Introduction: How to Make a Fold Out Sofa/Futon/Bed Frame

I enjoy relaxing on a sofa and in my bed, and so it may come as no surprise that I would wish to combine the two. After searching Ikea and several other shops, I found the average price for a "tri-fold" futon was in the region of 120GBP ($150). I found this pretty steep for what is basically some planks of pine and a mattress.

So I decided to make my own.

Let me make this clear before I begin: This Instructable is only how to build the frame. I have not yet worked out how I will make the mattress or if I will attempt to buy one, but in the instructables spirit if anyone has any suggestions, suggest away.

This futon folds in three sections to give a comfortably wide (4ft) and long (6ft-ish) bed that could sleep two (if proximity is not an issue!). When it is folded up it forms a sofa that is close to the ground and has an open angle (about 100 degrees) which I find very comfortable to sit on.

I am not a carpenter, crafstman or a great DIY-er, I didn't even take wood tech in school, so this instructable is very accessable. So get up off your computer and turn that empty space in your bedroom or living room into a versatile piece of furniture! If I can do it, so can you!

Step 1: Materials and Tools

This is the list of materials and tools I used during the project. The wood I used was pine as it is cheap, relatively strong yet a little springy to make the futon a bit more comfortable. The type of wood you use is up to you but in my opinion, pine works best. My local hardware store cut the planks for me at no extra cost, but depending on where you go they may charge 10% extra: this is worth it.


Wood:

12 x 1200mm x 95mm planks (20mm thickness: I think this is standard)
2 x 770mm x 70 mm planks (20mm thickness)
2 x 700mm x 70 mm planks (20mm thickness)
2 x 690mm x 70 mm planks (20mm thickness)

Also some kind of stain, oil or wax to protect it and make it look good.

Nuts, Bolts and Screws:

46 x 40mm screws (4mm head)
4 x 6mm bolts (6mm is the diameter: length needs to be no less than 45mm, 50mm is ideal)
4 x 6mm wingnuts (or regular nuts, but wingnuts are easier to use in assembly and disassembly)

Tools:

Pencil
Ruler (graduated in millimetres)
Set Square (or similar)
Protractor
Electric Screwdriver/Drill
2.5mm drill bit
6.5mm drill bit
Manual Screwdriver
Saw
Medium Grade Sandpaper
Rasp or planer (a rasp is a bit like reusable, very coarse sandpaper, but a planer would work just as well)

Optional

Scrap piece of wood to test drill bits and screws
Cat

The total cost of the wood came to around 33GBP ($40) and the screws, bolts and nuts totalled about 2GBP ($2.50). I alreday had the teak oil so the total cost for this project (assuming you have all the tools) is around 35GBP ($45), but again this depends on where you shop.

Step 2: IMPORTANT NOTE

When doing any measurements throughout this instructable, remember to MEASURE TWICE, CUT ONCE. This is very important as mistakes are easy to make and rushing things is not a good idea.

Other notes to do with safety:

- Always clamp wood that you are drilling or cutting
- Work in a clean, dry and well ventilated area
- Make sure you know how to use the saw and electric drill correctly and safely
- DO NOT work when you are tired or have drunk alcohol: you will make mistakes and you could injure yourself

Step 3: Preparing the Large Planks

For this step you will need the rasp or planer, and the glasspaper. You will be working on the 12000mm x 95mm planks.

1. Use the rasp to shamfer the edges slightly.

2. Glasspaper the plank to smooth the edges and surfaces, paying particular attention to the ends.
(The glasspapering is easier if you wrap the glasspaper around a small block of wood. I cut a piece of scrap I had lying around.)

Do this for all 12 planks.

Step 4: Marking the Smallest Planks (690mm X 70mm)

***Look at step 7 before doing the measuring to get an idea of what they should look like***


The smallest planks (690mm x 70mm) need to have a small section cut out of one end, the other end tapered slightly and one drill hole.

Small Section(requires some accurate measuring)

1. Measure 85mm down from one end and mark it.
2. At this mark draw a perpendicular line across the wood using the set square.
3. Measure an angle of 7 degrees from one of the edges. Rule a line.
4. Measure 37mm along this line (starting from the edge) and mark it.
5. From this point measure an angle of 95 degrees towards the end of the plank. Rule a line.
6. Shade in the section in the 95 degree angle and the other side of the 7 degree angle. This is the bit to be cut out (main picture).

Drill Hole(mark this before the tapered end)

1. Measure 30mm down and mark it.
2. At this mark draw a perpendicular line across the wood using the set square.
3. Halfway in (35mm) mark the drill hole.

Tapered End(basically two triangles)

1. At the end with the drill hole, measure 20mm down and 20mm across the top. Draw a line.
2. This is the triangle to be cut out.
3. Repeat on other side.

Step 5: Marking the Medium Small Planks (700mm X 70mm)

***Look at step 7 before doing the measuring to get an idea of what they should look like***


The medium small planks need on end tapered and a small triangle taken off the other end. They also need a drill hole at each end.

Drill Holes(mark these first)

1. At one end, measure 30mm down and mark it.
2. At this mark draw a perpendicular line across the wood using the set square.
3. Halfway in (35mm) mark the drill hole.
4. At the other end, measure 50mm down and mark it.
5. At this mark draw a perpendicular line across the wood using the set square.
6. Measure 15mm in and mark the drill hole.

Tapered End(at the end with the hole in the middle)

1. Measure 20mm down and 20mm across the top. Draw a line.
2. This is the triangle to be cut out.
3. Repeat on other side.

Triangle(at the end with the hole 15mm in)

1. Measure 25mm down on the side opposite the drill hole.
2. Measure 25mm across the top.
3. Rule a line between the marks. This is the bit needed to be cut out.

Step 6: Marking the Medium Long Planks (770mm X 70mm)

***Look at step 7 before doing the measuring to get an idea of what they should look like***


The long planks need one drill hole and one triangle cut out at one end.

Drill hole
1. Measure 165mm down from one end and mark it.
2. At this mark draw a perpendicular line across the wood using the set square.
3. Measure 15mm in and mark the drill hole.

Triangle
1. On the opposite side to the drill hole, measure 35mm down and mark it.
2. Then measure 35mm across the top and mark it.
3. Rule a line. This is the triangle to be cut out.

Step 7: Cutting and Drilling

1. Cut and Drill where you have marked on the planks. (6mm drill bit)
2. On the tapered ends, triangles and cut outs smooth and sand roughly (not too much as some measuring is yet to be done).

Now your six small planks should look like this:

This is a good time to test the folding mechanism of your futon. It should be fairly obvious where the hinges attach and so forth but incase it isn't...

- The tapered ends attach to each
- The other end of the middle section attaches to the long section
- The cut out section of the smallest planks should rest on the longest planks when folded up

Step 8: Note: Measuring the Screw Holes

Now we need to add some screw guide holes on the planks. These will make sure the screws go in straight ensuring the best fit and so the wood doesn't crack. This is the most tedious part of the build and also one of the most important. This is a dangerous combination so concentrate. It should not take much longer than 30 minutes.

ACCURACY IS KEY

Step 9: Measuring the Screw Holes on the Long Planks (1200mm X 95mm)

These need to be measured differently:

- 7 planks need to be measured one way
- 4 planks another
- 1 plank is unique

The "7" planks(there will be 4 holes)

1. Measure 150mm down from one side.
2. Draw a perpendicular line across the plank.
3. Measure halfway and make a mark.
4. Now measure 20mm either side of the middle and mark your screw holes.
5. Repeat at the other end.

The "4" planks(same as last time only they are 170mm down)

1. Measure 170mm down from one side.
2. Draw a perpendicular line across the plank.
3. Measure halfway and make a mark.
4. Now measure 20mm either side of the middle and mark your screw holes.
5. Repeat at the other end.

The "1" plank(2 holes)

1. Measure 150mm down from one side.
2. Draw a perpendicular line across the plank.
3. Measure halfway and mark the screw hole.
4. Repeat at the other end.

Step 10: Measuring the Screw Holes on the Other Planks

The different planks need to be measured differently. On the four shorter ones there should be 4 pairs of holes (8) and on the two longer ones there should be 3 pairs of holes and one single hole (7). They all need to be measured along the top edge (see step 7: the top edges are the edges farthest up on the picture).

Shortest planks(690mm x 70mm)

1. Measure 85mm in from the tapered end along the top edge and mark it. (85mm from the original end of the plank: in retrospect this would have been easier before tapering the end).
2. Measure 40mm from this mark and mark it.
3. Measure 135mm from this mark and mark it.
4. Repeat steps 2 and 3 twice.
5. Measure 40mm from the last mark and mark it.
6. You now should have 8 marks (4 pairs).
7. Rule perpendicular lines across the wood on all the marks.
8. Measure halfway in on these lines (10mm) and mark the drill holes.
9. Use this plank as a template for the second plank (see picture).

Medium small planks(700mm x 70mm)

1. Measure 145mm from the end with one corner cut off along the top edge and mark it.
2. Measure 40mm from this mark and mark it.
3. Measure 110mm from this mark and mark it.
4 Repeat steps 2 and 3 twice as with the small planks.
5. Measure 40mm from the last mark and mark it.
6. You now should have 8 marks (4 pairs).
7. Rule perpendicular lines across the wood on all the marks.
8. Measure halfway in on these lines (10mm) and mark the drill holes.
9. Use this plank as a template for the second plank (see picture).

Medium long planks (770mm x 70mm)

1. Measure 30mm in from the flat end along the top edge and mark it. (This is the single hole).
2. Measure 135mm from this mark and mark it
3. Measure 40mm from this mark and mark it.
4. Measure 125mm from this mark and mark it.
5. Repeat steps 3 and 4 once.
6. Measure 40mm from the last mark and mark it.
7. You now should have 7 marks (3 pairs and one single).
8. Rule perpendicular lines across the wood on all the marks.
9. Measure halfway in on these lines (10mm) and mark the drill holes.
10. Use this plank as a template for the second plank (see picture).

Measure these twice to avoid errors. It will save you time, effort and money in the long run.

Step 11: Drilling the Screw Holes

Using the 2.5mm drill bit, carefully drill on the marks as close to vertical as possible.

On the large planks, the holes should go all the way through the planks.

On the smaller planks, the holes only need to extend about 20mm in (doesn't have to be exact).

Step 12: Finishing the Small Planks

After drilling the screw holes we can finish the small planks. The top edge (the one with the holes) should only be lightly sanded as it needs to sit flush with the large planks. I gave the bottom edge a strong bevel.

Step 13: Assembly

Now comes the interesting part. The key to the assembly is preparation. Firstly, screw all of the screws through the long planks so that the ends are just poking out the bottom. This will make lining up the planks on the smaller planks infinitely easier.

The 4 long planks measured earlier attach to the medium short planks (700mm x 70mm) the 7 planks attach to the other planks (the 770mm x 70mm one and the 690mm x 70mm one) and the single holed plank goes on the 770mm x 70mm one). It should be fairly obvious but it is important to get them in the right place so the futon folds properly.

Screw the planks in place to end up with the three sections of the futon. Before finishing the futon, check that everything works. Assemble the futon using the wing nuts and bolts and test it. Everything should work smoothly but if not, you may need to make some adjustments.

(EDIT) I have added an extra diagram which should help you see what I mean.

Step 14: Finishing the Futon

Disassemble the futon into its three parts. Give the whole thing a good sanding to get rid of sharp edges and to prepare it  for treating. Then treat the futon with what you like. I used 3 coats of teak oil which gives it a lovely colour and smell and protects it. However you could use wax or even stain, whatever works. Reassemble and you have a fully functional folding futon frame.