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Mega Slideout Transforms Tiny House Into BIG Tiny House!

Mega Slideout Transforms Tiny House Into BIG Tiny House!

7/29/14 (7 years ago)

Mega Slideout Transforms Tiny House Into BIG Tiny House!

We liked the idea of living in a tiny house, but all of the towable tiny house plans we saw were too tiny for us. When we checked out trailers at an RV show, we noticed that slideouts added a lot of space. Even a 2 foot slideout made the space seem much larger. So, why not make a tiny house with a slideout?

After kicking around several scenarios, we decided that one big slideout would be easier to build than several smaller slideouts. The trick was designing a floor plan that would have rooms that would work with the slideout. We finally arrived at a plan for the slideout to contain the bedroom toward the rear and a living room at the front, with a wall that would serve as an office dividing them. A fixed bathroom would be at the rear and kitchen in the front that shared the living room space. This ended up being very convenient, since all the wiring and plumbing would be on the non-slideout side. Now we needed to come up with a slideout mechanism.

We studied slideouts on trailers and RVs, but they all extended straight out about 2 feet, and the floor of the slideout was offset higher than the main floor. We wanted about 5 feet of slideout and a completely flat floor. So, that meant that the slideout needed to extend out and then down to sit flush with the floor. After a lot of brainstorming and consulting with our resident retired mechanical genius, we can up with 3 booms with ball bearings that would ride on tracks inside a box mounted within cross tubes on the trailer frame. The bearing tracks would go straight out and then slope down at the end. We built a prototype with some scrap metal. That checked out, so we created a 3D drawing in Google Sketchup, which let us see it from all angles, animated the slideout in and out, and print dimensional plans and cut sheets.

Next, we constructed the boxes that would serve as the bearing tracks. We cut sheets of flat steel and welded them into boxes. It was really tough to make sure all the boxes were uniformly sized and square. Since they each had their own unique "personality," we named them Huey, Dewey, and Louie. Once we had boxes, we needed to cut the tracks out of the sidewalls. We printed out actual size templates from Sketchup and used them to cut templates out of 1/4" plywood using a band saw. We fine-tuned the wood guides the a disc sander and then used them as guides to plasma cut the tracks. Then began the grinding... endless grinding to shape and smooth the bearing tracks. We had to insert the boxes into the receiver tubes in the trailer frame every once in a while to make sure they would fit.

The other half of the slideout mechanism is the boom. We used thick steel tube and cut notches for the bearing mounts. After a lot of testing and fine tuning (and completely rebuilding Huey's box) they all fit in the frame and slid out and down.

After several days of searching the Web and calling manufacturers, we finally found reasonably priced, appropriately sized, right-angle gearboxes. While we were waiting for them to arrive, we started working on the lead screws. We made a collar for the end of each lead screw that would spin between two thrust plates. When the screw rotates through a nut attached to the boom, it pushed or pulls the boom. The gearbox attaches to the collar and turns the screw. And a round shaft connects all 3 gearboxes. A section of shaft sticks out the back bumper for a manual crank attachment. All of this was made to bolt in the frame so it could be removed for repairs. After our test assembly checked was working (using an electric hand drill for power), we plasma cut holes in the trailer frame and installed everything in the trailer. Spray grease on the screws and the sides of the box really helped it move easier. We also made cover plates to protect the mechanism from dust and weather. The last step was to weld a 24' long tube to connect all three booms and then weld angle iron risers on each boom to support the subfloor.

Since the slideout was a deal-breaker for our project, we were prepared to walk away if we could not make it work. So, we held our breath as we tested the completed slideout for the first time. And it worked! We were extremely relieved. Our big tiny house dreams were going to be a reality.


  • Flat steel for boxes
  • Thick steel tube for booms
  • Large steel tube for slideout frame
  • Angle iron for subfloor supports
  • 1" round tube for drive shafts
  • Misc. metal for thrust plate assembly
  • Bearings
  • (3) lead screws
  • (3) nuts for lead screws
  • Washers for screw collar
  • Right-angle gearboxes
  • Electric motor
  • 1/4" bolts and nuts
  • Thread lock


  • Metal band saw
  • Stick welder
  • Table saw for cutting wood guides for plasma cutter
  • Band saw for cutting wood guides for plasma cutter
  • Disc sander for fine-tuning wood guides for plasma cutter
  • Plasma cutter
  • Several hand grinders for grinding bearing tracks smooth
  • Drill press and hand drills
  • Metal lathe for milling custom lead screw fittings
  • Die grinder for hard-to-reach spots
  • Tape measure
  • Squares
  • Metal files
  • Tap & die for threading bolt holes
  • Hammers
  • Punches
  • Clamps
  • End wrenches
  • Screwdrivers
  • Spray paint

Make your tiny house a BIG tiny house with our plans!


  • Slideout "in" position Slideout "in" position
  • Slideout fully extended Slideout fully extended
  • Slideout gearbox, thrust plate, lead screw, and track box assembly Slideout gearbox, thrust plate, lead screw, and track box assembly