Hobbit themed Teardrop

[yayeric]

I'm building the trailer at The Generator, a very large - maybe the largest - makerspace in the US. It has about 70,000 square feet of space. There is a massive amount of knowledge and tools available for use. Since I never built anything more complicated than a bench or a boyscout's derby car, I figured this place would be very helpful in resources and knowledge.

First I bought some scrap metal from craigslist to build the trailer. The paint needed to be ground off, the metal to be cut to size. I also needed to learn to weld

I really did NOT like this product. I spent a month making this thing, and it cost me over $100 for the pads to grind the paint off.

Some other folks around the Genny were buying new steel and I decided to remake the trailer in the same fashion. This ended up being significantly easier, required less money in the end and saved a lot of time.

 

[yayeric]

Beginning with the wood working. I started this project shortly after Russia invaded Ukraine, so the baltic birch was VERY expensive. I think around $180 for a 4x8ft 3/4" , and $90 for a 5x5ft 1/8". Ugh....

Here is the template. I was very surprised with how strong the drywall tape and wood glue worked to join the two pieces.

Here the size walls are being glued togethor. A quarter inch oak planks was used to 'stretch' the wood

Never had an issue with using too much glue. I wanted everything saturated, even if there was a big mess to clean up afterwards

Here one wall was routered using the guide, holes cutout from the skeleton, and the seecond wall was router using the first wall as a template - I wanted both sides to perfectly match

 

[yayeric]

Here the foam was thrown in. I found that lining up the foam and gently punching it left an imprint of where I should cut. All pieces fit very snug. I sanded it down flush, bit messy but not too bad

 

[yayeric]

Here is where I began the 'project creep', where little ideas began to pop into my head, slowly adding complexity and greatly increasing the time and effort I was going to put into the trailer.

We had a cnc plasma cutter, and cut out the door trim. Had to learn Illustrator to create the files. I had some expert help on uploading the vector to the plasma table program and getting it cut.

 

[yayeric]

With the door decorations printed, I needed to build a door with the correct attachment points. Talked to an engineer friend about the best way to make a wood structure light but strong and she said, "TRIANGLES". I used illustrator to mark all the points where wood needed to be and made some triangles fit. I think it turned out quite nice and elegant

While staring at this door, I began to think about the door latch. I didn't like the options available on the market, so I decided to make my own. I followed "Artfully Rogue" build design.

The latches will be incomplete until I finished the door, get the coats of varnish on and everything mounted, to ensure I took into account the added thickness of epoxy, fiberglass, varnish and whatever unforeseen thing comes my way

 

[yayeric]

Built the front wall, added the foam and skinned them. I do wish I build the long beam in the front wall a little lower so the dado insert areas were center lined, but oh well.

 

[yayeric]

Building the floor

 

[yayeric]

Doing a test fit of all the pieces - everything seems to fit nicely! When the side wall was laying flat on the ground, all the inserts were at 90°. I was glad everything that was done on paper and transferred to wood worked out so well.

 

[yayeric]

This portion of the project took the absolute longest of anything. I think I spent about 8 months of free time building, tearing down and rebuilding, 7 or 8 times over until I had something that looked good and near perfect in alignment

I'm not an engineer, I cannot barely build a bridge, nor do I have an intuitive sense for how strong my materials would hold up over time. I decided I needed to utterly overkill this piece. I have decided that round doors are a poor design.

I had the following considerations to guide me

1) The door is round. Unless I want my hinge lengths to be the radius of the door, they have to be closer to the center. This doesn't provide the most leverage to hold the door

2) The door is as wide as it is tall - another negative. My hinges had to be strong

3) The door is heavy, about 50 pounds with all the trim, bolts, latch, etc....

4) I'm concerned of the door deforming the wall over time - I wanted to reinforce the wall

I tried some Home Depot or Lowes hinges - I liked the look but they were too wiggly, and when I found that the washers were plastic......

"Screw it", I told myself. I'll build my own. I decided to use a metal beam and weld the hinges to the beam. I also discovered weld-nuts, and thought that bolts you couldn't see are better than carriage bolts.

Here are my failed attempts

Initially I was going to weld these fingers into a beam, which would taper at the end. Weld nuts would hold the hinge to the door

 

[yayeric]

Those were pretty ugly. I was also getting a lot of binding in the hinge pin - I had a lot to learn about distortions in metal caused by heat. It was tough to keep everything from moving

Long story short: I put some more thought into it, and remade them completely. The CNC plasma table was down, so I carved everything from 1/2" steel by hand. AC/DC , Bon Scott era of course, became my favorite band during this process. Watching the metal pulsate red from the head, sparks flying, feeling the torque from the angle grinder with "Riding down the highway!" was a solid combination.

 

[yayeric]

To weld these on without being the hinges themselves or the beam I was welding them too was difficult. I wanted to weld them on and be able to drop a rod of steel through without it catching. Here's was worked for me

1) Unsurprisingly to any metal worker here, that you can't have too many clamps.

2) Used spaces with the clamps to ensure equal measurements across all the

3) Most critically, I needed to build 3 sides of a box, essentialy X, Y and Z axis support. for the small pieces I was welding onto the bar. This way, in order for the bar to bend, it would have to compress 1/4" steel that was 1" away.

Here are the support for the portion of the hinge I was attaching to the bar. All this material would be cut and ground off once everything cooled

Using spacers that I confirmed uniformity using calipers, everything was clamped with as many clamps was needed. I used bolts with the heads cut off, I found them to be less than 10µm different in diameter, close enough for me.

I quickly ran a test with some scrap. This was worked out well, even though it was very poorly done I had no bending in the beam. Straight as an arrow!

Before any welding began, I ensured the rod slid in and out easily.

Everything was tacked, and the only portions welded were along the longside of the beam, to keep the heat-affected areas of the beam within the interior of the hinges I welded on. With that X axis above needing to be compressed in order for the beam to bow, it ended up being straight.

Once everything was welded and cooled, the rod fell through the hinges, and the maximum change in distance between the hinge arms when opened and closed was 0.2mm. That was straight enough for me.

 

[yayeric]

An unforseen problem I encountered - how do I drill holes in a wall that line up with weld nuts on the inside of a beam? It would have been a lot easier to drill the holes in the wall, use those to drill holes in the beam for the nuts. I did this in the wrong order =[

Here was my solution. Using 'floating' pieces of wood, insert weld nuts into the wood and attach the floaters with bolts. Glue those pieces together

The weld nuts would stay in the wood, and be used as a guide for a smaller drill bit to drill into the wall. I did make a few mistakes on my first drills. I filled those holes with oak dowels, and remade them. Got it right on the second try.

 

[yayeric]

I needed a break from metal working. Bought some canary wood, trimmed it down to 7/16" and built some door trim.

I made the pattern in illustrator, cut out the two patterns I needed with a CO2 laser cutter on 1/4" baltic, and used that to make a router guide from 3/4" baltic.

 

[yayeric]

Started to get my walls epoxied. Also added some cuts to the door to make them appear like boards, and stained the walls with Saman's Emerald water based stain. I used the water based stain because it allows the epoxy to still bind to it.

 

[yayeric]

Ran a test fit with the canary trim - turns out the hinges take up some of that space. Had to shape the trim to fit

 

[yayeric]

Flipping everything over, adding wood to the interior for the door and galley seals. Essentially wood spacers.

 

[yayeric]

Not sure why I felt the need to build an epoxy table, but I did. Wish I didn't, it feels pretty limiting because now I have a table that I don't want to add anything on top of.

Any way, I had built one previously (it's in some of the previous photos), and decided to build another that was less busy. Found a piece of walnut with some gorgeous chatoyance and color variation.

My tips for epoxying a river table;

1) Use a melamine board. Epoxy still sticks to it but not very well
2) Build a mold with the melamine - floors and walls
3) Cover the floor and walls of the melamine board with packing tape. Epoxy doesn't stick to it, and it's very cheap.
4) Use hot glue and cover the exterior portion of the melamine to contain any leaks. You have to accept that there will be leaks, you can't avoid it and don't even try. These are steps to limit the amount of leaks you have.
5) Buy the correct epoxy - ensure it is good for the depth you're planning on pouring
6) Precoat the wood. Only precoat the layer you intend on epoxying at that moment. Apply a thin layer to any exposed wood, and flood the base. Allow this to dry to the point where no more bubbles with form. If you do not precoat the wood, then you will have bubbles that you can not remove. They constantly leak from the wood as the epoxy fills those voids, and once the epoxy solidifies enough to the point they no longer leak, you cannot remove them for the same reason. Pre coating a thin layer creates a bubble trap.
7) use a heat gun or torch to remove bubbles. It's better to wave across a section several times than to let the torch blaze it for several seconds - you'll cook the epoxy, and possibly burn the wood.
Keep covered in a dust-free area. Accept the fact that some dust will get through, but a sanding of the surface will solve that.

Here I'm using a router to remove the hardened surface layer of epoxy

Sanding those router marks flat.

Apply several coats of varnish, and you're good!

 

[yayeric]

Putting the trailer together. I wish I had more clamps. Tony Latham was right - this would have been significantly easier with 2 people. It was a mistake to do this on my own

 

[yayeric]

I didn't trust the loctite 3m premium adhesive to hold the trailer togethor. To satisfy my anxiety, I threw in interlocking 3/8" oak dowels

I also added 2.5" screws later on.

 

[yayeric]

Starting work on the interior. I wanted to cover all the plywood edges with walnut trim.


Started by installing the sliders for the cubby

Covered those up with some walnut. I was just making it up as a went

Here is a porthole for the galley. Thought it be nice to hand someone coffee without needing to open the door