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Gemma Jewel polymer clay necklace, part three
In Part Two I made a domed top for the Gemma Jewel Circuit. But I still needed to make the rest of the case.
The battery connector on the Gemma is orientated to the outside, but that will soon be a polymer clay wall. I wanted to make the plug accessible so I added a battery connector. In the case of the JST breakout (Pimoroni | Adafruit) it just makes the on/off switch and the battery plug easier to reach. But I could also, just about, squeeze in a 2032 coin cell battery adapter (Pimoroni | SparkFun) either. I soldered on short JST leads to match the Gemma socket.
Then back to the polymer clay! To get the shapes I wanted I had to order two round cookie cutters. The inner/smaller one is 32mm, the outer/larger one is 43mm. I conditioned the clay, here Sculpey Black, by hand and rolled it out to a thickness of 15mm. I used the larger cutter first, then centred the smaller cutter inside it. I could get the smaller cutter out, but the larger one wasn't moving without deforming the clay, so it got baked with the clay. (I also made small indents where I intended to place magnets later.)
The doughnut-hole clay, removed from the centre of the previous step, I rolled out to a thickness of 5mm, and cut out a solid circle with the larger cutter. (I made matching indents in the clay for magnets.)
In order to be able to attach this to a necklace I made a finding from 20 Gauge black artistic wire, forming a loop with pliers, leaving tails that I curved into gentle hooks. The idea is to insert the hooks into the soft clay before baking to get a sturdy hold. (I coated the wires in liquid Sculpey before inserting them for good measure.)
Time to bake the forms. After they cool drill/rotary tool out the indents to a diameter of about 3.5mm, to fit the magnets. I also tried my hand at wet sanding. It is a lot of work.
I placed a tiny ball of black Sugru in the holes, placed the magnet, pushed it in, and covered with another lump of Sugru. Left to cure.
I put the two halves together, held by the finding, and shook them. They fell apart easily. The ring was simply too heavy for the two magnets. So I drilled out four extra holes in each half and added more magnets.
I also added a little trim of Sugru at the dome-side of the ring, just to keep the Gemma Jewel circuit neatly inside the ring. (And a little extra around the anchor points where wire meets clay.)
Then I hot-glued the dome to the case. Hot-glue is not a good option, but I had a hard time finding anything that would stick the two polymer clay pieces together.
I turned on the circuit, checked the effect. So far so good! But while carrying it to the mirror it all fell apart. The weight of the dome and the ring was too heavy for six pairs of magnets.
I had wanted to get a bezel to place around the ring, but could not find one in anything close to the correct size. After it fell apart is was clear I needed one, however, so I took the wire from before and hastily wrapped it around the ring a few times, and formed more loops on the ends to sit either side of the existing finding loop, for a more secure attachment.
It is not tidy, but it is very secure. I had to BluTak the dome back to the ring, because even the hot-glue refused to stick, but it works. If I want to permanently attach it there are a few things I could try yet.
To review;
On to the next iteration! (I'm thinking of, at least temporarily, replacing the dome with an unicorn horn for Neopixely unicorn horn magic.)
The battery connector on the Gemma is orientated to the outside, but that will soon be a polymer clay wall. I wanted to make the plug accessible so I added a battery connector. In the case of the JST breakout (Pimoroni | Adafruit) it just makes the on/off switch and the battery plug easier to reach. But I could also, just about, squeeze in a 2032 coin cell battery adapter (Pimoroni | SparkFun) either. I soldered on short JST leads to match the Gemma socket.
Coin cell and JST switched battery adapters with soldered JST plugs
Photo by ![[personal profile]](https://www.dreamwidth.org/img/silk/identity/user.png){kind=small}
chebe
Then back to the polymer clay! To get the shapes I wanted I had to order two round cookie cutters. The inner/smaller one is 32mm, the outer/larger one is 43mm. I conditioned the clay, here Sculpey Black, by hand and rolled it out to a thickness of 15mm. I used the larger cutter first, then centred the smaller cutter inside it. I could get the smaller cutter out, but the larger one wasn't moving without deforming the clay, so it got baked with the clay. (I also made small indents where I intended to place magnets later.)
Using cookie cutters to make cylindrical walls of polymer clay
Photo by chebe
The doughnut-hole clay, removed from the centre of the previous step, I rolled out to a thickness of 5mm, and cut out a solid circle with the larger cutter. (I made matching indents in the clay for magnets.)
In order to be able to attach this to a necklace I made a finding from 20 Gauge black artistic wire, forming a loop with pliers, leaving tails that I curved into gentle hooks. The idea is to insert the hooks into the soft clay before baking to get a sturdy hold. (I coated the wires in liquid Sculpey before inserting them for good measure.)
Disc of polymer clay with home-twisted wire finding
Photo by chebe
Time to bake the forms. After they cool drill/rotary tool out the indents to a diameter of about 3.5mm, to fit the magnets. I also tried my hand at wet sanding. It is a lot of work.
Backing disc, ring, and dome of casing, baked
Photo by chebe
I placed a tiny ball of black Sugru in the holes, placed the magnet, pushed it in, and covered with another lump of Sugru. Left to cure.
I put the two halves together, held by the finding, and shook them. They fell apart easily. The ring was simply too heavy for the two magnets. So I drilled out four extra holes in each half and added more magnets.
Backing disc and ring, with six magnets each, and Gemma Jewel circuit packed in
Photo by chebe
I also added a little trim of Sugru at the dome-side of the ring, just to keep the Gemma Jewel circuit neatly inside the ring. (And a little extra around the anchor points where wire meets clay.)
Back disc, ring, and Gemma Jewel circuit neatly packed
Photo by chebe
Then I hot-glued the dome to the case. Hot-glue is not a good option, but I had a hard time finding anything that would stick the two polymer clay pieces together.
Dome hot-glued to polymer clay case
Photo by chebe
I turned on the circuit, checked the effect. So far so good! But while carrying it to the mirror it all fell apart. The weight of the dome and the ring was too heavy for six pairs of magnets.
Looking good, shortly before it fell apart
Photo by chebe
I had wanted to get a bezel to place around the ring, but could not find one in anything close to the correct size. After it fell apart is was clear I needed one, however, so I took the wire from before and hastily wrapped it around the ring a few times, and formed more loops on the ends to sit either side of the existing finding loop, for a more secure attachment.
Case with improvised wire bezel
Photo by chebe
It is not tidy, but it is very secure. I had to BluTak the dome back to the ring, because even the hot-glue refused to stick, but it works. If I want to permanently attach it there are a few things I could try yet.
To review;
- There are no shadows in the dome from attachment mechanisms,
- The back opens easily to be able to turn on/off the lights, and to change the battery,
- But, it is a bit chunkier than expected, and protrudes forward more than is desirable.
On to the next iteration! (I'm thinking of, at least temporarily, replacing the dome with an unicorn horn for Neopixely unicorn horn magic.)
Current state of case; wire bezel and BluTak
Photo by chebe