Thursday, January 28, 2016

The Roof Top Tent

The Build

I decided one afternoon just before finals week that I wanted to build a roof top tent for my car. This was going to be used on an upcoming road trip. My initial thought was that I could do it all for under $100. I didn't realize how intense the project would get with only 8 days to complete it. Luckily my friend Luke was willing to endure some long hours both in the shop making the hinges and in the garage sewing. We built the entire thing from scratch. Scrap metal and a little time in the machine shop produced a pair of hinges (the second iteration will be better). A 4' by 8' piece of plywood was the starting point for the base. The hardware came from Home Depot. The tent material I got from ripstopbytheroll.com. All of this was done for under $100. The padding sent me over budget by about $70. I bought a couple of mattress toppers from Target. Still, the project was done for about $725 less than a new RTT would cost for my car. And that's the cheap model! I have a few pictures from the build, the materials, and the different sites I stayed at on my trip between Boulder, CO to La Habra, CA.

SolidWorks 3D Model
This was kind of an unnecessary step but I figured I would do it just to prove the concept to myself. 

The Materials
I basically did the majority of the building in Home Depot. I bought the 4' by 8' piece of wood and had them cut it in half for me there. The conduit I bought in 10' sections. Since I didn't want to spend $50 or so on a conduit bender and another $10 on a hacksaw, I borrowed both of those tools from the tool rental in Home Depot. I measured, cut, and bent all of the pieces in the isles of Home Depot--wasn't sure I was going to get away with that all! I am currently looking for a better picture of the hinges (I will update as I find more). 

Tent Frame Folded
This is a picture of it after assembly. The hardware was purchased from Home Depot. I used 3/4" x 2.5" bolts for most of the frame. I added a washer on each side. 

Tent frame unfolded and bare
Frame shaping and paracord addition

I cut a 2' by 20" channel out of the foot area. This allowed for a space to climb up into the tent while leaving a foot print of 4' by just over 6'3" for sleeping. This was perfect for my 6'2" self. I also rounded the edges of the plywood with a router (not pictured). This ensures that the fabric doesn't tear at the attachment points. The paracord was used to hold the angles of the conduit frame as it opened. This served as a fabric support as well as a non-intentional method for folding the tent up!

Practice Piece
This is the beginning of the sewing. To start, I taught myself how to sew--a frustrating process I might add. Once I got the hang of it though it became sort of fun. The seam I used is called a flat felled seam. I used an instructables to get me through it (http://www.instructables.com/id/Flat-felled-Seam-and-2-alternatives/). I used this seam because I read a blog somewhere about the parachute industry using it. Its a very strong seam. It also said that ripstop is strongest with 4-11 stitches per inch. I probably would explore other seam options if I were to do this again. Maybe even using a different stitch option and sewing just once across each attachment would have been a better option. Everything I read led me to this seam and once I started my perfectionist side kicked in. I could not change the seam!! 

The top, head, and footwalls finished
The top is made of vinyl so I can look at the night sky as I fall asleep (thought my girlfriend would like that). This actually turned out to be pretty nice. The vinyl folded nicely as I sewed the flat felled seam. The nylon to nylon seams proved to be more difficult. 

Tent material just about finished
The nylon webbing that I sewed onto the base in order to attach the material to the frame is not pictured (will update). 

Bare frame mounted no car
Like I said, the hinges were somewhat thrown together. The frame is a little crooked in this picture. The RTT is mounted onto the crossbar rails with U-bolts (pictures to come). The ladder is not pictured here either. 

Final assembly
We attached the material to the frame through the webbing skirt with wood screws and washers (details to come). This was done after the frame was mounted on the car. If I had a little more time I would have used a button system with velcro to close the gaps. That is on the list for improvements.  Little suggestion, do not play your stereo, have your lights on, and your seat warmers on with your car off when it is 8˚ F outside, your battery may die.  

Folded Up and Ready to Drive
For now I am using a tarp to cover the folded tent. It took more than a few stops within the first 100 miles to really get this dialed down. Once we got it though, we nailed it. I had the same tarp on for all 5138 miles driven and there was only one hole which, I was able to fix with duct tape. The tent edge on the drivers side is mounted about 1" to 2" from the edge of my mirror. This allows for about 8" of cross beam support for the cantilevered side. The ladder, the main cantilever support, happened to conveniently fit on the unused 8" of crossbeam when the tent is folded. This saved about two inches off the height of the folded tent--since I didn't have to put the ladder on top of the RTT. The box is about 8" tall and sits 4" off the top of my roof. On the list of improvements is a fairing to deflect the wind over the top of the box. I suspect this will help bring my gas mileage to a more normal reading. 

Build Conclusion and List of Improvements


I learned a lot building this tent. Without the help of my buddy I probably could not have gotten it done in time. I taught myself how to sew, I became more familiar with various wood tools, a mill, a metal grinder, and drill press. This was an amazing project that taught me skills I will use for the rest of my life. I know now too that I can take on most projects. This is one of my first BIG personal projects. I am excited to have created this blog too! I will be posting many more.  

With the time constraint I put on myself, I was not able to add all of the ideas I had for the tent. So, here is the list:

1. First and foremost, I need a better driving cover. It takes about 2 minutes to set up the tent and 10 to 15 to really get the tarp secured on the folded RTT. I have been searching the internet for different materials. I will probably end up using a material very similar to what they use for boat covers. I will add to the blog as I make this. 

2. I could definitely make a better rain fly. Right now I am using a massive tarp and just draping it over the top. This is extremely annoying if there is even the slightest wind. I haven't thought of the best way to make a rain fly. If you have any suggestions, let me know in the comments. 

3. Another sleeping pad is necessary. Right now I have two very cheap 1.5" mattress toppers that I cut to size and put on top of one another. Just one more of these would drastically improve the quality of sleep. 

4. I would like to weather proof the base. I plan on disassembling, sanding, and staining the entire base. 

5. Add a fairing to deflect wind over the top of the tent. This should increase gas mileage. 

6. As for the hinges, those could use a second iteration. We definitely eye balled the hinges while we were making them. Though they work great, why not make new ones if I can find the time. 

That is just me being nit picky though. The tent worked absolutely flawlessly. I could not have asked for a better building process. So, again, thank you too everyone who had even the smallest hand in helping me build my RTT. 



The Trip: Boulder, CO to La Habra, CA


Limekiln State Park, Big Sur, CA
Watch the time lapse of the first set up here https://youtu.be/VTYLzxI9WHg. The first night we stayed in the tent was in Limekiln State Park. I saw this park the summer before and new that I wanted to come back. When we decided to do this trip I called and reserved the exact site I wanted. It overlooked the cove to the west and the rest of the campground to the east. It was awesome to say the least. The tent worked flawlessly. After a few beers and a great dinner we crawled up into the turtle shell and got a good nights rest. It was this night I realized that one more sleeping pad needed to be added to the list of improvements. Might as well be as comfortable as possible if I'm going to go through the time to build a tent to put on top of my car. 

Refugio State Beach, Santa Barbara, CA
The second day was a slow day. We woke up late, drove slow, stopped for cookies in Cayucos, and made our way to Refugio. This campsite is one I have been visiting since I was a kid. I basically learned how to surf on the point here. I have spent countless 8 hour sessions out there only stopping to get water and food. Unfortunately, no surfing was done while we were here. Not to say the walk on the beach wasn't a perfect sunset event on its own! This was a great last night on our trip home and we got to log another night in the tent. The road trip home came to an end after a short 4 hour drive home (200 miles seems like nothing when you just drove 1800). I did make a few more trips down south to surf and set up the tent while I was home though!! 

San Elijo State Beach, Cardiff, CA
Of those trips while I was home was this one to San Elijo State Beach. This is a picture from an afternoon I spent driving down the coast and surfing. I surfed Uppers for dawn patrol with five other guys out for about an hour and a half. I leisurely made my way to Cardiff and surfed all afternoon. After I set up the tent I figured I would hang the hammock too. I laid there and read for a few hours till a few friends of mine drove down to catch up, have a few beers, and hangout by the fire. We woke up early and surfed Blacks at 3-5 ft with fair to good conditions. Overall, a great little trip while I was home.

This also served as a light wind test for the tent. The wind was rolling up the cliff at about 15 mph. The tent seemed absolutely sound!!

The End


Our road trip was amazing! The trip would have been great without the tent but damn it was an awesome addition. There is nothing like transporting yourself across the country, drinking a few beers each night, and sleeping under the rain (well maybe the stars would have been better). I couldn't have asked for a better trip home or a better co-pilot. Although, I think co-pilots are supposed to help fly the plane (:

The Updates/Improvements:


There are updates on the way! Check back to see what I continue to change in an effort to make the ultimate DIY Roof Top Tent!