Honda Fit Camper Unit

Documents a camper unit I made for a friend. It is for a Honda Fit. Has a sleeping platform in the back with storage below. Also has a pull-out table in the back.

Materials

• One sheet (4 x 8) of 5/8" MDO (medium density overlay) Plywood (could use sanded A/C)
• Three 10ft pieces of 1 x 12 Pine (actually any species will work)
• One 8' 2 x 4 Cedar (actually any species will work)
• 9 x 2 1/4 exterior wood screws (for attaching the 2 x 4 table support

Tools

• Table Saw (for ripping MDO, cutting triangular supports, trimming the deck during fitting and rabbeting the 2 x 4 for the table support)
• Rail Saw (for cutting the MDO into manageable pieces)
• Chop Saw (for cutting 2 x 4 and 1 x 12)
• Router (for rounding all the edges and routing the slots in the alignment strips)
• Sandpaper (for rounding the edges that cannot be reached with the router)
• Ratchet Gun (driving the screws, though you can do it by hand with a screw driver)

A friend asked me to make a camper unit similar to one my daughter built for her Fit. It is a bed platform and storage underneath. The unit fits in the back of a Honda Fit when the rear seats are folded down. I use MDO plywood for the deck, 1 x stock for the support structure and index strips, and 2 x 4 for table support.. The rear compartment of the Fit is not completely flat so I include leveling shims to level the unit.

My daughter built a camper unit for her Fit, but then sold it, so I made this redesign. Review of the internet turned up the following web sites that gave me some ideas. I copied the idea of a slide out table from the last link. Fitfreak is a website dedicated to the Honda Fit.

https://militarydollar.com/2019/02/13/honda-fit-ca...

https://www.fitfreak.net/forums/general-fit-talk/9...

https://www.fitfreak.net/forums/general-fit-talk/9...

I wanted to make the unit to be easily assembled without bolt or screws. Wanted to have the individual pieces to be light enough to easily be lifted by a small person and wanted to avoid the use of hinges. To provide the longest platform and allow the front seats to be pushed back to their extent and allow the driver to recline the back, use of hinges were required. The piano hinges allow for a cantilevered 13". When disassembled the entire unit is small enough to store in a small closet.

Each model and year may have different dimension so measure the car that the unit intends to fit. Measure the length and the width. Be aware of the discontinuities. Determine if you want to be able to slide and lean back the front seats and measure accordingly. There is ~13 inches of difference between the seat forward with the back straight up and the seat all the way back and the seat leaned backward. The forward configuration results in a sleeping platform that is 5' 8" in length whereas the aft configuration results in a sleeping platform that is 4' 7" in length.

You can trim the platform deck with either a table saw, hand saw, circular saw, or rail circular saw. I used a rail circular saw (Makita or Festoon) because I was doing all the work by myself. The rail circular saw makes precision cuts easy with only one person.

The upper and lower surface of the platform deck as shown was the original configuration. Subsequent fitting trimmed the forward and aft ends to fit. The lower surface of the deck includes the indexing cleats.

There are several items in the support structure

• Longerons which run the length on the outsides of the support structure
• Ribs which run between the longerons
• Center-line Intercostal which run between the ribs
• Leveling Shims which raise the lower parts bed of the car to provide a level surface
• Alignment Strips index the longerons, ribs and the center-line intercostal

There is a leveling shim in the front and two in the back.

The front leveling shim is a 39" 1 x 12 pine board.

The aft leveling shims are a combination of a 24" 2 x 4 screwed to a 30" 1 x 4. The shim is placed with the 1 x 4 on top and extending 6 in beyond the 2 x 4 on the forward end.

With the alignment strips installed the longeron is supported by the aft alignment strip and at the aft end of the longeron by the leveling shim.

The alignment strips are 4 1/2" wide (could be wider, seemed like a good width) with ~13/16" wide, 3/8" deep slots routed into one side. The slot width seems a good balance between being too tight or too loose. The slots are used to align the longerons, ribs, and intercostal.

The longerons were initially too long to allow the front seats to be pushed back and reclined. As a result the front and the back ends of the longerons (and the deck) were trimmed and curved to fit the seat and the rear hatch area.

The longerons fit in the slots of the alignment strips. The cleats are loose enough to insert the longerons but tight enough to keep the longerons upright. You shift the longeron and/or alignment strips so the longeron fits into the slot and the alignment cleats on the longeron align with the slot for the ribs.

The forward rib has alignment cleats on the aft side. There are 2 support triangles secured to the fwd side of the fwd rib with piano hinges to support the hinged fwd deck.

Insert rib so the alignment cleats are on the aft side and the folding support triangular on the upper portion of the fwd side.

The center-line intercostal fits between the fwd rib and the aft rib. There are two cleats to support the aft end of the fwd door when the door is opened.

Insert the intercostal with the support cleats toward the rear and on the upper surface. The intercostal should fit in the slots in the alignment strips and into the alignment cleats on the aft surface of the fwd rib.

Caution: The intercostal can be installed in a multitude of ways, the only correct way is as described above.

Note: I chose to install the intercostal before installation of the aft rib because I thought it would be easier. You could try in in reverse order if you like.

The aft rib has a set of alignment cleats into which the aft end of the center-line intercostal fits.

Note: This rib can be installed either edge up as long as the cleats are on the fwd side.

Slip the aft rib into the alignment slots in the longerons and make sure the center-line intercostal is inserted into the alignment cleats on the forward side of the aft rib.

This is the end of the support structure assembly. All that remains is to put on the deck.

The fwd door have three alignment cleats. Two align the longeron and the third cleat help align the center-line intercostal. This third alignment cleat needs to be held back from the area where the center-line intercostal support cleat is located. The third alignment cleat and the inner of the other two cleats are held back from the edge of the door to allow the rib to be flush with the edge of the door.

A 13" extension tied in with a piano hinge to lengthen the deck to provide more sleeping space for a total of 5' 8".

With the extension folded on the door, slide the door onto the support structure. Place the door as far forward and locate the longeron between the two alignment cleats. If there is interference between the intercostal support cleat and the alignment cleat on the door, trim the aft end of the alignment cleat on the door to eliminate any interference.

Caution: When unfolding the extension make sure the support triangle is folded out. Putting any substantial load on the extension without the support triangle will result in pulling the hinge out of the door or extension.

Note: If I did this again, I would add some cleats on the underside of the extension (when extended) to assure the support triangle is not accidentally pushed back (see the last page of this presentation).

The mid deck spans the full width of the support structure. The panel is 9" x 40" and has indexing cleats on the sides.

Install up against the aft end of the front doors. The aft end of the mid deck falls midway across the aft rib.

The configuration of the aft deck is an indexing cleat on the sides and a rabbeted 2 x 4. The rabbet is for the slide out table. The 2 x 4 was glued with wood glue (as all of the cleats are). Several instances of bonding failure of the cleats when removing the deck from the substructure cause me to install some wood screws (9 x 2 1/4") through the deck and into the 2 x 4. The aft deck was trimmed to end at the same place as the longerons. The table sticks out another ~3" which give you something firm to grasp. The table can be safely pulled out 16".

The finished unit has a platform that is 5' 8" long (if you pull the table out as far as the rear door will allow you without interference) and is 40" wide.

The storage in the front is accessed by lifting the fwd doors. This
compartment extend to the rear of the mid deck. The storage in the front is shown with both doors removed. For routine access simple lifting the door should suffice.

The storage in the aft is accessed by lifting the aft deck. If you find it too difficult to lift it with the table inserted (the weight and the table wanted to slide forward), remove the table. The storage in the aft is shown with the aft deck flipped over. For routine access simple lifting the aft deck should suffice.

There is additional storage under the 13" fwd extension as well as along the small spaces between the longerons and the wall of the car.

This is an example of how the table in the aft end would function.

There are a number of changes I would do if I made this again.

1. I would use a cleat to restrain the support triangle.
2. The cohesive strength of the MDO surface is low. If the gap for the longeron, rib or intercostal is too tight, and you do not lift the deck up without prying, you will delaminate the cleat off the underside of the deck. I did this several times during the cutting and fitting. Use a screw to secure the cleats.
3. The deck could be thinner perhaps 1/2" or 3/8". It depends on how much of a trampoline effect you feel is acceptable. When the deck flexes, there is considerable force on the cleats. Thinner deck will really make attaching the cleats critical.
4. The space above you when you are sleeping is a function of the height of the storage area and the sleeping pad/foam you choose as well as how claustrophobic you are. If you need more space, reduce the height of the longerons, ribs and intercostal.This could be done after the camper unit has be made by ripping the longerons, ribs and intercostal on a table saw.
5. You could attach the mid deck to the aft deck with a piano hinge and the two fwd doors with a piano hinge. It will make lifting the aft deck easier, but the combined weight of the mid deck and rear deck will be greater.
6. Install a stop on the upper surface of the table to prevent the table from sliding forward when the aft deck is lifted. A finger size hole in the top of the stop would also act as a place to grab when pulling out the table.