Introduction: Teardrop Trailer Tiny Home
Greetings fellow Makers! This little camper was my tiny home for a summer while I worked remotely and traveled around the National Parks and Rocky Mountains.The original post came from a post on instructables.com, and I am indebted to all the people who posted their tutorials.
As with any big project, it really pays to plan ahead and think through your design. I recommend buying a graphing paper notebook (or using SketchUp free software) and drawing to scale.Make your design unique! If you have access to a CNC machine, you can plan out super cool designs (design idea 2). Spend time thinking about the elliptical--or teardrop shape--design. Not only will a great shape have that iconic aesthetic, but it will improve aerodynamics and therefore fuel efficiency. You'll make friends wherever you go with a beautiful design because people will just come up and talk to you about it! Teardops that miss the mark on the curve can look awkward. Here are some resources on that: math of elliptical, Fine Woodworking Example, Classic Profile Example.
I will mention several resources throughout this instructable; however, here are some websites and blogs that I found helpful in the design process:
- Teardrops n Tiny Travel Trailers (TNTT) online forum and community
- Make: Zine article on Teardrop Build
- Vintage Teardrop Designs
- CoolTears Magazine
- Wikibooks Build Process
- Blog 1
- Blog 2
- Blog 3
- Blog 4
- Blog 5
- Blog 6
- Wyoming Woody Teardrop Builder
- Design Ideas by DIYRV
The tools that we used belonged to this Makerspace. For anyone who is interested in learning or building things with their hands, I encourage you to get involved with your local makerspace, which you can find with this interactive map.
For those who interested in the financials of this project, you can check out this spreadsheet. The spreadsheet also links to suppliers and parts. The only resource I will mention by name is Vintage Technologies, which has high quality (albeit very expensive) supplies.
Step 1: Trailer Construction
Choose the type of trailer you want. You can often get VERY cheap, heavy duty, used military grade trailers on government auction sites like this one. Of course, craigslist is a great resource for used trailers, but be careful you don't buy one with serious safety issues. Many retail TearDrop shops will outsource the trailer construction and opt for higher capacity specifications such as axles capacities over 2,000 lbs and heavy duty rectangular steel tubing, as opposed to weaker "three sided" channel tubing found in most kits. I talked to at least one manufacturer who told me that he took a significant loss on his first line of TearDrops because he used kit trailers. He has since upgraded to very heavy-duty trailers, but initially customers returned with bent trailer tongues and twisted metal. If you're going to buy from a manufacturer, be sure they didn't skimp on the trailer; not all manufacturers are kind enough to replace trailers after failure.
If you're going to go with a kit trailer, just choose a good one. I chose a kit trailer because it's cost effective. First, lay out and organize all of the parts. This particular trailer kit required a ton of bolting things together. As far as kits go, as long as the assembly is done correctly and the weight placed on the trailer and tongue do not exceed the design specs (including a large margin of safety), trailer kits offer the best value over more expensive pre-built, higher capacity trailers. This is especially true if your homebuild design is a small 4' x 8' base.
The most common homebuilt TearDrop trailer that I see is the Haul-Master Harbor Freight 48" x 96" 1,720 lb Super Duty Steel Kit (was $349, now $449). I started with this kit, but after assembling the trailer, I felt the 4' x 8' base was too small and the kit construction could have been better (one of the six bolts used to connect the tongue to the coupler was severely misaligned and a new hole needed to be drilled). I sold the trailer (LPT: you can sell "new" assembled trailers on Craigslist for more than the cost of the kit because people don't want to spend hours assembling it). I upgraded to the Northern Tool Ultra-Tow Aluminum 5'x8' 1,715 lb Payload Capacity Utility Trailer ($689).
If you have the equipment and skills, you're probably better off welding your own trailer from steel tubing (like this guy). There are several guides (trailer welding guide 2) on the internet that can help you.
As you can see in the pic, I had to flip the trailer upside down to make sure everything was bolted right. Invest in some squares (pictured), and take your time to ensure that everything is square and confirms to manufacturer's specs. These trailers take a ton of stress on the highway with all the weight; you want to take your time and do it right. In particular, you want to make sure the corners are a perfect 90 degrees and the distance from the wheel axles to the hitch coupler is equidistant on both sides (see SketchUp pic).
I reinforced my trailer with 1.5” 80/20 aluminum rail bars meant for aerospace applications (pictured). I wanted to “overbuild” everything, I decided to fabricate special brackets that could reinforce critical load-bearing points. The picture of aluminum being drilled is a bracket used to attach the jack in a way that was stronger than the standard bolt on design.I would recommend you reinforce the tongue as it takes a good amount of abuse, random lateral forces and pulling tension. Although, my tongue rails held up, eventually the aluminum split under the coupler (pictured) and needed to be re-welded (see pictures with fix annotation).
You can see that my trailer wheels are pretty scrawny and only rated for 55 mph (we drove up to 60 mph). You can easily replace those with thicker, heavier duty wheels (which I recommend). The one benefit of those scrawny trailer tires is that they're ubiquitous. You can find them in almost any auto-supply store or Walmart.
Step 2: Trailer Platform/Base Construction
I built my base platform out of wood. If you go this route, you're probably going be buying standard 2x4's from your local home improvement store. As you may know, this type of lumber is often rough and warped. The first step is to take a table saw and planer and square up those 2x4's. Again, given that this is the foundation for your home on the road, you want to take your time here. You can see that I wrote detailed measurements on the wood and took my time to ensure precision and perfect fits. There were metal bolts that stuck out of the trailer, and I had to use forstner bits to drill cavities in the wood rails for all those little bolts. Yes, this was pretty time consuming to get everything square, but I wanted the foundation to be perfect and an ultra-strong platform for the entire shell.
I lined up all of the pieces on top of the frame. Because the frame had all sorts of unevenness and bolts, I had to measure precisely where the bolts would stick out, so that I could reliefs into the wood frame base. I also employed a ton of washers to make sure all of the spacings were right.
Next, once you have a basic frame over the trailer rails, you can put down some sanded plywood (I don't recommend particle board) and lay it over the wood base frame.Once you've screwed in all of the flooring plywood, you can unbolt the entire platform, remove it from the trailer, and begin to apply a thick weather-coating protection layer of tar. To waterproof the underside, I used Henry’s Asphalt Emulsion. I really put it on thick and applied two coats in different directions.
At this point, I wanted to get the trailer fully registered and licensed because I was going to be driving it along the roads. The friendly state police performed a VIN inspection and inspected the kit trailer for road worthiness.
Now that you have a road-worthy trailer, you should use it to pick up all the supplies (like 4x8 panels, etc.)
Step 3: Side Wall Construction
With the base complete, now it’s time to move onto the side walls. I took 15/32 sanded wood plywood 4x8s and started with them. Because the trailer would ultimately be about 10 feet long, I had to connect two panels together at a reinforced seam.
I drew a grid onto the panels to match the graphing paper grid lines on my scale sized sketches on graphing paper. My design is loosely based on the Wyoming Woody teardrop design kit (the SketchUp .skp file is available in the photo gallery or from this website).
Next I took a jigsaw and started cut out my sidewall design, and then I used a sander and router to even out all of the slightly uneven edges and tiny nicks.Using a drill and jig saw, I cut out the holes for all of the components. Next I used an airgun to affix squared wood strips to make the skeleton for the side walls. I wanted the sidewalls to be thick, but they had to be hollow in order for it to be light.I created a frame-skeleton in a piecemeal fashion and then used a router with a special bit to cut off all of the excess and make sure it all lined up.
At this point, you take more of your insulation board and fill in all the gaps. Lastly, you take the opposite sanded plywood sidewall and make a lil sidewall sandwich with the insulation in the middle. The bottom part of the sidewall had an overhang that fit the platform bed (see image). I applied glue to this seam and screwed the sidewalls in tight (while someone helped hold it square with a large framing square). I reinforced this connection using large (six inch) metal L brackets to hold that 90 degree angle. As you can see in the pics, you may want to add temporary wood supports.
Step 4: Building the Roof
The sidewalls were surprisingly sturdy at this point; however, I recommend starting on the roof fairly quickly to add structural support to those walls. I actually built out a basic frame for the kitchen galley before I started on the room to ensure those sidewalls are extra sturdy while you're screwing in roof beams.
For those cross beam supports (the ceiling joists), I used 2x2 beams (squared) and reinforced every corner with L brackets. I framed in supports for the roof star-gazing window and FANtastic fan (see pic). At this point, you really need to think about your electrical wiring configuration. I had a ton of electrical going along the roof to power the fan, two dome lights and a gooseneck dimable reading light (pictured), so just make sure you're not forgetting about that!
What comes next is possibly THE MOST ANNOYING part of the entire build: adding the roof. Why is this so annoying? Even though birch plywood is semi-flexible, it doesn't want to bend into the nice beautiful elliptical shape. How do I do this? I created scored channels (relief cuts) that allow the birch plywood to bend. The more channels you add--and the more they are evenly spaced--the nicer the elliptical curve will be. Of course, given that this birch plywood is already VERY thin, you have to be careful about the table saw blade height. One wrong move and you can cut that expensive birch plywood clean through.
Now that you have a flexible roofing material, you need at least one other person to hold that plywood up on the ceiling against the joints as another person takes the airgun and shoots a bunch of brads in. At this point, you're inside the teardrop shell pressing the plywood upwards against the roof framing and applying the interior part of the roof shell. You should also predrill some holes and use a couple (not too many because you want to be able to hide them) wood screws. If the plywood is not bending to the exact elliptical shape, you can take boiling water and moisten the wood. This will loosen up the fibers and give you a little bit more flex play. There might be a little gap along the seams where the roof plywood meets the side wall, but I wasn't too concern about this because I would later add a thin bead of beetle-kill pine wood as a trim. Once you put in the trim, the gap is invisible and it looks perfect.
One thing that I did (I am not sure if it helped) was fill in those channels on the opposite side with a compound mixture of sawdust and wood glue. I am thought adding some filling to those channels would ensure that the wood wouldn't split over the long run at those thin points.
Next up, we cut out insulation panels and inserted them into the gaps. We filled in all the little cracks with great stuff spray foam.
Lastly, you want to add the outer shell layer to the roof. This isn't nearly as hard as the interior roof shell because you have gravity and an already very rigid frame working in your favor. One thing you can do is take straps to pressure the plywood to conform to the shape of the teardrop. Again, if the wood isn't bending perfectly, you can moisten it with some water (pictured).
Step 5: Kitchen Galley and Hatch
My design for the kitchen in the back hatch how to accommodate the following:
- A kitchen sink
- Plumbing for sink and external shower, including a water pump
- Cavity for air conditioning unit
- Cavity for electrical distribution panel and wiring
- electrical outlets
- Gas line for stove
Building out the kitchen is just slow and time consuming. I used beetle kill pine as trim along all the sides, and I covered the edges with aluminum rails. I used a horizontal bandsaw (pictured) to custom cut all those little aluminum L-shapes. If you go this route, cut slow and use a ton a lubricating oil.
To make the hatch, I made template that matched the profile on the back and cut all of the ribs from this template using a guided router bit. While you are framing the hatch, you should do it in the back where it will actually sit when closed. You can add little wood shims and spacers to get the exterior perimeter of the hatch frame lined up perfectly to your frame shape. You also need to measure very precisely how the the hatch hinge (often referred to as a "hurricane hinge" will connect to the hatch and the trailer frame. I inserted some pics from elsewhere on the internet to illustrate how that hurricane hinge works.
Again, I scored channels in the birch plywood to bend the plywood skin around the outside of this sharp corner. At this point, you should wire the dome light and insert the galley hatch latch handle assembly. I didn't use plywood as the interior skin, but rather I used outdoors khaki waterproof duct canvas. I simply used a staple gun to affix the canvas to the inside of the hatch neatly.
Later on, galley hatch pneumatic trailer 120lb. Gas Props were added to keep the hatch safely open.
Step 6: Aluminum Exterior Skin
The Aluminum Exterior Skin is what gives the teardrop its iconic look and feel. It really "makes" the project. Beyond that, the aluminum does a fantastic job of actually protecting the shell from the elements.
It is likely that you have a metal supply shop near and you don't know it, but a quick google search can help you find a local aluminum sheet supplier. Try to shop around a bit because prices can vary greatly for small volume orders (most of these places are more like distributors for other manufacturers). I went to Olympic Metals in Commerce City, CO where they let me pick out my aluminum sheets and could not have been nicer! They snipped all of the metals to size.They even helped me strap the aluminum to my trailer.
Next we had apply the aluminum skin. I coated the metal sheets and sidewalls with Weldwood contact cement and let it cure a bit. Because the weldwood cement sticks as soon as the glue is cured, I temporarily tape dowels to the camper so the skin wouldn’t latch on to camper, which require me to pull it back off and possibly damage the skin. Once the skin is on, I used a wood dowel to roll out the skin and apply a lot of pressure so it sticks. This part is pretty physically exhausting, but you want to ensure the aluminum skin is evenly applied and doesn't have "bubbles" or uneveness. Once the cement dried a bit, I used a router with a special metal cutting trim bit to cut off the excess aluminum. Again, when cutting metal, go very slow and add lubricant such as WD-40. It pays to buy a quality metal-cutting router bit. Lastly, PLEASE wear safety goggles. You'll have little metal fragments spinning off and flying very quickly through the air.
Once the aluminum sidewalls were trimmed to size, you can apply the roof. The top pieces of aluminum skin were glued and strapped to the camper to press them onto the hard shell. Next we had to cut all of the aluminum trim and moulding that act as the seams and edges of the aluminum skin.
Step 7: Installing Doors, Windows and Components
This part was (for me at least) very quick. At this point, you should have all of the holes for your components already cut out. After applying to aluminum skins, you might have to use the aluminum router trim bits to cut holes in the metal for your fan, window, etc. but you should be ready to go. Many people build their own doors and components. I've heard that it can be a pain and introduce problems, such as leaking. The door that I purchased was ungodly expensive, but it was also very high quality. When it shut, it felt like you were shutting the hatch to a space capsule. The locking mechanism was also very high quality. My recommendation would be to pony up for the door, even though it is expensive.
If you're like me and you have custom pre-made components, then all you have to do is apply butyl tape around the edges of all of the components before installation and snap them into place. When you push the components in, you can use a utility blade to slice off the excess butyl tape, so it's all nice and flush. Then you can pre-drill several holes for the screws, insert screws and you should be good to go.
If you apply components from vintage technologies, they're often made so that you can weave in a rubber seal along the edging, which can hide the screws. I installed the following components:
- Side window
- Star gazer window
- Fantastic Fan
- External RV shower
- Rain gutters for both door and window
- External 20 amp electrical outlet
Step 8: Electrical and Solar
There's no easy way to do the electrical. If you're not already a pro, it requires some willingness to learn and experiment. There are blogs that can help you along (blog example 2), but it just takes patience. I used a common power distribution unit for campers--the PD4045 (link below). It can hook up to both shore and solar power, and run both DC and AC lines. Most camper components are 12 volt DC, including the solar panels which charge the batteries. To make your life easier, you might just want to run all 12 volt DC, but install a cigarette lighter type outlet onto which you can hook up a DC to AC converter. I received a ton of help from some electrical engineers at the local Makerspace. If you're not confident with electrical, you might consider outsourcing this part OR buying a case of beer for someone who knows a lot about electrical systems in exchange for their help or sign-off on your design. I'm not going to lie, I got lucky because in addition to those electrical engineers at the Makerspace, I regularly interacted with professional datacenter electrical engineers in my line of work. Not only did they contribute spare components, but they also helped me design it.
Here are some guidelines:
- Use the appropriate guage wiring with a large margin of safety
- When in doubt, consult someone who knows a lot more than you
I installed the following electrical components:
- Progressive Dynamics PD 4045 KV 45 Amp Distribution Panel
- Renogy 100 Watt Solar Panel
- EverStart 114 Amp Hour Premium FLA Deep Cycle Battery
3/4 inch electrical conduit
Red Cover Rocket Toggle Switches (5PK)
- Dual USB Charging Socket
- Lumitronics LED RC Exterior Porch Light
- Gold Stars LED Dome Light Fixture
- Dual USB Charging Socket and DC Volt Meter
- Acegoo LED Gooseneck Reading Light
- 12V14 Guage Copper Strand Wiring
- TA10 12 Volt Receptacle
- TA02 120 Volt 15 amp male receptacle
- Siemens Q1515 Double 15 amp Breaker
- TYPE QTSiemens Q 130 30 Amp Breaker
- 12 Terminal Bus Bar
- Standard Fuse 100 piece Variety Pack
- Siemens 20 Amp Circuit Breaker
- Electrical Terminal Variety Kit
- 8 Guage Stranded Copper Wire
- Inline Fuse Holder With Cover
- Power Disconnect Switch (EPO) 300 Amp
- Amarine 12V Water pump 35 PSI/1.1 GPM
Step 9: Plumbing & Finishing Details
We kept the plumbing very basic: we have a 7 gallon water tank that sits in the back. A tube drops into the water tank. The tube is connected to a 12 volt pump, which sucks water up and provides just enough pressure to keep the water flowing to the sink and shower. All the little tubes and plastic plumbing parts ended being oddly expensive. To be honest, when we were at camp spots, we rarely used the plumbing. It was just easier to remove the water tank and put it on picnic table and use water straight from the tank.
The finishing steps are not fun to write about or do. Pretty much for us, it involved sanding a lot of wood, applying polyurethane, polish, sealants, etc. We also custom fabricated some aluminum fixtures and 3D printed some custom parts (including little teardrop key chains for the keys).
Second Prize in the
Tiny Home Contest