Today we're gonna be making a piano shaped ceiling lamp. In the picture you can see the layout I've chosen for the piano tiles: it's made so that it doesn't look very symmetrical (that's intended), but you can change it if you want, since it uses the same amount of pieces as if it were symmetrical. If we esclude the cost of tools, black cardboard and current transformer (which I already had), the whole project costed around 45€.

Supplies

You will need AT LEAST (which means, without considering the thickness of the blade you'll use to cut the pieces, in an ideal world where no one makes mistakes):

- 112x32 cm plexiglass (2,5mm thick) -> I bought 100x50 cm and it was ok (pretty hard to fit all the pieces, but definitely possible)

- 112x32 cm plywood (6mm thick) -> I bought 120x40 cm

- 2x4,5 cm wood strip (at least 180cm long)

- 0,9x7 cm wood strip (at least 200 cm long)

- 3x3 cm wood strip (at least 20 cm long)

- 19x25 cm wood board (any thickness, recommended 0,9 cm)

- 1 cm round dowel (at least 64 cm long)

- 52 tiny wood screws (the smallest you can get, preferably with flat head)

- 2 screws with a black head, 2 long screws to mount the lamp to the ceiling

- 5 m white LEDs

- 220V AC in, 12V DC out, 4Ah transformer

- Some length of wire

- Black acrylic paint

The main tools I used were a drill, a miter saw (allowing for 34 cm cross cuts), a scroll saw and some fine sandpaper (240). You may also need a few electrician's tools.

Step 1: Cutting Wood and Plexiglass to Length

First of all, you'll need to cut the wood to length. The store where I bought it could make straight cuts for free, but they wouldn't cut the plexiglass. The solution I found was to mount the blade of my scroll saw sideways to allow for a continous cut along the long side of the piece. I only cut it roughly around 33 cm so that I could later refine the cut on the miter saw.

1) You'll need to cut 6 (16x32 cm) panels and 2 (8x32 cm) panels of both plywood and plexiglass.

2) You'll also need to make a box which will contain the transformer for the LEDs, so you can cut a few pieces from the 0,9x7 cm wood strip. I suggest to make 45° cuts with the miter saw to make assembly easier. Cut 2 pieces of outside length 25 cm and 2 pieces of outside length 19 cm (you can change these measures, but I personally used these).

3) You'll need to cut 10 black piano tiles. Cut the 2x4,5 cm wood strip into 10 pieces, 18 cm long. You can give them a 30° bevel on one side so it will more likely resemble a real piano.

4) You'll need to cut the 1 cm diameter dowel into 2 cm long pieces. You'll need at least 32 pieces. You can cut the dowels longer, it will affect the distance between the LEDs and the plexiglass.

Step 2: Hand Cuts and Test Fit

I also made a few more cuts by hand. You'll need to cut a 2x18 cm notch out of some of the tiles, as shown in the picture. That way, the black tiles which will protrude from a piece won't go on top of the piece next to it.

I'd recommend to do a test fit after this step. The shape of the piano won't change much after it, so you better be sure you got it right :D

Step 3: Drilling Holes and Mounting LEDs

You now have to glue all the tiles to the remaining length of the 0,9x7 cm wood strip. I chose to glue the strip along the top side of the tiles to account for the weight that the black tiles will add on that side and to avoid covering too much of the void space between the tiles (where there will be an L shaped void)

You'll also need to drill a few holes to accomodate the wires for the LEDs. Since there will be 14 white tiles, I made 14 LED strips, 28 cm long (that's the length to which my LEDs could be cut, it may vary to you). You'll also need to make as many weldings to join the fresly cut LEDs to the wires that will power them xD.

I suggest to use at least 30 cm wires because they'll later be joined on the back of the lamp.

Step 4: Sanding Plexiglass and Painting Tiles

I gave the plexiglass a light sanding with 240 sandpaper and then a sponge with scrubber. I made sure to only sand one side of the plexiglass while keeping the protective plastic on the other side. I also put a strip of paper tape along the middle of the 16x32 pieces so that it wouldn't be affected by the procedure. The result is an opaque plexiglass along the tiles with a transparent line in the middle that clearly separates the two adjacent tiles.

Next, I painted the black tiles in one go by inserting a long screw on the back, painting them while holding only the screw and then suspending it with a string to dry.

Step 5: Mounting Plexiglass and Black Tiles

Next, I mounted the black tiles where needed by drilling tiny holes (1,5 mm) through the plexiglass and the black tile both, using the screw. I tried doing it with glue, but the plexiglass just won't stick! Plus, the screws add a nice """rustic charm""" (quote).

I glued the 2cm wooden dowels near the four angles of each set of tiles and drilled holes through them. Then I marked the position of the holes on each corresponding piece of plexiglass and drilled bigger holes through them (big enough so that the screw body can pass but not its head). Be careful on where you place the wooden dowels because some angles are covered by black tiles half-protruding from the plexiglass!

Step 6: Making Box and Connecting LEDs

You now have to make a box to accomodate the current transformer. Use the previously cut strips of wood and the 19x25 wood board. In case your ability of making boxes is as bad as mine, you can run a strip of black cardboard along the edge so it will look a lot cooler and perhaps absolutely intentional!

Drill a few holes where needed on the box so that the wires can enter it and then glue the box in the middle of the lamp. You can add a few scrap pieces of wood to also glue the side of the box that doesn't touch the long wood strip to the tiles (it will make the connection a bit sturdier).

Make some welds to join the LEDs' wires on the back of the lamp. You can use some hot glue to fix them in place.

I also added the remaining LEDs from the 5m batch on the back of the lamp to make a nice glowing aura effect. Insert the welded wires inside the box through the holes and make a final weld to join all of them to the current transformer. Don't forget to test the LEDs by connecting them to the transformer each time, before you weld them.

Step 7: Mounting the Lamp

Unfortunately I didn't make a photo of the mounting mechanism, but I have drawn a scheme. The 3x3 cm wood strip has to be cut to length in order to fit perfectly inside the box as shown. You then have to make 2 holes in the middle of the box such that you can put two black screws (which will camouflage with the black cardboard) right in the center of the strip. You can then mount the 3x3 strip on the ceiling using 2 long screws and 2 fischer wall plugs and only then align the whole lamp to the 3x3 strip and put the black screws in!