6x10 for a family of 4

[bartek]

I've been building for a few months now, hoping to finish by the spring. It feels like it's a good time to get the photos organized and catch up creating the build log...

The trailer is pretty wide - 78 inches on the outside (and the wheels stick out a bit more) and 10 feet long. The idea is that since we have 4 people to fit in, we'd sleep sideways. The inside of the cabin is 8 feet long (so, the bed will be 8 feet wide), going up half way to create 2 4 feet bed - kids will sleep on the one above the wheel wells. It will probably be a pain to get out of the trailer from that section, but they are used to jumping all over us anyway

I'm building on a NT 5x8, although I have changed the axle to Torflex, added tongue extension and upgraded the wheels. I was hoping to weld a custom frame, but I can't weld to save my life and I wasn't convinced I wanted to learn on something which will be going 60mph on a highway... Got some quotes from local welders, but the cheapest was almost 3 grand. Ultimately it was much cheaper to just get NT frame even with shipping and discard pretty much everything other than the frame itself.

This is what the final design is supposed to look like (I'm also thinking of adding a custom tongue box, but the trailer is ending up a little front heavy, so I may need to give up that idea)





I'm mostly following the method described in Tony's book, although I adjusted the design to accommodate additional width and length.

And the very first photo I took of the process - brand new NT trailer just after arrival:

[bartek]

Due to the size, wall profiles ended up needing 3 separate sections of plywood. I started by joining 3 pieces of 3/4 ACX plywood using tongue and groove joint, but wasn't quite happy with how stiff that felt, so I added a few butterfly joints in a couple places





Since I don't trust myself to hold the jigsaw straight, I used a CNC to cut the wall template. This was done from a cheap 1/8 utility plywood I found at Home Depot. Ended up being a little thin for a template so I had to watch it pretty carefully to make sure the guide doesn't slip, but it ended up working fine.
My CNC is small, and can't cut pieces wider than 2ft, so I ended up cutting a few separate segments (front, top and back).



The template was stapled to the plywood and I cut the first wall, which was later used as a template to cut the next wall. I didn't cut the door and window openings right away, since I didn't have them ordered yet and I wanted to double check the exact size.



Finally, I created a top space to hold the headliner by running a number of overlapping passes with a flat router bit and an offset guide:



In the hindsight, I ended up removing way too little plywood, since I was worried about the walls not being stiff enough. Definitely an overkill, given the torsion box design of the walls, but I didn't at the time appreciate just how much stiffness will be added by the two outside skin layers of plywood.

[Bezoar]

I like your profile and the colors on your model look great!

I struggle with the same thing on weight versus strength. I'm used to building things that sit in one place, not get pulled down the road! I read about the strength added by the two sides of ply, but you only learn how strong once it is too late to remove more material.

I'm looking forward to seeing your progress!

[bartek]

Thanks, the profile is a actually a bit modified and vertically stretched version of a teamberleaf teardrop - I really like how they look but wanted something taller with a little more headroom

[bartek]

To support the length of the trailer, I added a set of supports in the back and front. I'm not quite sure if it's an overkill, but I figured since the trailer overhangs 18 inches to the back, I wanted it well supported. The whole thing is screwed to the metal frame and supported from the bottom on 3 1x1 metal tubes.
I did something similar on the front side, except it's only 6 inches long and has a cut out for what's supposed to be a tongue box.
Before attaching, the 2x4s facing the metal frame and the bottom plywood was covered with Henrys's roofing patch (what a mess by the way)
This picture from the design probably best explains what I did (it only shows 2 of the 3 tubes, the third one was added in the center):



And the picture of the back support under construction



This also helps with the side profile which I wanted to be built such that it hides the metal frame

[bartek]

The floor was made from a sandwich of 1/2 ACX plywood, 1x5x1.5 joists and another layer 1/2 ACX plywood. This was so the overhang on the sides (and front and back) was well supported. The bottom layer of plywood was also extended by 3/4 on the sides to act as support for the walls.
I covered the bottom of each plywood section with Henry's roofing tar (again - what a mess, I should have listened) and assembled them using tongue and groove after flipping them over. The joints were then again covered from the bottom with the tar.
I had to drill a number of holes to match the screws on the trailer frame. These were painted with a primer and later I decided to fill the holes with epoxy (both for waterproofing and to hold the screw from the top in case I ever need to tighten them)




Finally, the insulation was cut and fitted in between the joists/frame and another layer of 1/2 plywood was glued on the top.

[western traveler]

Looking great!
I am interested in how this NT trailer is working out for you being extended to 10'.
A few questions if you don't mind;
1. Did you weld the three 1x1" tubes under the rear crossmember at the rear or?
2. Was there welding done to lengthen your tongue?
3. Did you just go with bolting the frame together or did you add welds at the corners?

I am in the planning stage of my build and not a welder...at least not yet..

I like that you are going with the woody design! I hope to do the same...

[Bezoar]

Looking good! You are making progress. I just finished my top of the floor - tomorrow I flip and start cutting foam. This build would go a lot faster if they didn't expect me to go to work every day! Can't wait to see the walls up. You'll be camping before you know it.

[bartek]

Looking great!
I am interested in how this NT trailer is working out for you being extended to 10'.
A few questions if you don't mind;
1. Did you weld the three 1x1" tubes under the rear crossmember at the rear or?
2. Was there welding done to lengthen your tongue?
3. Did you just go with bolting the frame together or did you add welds at the corners?

Thanks wester traveler! No, I simply bolted them to the bottom of the frame. To be honest, I don't even know if these tubes are necessary - the back "extension" was bolted to the frame anyway, and the back only needs to carry the weight of the galley. Still - felt better to just have those in place.
This is what they looked like just before I put them on:



For the tongue extension, I followed almost exactly the steps described in this thread: http://www.tnttt.com/viewtopic.php?p=1065563#p1065563
All bolted, no welding (I don't know how to even if I wanted to ). The whole thing feels stronger than the original trailer, since the tongue extension engages both plates on the front, which I think will help with common failure point of the NT trailer.

For the frame - I simply bolted it, I figured there is a lot of strength coming from the floor once it's all bolted together. But then it's my first build, so take it for what it's worth

[western traveler]

Thanks, and that is actually a relief to hear!

[bartek]

After the floor was finished, I put up the wall skeletons and the headboard. This being my first build, I wanted to do it this way rather then installing perfectly finished walls, to keep the flexibility to change later in case I messed something up. This has proven useful - I had to add blocking for porch lights which I forgot about, and I had to adjust the shape of hatch opening as well. Also, some of my wiring runs inside the walls, which would be very hard to do otherwise.
Now, I'm sure finishing vertical walls will pose it's own challenges, but I'll deal with it in it's own time...

Also, in the meantime the doors and windows were delivered, so I was able to cut out openings - this was done with walls already installed, but didn't pose any particular challenges.



Right after I skinned the insides with the 1/8 birch plywood. I couldn't quite get the joint between plywood sheets to be perfect, so I'll need to come up with some sort of trim later.



I used laminate cutter bit to trim the skins - it had better clearance than my bottom bearing router bit, and also seems to leave a cleaner cut (likely a testimony to poor quality of my other router bit )

[bartek]

Next up, a set of front cabinets, which will provide much needed storage space, but also will help holding the walls together.
The top cabinets will have doors which swing up, although I'll likely work on them at a later date.
Right now I'm just trying to complete this project in time for the summer, so leaving all non-essential bits until later.

[bartek]

Top and bottom cabinet were built separately. Each has a frame built out of 1.5 x 0.75 pine.



For the sides, CNC came handy again, since I was easily able to replicate the profile and get the curve just right. Could have probably used the template I created earlier as well, except it got destroyed when detaching it from the side walls (didn't expect anything less from 1/8 plywood )
Cabinet sides and bottom are made of 1/2 inch plywood, and then skinned with same birch plywood I used for the walls so it's all matching.



Finally, I cut out openings for the lights (top cabinet only) and wires. These are later covered with 1/8 skin, so the wiring is obviously not visible



And the set of 2 cabinets ready to stain

[cmrcmk]

Looking good, Bartek! I'm also sizing for four so I'm keen to see your thoughts and tweaks to make it work in a teardrop.

[bartek]

I'll let you know how this works out in practice, so far I'm thinking 8x6 sleeping space should be enough for 4 of us, not much smaller the tent we used before. The only challenge I anticipate is because we'd be sleeping sideways, getting out from the kids sleeping area (the 4 feet on the back, further away from the door) may be a bit challenging. I doubt they'll care though