All aluminum hard sided popup toy hauler

[Grummy-TNT]

Nice looking project. I'm curious what your frame weight was ? And, I'll be real interested in what your final weight ends up to be. Most factory built full aluminum single axle 6x12's run up to 1300 or so lbs.

 

[coal_burner]

So far it's up to only 320 pounds.

Almost 200 pounds of that is just the big honking steel axle and the wheels, even though they're super light weight aluminum rims.

 

[Wolfgang92025]

Nice looking build.
I'll keep watching your progress.

 

[coal_burner]

Digressing for a moment here.
The hitch height on the Tesla is low, which is good because I'm trying to keep my overall height down, but it ends up being lower than the top of my frame rails resting directly on the axle.

Apparently I tightened that ball more than I remembered, so the torch came out to assist.

The new ball has a 2 inch taller shank, which gives me an almost perfectly level trailer deck when hitched.
It did, however, rust most of its chrome off within the first couple weeks of being installed.

 

[coal_burner]

Here we are, one and one half walls welded in place (the right wall is only completed up to the doorway)

My welds have become much more consistent. I welded a couple wall studs slightly off vertical, so I grabbed them with a pipe wrench to straighten.
I figured I'd probably snap the welds, but instead I managed to actually bent the 1.5" square steel tube.
Since any wave in my wall frame will probably look exaggerated when I cover everything with smooth aluminum sheet, I decided to cut the welds, straighten, then re-weld.

Since this is a pop-up, and the walls are not held firmly by being connected to the roof, that means there's a three foot long lever arm acting on the weld connection between the wall and floor.
Just because I'm a belt and suspenders guy, and I want this thing to last forever, I'm putting gussets between every wall stud and floor beam.

The gussets are made with some of the extra stock from. My floor joists.

 

[featherliteCT1]

I like it a lot!!!!

 

[pchast]

Looks good!

 

[coal_burner]

Lots of gussets welding going on.

I've been slowly learning all the ways one can screw up aluminum tig welding, and correcting.

I invested in a diamond sharpening wheel for the tungsten electrodes instead of a dedicated stone wheel, and the Weld penetration got better.

I invested in much larger gas cups and gas "lens" for the torch tip, and the Welds became much cleaner.

I bought an argon tank four times the size of my original, since since I'm now using twice as much argon because of the gas lens.

And finally, I'm building a tent around every single Weld I'm making, since even the slightest breeze blows my gas blanket off the work area, ruins the Weld, and costs me 15 minutes re-sharpening my electrode and grinding the contamination out of the Weld.

 

[coal_burner]

My new problem is that the gussets are tilting my walls.

If I brace my wall studs perfectly vertical, then Weld a gusset in place, the entire gussets goes up by a few hundred degrees and expands.
Since the wall is being held vertical, the molten edges of the gussets are squishing shorter as I Weld, and when things cool down, they pull the tops of my walls inward by somewhere between a half inch and a full inch.

The hard part is that the exact change in length of the gussets are determined by the temperature the gusset got up to during that SPECIFIC Weld.

I've been welding gussets, checking how out of plum my wall stud got, using a cutting disk to cut straight through the center of the Weld, then hammering a wedge into the gap to push the wall slightly out of vertical in the opposite direction, then bridge welding the gap, pulling the wedge, and seeing how close to vertical I've got.
(Wow, that's a run-on sentence)

Some of my Welds now look super wide because they're actually 3 Welds done one atop the other.

This seemingly simple part of the project is taking WAAAYYY too much time!

 

[coal_burner]

Since the gussets are so tedious, I'll do a couple of them, then work on a different part of the project.

The quarter rounds on the front walls of the trailer are slowly happening.

Here's where I cut a bunch of slices out of 1 side of my 1.5" square tube, bent it to match the exact curve of its complimentary former, and bridge welded over the gaps I cut.

I still need to grind away my previous welds on the lower curve formers and Weld them again using my much improved skill set.

Note the lack of scorch marks and burn through in all the newer welds.

 

[OP827]

You welds are looking much better !

 

[coal_burner]

I've been moving slow with this last addition to the trailer base.
Since the hard shell is going to slide up/down around the outside of the base, all the walls need to be perfectly parallel and vertical.

I built a full trailer width former out of wood to make the top of the curved corners match the bottom of the curved corners.

I came up with a couple bush-league anvils to hammer the aluminum into the exact right shape.

Now that it's welded up, it looks like variances in my walls are less than 1/8" so that should be able to be made up for by using some 3M HST as an adhesive shim before riveting.

 

[coal_burner]

With the wall frames complete, I hooked up the lights temporarily again so I could use the camper to pick up 1" 25psi foam board for the composite floor.
Being able to park in a pair of pull through spots is almost as convenient as I thought it would

 

[coal_burner]

Testing her out at various speeds on the freeway, i discovered that it takes about 450 watt hours per mile to tow at 70mph; this should give me about 160 miles of range between battery charges as it sits.

Consumption should go down as my wheel bearings wear in, but should go up as i add weight.
Im curious what's going to happen once I get the aerodynamic skin on the trailer.

 

[coal_burner]

Starting on the foam and fiberglass composite floor now.

I made a test piece of floor on 1" thick 25psi foam.
It had 2 layers of 18oz fiberglass cloth on 1 side, and 1 layer on the other.
It flexed more than I'd like, so I'm going to double the foam to 2" thick for the actual floor.

 

[coal_burner]

The actual floor is 2 layers of 18 oz. Cloth on each side, over a 2" foam core.

Knowing that the floor will be super rigid after the epoxy hardens, I weighed down the fresh layup with a bunch of bricks (on pieces of wax paper) to make sure it conforms to any irregularities in the frame.

After allowing the epoxy to hardens for a couple of days, I flipped the foam over so I could skin the back side.
No bricks this time, since that would try to flex the floor. Backwards from how it's supposed to be.

 

[coal_burner]

I made the rear floor section the same way as the front.
I made the floor in two 5' x 8' pieces because a single layup at that size took 3 hours, and I'm certain I don't have the stamina to spend 6 hours with no breaks, mixing epoxy and squeegeeing it into the fiberglass to make a single 5' x 16' piece.

Each floor panel ended up weighing 58 pounds.

 

[coal_burner]

Setting those floor sections off to the side for now, I added the little bit of framework to form the wheel wells that I'd forgotten about up to this point.

 

[coal_burner]

Somewhere in-between those previous steps, I added straps to hold my fresh and gray water tanks.
I drilled holes down through the 1.5"x3" floor joists to drop carriage bolts through.
After tightening down the nuts on the bottom, the square stainless steel bolt necks crushed down into the aluminum, guaranteeing they'll never be able to rotate.

The straps are only made of mild steel, but I'm keeping them from tou hing the aluminum with stainless steel washers.
I don't want any dielectric action going on down there.

 

[coal_burner]

Being a bit worried about an 800 pound motorcycle's weight bearing down on two small contact patches on the composite floor (especially on rough roads), I'm planning on using a removable 10' long piece of 8" wide aluminum C channel as a load spreader.
It'll bolt through the floor using a pair of 3/8" stainlessnless bolts, into the trailer frame.

Since i dont trust 1/8" thick aluminum to hold a thread under any type of load, I built a couple of aluminum cages to capture the big 3/8 stainless nuts.

These are welded to a couple floor beams along the centerline of the trailer.

As a bonus, this will remove any possibility of the wheels moving side to side, and i can weld up a front wheel chock to keep the bike from moving forward no matter how hard i brake.