, and put the 48" wide roof inbetween the sidewalls also. Fill with epoxy filler, and paint with epoxy paint.

But I'm with Angib. A 5' wide teardrop is far more comfortable. And the 3' scraps? Use them up on your cabinets! ;)

Mike...

PostPosted: Tue Mar 22, 2005 1:54 pm
by benjamin
This brings up a good point that I still do not have an answer on. Please don’t think I am trying to hijack your thread but if I can tag along to get a few things cleared up I would appreciate it. I have a 5’ frame I want a 5’ wide TTT I plan to use 5’ sheet aluminum so if I have to place the ply wood outer over the frame that will make my TTT 5’ 1 ½” my aluminum no longer fits. So let me throw this out if I use the ¾” ply and mount the walls on top of the frame and use ¼” masinight to enclose the outer shell so I can skin over the top of the frame with out having a seam to cover. The corner cover should be able to cover up the added width. I had planned to bring the frame in about an inch but that messes up my axle mounting. I had even thought if I enclose the whole thing with ¼” hard board I could get by with ½” ply.

Okay as to your question no you will not lose much if any structural integrity. I know as that is what I do for a living. As long as you fasten the walls securely the weight of the walls is not that great and most all fasteners have high shear rate. As long as you do not mount to the ply wood floor you should be fine. Ply wood has compressive strength as well as a spanning strength how ever of you drive a screw or nail into the side or edge of the ply you are working against all of its strengths. It will not hold you would be better off using 1x12 planks at the grain will hold the fasteners better than the glued edge. So if you chose to mount this way make sure you secure the walls to the frame or add 2x blocking to the floor.

PostPosted: Tue Mar 22, 2005 2:15 pm
by mikeschn
Gee, I wish I had a PhD in sidewall attachment engineering. :lol:

What I would try to do is set the 3/4" structure of the walls on the frame, and let the 1/4" luan skin cover the frame. That way your teardrop will only be 60 1/2" wide, which can be covered with 5' aluminum and your edge molding.

I know, I've probably taken some liberties with your sidewall design, but you gotta admit, it would work!

As for the wheels, get some really wide fenders! :?

Mike...

PostPosted: Tue Mar 22, 2005 4:12 pm
by Syekick
I was thinking of a 5" width but got all wrapped up in 2D thinking.

While trying to maximize the interior width to 60" I forgot that any width over 60" will require that I stretch the 5' aluminum skin by 2". Ha!
So the attachment method really doesn't matter after all. Unless...

I'll whip up some 0" width side walls this weekend and become rich. :twisted:

Here's what I did.

PostPosted: Tue Mar 22, 2005 4:39 pm
by Q
Using a HF type trailer I layed down a 3/4" plywood floor. Flush with the edge of the plywood I attached (glued and screwed) a fir 2X2. I attached the 3/4" plywood walls to the outside of the 2X2s using glue and wood screws every 6 inches. I made the front wall and roof from 2 layers of 1/4" plywood 4' wide and inset it so the top of the top layer was flush with the top of the walls. 2X2 roof beams supported the plywood as I bent it.

When you're as big as I am, every inch of shoulder width helps.

Q

PostPosted: Tue Mar 22, 2005 4:42 pm
by angib
Syekick wrote:I'll whip up some 0" width side walls this weekend and become rich.

For walls this thin, I recommend you make them from unobtanium - it's the only material that's strong enough.

Andrew ;)

PostPosted: Tue Mar 22, 2005 6:22 pm
by fornesto
I attached mine to the sidewalls of the frame, but already had little horizontal tabs welded under the frame, projecting about 1" out to the sides. These tabs created a sort of shelf, which I laid the sidewalls on, while I drilled and connected them. I also used construction adhesive. I would definitely try to use a secondary or thirdiary support system besides the 5 or six bolts. They will stretch the holes in the plywood and eventually rattle. I like my tab, adhesive, and bolt system.

sidewalls

PostPosted: Tue Mar 22, 2005 7:29 pm
by David Beckett
I moved my walls out a few inches by building a separate base that rests on top of the trailer. I also made it removeable. The base is 2x3's with a 1/2" plywood floor.

Pictures are available on the link below.