Wi-Fi Infinity Mirror Table including a USB Charger

Wi-Fi Infinity Mirror Table including a USB Charger

As it's common the first picture shows the finished product so... tadaaa.

While writing my bachelor thesis my old couch was worn-out enough to justify a replacement. Because my new couch is bigger than the old one and the old coffee table was even smaller than LACK by Ikea, I needed a new coffee table, too. Procrastinating me decided that it would be a great idea to build one myself and so I started looking on /r/diy, Pinterest, etc. I finally found a great table made by /u/squishy0eye (https://redd.it/5005n6) which isn't just a regular infinity mirror table but has led strips arranged as a "city". I decided to use the same principle but started planning and building from scratch as I will show in this album. The table should also be Wi-Fi controllable and have a USB charger inbuilt for smartphones or a SHIELD controller.

The whole table cost ~600€ (additional ~300€ for tools) as I used following materials (cents rounded):
- IKEA MINDE mirror: 16€
- two-way mirror foil by Velken-Folientechnik: 19€
- tempered glass (126 x 46): 83€
- LED strips from ebay: 14€
- Mean Well RS 75 12V power supply: 17€
- 52m H07V-K 1,5 wire: 20€
- USB charger by Dodocool: 15€
- 19mm mdf with priming foil: 130€
- paint by Hesse-Lignal (see specific pictures for names): 142€
- other electronic components: ~30€
- small parts like glue, sanding paper, duct tape, filler, glass drill: ~120€

Tools I used (tools without prizes shown I had bought before this project started):
- Bosch POF 1400 ACE router with Bosch trimming cutter 12,7mm and Bosch slotter 10mm (87€ + 19€ + 17€)
- Bosch PKS 55 A hand-held circular saw with Bosch saw blade "expert for wood" (88€ + 24€)
- Bosch PST 54 jigsaw
- Bosch PBH 2500 SRE drill hammer
- crimping tool from eBay (20€)
- ZD-931 soldering station (45€)
- 8 clamps
- hot glue gun by Einhell
- knife, side cutter, screw drivers, spatulas, ...

First of all, the infinity mirror effect occurs when an object or a light source is placed between a mirror and a two-way mirror.
The light is completely being reflected by the mirror at the bottom and on the other side the two-way mirror also reflects most of it while some light can escape through it. The escaping light is now visible for a spectator.
The remaining light is again completely reflected by the mirror and again a little bit of it can escape through the two-way mirror. However, the light has now travelled twice the distance of the gap and so the light source or object now seems to be twice as deep down the gap. This goes on theoretically indefinitely but is stopped by all light being escaped from the gap or at least being not visible anymore.

For planning and rendering some images (see next pictures) of the desk I used Autodesk's Fusion 360. The design of the desk is inspired by a coffee table by Paul Frankl. The dimensions of the measurements above are metrical millimeters (1mm = ~0,04 inch). The whole table is separated into four parts from top to bottom:
- the top layer which holds the two-way mirror and is responsible for the distance between both mirrors
- the between layer (A-A) which holds the mirror on which the LEDs are being placed; on one side two USB ports for charging electronic devices will be positioned however these are not planned in advance but will be added on the fly
- the lower layer which provides stability by just being a board with a hole sawed out in which the electronic components will be placed
- the feet

Each piece of wood has at least one dimension being a multiple of 19mm because that's the size the mdf was available in. The overall width and length are a result of the dimensions of the IKEA mirror (120cm x 40cm) because it was cheap opposed to a custom-built one and so became the basis of all other dimensions.

This is the "city" consisting of buildings the LEDs will be wrapped around. The buildings each consist of four pieces representing the walls and a thin cover to hide the insides (not shown here). The LED strips are led outside by 1cm x 1cm holes in the walls which are here represented as small gaps between two walls. These openings are placed 1cm above the mirror so that the LEDs are placed right in the middle of the gap between both mirrors. This makes the distance between each "story" identical opposed to the situation when the strips were placed directly above the mirror. In that case, there would be a repetitive pattern of two nearly connected stories followed by a big gap.

A rendering of the table looking from the front.

A rendering of the table looking from front-left.

So, I began by ordering the tempered glass (126cm x 46cm, 8mm high) which i thought would need the most time to reach me. It was ready to pick up after three days... I carefully chose the foil to make it a two-way mirror by ordering some free samples by different companies and finally picking the one I liked the most.

The application process is pretty simple: Spray the provided lubricant on the foil and the glass so you can still move the foil when it lies on the glass. The favorable location for this process is the bathroom right after you showered so the steam binds the dust and thus prevents it from flying around and landing on the glass. In my case, there was some dust between the foil and the glass anyway but probably I didn't shower long enough before. When the foil is positioned as wished a scraper is used to remove the water between both surfaces. Afterwards the workpiece should dry for a few days while not being stressed.

The result looks like this - there shouldn't be any distortion of the reflection as it is the case with some cheap foils. This one does its job well so I can move on to the next step.

I drilled holes into the mirror, one under every building. The drill I used does its job by essentially grinding a hole into the glass.

Here you can see the small pieces of glass that grind through the mirror. More expensive ones use diamonds instead of glass but that one was cheap (~7€).
It is very important to cool the drill by pouring water on the glass before drilling or having a second person continually spraying water. When everything works fine one hole can be made in less than a minute.

Right after drilling the holes they may have sharp borders which should be smoothed by sanding to prevent injuries of people touching them or the wires which will later be led through them.

The mirror after drilling all holes.

The direct surroundings are a bit ugly but will later be covered by a building. The important part is that everything is smooth now.

Two months later the mdf was ready so I started building the desk itself in early January. It is covered with a priming foil which should make painting easier.

The top layer, between layer and the feet to check whether every part is present. The lower layer didn't fit in the picture but it only consists of two boards so it's not that spectacular. In this picture, there are four joists in the between layer which were later reduced to three ones because four are simply too many considering the size of the table. The schematics at the beginning of this album show already the final version.

Then I began gluing the pieces together. Because nearly every part has a width of 38mm I had to first glue the 19mm parts onto each other before assembling the table itself. A lot of clamps are needed for this step and it is recommended to place a piece of wood between the clamp and the workpiece to avoid imprints. High pressure however is important to make the glue set and I found that gluing primer foil works well with the same glue I used for wood.

Both boards moved a bit when tightening up the four clamps so I had to keep them in place by also applying clamps at the sides of the workpiece.

Cutting a hole into the lower layer before gluing both pieces. The jigsaw worked well for the rough part while the router later was used to make the edges straight.
When doing something like this always wear a respiratory protection (at least class FFP2) since you really don't want to inhale mdf which is pretty toxic. This is even more important at using the router and sanding because the dust particles are even smaller then. Also wear eye protection and gloves for obvious reasons. In the entire process of making the table I used up 8 respiratory protection masks so don't just buy one when starting a big project like this. When the inside of the mask is getting dirty it's time to replace it by a new one.

At the top of the picture there is a long side of the between layer. I marked the USB ports whose holes consist of two parts: A small opening facing the outside of the table which perfectly surround the USB port itself. Facing inside the table there is a bigger opening that allows me to maneuver a bit better and bend two little pins attaches to the USB port to keep it from moving.

I didn't want to have a power cord hanging down from the top of the table so I decided to run wires through the feet and connect them to the power grid with the help of a IEC connector. There is also the main switch positioned nearby to turn everything including the USB charger on or off. I marked where I had to mill or drill the cable channel.

I nearly milled at the wrong side of the vertical part of the foot but luckily realized my mistake before doing so. This vertical part will be turned around 180° and then glued onto a second plate to achieve a 38mm thick part with a cable channel inside it. The wires will be led from the horizontal part through the tiny hole at the bottom of the vertical part up to the lower layer where the power supply is meant to reside.

When gluing wood one should apply some glue with a brush on both parts and then press them together by using clamps. The important part is how much glue should be applied.
I regularly messed up and applied way too much glue. Luckily there is such thing as a trimming cutter which removes the excess glue and levels the sides in case the pieces moved a bit while gluing them together or didn't have the exactly same dimensions before.

At the top, you see an example of a glued part right after drying and at the bottom of the picture is an equivalent workpiece which I had already processed with the trimming cutter.

For building the between layer and upper layer I needed to saw at exactly 45°. Doing this by hand is probably possible but not as easy as it might sounds like. I tried it and had to realize that my cuts weren't that precise.
So, sponsored by my dad I bought a hand-held circular saw (Bosch PKS 55 A) and an appropriate saw blade (Bosch "expert for wood", 160 x 20 x 2.2mm).
In case you are in the same situation as me please don't use the included saw blade since it's way too rough. Also, it makes sense to compare prices - the hardware store where I bought the saw offered me a saw blade which cost 50€ more than the original Bosch one I bought on Amazon.

When being tilted to 45° the saw didn't cut completely through the wood but the small remaining edge was easy to remove later.

I had to find out that the tilting mechanism of the saw doesn't actually stop at 45° but at ~48° so it needs to be set to 45° and not just tilted to the max... Lesson learned and luckily nobody's going to see this because the gap is facing inside the table.

The mirror fits perfectly so the seam (~5mm) is deep and wide enough.

Gluing the boards of the lower layer after gluing the between layer onto the upper board and leveling the inner edges.
After this step, I was able to use the trimming cutter for leveling the lower board and upper board of the lower layer and voilà the hole inside the table now has smooth walls.

There is a small cable channel leading the wires from location where the foot will be attached to the inside of the table.

After isolating the cable channels with a Hesse-Lignal coating I started to assemble the feet and thus install the electronic parts. I bought a cheap crimping tool from eBay to connect wires to the plug and to the switch because soldering shouldn't be done at working with 240V. In case there is a cold solder joint this joint works like a resistor and may get hot enough to start a fire which is really not what I want a coffee table to do.

To not bend or crush any wires I put two separators between the lower layer and the vertical part of the foot.

So that's what the inside of the foot looks like - each connection is separately isolated with a shrinking tube so the foot is ready to be glued.

Nearly at least. When moving or even pulling the cables I don't want the joints to loosen so I fixed the cables in place with hot glue.

Before now gluing the feet and the lower layer needed to build the supports (the small vertical parts of the feet). I first built a single one and then decided to use the trimming cutter to replicate it.

That way I had two identical supports - one for each foot. Since I didn't want to stress the trimming cutter too much I roughly cut the second support in advance and then used two sided duct tape to fasten it to the finished one.

The supports are held in place by a tongue on each side glued into a respective groove in the lower layer or the foot. The tongues were pretty hard to mill because the rip fence of the router didn't have much space to lie on. It is however recommended to improve the stock one by screwing a long piece of wood onto it which makes it much more stable as I find.

These are the buildings already isolated but without a roof yet.

Using clamps in this case would have taken too much time so I used wall paint instead to produce pressure. As roofs, I used thin plywood which I roughly cut and then glued onto the buildings. After drying I used the trimming cutter to level the roofs and the walls.

These are the finished buildings before painting.

The seam of the upper layer which holds the two-way mirror needs to be as perfect as possible which is pretty hard to achieve given the dimensions of the parts. Because each part actually consists of two pieces of mdf I had two tries per part to get it right. I milled both pieces and picked the one with the better seam to be on top. At this point the seam just consisted of a single groove at the crucial part: The transition to the border.
The worse one was then filled and with the filled side glued onto the better one.
This picture shows both parts already with glue applied.

These are the two planks that are going to be glued together seen from a greater distance to show the dimensions in relation.

After gluing that's what the profile of the top layer looks like. For sawing 45° I used the hand-held circular saw again and well, you can see how deep the saw blade actually went since this part is simply to wide. I had to saw the remaining part by hand after which it looked like shown in the picture. Finally, I smoothed the surface by sanding.

There are special clamps to glue something at 45° but a quadratic piece of wood works, too. After this step the top layer was made up of two parts which each were formed like a "L".

Those two "L"s now needed to be connected to each other. To achieve the right dimensions of the upper layer I used filler as glue. The result didn't look that nice but once it's painted in black it won't be visible and the connection with seems to be pretty stable so far.

I took this photo directly before gluing the first foot to the lower layer. The grooves in which the supports will be glued are now also existent so everything is ready to glue. On one support there is a piece of priming foil missing because it was ripped apart by the double sided duct tape I used to fasten both pieces while using the trimming cutter.

Gluing the feet wasn't the most fun part because it was pretty hard to make the feet stand even on the ground. In case the support is a few millimeters too short the foot would tilt inwards and when it was too high it would tilt outwards. This part needed some improvising to compensate these inaccuracies but in the end everything worked out fine.

The joists needed to be shortened a bit to fit in the between layer. For gluing I couldn't use clamps (nowhere to attach them) and so I used spatulas to apply pressure.

The now existing gap between each joist and the surrounding border was filled with a combination of glue and mdf strands. After drying it got very stable so I can only recommend this. I would however assume that a gap shouldn't be larger than this to still be fillable with this recipe.

That's what the table looks like before painting - luckily everything fits.

I nearly forgot to round the edges which is a very important part. Not just because of the look of it but the paint might not be very durable on sharp edges.

After rounding the edges and sanding every piece of mdf without primer foil needed to be isolated by coating it with Hesse-Lignal DG 572. After drying and some sanding the filler (Hesse-Lignal DP 492-9005) can be applied.

The filler is black as is the actual paint (Hesse-Lignal DB 46125). While the isolation and the filler were meant be applicated with a spray gun the actual paint was made to be applied with a brush or a paint roller.
I used a roller for each of them and smoothed the surface with a large brush. However, there was a bumpy texture after painting and drying so I sanded the whole table again to apply a last coat of paint (Hesse-Lignal DE 557). This picture shows the mostly sanded table before the last coating.

Here a picture of the bumpy texture after painting the DB 46125. As usual the camera makes everything look worse than it is but obviously, this is far from smooth. I can only imagine that the temperature or humidity weren't appropriate since I did the painting in the basement with an open window to allow the air at least a bit to circulate. The temperature inside of course adapted to the one outside so it was way too cold in the room considering the recommended temperature written in the data sheet of the paint.

For the last painting session with the DE 557 which is a clear varnish and a bit glossier than the other paint I used I made my own spray booth by using foil. I used a water boiler to produce some fog inside so the dust is bound and not flying around. I was just about to start painting when...

... I made a step back and hit the top layer which hung on an obviously not so stable suspension. It slipped, it fell, it broke. Luckily there were clean cuts at the connections that were made with filler so I could glue the pieces together without much remodeling. Therefore, I used a two-component adhesive which works fine and is stable after a brief time. After that was done I painted the still visible cuts until they were hidden (5 coatings). Finally, I could apply the clear varnish (after some sanding of course).

Simultaneously to building the table itself I planned the electronics. I use an ESP8266 (ESP12-F on an adapter plate) for controlling the LED strips with the help of three IRF 7401 MOSFETs. As firmware, I chose an altered version of the RGBWWFirmware (https://github.com/patrickjahns/esp_rgbww_firmware) which for example includes a great webapp that allows me to choose a color and offers a lot of settings next to a JSON API I can use for smart home integration. I removed the behavior of resetting the Wi-Fi settings when CLR is LOW on start because the adapter plate simply does not provide a CLR pin and thus I can't pull it to HIGH. Without doing this the controller forgets its settings every time it's being started which gets annoying quite fast.

After having everything working on a breadboard I used Autodesk EAGLE to create this layout. The power supply outputs 12V which I first step down to 5V with a TSR 1-2450 and then to 3.3V with a LM1117T. The IRF 7401 can handle the power which is consumed by the LEDs while being controlled by 3.3V and only get warmer a little bit (I think around 3°C above room temperature). They might cost a bit more but because under the mirror there won't be much air circulation they are worth it.

That's what the board looks like after routing.

The board after soldering. I used 1mm wire to connect solder joints because of the power which might run through it. Probably not through the ESP but through the LED relevant parts and I thought I could use it for everything else as well. The wire works fine but don't expect being able to achieve a 90° corner without overlapping another soldering point.

The board from above - for the MOSFETs and the ESP8266 I used pin strips because I might have to remove them from the board in the future for reprogramming or replacing.

After that I soldered wires to the LED strips. Using 1.5mm^2 wires this was a pretty tough job and I found out that the easiest way is to alternating solder one wire to the front and one to the back to not make the LED strip wider than 1 cm. Otherwise the strips wouldn't fit through the 1cm high holes of the buildings or they would fit only diagonal. In the latter case the strips would break when being bent so that out of 8 buildings only 2 worked after the initial soldering which I did without alternating.

While planning the buildings I didn't have in mind that the LED strips can only be separated after every three LEDs. This led to some overlapping at wrapping the strips around because I couldn't just cut the needless part away. However, by cutting at the cutting marks, overlapping the ends a bit and then soldering them together again it is possible to shorten the strip.

That's what the table looked like after installing the electronic components without the LEDs.

From another angle the board right next to the power supply. The USB charger is located on the other side to be nearer to the USB ports.

I built the USB cables myself because I wanted to use the 1.5mm^2 wires instead of the thin ones which are normally being used. I was afraid that the charging speed would might suffer when there was an additional 70cm of cable between the charger and the electronic device. By using a greater diameter, the resistance was lowered and so the risk was being minimized.
As charger, I use one by Dodocool which supports Quick Charge 3.
I built my own power outlet to not influence the guarantee of the charger and being able to easily replace it in the future if needed.

After placing the mirror on the table and connecting the LEDs to the board everything looked a bit messy but there is a system: Every cable lies above the cable left of it. That way this construct maybe looks the way it does but at least is stable and no cable is hanging down. Maybe I will tidy up sometime in the future or maybe I will add a cover that hides the electronic components altogether, future will show.

A USB port from outside. Luckily the surrounding hole is not visible and it sits very tight. The ports won't be as visible as in this photo when the upper layer is connected to the rest on the table so they will stay more in the background and not attract so much attention.

The painted table with the mirror and the city on top. To fasten the buildings to the mirror I used double sided duct tape. Some of the buildings moved around a bit after some time so I used even more duct tape to keep them in place.

Finally, I added the top layer with the two-way mirror. It will be connected to the rest of the table by two-sided duct tape. I don't want to really glue it because in case I need to replace the mirror or need to fix the LED strips there would be no way to access them without damaging the table. Using duct tape is a good compromise between stability and maintainability but for now I won't even apply this one because I first want to see whether the glue of the LED strips is strong enough to keep them in place and being able to quickly reattach them if needed. The upper layer weighs enough so that it can't move on its own thus there's no problem.

When turned off the city is barely visible and the reflection is as not extreme (and thus annoying) as a normal mirror would be. Solely when watching TV the screen which is located directly behind the camera is being reflected so I will probably buy a tablecloth soon.

Even when the sun shines into the room the effect is clearly visible. When turned on at max. brightness the power consumption will be at ~58W; when being used as a dim ambient lightning the consumption is much lower (~3W).

Both mirrors seem to be parallel to each other else the towers would seem to be bent.

Enter the portal

Changing colors via Wi-Fi.

Finished product in green - the brightness is set to a very low level so the exposure time could be longer to capture the desk itself and not only the LEDs.

So that's the final picture for now. The table consumed hundreds of hours since I started around six months ago so I'm glad to have it finished now. Would I build a second one? Well, now knowing how much work it all was and how much the table finally cost I probably wouldn't. On the other hand, I learned a lot while working on this project and I think that makes up for the price and for the invested time. So, I would do it if I hadn't done it yet.

Finally, thanks to everyone who helped me and kept me at working especially my family, my girlfriend Lisa, Felix, Mirko and Maurice.