Portal Lamp: Prototyping and Presentation
Monday, 26 October 2015
Final Assembly
Finally with all the components ready it was time to assemble everything for the last time. this included wiring up the electronic components as well. It was quite fiddly to get everything in place and tightening everything to the right tension while running the cables though and soldering the connections.
Once everything was in place I used dobs of liquid nails to hold the circle halves together. I didn't want to overload the liquid nails in case I need to open it back up for any reason. I left it to dry overnight with weights on top to ensure I got a tight bond.
Finally I screwed a piece of painted MDF onto the bottom to allow a bit of extra depth for the tech pack and also to give the structure a bit of elevation from the table. I also covered the base with black felt to make it sit nicely on furniture and conceal the screws used to connect the base.
As it turned out I did need to open it back up the next day. When I tested the lights again they had stopped working and I reluctantly had to decide how I was going to open it back up. Coincidentally the earlier problems I had with the bonds on the copper rings breaking became in my favor as I was able to squeeze the inner ring out to re solder the faulty area.
Once I finally had the lights working again it was time to join the base and install the tech pack into it. The top of the base is a piece of copper that the touch mechanism is attached to. As this piece of copper didn't require any bending I was able to leave its protective film on so that it keeps its original shine.
Half of the base is hollow to house the tech pack that is quite big due to the touch mechanism. Although it does give the base some extra weight. The earth cable is soldered onto the copper plate through the hole to allow it to be the switch.
Finally I screwed a piece of painted MDF onto the bottom to allow a bit of extra depth for the tech pack and also to give the structure a bit of elevation from the table. I also covered the base with black felt to make it sit nicely on furniture and conceal the screws used to connect the base.
Copper and Lights!
I had a lot of trouble joining my copper circles. I usually use silver solder for projects like this but I hit an issue when I found that my gas bottle couldn't reach a high enough temperature to melt the solder. After this trouble I resorted to using soft solder which I later came to realize was not a very good substitute. Two of my rings broke apart and needed constant care and repairs which was not ideal. The solder was also very bulky and took a lot of time and effort to sand off the surface of the copper.
After a lot of sanding I polished the rings with jewelers metal polishes and polishing attachments for my Dremel. I used both tripoli and rouge polishes to give it a good shine and smooth finish. I wanted to get it shiny so that the light could reflect onto the lamp's surroundings.
One of the things I found from the first prototype was that the LEDs were too bright. My solution to this was to use a thin sheet of plastic covered in car tint. This not only meant that the lights were not as bright but also allows the bright yellow colour of the LEDs to be concealed while the lamp is turned off.
I used electrical tape to hold the LED strip in place, making sure to line up each globe with its hole. As I wont be able to access this area after the structure is fully assembled I needed to make sure that these will stay in place.
Int he below photo you can see the copper rings sitting in one half of the top circle, I intentionally lined up the join in the small ring with the top of the circle because this is not in direct line of sight when the lamp is positioned on a table. You can also see the wiring coming out of the bolt at the bottom. I used speaker cable for this because it is thin and comes joined together so it is nice and tidy. I coloured one side of the wire in red so that I knew how to connect it to the next component.
This was the first time I saw the lights working inside the structure and I was so happy with the result, the light is such a warm colour and not too bright to look directly at.
Mock Assembly
At this stage I finally had enough components to assemble the structure and effectively see if the design will work in reality. It was a possibility at this stage that I could have underestimated the total weight and I would watch it fall over unable to support its own weight. Luckily I was happy to find that it was much heavier and stronger than I expected, and therefore quite sturdy.
I struggled for a long time trying to find a way to join the circles whilst still being able to run the electrical wiring through the moving parts. Eventually by calling in a favor (and a few beers) I got a friend of mine who is trained in metal milling to hollow out a few bolts for me. These were the perfect solution because they are able to be tightened to hold the components together but can now also house the electrical components as well.
The mechanism that I used to allow the top circle to move from side to side is very similar to the one I designed for the earlier prototype. Basically bolt holding the top circle screws into a bent piece of aluminium (actually made from an old toilet roll holder) which pivots from the middle to sit in five positions. There are magnets that hold it in place in each position and one big magnet built into the lever.
I was so happy to see this baby stand for the first time, and it even swivels! At this stage only the outside copper pieces are in place and the top and bottom circles are just held together with tape but getting this together definitely helped me to get my head around how everything will eventually come together. I played with different positions and was glad to find that it is stable in every position.
Saturday, 24 October 2015
Finishing: Varnish
Once the timber pieces were ready I sanded them until very smooth gave them three coats of varnish. I used a water based clear varnish because it it quick drying with minimal cleanup. It also allows the timber to keep its natural texture rather than a super glossy finish.
This photo was taken after the first coat. It is interesting to see that difference in colour as the two more solid pieces were cut from the same piece of timber and the other four were cut from another. The colour did get a bit more similar by the final coat but ultimately I am not worried about the difference as the two darker ones will have copper plates on their flat surfaces where you see the most difference.
Thursday, 22 October 2015
Construction: Drilling
Part of the design is that the top circle is able to slide from side to side, so to make this happen I had to cut a slot into the top of the middle circle. I made a scale drawing to figure out how wide this slot had to be in order to get the correct angle of movement.
I had considered making this cut using the router but then I found out that the base plate of the drill press is able to rotate. It was quite convenient that there was still a hole in the center of all the circles that I had used on the router table, I was able to bolt the timber to the base plate to keep it in place while I drilled.
I drilled the holes as close together as I could without the drill slipping which meant that there were still small joins between the holes. I chiseled these out, being careful not to split the grain in the wrong direction, and used a file to make the inside surfaces even and made sure that the blot has enough room to slide without being so loose that it will flop around.
Sunday, 18 October 2015
Tech Pack: Touch Mechanism
I wasn't sure if it would be possible to create a touch switch for my lamp but I thought it would be really cool if I could! I wasn't sure how the mechanism would work but I bought a cheap old touch lamp off Gumtree and asked an electrician friend to take it apart for me and see if I could salvage something from it.
With a few small hiccups we managed to put something together that works. It has a bit of a quirk because the original lamp had three brightness settings, and my LEDs are not designed to function that way, so it turns on with one touch like normal but to turn it off you have to touch it three times as if the other settings are still functioning. At this level I am happy to deal with a small quirk like this because it is just a prototype. I am sure with more resources it could be made without any problems.
Here is a video of the tech pack, not yet wired in, but working!!
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