GPW, First I want to say that all of my ideas have been "borrowed" or inspired by this fine and very talented group of collaborators.
Now the legal bit: While I do have an associates degree and can run a stress calc here and there, really all that gets me is a more experienced perception of "That looks about right". That being said, I am never afraid to give my opinion, but it is just that; my opinion. You assume all risk, same as me, same as anyone. If a novice sees this and thinks, "oh good, he knows what he's doing, I'll just copy him", feel free....but, know that this is a prototype effort, no guarantee.
Do I think it will work successfully and have all of the integrity of a traditional? Absolutely (IMO). Do I think it will be lighter than ply? The foam parts surely will be. The whole thing? Schmaybe (love that!). Depends on who's trailer we are comparing it to. Are any two ever the same? When I get the model a little further along I will look at the 'mass properties' generated by the software, and (assuming I have designated the proper densities for each component) we'll see what it says.
Eagle & Bonnie, Thank you for the welcomes and compliments.
Bonnie, I will confirm and post up some more details on the frame, perhaps tomorrow evening. I use the design software provided to me by my employer, but to do so, and to have access to my design, I stay after work (up to 3 hrs at a go). It was a long day for me today repairing an industrial mixer (anyone need 3000 lbs of denture adhesive with a tiny little bit of food grade grease that leaked into the batch; we're only going to throw it away (properly)
). From memory the side rails and rear xmbr are 2x2x1/8 wall SQ tube. The intermediate xmbrs are 1-1/2 x 1/8 angle. The tongue and front xmbr may be 2x2x3/16 SQ tube, unless Angib says 1/8 wall is ok (he is, after all, the trailer frame Guru here
). The body mounting clips along the front and rear xmbrs are the same 1-1/2x1/8 angle, or I may miter them from extra SQ tube so that they have built-in side gussets (as seen elsewhere on this forum). The two rear corner clips may go away and get incorporated into the jack mounting plates. The field of the floor is attached through holes in the flats of the L shape xmbrs.
Not visible in the images above are the 2 x 4 SQ bolt blocks (1-1/2 x 3-1/2 x 3-1/2) built into the the floor panel at each of these locations. Also, the intermediate xmbrs are strategically placed to align with the 2x boards built into the floor panel frame that back up the floor skin butt joints (remember my floor is 64 wide, but I expect to be able to use most of the drops for the cabinetry). All of these bolt locations will be populated with threaded inserts installed before the upper floor skin goes on, capturing and hiding them under the finished floor.
I added the little SQ tube extensions with the capped miter cuts behind where the tongue tubes tie into the main rails to act as rock sliders, but I don't like the way they look 'hanging down' right under the doors, and don't really expect them to be needed anyway. The gentleman working on all of the special tooling in order to go into TD production, I believe he is in Colorado, has very nice looking compound miters on the ends of his tongue rails, and I may "steal" that look instead.
The front vertical corners of the trailer frame main rectangle will be fitted with quarter sawn segments of 1-1/2 OD tubing to give a 3/4 inch radius matching the radius of the roof/wall joint. (I think big Mike is worrying about this wall/roof radius too much, kind of like many do about their first hatch
but what do I know
I've never built a camper...so no disrespect intended
Re: galley access. So let's add this up, roughly, the front wall is 1-1/2 thick (plus luan), the mattress is 80 inches long (forget how much I left for tucking), the galley bulkhead is 1-1/8 inch thick (3/4 + 2x3/16), call it 83 or 84 inches if I remembered to leave room for tucking the bed covers.
So that's 7 ft, and I said, if I am recalling correctly, that the floor length is 10ft6, so that's 3ft6 in the galley.
After rechecking the model I see that my memory is not so good. The actual length from the front of the floor all the way back to the rear edge of the galley is 9'-8" (+5/16") and the cabin inside dimension is 82 inches. So that makes the galley counter 31-1/2 inches deep; easily reach the back. The top galley shelf is at 64-3/4" high, so is also easily reachable by me (and most non-vertically challenged sorts). For those who are vertically challenged, BBQ tongs are standard camping equipment and can be pressed into service as "grabbers"; multi-taskers.
The hatch ribs are 3 inch deep (IIRC) and the counter edge is 3/4 thk (1x), with a little clearance for fudge. The cubbies to the left of the cooler space have an additional 3/4 face frame set back under this counter edge, but the cooler tray, when pushed in, only sits back far enough so that it does not stick past the front of that. Don't remember the cooler long dimension off the top of my head, but the tray is a little longer. So the back of the galley counter is about 3 ft off the ground and a little more than 3 ft back. Will have to check the specific numbers on the top shelf. I'm 6ft and I have some reach on top of that. The wife is 5-2 and she claims that the upper cabinet shelves in our home kitchen are "useless", so that will be my territory. I do most of the more ambitious cooking and have been told that, "just because we are going camping it does not mean that we will not be on vacation", so I expect to do the majority of the cooking (one of the skills that I did not mention yet), or to coordinate with my sister, who is also creative in the kitchen.
...and Eagle, way to put your foot down on the foam vs. ply controversy. I'm proud of you for your no BS take on that. Bam, that's that, now play nice
Steve, Got the interior panel skin-on-foam idea here (maybe it was yours?). Decided I wanted the rich wood interior (if luan can be made to look rich, maybe gunstock red stain), and thought it would be an easier application than the canvas. Yes canvas outside, because I think it will be easier to seal and maintain than wood, easier for someone with little fiberglass experience to apply, less clean-up and, presummably, more environmentally friendly. "Glue" for canvas will be chosen from one of the top contenders (TBII, Latex paint, water based contact cement, or lagging compound). I'm undecided, not in a hurry to decide just yet, and, based on the experimentation by others to date, think any of them would give acceptable results. Glue for interior panels to foam will likely be the contact cement or PL.
It occurs to me that I said the cabinets will be 1x. Meant that the face frames would be 1x, but the shelves and any dividing panels will be the 1/4 (3/16) luan. The under galley counter dividers will be 3/4 sandwich.
I also intend to erect the galley bulkhead and as much of the cabinetry framework that makes sense before the walls go on for easier access and work flow.
Poet Creek Or Bust!
p.s. How do I get a signature line to automatically show at the end of my posts?