Introduction: DIY Modern Bench
In this instructable I will show you how to make a modern bench, using simple joinery to produce a piece of furniture you can be proud of. I will include full technical drawings, step-by-step instructions, and a full set of CAD files along with a detailed materials and tools list.
Step 1: Tools
I do not expect everyone to have all the tools I have used at hand so I will try and provide alternative methods and tools where possible.
- Drill (I use an 18v cordless drill but even hand drill would do, just take your time)
- Bandsaw or Jigsaw ( I was lucky enough to have access to bandsaw however a jig saw will do fine with a low T.P.I blade)
- Router or Laminate trimmer (potentially not need if you CNC the leg sides)
- Sander ( I used a random orbit and a belt sander but I used to use a block of wood and a bit of sand paper which would work fine here)
- Table Saw (optional)
- Surface Planer (optional)
- Thicknesser (optional)
- Laser Cutter (optional)
Step 2: Materials
I have used Oak for the majority of the frame however for a cheaper option you could use Ash or other similar hardwoods.
4x Leg side - 470mm x 70mm x 23mm
2x Top rail - 420mm x 70mm x 22mm
2x Bottom Rail - 420mm x 70mm x 20mm
2x Brace - 460mm x 50mm x 20mm
1x Cross rail - 1340mm x 70mm x 25mm
(some of these dimensions are slightly oversize so as to allow a little room for error and make cutting a bit easier, use the technical drawings for final dimensions)
For the base I would recommend a sheet material such as birch ply, however you can use solid wood if you want but be aware the cost and weight will go up significantly. You can also change the length as you please.
1x Seat base - 1500mm x 420 x 18
Any yellow carpenters glue, I used titebond original
Wood Primer (I used a cheap own brand)
Eggshell Duck egg blue or whatever colour you want
P38 automotive filler
Step 3: Fixings
- 2x M8 60mm countersunk Allen key machine screws
- 4x M6 50mm countersunk Allen key machine screws
- 2x M8 25mm cross dowels
- 2x 12mm dowel pegs
- 2m of 8mm white hardwood dowel
- 4x right angle brackets
Step 4: Templates + CAD Files
Step 5: Face Side and Face Edge (optional)
These next few steps are here if you wish to process your own timber from rough sawn to fully prepared stock. You can omit this step if you are buying your wood from a timber yard, who will be able to prep and thickness the timber for you.
To start, take your board to the dimension saw and cut the board into more manageable pieces; at this stage you want to cut 25-50mm oversize as you are not cutting to exact length at the moment. The board I started with was over two meters long so would have been hard to control and move around. Making the piece smaller allows you to work more safely!
After dimensioning the timber, go over to the surface planer and set your guard 2-3mm (picture 2) above the thickest point of the timber, with the feed table set to about 1 - 1.5mm (check the piece goes all the way through before you start!). It's very important during these steps to use all the proper guards and PPE (personal protetive equipment) as these machines are dangerous.
Once you have a nice flat face turn off the surface planer and drop the guard to cover the blade. position your timber on it's side (picture 3) to plane the edge. Again, you want to check the piece runs all the way though without getting stuck on the guard, so allow 2-3mm extra space between the piece and the guard. When running the piece though the planer, keep pressure against the fence and listen to the wood.
If you get any tearout on the wood, turn the piece round and try again (do not change the direction you feed the wood in!). Tearout is caused when the knives in the blade catch in the rising wood fibers and the blade tears rather than cuts them.
Remember to check your fence is square to your table, using an engineer's square at the cutter mouth.
Step 6: Ripping on the Bandsaw (optional)
Depending in the how prepared the material you have bought is, you may need to rip some of the pieces on a bandsaw to get a more efficient use of material.
For example, for my rails I cut a piece of rough sawn 1000mm x 55mm x 85mm in half (after adding a face and face side) to produce two pieces at a planed and finished size of 75mm x 20mm x 1000mm. I did have to add a new face and face edge on one of the boards.
After ensuring I had a face side and edge on all of my cut pieces, I moved on to thicknessing, the next step.
Step 7: Thicknessing
With your face side and face edge done, you can now move on to thicknessing. Start by setting your thicknesser to 1 - 1.5mm below the thickness of your timber at its widest point. Put your timber in face edge down and gently push the timber into the path of the blade. Continue until you are at your desired width and then start on the face side.
The reason you always start with the face edge instead of a face side is so the material is at its thickest when it goes in. This means the board has more support and will produce a better finish. As a big plus it's also much safer.
Step 8: Ripping the Rails and Braces
For this step there are, as always, different approaches, with varying levels of accuracy, time and difficulty. I will focus on using a table saw; however I will list and describe alternate methods. If you use the table saw method, try to use a table saw with a riving knife.
Method 1 - Table saw:
- Set your blade angle
- Adjust your fence, if possible so the fence is only half way up the table (stopping the material potentially squeezing against the blade and fence, possibly causing kickback)
- Set your guard as low as possible while sill being able to move the material freely
- Using push sticks slowly push your material towards the blade keeping pressure from the side as shown in picture one
(DO NOT USE YOUR HANDS FOR THIS! USE STICKS)
Method 2 - Hand plane:
- Remove the lever cap and chip breaker
- Sharpen the blade
- Reassmble the Plane
- Set the blade to take the finest shaving you can
- Gradually increase the amount being taken off by using the thumb wheel
- Stop once the plane begins to 'judder'
- Reduce the amount of blade until planing smoothly again
- Check regularly using a steel rule and square
- Adjust using the lateral adjustment lever if necessary (left, right adjustment)
Method 3 - Bandsaw/Jigsaw/scrollsaw
- Set the table or base to the required angle
- Starting slowly, begin to cut making smooth and gentle corrections
- Be careful of blade wander if using a jigsaw
- Remove blade marks with hand plane/belt sander/block of wood and sandpaper
- Take your time cutting and sanding
Method 4 - Surface planer
- Set fence to required angle using a sliding bevel or inclineometer
- Plane taking off 0.5mm or less
Method 5 - Hand sanding
- Mark guide lines around the piece
- Using sandpaper attached to a flat surface sand taking even strokes
- Check progress with steel rule and square
- Adjust sanding pattern where necessary
Step 9: Alternate Ripping of Rails and Braces (Method 6)
So, in the previous slide I stated a fair few ways to rip the rails; here's another:
- mark angles on lengths using a sliding bevel or protractor
- set angle on saw
- add appropriate support pieces for the rail or a jig if you want
- line up the splinter guard wit the the angles you marked
- Using a low tpi rip blade cut the pieces
- Dimension with a hand saw or sliding mitre saw
Step 10: Making the Leg Side Template
To make the leg side template, I used a local modelmaking shop's laser cutting service (4d modelshop). This was because I wanted a quick, accurate result. Using the very accurate (and expensive) laser cutter, I was able to cut the 9mm MDF in under five mins. However, if you do not wish to pay for lasercutting, you can always make the template by hand.
Using the the first picture transfer the measurements to a piece of 9mm + mdf or plywood. After cutting the piece to 470mm and using a bandsaw or a jig saw, cut the two angled edges (you could use a table saw and a tapering jig if you want to be more accurate). After this, cut out the notch using the bandsaw or jigsaw and proceed to sand the edges, ideally with a large table belt sander, but this could also be done with a large block of wood and sandpaper. Alternatively, you could glue some sandpaper to a large tile or sheet of mdf, clamp it, and use that to sand. The more time you spend on your templates the better and the less work the pieces will need.
Step 11: Leg Side Jig
Using the provided CAD file and or technical drawings construct the Leg Side Jig; I have used various MDF offcuts, but use whatever you have to hand following the dimensions on the plans.
Once completed, you will need a router bit with a bearing guided cutter, on either the bottom or the top. Being on the bottom allows you to secure the leg template as shown; however, it does require a long cutter. If the bearing is on the top you will also need to place your template on the top of your piece.
If the cutter is short, you will need to make the cuts in stages. This is not a problem; it will just take slightly longer.
I used a variety of clamps and gorilla double sided tape to hold the piece in place while routing. This proved very effective; however, the double sided tape was incredibly strong and a nightmare to get off.
WARNING NEXT SLIDE IS GRAPHIC, SKIP IF YOU ARE SQUEAMISH
Step 12: DISASTER!!!
While separating the template from one of the leg sides, I slipped and took a large slice out of my left thumb.
This accident was unfortunate - but preventable. You should never have your hand in front of a chisel even if, like me, you doing something seemingly innocuous.
To prevent this accident I could have been used a bench dog or a board clamped to the end of the table instead of trying to hold it with my hand. (The reason I wasn't using any clamps is because to clamp down what I was trying to separate seemed counterintuitive at the time.)
Step 13: CNC
After the accident with the chisel, I was left unable to use my hand held router, along with most of my other tools. To continue with the bench, I decided to have my bench legs cut on a CNC router. I found a local company who used my dxf files to cut out my leg sides.
The cutting cost was £60 and far exceeded my expectations.
Step 14: Planing the Radius on the Support Rails
As the CNC leaves a radius on the inside corners where the support rail sits, I used a No 4 1/2 plane to round off the two inside edges. If you do not have a hand plane, you can use sand paper or a file to add the round over.
If you do not want to round over the inside edges, you can square off the corners with a saw and chisel.
Step 15: Threaded Inserts on the Leg Sides
- Using a ruler mark out the centre of the cut out for the support rail
- make a centre using a centre punch or sharp implement (compass tip, brad point drill bit... etc)
- Drill a pilot hole using a 2-3mm drill bit
- Bore out the pilot hole to 8mm using a lip and spur/brad point or if you have it a forstner bit
- Insert the threaded insert using a 6mm allen key or allen key attachment for your drill
Step 16: Drilling the Support Rails
- Mark the rails for the two holes corresponding to the leg sides
- Clamp or mount the piece in a vice, as shown, to drill the pilot hole. The reason you need another piece pressed firmly against the back, is to reduce breakout at the back of the piece
- Drill pilot and 6mm hole
Step 17: Mock Up
Here is a picture of one of the leg sides together, minus the dowel joinery.
Step 18: Dowels
I have used dowels to join the top rail, middle rail and the support.
First, mark out the leg sides, using a protractor or sliding bevel, as shown in picture one; then divide the centre line in three, to mark out the centres of the two holes, on both the top and middle rail locations. After that, clamp or secure the pieces together, to drill a pilot hole through both pieces (pic 2). Next, separate the pieces and bore out the holes to 8mm using a forstner or brad point drill bit(pic 4); remember to use a piece of wood behind the leg side to stop tearout.
Once complete, install the middle rail (without dowels and glue) and drill a hole about 20mm off centre into the support rail (pic 4). This will help the locate the pieces during the glue-up.
Cut lengths of 8.5mm dowels oversize of whatever depth you drilled (pic 5). I believe mine was around 50mm. Finally, round off the end of the dowel, using sand paper or a chisel.
Step 19: Glue-up
As gluing up the pieces is a quick but fiddly process, I did not have time to grab many pictures. Nevertheless, here is a quick guide:
- Sand all inside surfaces up to 180 grit
- Add glue to the dowel holes, rail sides and support rail top (I used titebond original)
- Assemble the frame and use a mallet to whack the dowels into place; it will sound hollow until you hit the end of the hole when the dowel is properly seated
- Use a wet kitchen roll to clean off any excess glue
Step 20: Fitting the Cross Brace
Taking the cross brace, cut the two ends at 10 degrees. You can do this using a table saw, as shown, or with a sliding mitre saw, or a simple handsaw.
Attaching the cross brace:
- First, drill a 12mm hole using a brad point or forstner bit through the support rail and into the cross brace
- Insert a 12mm dowel peg, with glue inside the cross brace hole
- Then drill an 8mm hole above, using a brad point
- Using a countersink drill the support rail for the m8 screw head
- Drill another 12mm hole, this time from the side of the cross brace to intersect the 8mm hole
- Insert cross dowel and assemble
Step 22: Oil
For the finish on the Oak I used a product called tru-oil, which is a gunstock finish often used in guitarmaking.
- Using a cotton rag apply tru-oil to each piece generously
- After the oil is applied, wait for 5 mins and wipe off excess, using a lint free rag
- Repeat 3 or 4 times, sanding between every other coat with 240 (or finer) grit sandpaper
Step 23: Seat Base
For the seat base, I used a piece of 18mm exterior ply, although I may replace it with a piece of birch ply. I cut the piece slightly oversize from the plan, as I wanted to be able to fit my mug of tea on the end; probably ended up around 1600mm.
So here's what I did:
- Bought the plywood scrap
- Cut it to width, 419mm to allow 1mm of play
- Sanded to 80 grit
- Filled the grain with p38 car body filler
- Sanded flat to 180
- Applied wood primer (Wilkinson's cheapest)
- Applied a coat of duck egg blue eggshell
- Sanded to 220
- Applied two more coats of duck egg
Step 24: Finished!!!
All in all, I'm very happy with the look and feel of the bench. Now me and my girlfriend can have a cool and surprisingly comfortable place for up to 3 friends to sit on. It looks good with other modern/mid century style furniture and is strong yet light, weighing in at under 15kg. Because it uses simple joinery it's a really achievable project, and it can also flat pack for easy transport.
If you do build this bench, please send me your photos; I'd love to see them!
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