Sideboard With Turn to Open Doors

My friend asked me if I could make her a sideboard to fit in the corner of her living room and she send me a couple of links to some similar ones she liked the look of. They all had geometric patterns on the front and a couple had hexagons which I liked the look of so I decided to make one with these.

When I was thinking of the whole piece I couldn't quite imagine what kind of handles would work well and though that no handles would look much better....so I had to come up with a plan.

A couple of things came to mind, the first was a part you could push down which would open the doors slightly so you could then open them, but this would involve springs etc. and I thought it would be more prone to failure. I also thought about a 'slide to open' mechanism involving a wedge of some kind but couldn't think of a clean/nice way to do it so I came up with a fairly simple 'turn to open' mechanism.

It's a nice basic mechanism where there is a circular knob recessed in to the cupboard top, this is then attached to a circular piece of wood to the underside of the top which is mounted eccentrically. In the starting position the circular piece is such that the front of the doors are flush with the frame and when turned 180 degrees the doors open enough to grab from the top to completely open. This would make the doors handleless and the top of the sideboard flush/on the same plane.

Material
Hardwood - I used Brown Oak for its amazing character
Plywood - for the cupboard doors
Blackboard paint
M6 threaded rod
3 No. M6 nuts
M6 washers
M6 Insert nuts for the mechanism and legs
M6 machine bolts for the legs
Threadlocker
Wood glue
Impact adhesive
Oil for finishing

Tools
Table saw
Band saw
Mitre saw
Router
Drills
Random Orbital Sander
Hand plane
Lathe

I started off by drawing the sideboard on a 2D CAD program (nanoCAD is good and free) to get the proportions right and to get the dimensions of the doors which would fit the hexagon pieces. It also let me experiment with the orientation of the hexagons which I could then show my friend for her to choose which she liked the best.

Unfortunately I can't find the CAD files anymore so cannot attach them!! Sorry!

Once I had it all drawn up I looked at how much wood I'd need to buy and went to the shop to buy the wood. As brown oak has very random patterning the shop leaves you to it to look through the planks at your leisure until you get just the right pieces. I generally choose the planks with the most patterning on them but there is always a bit of a surprise as a lot of the detail comes out when you've got it home and planed it.

I started by cutting the planks in to pieces for the top and sides before putting them through the planer (jointer) and then the thicknesser (planer) to get them all flat and the same thickness.

I then joined them together with biscuit joints and glue before leaving them a couple of hours in the clamps to dry.

As the larger bits were drying I had time to start making the hexagon pieces. They are not whole hexagon pieces but each one is made up from three separate parallelograms all of the same dimensions.
I started off by ripping some wood to the width of the parallelograms and then cut each of those in to thinner strips on the bandsaw.
To make consistent pieces I made a simple jig to attach to my crosscut sled. I started off my determine an exact 30 degree angle which can be done with a pair of compasses quite easily. It's the same method as drawing a hexagon, which as all the sides are equal to the radius you only need one setting on the compass to draw one. I started off with drawing a circle where the centre was located on the very edge of the cutting line of the crosscut sled. I then moved the compass so the centre would now be at the intersection of the cutting line and the top of the previously drawn circle. I then drew a partial arc where the new circle would intersect with the first circle (to the left of the cutting line). I then drew a straight line between the intersection point and the centre of the original circle. This gives you a very precise angle you can then work with.
I then screwed a scrap bit of timber to this angle positioned up the sled (parallel to the cut line) so when the very end of a pieces touched the front fence it would give me a parallelogram with four equal sides.

All I had to do is repeat this many times until I had a massive pile of ready to use pieces.

The main body was made up of an oak top and a base with mortices cut in to them for the sides and back, two oak sides with tenons cut in to them and a plywood back piece.

I started off by making the mortices in the top and bottom pieces using a router table with a fence where the grooves would be cut short to the front and the back so the joint would be eventually hidden. I also cut a thinner slot along the back for the plywood to fit in to. While the fence and router was set up for the back I also cut full length grooves along the back of the side pieces.

Next I changed router bit and started cutting the tenons to the top and bottom of the side pieces. I started of cutting them wide, testing the fit to the mortices and adjusting bit by bit until they were a nice snug fit.

Before gluing together I dyed the plywood and dry fitted the whole body before gluing and clamping.

I started off by sanding one face of the parallelograms so they ended up being wedge shaped which would give the final effect more 3D. Once I had finished all the sanding I started gluing my pieces on to some plywood I cut slightly over-sized.

I used impact adhesive to fit the pieces to the door so I used a dust mask with some filters I had that can be used for ammonia etc so should be good enough for this. I started at one edge gluing piece by piece making sure that all the pieces were orientated the correct way to give hexagon shapes. This sound easy but after a bit your eyes get 'confused' and you have to take a step back to make sure you are doing it properly!

I then painted the inside of the doors with blackboard paint, made some edge trimmings, cut the door to size and glued the edge trim to the doors securing with masking tape.

My friend wanted circular legs so I started off my gluing some off cuts of the brown oak in preparation for turning.
Once they were dry I turned them all on the lathe with a nice taper and then cut an angle of around 10 degrees to the top and bottom.

I then cut a couple of straight pieces of oak to the same width as the leg diameter at the top and screwed the legs to it. These would then be bolted in to the main body by using insert nuts placed in to the base.

I started off by turning the main body of the mechanism which was basically a shallow dish with a central straight part glued to the middle.

While that was drying a made a template to create the circular recess in the top of the sideboard. I used a piece of hardboard and cut the diameter of the circle taking in to account the diameter of the router base and the diameter of the router cutter, so when the router was placed inside the circle it would cut the diameter of the handle with a millimetre gap around the edge.

Before cutting my nearly finished furniture I tested that the diameter of the cut was correct before clamping the template to the main body, taking a deep breath and cutting the circle. I cut it with several passes making the cuts small at the end so the recess was the same depth as the handle height.

I then drilled a hole as centrally as I could in to the handle mechanism and epoxied some threaded rod in to the hole.
I then took a quite large bit of oak and turned a circle with rounded edges on the lathe for the underside of the mechanism. I then determined the position of the off centre hole so that at it's minimum width the doors would be flush to the sideboard frame and drilled a hole slightly less deep than two bolts.
All I needed to do was to drill a hole centrally in the recess to the top of the sideboard. This did take a few attempts as only a fraction of a millimetre off is quite obvious with a circle inside a circle. My first two attempts were slightly off so I had to make a dowel the same size as the hole to fill it in before leaving it to dry and re-drilling. In the end I got it right on the third attempt!!

All that was left was to assemble the mechanism. So the threaded rod was epoxied in to the turning handle, this then passed through the hole in the top, to the underside I used two bolts tightened against each other to create a locking nut (I also added threadlocker for good measure), the eccentric circle was then fitted on to the thread (hiding the bolts) and then finished off with a washer and nut to the bottom to hold it all together.

Now it was all coming together I needed to make a couple of shelves. I used plywood painted with chalkboard paint and added wood trim to the front edge (to match the inside of the doors). I then drilled some holes for some metal dowels to hold the shelves followed by cutting some slots in the shelves that fit in to the dowels.

I then screwed some inset cabinet hinges to the frame, drilled some holes in the doors to match and fitted the doors to the frame. Only a little adjustment to the hinged was needed to line up the doors to each other and the frame.

I then oiled the whole cupboard with a few coats of danish oil.

My friend was very happy with the result.

If you enjoyed this Instructable a vote for me in the Simple Mechanics contest. Thanks for reading!