Well, this is my first instructable. I'm not regular in constructing things; actually I got into this because of this instructable.
I wanted a floor lamp for my home and having specific requirements either I couldn't find anything I liked or everything was way too expensive for me. I stumbled upon one with a ceramic base and multiple copper pipes that was +300$ and I said that I could do something like this by myself.
So I made a design with three copper pipes on a concrete base.
Step 1: Base Design
I decided to use a plastic wash basin as a cast so I went out and found one that fitted my needs. In order to support the pipes I used 1/2'' pipe extension so I can disassemble the lighting in the future and separate the base from the pipes if I need to move it. You can use any coupling that has a male thread (for example) but have in mind that the overall height of the base depends on the length of the coupling. Also the pipe extension has the female input which can be helpful). The pipe extensions I used where 76mm long so the overall height of the base ended up to be 100mm resulting in a heavy base. On the other hand a heavy base is good thing to compensate the length of the pipes and keep them in place.
Anyway, I designed an equilateral triangle as given in the sketch and the attached drawing and printed it as a guide to drill the basin. Being afraid that I'll break the basin I put on some duct tape but I think I could just drill it without it. Next, I drilled a piece of wood to take in the threads of the pipe extensions and support the basin because the concrete would collapse it.
In order to hide the cable connections the base had to be hollow so I used a cooking pan on top of the pipe nipples.
The most difficult part of my construction was to keep the nipples leveled and steady because the concrete would move them (eventually I couldn't do it; one of the pipe was not completely vertical). A first thought was to drill the three holes of the triangle on another piece of wood (check the picture with the level) that could keep them in place but lacking the correct tools (and skills) the holes where not good. Finally I used some other brass pipe nipples (male to male) through the cooking pan that I tried to level after pouring the concrete (you can see the nipples in the next steps). Unfortunately I don’t have a picture with the cast of the base before pouring the concrete in.
Step 2: Protection Earthing
Since the lighting is made of copper and it can be touched I had to ground it. I had to connect the three pieces of copper and I did it within the concrete where it is not visible. I used pipe ground clamps to connect the cables and the pipes. I used multicore flexible cables (blue and brown in the image) - not rigid- to keep the extensions steady and left two pieces of copper through the cooking pan (rigid copper in the picture) to connect the protective conductor from the mains. The wire that you can see in the picture (not copper) is only used as reinforcement for the concrete; it has nothing to do with the earthing.
Step 3: Concreting
I don't have any photos from the making of the concrete because I couldn't at the time. There are plenty of instructubles around to explain how to make it better than I can.
I used ready to use concrete mixture in a bucket following the given instructions. I also sprayed some oil on the basin to take it off easy after the concrete had cured.
The result is on the pictures. The bottom of base. You can see the three nipples I used to level the embedded extensions and the two pieces of copper for the earthing. Also you can see a passage for the cable to enter the place under the base. I also used a rasp to flatten the edge of the base.
Make sure to have enough concrete mixture. I didn't calculate it accurately and I ended up having a two-colors base because the grey one finshed before the job was done. I had to go buy another pack of concrete but at the time I couldn't find the same brand.
Step 4: Cabling
I applied a varnish coating on the base so the hot glue used to attach the cable connectors would stay in place. I used a three-wire cable (phase, neutral and earth) and made three parallel connections for each of the pipes. Before connecting the cables I measured and cut each one according to the desired length of the copper pipes. Have in mind to cut 10-20cm more than the exact length of the pipe to have enough for the light sockets.
Also I screwed a clamp on the concrete to tie the main cable and protect it from unwanted pulling.
Make sure to firmly secure all the cabling on the base so they won't tear by acccident.
Step 5: Puting on the Pipes
The height of the lighting is just a matter of taste. I had decided to use edison bulbs so having in mind the total length of the bulb and the lamp socket I cut three different pieces of 1/2'' pipes. One 135cm, one 150cm and one 165cm. Firstly I passed the cable through the pipe and then I attached the pipe on the extension. One at a time. To fasten the pipes on the extensions I used female quick connectors.
Step 6: Connecting the Sockets and the Dimmer
I bought some nice black lamp sockets and then I made a little hole to each pipe to secure the socket on it. I stripped the cables and connect it to the socket. Be careful to first put the ring of the socket on the pipe.
To connect the foot dimmer strip a piece of the cable with extreme care so you wont hurt the conductors. Then connect it according to the diagram on the dimmer (phase, neutral, earth). I couldn't find a decent foot dimmer on an international site so the link is from the Greek store I bought it.
Notice that I had to bridge the earthing conductor (green/yellow) since the output of the dimmer only has to conductors.
Pay attention to the chosen dimmer. If it has a cut off switch or not, if it suitable for led lamps, what is the minimum/maximum power it can serve etc. The one I had cannot switch off the led filament bulbs and just has two levels of brightness. Alternatively you can use a foot switch instead of the dimmer.
I hope you like the result and maybe can enlighten me with some piece of advice, especially on the matter of the leveling of vertical pipes. There is another little table lamp I had the same problem.
If you liked it a lot you could vote for it on the current contest.