Overlanding Rig - Panda

Sleeper Platform

Camping is a crucial part of overlanding. If you're going to be out in the wilderness for multiple days, you're going to need somewhere to stay. I'm not a big fan of tent camping, but sleeping in the car seemed like an attractive alternative. Hence, the sleeper platform build was initiated. Being able to use the middle row of seats while carrying the platform was critical to me. That meant it needed to fold or stow away in the trunk when not in use. 

The design concepting progressed from physical sketches to digital sketches and finally to 3D modeling. As a fan of 4-bar linkages, I knew that this would be a good application - especially given the requirement that this needed to fold into the trunk space behind the middle row of seats. There's little space to have a platform that has a single hinge and folds back on top of itself, so a 4-bar would be perfect to bring half the platform back into the trunk. 

I began building a physical prototype out of foam core. The interior of the 4Runner isn't level or coplanar all around, so I needed to create profiles for the platform supports. The height of the rear-most vertical is dictated by keeping the top of the platform level from the highest point in the rear of Panda - which in this case was the top of the "fold flat" middle row of seats. 

The foam-core prototype functions! Two four bar linkages and the front half of the platform can fold back onto the back half. 

Here's the prototype set up in the back of the car. It fits quite nicely! The mechanism actuation isn't smooth due to the nature of foam-core mockups, but it demonstrates that the design can work.

Began cutting the pieces out of plywood. The twin rear double-stack assemblies (per module) are critical since they house the 4 bar linkage. 

Completed the rear module sides and front supports. Finally cut the platform tops to bridge everything. Starting to look like a cohesive platform! There's even room underneath for storage. 

Cut some profiles to go around different features on the back of the middle row of seats. 

Making aluminum links for the 4 bar linkage system.

Each of the links has an aluminum shaft press-fit on one side and a threaded rod assembled to the other side. 

Aluminum linkages assembled into the rear double-stack assembly.

Carpeted the tops of the platform. Since this is going to be my bed while camping, I wanted to soften the user-facing surfaces (similar to the carpet you'd find in the vehicle itself). I went with carpet that is typically used for vehicle acoustic applications.

Acquired some sofa cushion foam to use as my mattress. It needed to be trimmed to size so it would lay flat and cover as much of the sleeper platform as possible.

I have experience with a sewing machine so I decided to sew my own microfiber cover. It was the largest piece I had ever attempted to seamster, so it took some effort to successfully finish. The end result is snug over the foam and comfortable!

Sleeper platform in action!