Introduction: Custom Birch Ply Furniture
This is an instructable about the piece of furniture I made for my A Level design course. It took me the best part of 4 months with about 4 and a half hours a week. I think it came out well and my Dad (who i made it for) really likes it. It is made completely from birch plywood, except the hardwood (sapele) strips on the drawers and shelves.
It was designed to hold all of my Dad's records, some of his CD's and his sound system. Since then he has treated himself to a new record player and amp, to go with the furniture apparently! I think all of the wood I used came to about £150 - £175 definitely no more than that.
Step 1: The Specification & Initial Design
It's really important to come up with a wide range of designs that match the specification you have. My specification was fairly long at about a page of A3 but it could have gone on to be much longer.
Then I started to design Ideas around the spec and what my Dad wanted.
I hoped to come up with about 6 initial ideas, but thought 5 was in the end enough.
These designs were then shown and then we picked the favourite, which happened to be the final idea on the Int. Des. 2 sheet.
Now we have a rough idea we need to develop the design for production, scale it to actual size and make sure it will actually fit the specification.
Step 2: Design Development & CAD
You can see from the first two sheets I tried to develop the shape and manufacturing processes in my design to be simpler and more suited to purpose. For example I had to scrap the idea of having a single ply moulded top was really quite dfficult and most probably not even possible with the resources I had. .
When I had the rough ideas from my development I continued my development on Solidworks CAD software, and on this i finessed the elements of the design.
You can see how I first designed the side units and the drawers then joined them together with shelves to create the whole unit.
When coming up with a scale for the whole thing I went round and measured all of the existing stuff that had to fit in it, like the records it was supposed to hold all of the electronic equipment and these gave me a rough starting point for the scale of the project. CAD software is also really good for this as it can give you a much more detailed perspective of the relative size of the different components.
Step 3: Manufacture 1 - Frame and Drawers
My first steps were to transfer the designs from Solidworks to the final 2D output for our college's CAM Router to cut out. You can see here in the pictures the outlines for my drawers, with the different colours indicating the different passes of the router. The second print screen is of the shelves which were to go in between the units. The frame, drawers and shelves were all cut out this way.
Then I had to sand and dry fit the whole piece. This involved squaring out all of the forty mortise and tenon joints so they would fit snugly together, and all of the housing joints so the drawers and frame fitted together well. Then I rubbed down the piece with increasingly fine sandpaper, wetting it in between sanding to bring out the grain and hopefully get a better varnished finish.
Then I glued the frame and the drawers together using a standard wood glue, clamped them and left them overnight until the glue had set.
Next the complex bit!
Step 4: Manufacture 2 - Curved Tops
This was the most technically challenging piece of the build as I had to decide how to manufacture the curved wooden tops and drawer fronts which give the piece its characteristic look. In the end I decided to use a vacuum forming technique, whereby several thin veneers are layered on top of each other with resin in between each sheet. Then the whole piece is placed on a mould in an airtight bag, the air is sucked out and the wood is formed to the contours of the mould.
I cut the mould out on the CNC machine and then bolted the whole lot together. This was then aligned and sanded to give a very even surface to reduce deformities in the moulding process.
The layers are then placed in the mould after being glued together with a resin which doesn't rely on air to go off, due it it being in a vacuum bag. The vacuum is turned on and then left for 24hrs for the resin to set.
The next day I took it out of the bag, peeled the newspaper off it and set about sanding and squaring off the piece, (which was made deliberately bigger than necessary) to fit it to the frame.
Once I was satisfied with the dry fit, I glued and clamped it into place before finishing it all off.
I then chose to do the initial drawer fit before the varnish was painted on. Then i removed them before starting the next step which was to prep for Varnish.
Step 5: Problem!
It turned out that for some reason either me, or the computer, had forgotten to cut out a whole shelf for the piece (personally I like to blame the computer). Obviously I only realised this after I had glued the main frame together(!) and this meant I had to think of a cunning way to retrofit on a whole shelf...
In the end I decided to cut out wedges out of the sides of the shelf and screwed the corresponding wedges onto the sides of the frame where the shelf would have normally sat. Then I just glued the shelf onto the wedges and put something heavy on it to help it stay in place.
Step 6: The Finish
For my project I chose to use a clear satin varnish to really show off the grain and colour of the wood that I had used. To apply it I used a variety of paint pads and fine high quality synthetic brushes, and I must have put on about four coats all In all.
I sanded it in between every coat going up to very fine 1200 grade wet and dry paper to get a really nice finsh. I put less coats on the undersides of the shelves but had at least 3 to properly seal the wood and make it durable.
Then to get a really nice shine on the tops, I actually ended up using car polish to buff it up and it gave it a really smooth, shiny surface bringing out the wood grain.
Once I had varnished it all I put the drawers back on and the piece was finished!
As I said my Dad really liked the piece and it is still going strong in the front room!
The finsished piece weighs a ton especially with all the gear on it as it is pretty much all solid 18mm ply!
If I wewre to improve it in some ways I think I would add more supports between the units, which would make the piece a lot sturdier when you moved it, but apart from that I was pretty happy!