My wife runs a small bakery here in Central MA called Brynne's Bread (www.brynnesbread.com) and for the past eight years she has loaded up the back of the truck with tents, tables, crates, shelves, and other wares to display and protect her products at festivals and farmer's markets. Suffice to say the loading, unloading, loading again, and unloading again gets tiresome and also burns a lot of hours. We wanted something that could roll up to the market spot, open up and be ready in minutes. We kicked around numerous ideas of speeding up this process while creating a unique marketable image. We looked at trailers but were once again using our family vehicle to move it around. We tried looking at antique trucks but found that their size and overall reliability were going to be a hinderance. We needed something small, cost-efficient, unique, and attractive... cue the mini-truck. With this Instructable I am going to show you how to make a micro market truck that can be used for a myriad of purposes. We purchased a 1990 Subaru Sambar as the base of our micro market truck. These little trucks come right over from Japan, so they are right-hand drive. They are also classified as kei trucks in Japan, so they are small (ours is only about 10' long) and have equally small engines (660cc 4 cylinder). But, they are easy to work on, parts are accessible and affordable, and they are a blast to drive... did I mention they are four wheel drive? The bed of the truck is low to the ground (an important part to our display) and the sides and back of the bed fold down.
One of the biggest time gobblers during any unique process is finding inspiration from other folks. I can tell you that it took quite some time to narrow down our search to this unique machine and to design what the rear bed was ultimately to look like. I found a lot of inspiration and help from Daphne's Caravans, and after reaching out to Daphne for some advice I was well on my way to designing the truck. All told the entire thing cost about $6,500 (that includes the truck), but I am sure that you could design a similar structure for another similar flatbed truck.
Step 1: List of Materials
1990 Subaru Sambar
1-1/2" outdoor screws
Simpson Strong-Tie right angle connectors
1-1/2" washer head screws
3" outdoor screws
Beams / Rafters:
3" outdoor screws
Siding and Doors / Awnings:
1-1/2" outdoor screws
Roof Sheathing, Waterproofing, and Covering:
1/4" flooring underlayment (easy to bend around curved roof)
Grace Ice and Water Shield self-adhering membrane
Hinges, Hardware, and Gas Struts:
20# Gas Struts (These did not work, but they are still a good source)
Toggle clamps (to hold the side doors tight while driving)
Step 2: Get Yourself a Mini-truck
We found our mini-truck on good ole Craigslist from a guy who was working with a friend on importing them to the states. We ended up paying $5,500 for the truck and it was already registered in VT. The truck had no visible rust, a solid motor with only 31,000 Km on it, and a really clean interior. We have a friend who is an auto body mechanic who is going to help us tidy up some of the rust and add a nifty stripe along the side of the truck that matches the metal roof on the back wagon. Otherwise all I had to do was change the filters (oil, air, gas) and replace the four wheel drive solenoid and vacuum lines (super easy fix). All of our parts came from G&R Imports and they have been great to work with. We opted for the Subaru Sambar since we currently own a Subaru and are very happy with the quality, also the Sambar is one of the only mini-trucks with a 4 cylinder engine. The thing is no speed demon, but it will run well at 50+ mph and even up to 65 mph for a while. That is impressive since it basically has a motorcycle engine in it with 4x4!
Step 3: Design and Scale the Rear Display
Before we threw down the cash and drove the mini truck 2 hours home I decided to draw up some scale models of the truck along with the wagon on the back to see if all of the pieces fit together. I did the drawings in a 1:10 scale so that I could easily scale up the parts when I needed to get my orders together. This allowed us to visualize how the entire set up would appear and to determine what trouble spots we might run into. The sides of the wagon were to be large doors that open with strap hinges and gas pistons (also called gas springs or struts) to act as an awning for patrons and my wife. The back doors are also on strap hinges and open outwards with added display space on the backs of the door. We were determined to make a clear, open display that would allow plenty of light in and the design I drew seemed to fit the bill pretty darn well.
Step 4: Making the Frame / Foundation
The entire structure is designed so that it can easily be removed if ever needed. To accommodate a design as such I needed a foundation that was rigid and easy to remove from the bed of the truck. I used half-lap joints, screws, and wood glue to build the frame so that it fit with only 1/4" of space between its most outside edge and the bed of the truck (to accommodate hardware and screws for the posts). The frame was made of 2x6 stock so that we can use the "meat" of the wood to add on additional displays and for overall rigidity.
Step 5: Posts
The posts were simply made of 2x4 stock to minimize weight. They were notched out to fit over the rails of the bed so that the door/awnings would go over the sides of the bed to help shed water. I had to notch them out by about 1-1/2" leaving 2" of stock to attach to the frame. Since this was a smaller amount of stock than I was comfortable with I decided to use some right angle connectors from Simpson Strong-Tie. I made the posts 60" tall so that the roof of the structure would be high enough to clear anyone 7' tall or less (that would be 60" plus the height of the bed of the truck from the ground). Before I attached the posts I had to remove the rear tailgate support chain hardware, which will be reaffixed to the structure. Make sure the posts are level to the bed of the truck, unless you have your truck on completely level ground (which mine was not).
Step 6: Beams / Rafters
The roof of the truck was to be curved, similar to that of a gypsy wagon. After kicking around a million different ideas (at least it felt that way) I decided on a more simplistic approach in lieu of the curved rafters I had originally intended (you can see them poking out in the drawings). Daphne's caravans have a reoccurring theme with the way she uses beams parallel to the length of the structure. She tapers the top edge of the rafter to meet the curve of the roof and all of her caravans look fantastic and hold up to the test of time... so that is the direction I decided to move towards. The most outside rafter was tapered at 20 degrees, the top most rafter had a taper of 0 degrees and the two on either side of the middle one had a taper of 15 degrees. I cut all of the tapers on a table saw. The back of the structure has an overhang of about 18" and the front has a small overhang of 4". Once again, be certain that everything is square and level to the bed of the truck before screwing it all together. I used 3" outdoor rated screws to assemble the two side beams. Before moving on I used joining joists to pull the structure together and prepare for the next step. You will see how the middle beams are assembled in the next step.
Step 7: More Beams and a Bit of Siding
To side the structure I used 1x10 barn siding from a local white pine sawmill. This stuff is lightweight, easy to work with, weathers beautifully, and looks fantastic. It is about 1/2 the weight of plywood, which is kind of important for a little truck like this with a load capacity of 350Kg. Before working with the other beams I sided the side closest to the cab of the truck and then marked off where the arch would be for the roof along with the three notches cut out of the siding for the beams to pass through (both on the front and back of the structure). The beams are supported by a notched piece of wood that is 4" wide. The notch straddles the cross joists placed in the previous step and help support the roof. Note that this is a tiny roof overall, only 5' wide and 8' long. If you were planning on making this much larger I would suggest a more substantial framework to hold up the beams. Once again, the top beam was not tapered at all while the ones to the left and right are tapered 15 degrees to fit the curve of the roof. I marked out the curve with a flexible strip of ash and then cut both the front and rear in unison to match them up.
Step 8: The Roof and Additional Support
I used 1/4" floor underlayment for the roof as a base and screwed it down using 1-1/2" washer head screws to prevent it from lifting up at all. I ended up having to get a couple of sheets of the underlayment since the arch of my roof was about 60" in total and the entire roof was 8' long. After cutting the plywood with a circular saw to size I squared it up on the roof and simply screwed it down. To screw it down I started on one side and placed a screw at the center of the sheet of plywood on the very center of the outside beam. I then made sure it was all squared up and bent the other side over to the opposing beam and screwed that down. I used about five screws per beam evenly spread out (that is for a 4' wide section of roofing, I had to use two of those to span the entire length). After getting the plywood affixed I decided to put the corner braces in. Since this structure does not have walls along its length there is a substantial amount of torsional rigidity lost without the shiplap siding a gypsy caravan would have. This structure will have large doors on hinges, so I needed to bulk up the rigidity of the structure by using some simple braces. I used 18" braces near the top corners and small 9" braces near the bottom to maximize the amount of display room. They were all predrilled and screwed into place with 3" PT screws. After doing this the structure became extremely rigid.
Step 9: Seal It Up!
After the underlayment was affixed and the braces in place I decided to seal the roof with Grace Ice and Water Shield. We are having a bit of a cold November (probably noticed the snow in the pics) so the "self adhering" component of the ice and water shield wasn't working so well. I know you are supposed to put this stuff on when it is at least 40 degrees but the way this winter is looking that might be tough from this point onwards. I ended up cutting the ice and water shield to size (plus an inch or two over to overlap the side of the beam to make it very sealed... it will be covered by trim later on). Then I put it into place and stapled the very bottom edges to hold it in place for the next step. Using a heat gun I carefully heated up the membrane so that it would adhere to the wood. Once I get the metal roof on top of it and let the sun heat that up the whole thing will adhere quite well, this was just so that it was water tight for now while I work on the next steps. The nice part about working with Grace Ice and Water Shield during this time of the year is that it does not stick to itself which is a total pain and can ruin a nice long sheet of the stuff. You can see how I overlapped the pieces and made sure it was all squared up. The stuff I used was shipped to me for free from the big orange box. It was nearly half the price of most of the other stuff but wasn't stocked. I ended up paying $70 for 195 sq ft and will use the remaining for a future project.
Step 10: Add the Side Doors
I used the same 1x10" shiplap siding for both the side flap doors and back barn doors. The hinges are Acorn brand 13" forged iron ordered from Hardware Source (see the link in the materials section). The doors were simple enough to make. For the flap doors cut the shiplap to length and use three cross brace boards on the back with washer head screws to put them together (the screw head on bugle-head screws will pull through over time, so user washer-headed screws). I also put two trim pieces on the outside face of the boards along the edges. This not only made the entire thing more rigid, but also cleaned up the end grain a bit. You will see that the rear braces do not go the entire way down the door since I need the door to close flush onto the side of the bed and to properly overlap the bed so that water will not enter the structure. I put a piece of trim on the body of the structure near the cab to cover up the end grain of the front boards and the end grain of the side doors. I ended up making the trim so that it was rabbeted (essentially a groove along the edge so that it would sit flush on the far end of the structure and cover the end grain neatly). You can see the trim in place with the last picture.s
Step 11: Add the Rear Doors
The rear doors are just as simple as the side doors. I ended up having the doors come straight down to the top of the rear bed. I had to first put trim pieces on the rear posts to both cover up the end grain of the side doors and trim up the rear section neatly. The doors are made of vertical shiplap with two cross braces per door at the top and bottom of each. These cross braces coupled with the strap hinges added plenty of rigidity. The doors were 44" tall by ~26" wide. I cut off one of the shiplaps on the hinge side and then kept the shiplap on the opposite side to act as a junction for the two doors to meet. I also placed a small piece of wood at the center of the top trim to act as a stop for the doors. There will be a more elaborate latch put into place later on down the road. Make sure that the doors clear the tailgate so that the tailgate can drop down without interference.
Step 12: Stepping Back and Thinking a Bit
I ended up picking out 20# gas struts to be used for the two side doors. After doing a bit of research I found that a number of sources suggested sizing the struts so that their capacity was just a bit less than the door's mass. Of course there are a heap of other considerations to take into account including the door length and depth. This way you can determine the total amount of force necessary to both help lift and hold the door in place. Suffice to say that my initial purchase didn't fit the bill and the gas struts were grossly undersized even though the door weighed approximately 50 pounds. Also, the stroke was way too short and the initial 50 pound door had to be lifted for quite a ways until the gas springs started with the assist. I am 6'4" so it is no problem at all, but my wife is a foot shorter. I found another company that supplies more substantial gas struts with a 16" stroke and 34" total length. I am in the process of contacting the company and seeing if they have any insight into the matter. It's a bit too cold to work on it anyhow (5 degrees this morning 11/23/18) so I am going to have to wait until it gets a bit warmer to put the metal roof on and put the gas struts in. It wont' be stained until spring of 2019 and once the stain is dried I will paint my wife's logo on both of the side doors and something on the front and back. All of these photos will be added as time goes on but I figured I would publish this now to give anyone interested some good starting information.
Step 13: Finding Time to Put on the Metal Roof
I decided to put the metal roof on in between the short time I get home from work and darkness (4pm during this time of the year). I ended up using what is called coil metal roofing that I ordered from my local farmers co-op. The roofing comes painted and in various widths (I ordered 42") and I ordered the color matched rubber washer screws to affix it to the top. It cuts easily enough with a sharp set of tin shears since the roofing is only 29 gauge. When I ordered the roofing I had to choose between a 15' roll or a 30' roll. I needed only about 17' of the material so I had to commit to a 30' roll... not a big deal since I am sure I will put the other material to good use in the future. After cutting the sheets to size I cut the rounded corners on the two rear corners and two front corners. I also had to cut the front sheet's width down to 22" so I wouldn't have a ridiculous overlap. Most important thing to remember is to always start by affixing the rear-most sheet first and then progressively overlap the sheets moving to the front. This will prevent driving rain from going into the joint and prevent the moving air from lifting up the roof. I used screws along the outside edges only spaced about every 6" and then across the front edges of the beams. This should be completely fine and gives a cleaner look while preventing having more holes than necessary in your roof.
Step 14: Additional Hardware
I used a few different types of hardware to keep the doors held tight in place while traveling. For the side doors I used toggle-like, cam-action clamps that supposedly have 220# holding force. The actual toggle gets attached to one side (either the door or the structure itself) and then its mating hook gets attached to the opposing side. In my case I had to attach the toggle closest to the cab to the actual structure and the hook to the door and for the back one I had to attach the toggle to the door and the hook to the structure (see the pics for more detail). Basically you need to tinker around to get these to work well for your application. I had to add small blocks of wood to the structure to bring everything along the same plane.
As for the back doors, I used a fixed bolt to hold one door in place. This allows you to use a barrel bolt across both doors to hold them tight. I ended up ordering a fixed bolt that you are supposed to mortise into a door by accident, but it still mounts nicely and looks good enough. You can also use what is called a chain bolt, which would work just as well. Finally, I attached the barrel bolt and made sure everything was in working order.
Step 15: Adding Some Trim
I added trim along side the eve of the roof using 2x4 stock that was cut to width (2-1/2") and then ripped at 30 degrees to leave a tapered side, almost like simple crown moulding. This neatly covered up the grace ice and water shield that purposefully extended past the roofline and neatly finished it all off. To cover up the ends of the beams I used a curved moulding I made out of 5-1/2" wide s4s pine. Using the piece of pine I originally cut for the arch of the exterior siding as a template I marked off the proper ellipse on the trim board and then cut it on the bandsaw. I used two separate pieces of trim for both the front and back, joining them at the middle of the center beam. I taped both pieces together and used a drum sander to both finish sand them and bring them to the same final shape.
Step 16: Gas Struts to Hold Open the Side Doors
I will update some additional photos later on since I did this in the dark... December 21st is coming soon!
This was my third set of gas struts (also called gas springs) and they finally fit the bill. The first set were too short and did not have enough force to even assist in opening the doors. They were 20 pound struts and I decided to use two per door. The next set were 50 pound struts that were a total of 28" long. These were the correct length and after a fair amount of trial and error I was able to get the doors to open to about 100 degrees and close flush with the bed of the truck. The only problem was that they only held the door up a bit and then the door slowly came down to about 70 degrees... not so safe for the patrons and kind of defeats the purpose of the display. Back into the box they went and I ordered four new 90 pound struts that were 28" long. These did the trick and the door opens nicely from 0 degrees up to 100 degrees with no problem at all and then they hold right in place. My doors were six feet long and four feet deep and I placed the upper gas strut support 8" away from the hinge joint on the door and 22" down from the hinge on the frame of the structure. This allowed the door to close flush but open to 100 degrees easily. I will be honest and say that it took some trial and error but once it was done it was like a magic trick. I put the piston chamber at the top with the proper connector and the piston end facing down towards the structure itself. My door was about 50 pounds total in mass so the applied force of the two 90 pound struts exerted 8" from the hinge joint is plenty to hold the door open and requires only a fair amount of energy to pull it back down to the closed position. The video I posted shows how it opens and closes. Pretty nifty, right?
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