Foundations.

When I first approached this project I had ZERO idea where to start. This is likely why it appealed so much to me. It's like legos for adults without instructions!  If you take a bit to link around the net and research other peoples methods for trailer design/ fab, you will find many contradicting opinions. "Only build it on a stock trailer!" "Build it custom, but light and flexible like an RV." "Only use rectangular tube, NO angle iron!"

So, 
with a dizzying number of factors to weigh, I started by asking "What do I actually want it to do?". 

1. I want to have a solid tolerance in axle capacity above my expected load weight, so as not to risk a failure. 
2.  I want to set the walls as far apart as possible while maintaining the maximum legal width 8'6".  
3.  I want to the design to allow me to use fewer materials, and attach the walls easily. 

After hours online fiddling with modifications to standard trailer specs, sitting down with 2 trailer distributors, and 3 fabricators, I have come to this list of pros and cons:

Stock Trailer

Pros: 

1. Less design work!
2. Cheaper!

Cons:

1.  They are not designed for Tiny Houses. Dependent on what type of trailer you buy, many are made to support the majority of a load in the center middle, unlike the weight distribution of walls around the perimeter. 
2. Extra cost to modify. In order to avoid drilling into your frame and weakening the structure of the trailer, you'd need to weld sacrificial metal to drill through and attach to. This cost of modification can bring your total near the cost of having a trailer purpose built. 

Custom Trailer

Pros:

1. Design exactly what you need! No need to round up to a 24' or down to 16' trailer when you want 20'.  Place extra cross members where you need support for walls. Pop the width out from 8' (as most stock trailers are) to 8'6". When you are fighting for inches of interior space this counts. A lot.
2. It's more Awesome! Be honest, design work isn't actually "work" anyway.

Cons:

1. It is more expensive. Though, when you are building a Home, the foundation is a fine place to invest.
2. You are responsible for the design. If you ask a fabricator to build to spec and it fails, its on you. So, just go buy doughnuts for some engineering students and ask for their help!

A custom trailer it is!!

Here she is folks, all shiny and new!

Out of the 3 fabricators I spoke with, I chose to work with Seth Vincent at Great Northern Trailer Works. 

1350 South Calapooia Street

Sutherlin, OR 97479

(541) 459-6214

gntrailers.com‎

These guys did phenomenal work. We sat down with my reference images for the upper deck of the trailer(below), and talked out the function of design. Seth gave me some great feedback in strengthening the framing around the axles, filled in the blanks for the tongue, hitch, axles, brakes and lights. Everything was completed on time and to spec. It was a great feeling towing home a shiny powder coated trailer I designed. I could not be happier with them. Check em out!

Here are the specs:

- Bed length 25’
- Bed width 8’6”
-Deck height  2’ 7”
-Cross-member(s) Height (recessed 1.5” below Deck height): 2’ 5.5”
-Wheel well protrudes 3” vertically above Deck.
-Outer frame: 4”x6”rec tube
-H frame: 3”x8” Channel
-Cross members: 4”x4” Angle
-Cross members 3”x1.5” Channel
-Wheel Well Material: ¼” steel plate



 
Other Components: -2(two): 7K Electric Braking Axels
-4(Four) ST/235/80 16” Tires & wheels
-7000Lb tongue jack
-5 position 2-5/16” Coupler
-Black Paint

Below are my original SketchUp designs.

Top View

Perspective

Wheel well detail

Components

 
I'll be putting up some better detail photos of the trailer in the next few days, when we get some good picture takin' weather.

**Update**

This week I bought my very awesome, very shiny miter saw off Craigslist and finally am ready to buy framing lumber! Pics to come!
 

Best,

J