Wooden Pifi

I had a pair of old speakers from a Sony hifi I had in the 90's and wanted to have a semi-portable hifi that I could use in the kitchen and outside in the summer.

I use XBMC on my home theater system and saw that there is a few distro's that are based on it so having researched a bit I decided to go with OSMC which seemed like a good solution for a Raspberry Pi 2.

I did need an amplifier and not being good at electronics I needed to buy one so I went with a cheap one from e-bay that is often used in cars and motorbikes. After plugging it in and testing it I was happy with the result for such a low price of £16.

The cabinet is made out of oak as I had some left over from making a shelf. It was the cheapest oak I could find - its a calibrated French oak QF4 Grade which is a rustic grade. There were a few large knots in the lengths I got but I just see that as plus as these always add character. At £5.67 per meter (205mm wide 24mm thick) I don't think anyone can complain!

Materials

Speakers

Raspberry pi

Mini amplifier

Extension plug

Cables and plugs for electricals

Hard drive (for stand alone player)

Oak

Plywood for lid and bottom

Tools

Table saw

Router

Chisel

Drill and drill bits

Pliers and wire strippers

Sandpaper and oil for finishing

Probably other things I've forgotten to include

The cabinet its self is a fairly basic box using housing joints (I think they might be called?) with a floating ply bottom and a veneered ply top that will slide on and off to give access.

The first thing to do is to establish where the knobs for the amp and the speakers are going to go.

I decided to make a box out for the amplifier so the wood around the amp would be quite thin (2-3mm), this should enable me to take the knobs of the amp and just make holes for the potentiometers and put the knobs back on later. To make the box out I worked out the distance from the edge of the router bit to the edge of the router base and fixed some scraps of wood at this distance away from the area I wanted to remove. As this would be inside and not be seen I didn't mind about holes so fixed the wood down with some brads with a nail gun. It was just a case of routing out the hole at increasing depths until I was a couple of millimeters away from the bottom. I then marked out where the knob holes need to be and got out my drill.

Next was the speaker holes. I find the best way to cut big holes is to use a router on a circle cutting jig. It does sound quite fancy pants but its pretty much a length of timber bolted to a router with a small hole in it. To make one get a length of timber around the same width as your router base and longer than half the diameter of your circle, attach it to the base of the router and plunge the router bit through the base. To get the correct diameter of your circle mark a point from the outside edge of the bit along the timber to the radius of the circle.

Take a drill bit and drill through the jig at the marked point and also drill through the front face at the centre of the speakers. Take out the drill bit and insert it through the jig and the timber. You can now cut out the speaker holes little by little increasing the depth each time.

The tweeters being small only needed a fairly small hole so I used a fostner bit on a pillar drill for these.

I wanted access to the usb ports and the ethernet cable port on the raspberry pi and wanted to add a fused switched mains inlet socket to the rear so I needed to add a couple of holes to the back.

I first needed to establish where the rapsberry pi was and therefore how I was going to fix the pi to the base. I have made a box for a pi before out of ply and a few screws which could be adjusted up and down on a small bolt. I used the same technique here so dilled the holes and set the pi on the base. I then marked out where the hole needed to be and drill out most of the waste with a fostner bit. The edges where then tidied up with a chisel. After I had completed this I dry fitted the base to the back and realised the I couldn't use bolts to all four corners to the pi and once all fixed together I wouldn't be able to fit it. I therefore substituted the front bolts with a couple of small blocks of wood with holes through them. I could then slide the pi through the hole and on to the rear bolts. The small blocks could then be slid underneath and secured with a bolt.

The inlet socket was easier. Just marked it out, removed most of the waste with a drill bit and squared off with a chisel.

Next the sides of the cabinet needed to be made. I will be using a router table to create my joints and I prefer to cut the rebates/rabbets first to the width of a router cutter. Once these are cut the tenon to the side pieces can be created to just the right thickness by slowly raising the router bit, taking a cut and testing the fit. If its too tight just raise the router a little and keep repeating until the fit is a little tight. As I am using a housing joint the thickness of the 'tenon' will be reduced slightly when the piece is sanded, hence why I cut mine slightly too tight.

The rebates/rabbets for the bottom and the lid needed to be cut. I was using plywood for the bottom and plywood with walnut veneer for the top so I used a router bit as the same thickness as my plywood. I wanted the lid to slide on and off so I ended up sanding the underside of the edge of the top so it was able to slide without too much trouble. As you can see from my photos I made a mistake and cut grooves on the wrong face of the side pieces so I just made the same cuts on the other face and now I had a 'design feature' on the side of my cabinet.

I then dry fit my box to make sure it was all going to work OK and before I put it together I established where I needed to drill the holes for the raspberry pi. I also added a couple of small bits of wood to raise the amp to the correct level and to which I could secure it with screws.

I was happy with the fit so glued and clamped the box together and waited for it to dry.

Once it was dry I applied a finish. I liked the pale colour of the oak so wanted to keep it as close to this as I could. I used Liberon Black Bison Wax as I have used this before and it tends to darken the wood the least out of everything I have. I applied the wax and left it on for about an hour and then buffed the box with a buffing attachment on my sander. This make the oak smooth and shiny! Nice.

I wanted to have just one external plug for my music box so I used a 4 way extension plug which I wired to a fused switched mains inlet socket. This idea came from this instructable 2-Player-Bartop-Arcade.

Once the cabinet was complete I determined where all my bits and pieces were going to go and fixed them all in place with screws and off cuts of wood, keeping all the wires nice and tidy with sandwich bag ties!

I was going to reuse the knobs from the amplifier but having put them on they didn't look quite right.

I had a few pieces of spalted beech and thought that these would look good as little knobs. My turning skills are very limited and I have only turned a few things before so this would be a good opportunity to practice. I first cut the spalted beech on my table saw to get it to approx. the right size and mounted it on my lathe. Using a variety of turning tools I managed to get the outside shape of the knobs along the piece of beech. I then released the wood from the lathe and cut the knobs off with a saw. I then sanded the tops and bottoms of the knobs and drilled holes in the bottom of each one to fit on to the amplifier.

For this project I am using a Raspberry Pi 2 which is much better spec'd than the first version. This makes it ideal for something like OSMC which is relatively processor heavy. I did try a version of XBMC on the Raspberry Pi 1 but it was a little too laggy for me.

To download go to https://osmc.tv/download/. This will download an installer which will ensure that you are using the latest version. During set up you can put in the details of your wireless network which make things a little easier as you don't have to go in to any config files etc once you have it all up and running. All you need to do is pop in a micro SD card in to your computer and set the installer off - its very simple. Once it has finished just put the card in to the pi and turn it on.

To control the pi I have an app on my tablet called Yatse which I use for my home theater system in my front room, I can use the same app to control the pi too without too much hassle. I just have to search for the pi when its turned on and enable it. I can then control OSMC with my tablet. I would recommend attaching a monitor the first time so you see exactly whats going on, but once you have set everything up there is no need for a monitor.

If you want to go in an control the pi from the terminal you can connect it via SSH using a program called PuTTY there are many tutorials out there just do a quick search and you'll find many.

If you want to transfer files across to your pi without putting your SD card in your computer you can use FileZilla which works in a similar way to PuTTY again a quick search will help you if you get stuck.

Overall I'm very happy with this project and can't wait for the summer to try it out properly outside with a nice fire. It sounds pretty good and the volume is loud enough for my purposes. The hardest part for me was getting the raspberry pi up and working the way I wanted it to but perseverance always wins in the end.

I hope this is of use to someone and gives a couple of ideas to people. Thanks for reading!

By the way I am entering this in to the DIY audio and Pi day contests so if you liked it, it would be great if you voted for me. Ta!