I am not a carpenter, I know it is over built and could probably be built with lighter timber and less legs. However we aren't light in my family and I will not put my fathers already fragile body at risk with something which could conceivably fall down. My father set a criteria that it must be able to be pulled apart for storage in the vans annex should they desire to so its on removable legs and the back can slot in and out. The cushions are old bed mattresses made out of sponge rubber from the van. I am planning on cutting them down some and recovering them with nicer material.
Step 1: Plan It Out!
Step 2: Collect the Materials
The list of materials included:-
2 of Porta 40 x 18mm x 2400mm DAR for the adjustable supports
1 of Porta 90 x 18mm x 2400mm DAR for the front face
3 of Porta 90 x 90mm x 1200mm DAR for the legs
1 of Tasmanian Oak Dowel for the support structures
1 of 2400mm x 1200mm x 18mm Marine plywood sheet for top and back surface
4 of Anti vibration rubber squares 100mm x 100mm x 12 mm (recycles black rubber) for feet.
24 of M8 x 100mm Bugle head Hex drive screws (gold colour)
24 of M8 x 50mm Bugle head Hex drive screws (gold colour)
6 of brass hinges ( I used 30mm long ones, in hind site piano hinges probably would have been better)
20 x Brass screws 5/16 x 50mm to hold the rubber feet on.
6 x M6 x 70mm Bolts, nuts and washers for the adjustable supports
a gloss clear polyurethane varnish
Step 3: Tools
Step 4: Mark Up and Cut the "dragons Teeth"
Cut 3 of the 90mm x 30mm x 2400mm pieces down to 1940mm long. These will be 2 dragons teeth lengths and an un marked back piece.
First I marked out 100mm sections on two of the 90 x 30mm x pieces with diagonals to make the teeth. There was a gap in the teeth in the middle to accommodate the centre unmoving top section.
Ended up drilling out the corners so that the dowel would sit neater into the resulting spots. Once marked and drilled used a saw to finish the cut. I clamped the two sections so that they would be as close as possible to identical after they were finished. Of course they required a fair bit of tidying up with a file and sandpaper afterwards.
Step 5: Preparing the Legs
To make them strong we made them out of 90 x 90 mm pine, to weaken them we decided that they should be able to be removed so we cut 100 mm off their length, hollowed out the top of that 100mm and put in a screwable table leg mount into it. Mark up the top of the remaining 300mm leg and drill a lead hole for the leg screw and put it into place with some good glue to hold it tight. Hollowing out the 100mm bit to a depth of 1cm with a large drill bit was a pain. A router would probably do a much better job of it too!
Step 6: Lay Out and Join the Frame Together.
Unfortunately I didn't take a photo of the frame in all its glory so the picture above shows how it looked. The overall frame ended up being 1980mm long and 700mm wide.
It is held together with two pairs of 120mm Bugle head screws at each right angle section and four pairs for the middle legs and bracing.
Pre drill the holes for the screws at each corner so as not to crack the pine. You also need to ensure the whole thing holds together tightly and sits level before screwing together.
Step 7: Set Out the Top Sections and Add Hinges.
We had the major parts of the plywood sheet cut at the hardware store. These were in the pattern shown in the above picture.
We laid the smaller sections down on the frame in the same order shown to make sure it all fit properly. The left two pieces are the leg support sections. The smaller right piece is the centre anchor section for the bum, which is screwed directly to the frame. The largest piece is the back support. NOTE there is deliberately an empty section at the back of the chair. In this version I made it 100mm wide. It only really needs to be about 60mm wide. The additional 40mm can be added to the width of the plywood (making it 640mm)
Screw the centre section to the frame first.
It is easier to join the two leg support pieces together using two hinges at this point. Because the bend direction is down theses hinges are installed underneath the plywood. Make sure they are properly lined up and the sections are parallel.
Then join the leg sections to the centre section with 2 hinges on top. (you could also make the hinges hidden by the joint but I have always hated putting screws in the end of plywood, bad things happen)
Finally join the back section to the centre section with 2 hinges on top.
Step 8: Support Brackets
Drilled a 25mm hole through the ends and put a section of dowel through each end. This makes the adjustable support bracket which will slot into the dragons teeth. As I said previously the dragons teeth can be oriented towards the centre as well. I like it this way as the tension holds it nicely.
As there are 3 sections to adjust you need three brackets of different lengths. Each bracket must be able to fold completely away to allow the bed to become a seat.
You can only work out the lengths needed once the bed is assembled and by placing the brackets in the right section. Crawl under and mark where the ends are and you know where to screw the rails to connect the brackets to the plywood. The thigh support section only needs a very short bracket (one pair of dragons teeth long (around 250mm) The calf section needs a longer one which fits into the next section of dragons teeth and then reaches around the middle of the section (see the first photo)
Drill out holes for the bolts into the rail and bracket ends and connect them.
We also found that we needed shorter supports at the head end for lying most of the way down.
These were also cut from the 40 x 18mm material and 2 sets for different heights made and cut. They were also bolted to rails attached to the plywood (see the diagram).
Step 9: The Back Board
First we cut out slots for the various support structures so that the back could slide into the gap left at the back of the bed.
We also screwed angled stops of timber to fix the angle which the back could lean back. These were screwed to the back of the rear dragons teeth as shown in the diagram.
We put blocks on the back of the back board to ensure it only slid so far into the bed. This is actually probably superfluous.
Once finished the back slots nicely into the hole and cannot rock back further than the stops. It would hold its angle better if the back blocks were angled but we just didn't have the tools to do that. (maybe future modification)
Step 10: Finishing Up.
All flat surfaces were sanded smooth and 3 coats of gloss polyurethane lacquer were painted on as per instructions.
Given my fathers strength and mobility issues holes were drilled in the deck and ropes fed through to allow him to lower the bed into its seat configuration with a minimum of bending and visibility required.
Another little refinement was the addition of a Hover Bar for iPad from 12 South to the back to hold his iPad air in an easy to see position. (The fix to allow the Bar to hold the iPad air could be another Instructable by itself as there is no clip at this point from 12 South to do so)
Step 11: All Done!
Hope you like my first Instructable! Any suggestions, constructive criticisms most welcome.