On the topic of intricate diamonds and bad time management
In the spirit of full honesty, and so that I may one day learn from this, I will admit that my time management skills in this assignment have been… not ideal! Nevertheless, I think it turned out quite well!
The intricate
I got a little bit carried away with Adobe Illustrator this time. I ended up learning how to create custom brushes, define curvatures, and break things in the strangest ways. I don’t think I had any definite idea of what I wanted to design when I started, but it sort of just flowed when I got to it. A gear shape, some fancy curls, spear-like tips and some other holes here and there, and the design was finished! Looked pretty simple and mechanical, but it had a hint of “fancyness” that I really liked! And thus I chose that as the design to cut.
The Diamond
This is when things started to go wrong. Due to my exceptional time management skills, I found myself at the last day of the assignment, having yet to cut the diamonds. Early rush trip to the OEDK, fired up the water jet cutter, and… Errors. Errors everywhere. I/O Error when trying to boot up the machine, pathing, connectivity, and offset errors in the Layout app, tool parameter errors in the Make app… None of these errors showed up in the video, and they were not talked about anywhere on the instructions for the machine. With no choice left, I spent a few hours just trying to get the machine to cooperate.
I finally did! And the reward was great. Both diamonds cut effortlessly, without any visible defects, and even the smaller geometry on the part came out very visually pleasing!
Post Processing – Polishing and Chamfering
Right out of the cutter, the diamonds look fine. But thats it, just fine. There were two very obvious techniques that could easily be applied and they would make the part feel a lot more finished.
The first technique was sanding the surfaces with some sandpaper. I chose three different grits, 240, 320 and 400. I sequentially sanded the surface of both diamonds in increasing order of grit. After the final sanding with the 400 grit paper, both surfaces were much smoother, and much shinier as the layer of alumina that usually builds up on aluminum had been sanded off.
Next, for the second technique, I decided to take a file and add a chamfer to the sides. This gives the piece a much more solid look, especially at the tips. It no longer looks like a slice of sheet metal, but rather, a solid part. All of the strokes with the file were done in the same direction, to prevent the chamfers from looking scratched. This also gave the diamonds a nice edge glint when exposed to strong light.
Post Processing – Laser Engraving!
Not quite. I planned on using laser engraving for my third choice of technique, and in my head, seemed like an awesome idea. I had the pattern ready and everything! Some fancy multi layer swirls in various tones of grey. On the brigth side, I learned a lot about the new laser cutter, and I am now comfortable using it, which will help greatly later on. However, I regretfully inform that all of my attempts at engraving on the diamonds resulted in exactly nothing. The following picture is the state of the diamond after about 5 tries engraving it and at the end of the 6th.
If you look closeley, it looks like a nice polished piece with no engravings on it. You might even guess that nobody engraved anything on it! And that is absoluteley right. After all my efforts, not a single marking was made on that surface. I do not have any experience engraving bare aluminum, only anodized, so I was probably doing many things wrong. Sadly, it seemed like the engraving was not going to happen.
Post Processing – Change of plans
By now, unfortunately, I had spent almost all of the day working on the diamonds, and the OEDK closed. This means I had to leave, and thus, could not access any of the other tools such as paint or the sandblaster. After the faliure of the laser engraving I was still missing a third technique, so I scouted arround the house to see what I could find that could be used to further process the diamonds. A housemate jokingly suggested that I color the whole diamond with a sharpie! Which, honestly, I did seriously consider for at least 5 seconds. Interestingly, this thought of coloring the piece got me thinking about annodizing, which made me think that maybe, if I could heat the part up hot enough, I could forcecully form a layer of alumina oxide, which would make the surface of the part matte, and hard. Essentially a colorless annodization.
So I tried! In this house however, the hottest thing we have is the oven. And the oven only goes up to about 350ºC. Anyhow, I tossed the diamond in there and “baked” it for about an hour and a half at 350ºC. When I pulled the parts out… No result whatsoever. I thought this might happen, as I was not sure that the temperature was going to be high enough, and it wasn’t.
Without loosing hope, I kept brainstorming, and through this process I ended up remembering the time back in highschool when I was performing some electroplating experiments for my chemistry class, to try and devise a method of electroplating brass onto a copper surface. I immediateley thought that it woulld be awesome if I could electroplate part of the diamond, to demonstrate corrosion resistant protection as my final processing step. I did also realise that back then I was working in a lab setting, with lab gear, and lab grade chemicals, not in a college house, with kitchenware, and “house grade chemicals”. Undeterred, I formulated my plan.
Electroplating Aluminum
From previous knowledge, I knew aluminum reeeally hates copper. So copper plating was never going to happen. The closest reasonable match for aluminum was tin. So there is the first step, find tin. I am no chemical engineer, so I posses no chemistry equipment. However, I am an electrical engineer, and I do a lot of hobby electronics and such. So I knew I could get tin out of a piece of lead-free solder! 100% tin! Now I needed an electrolyte, and a beaker. For a beaker I used a plastic cylindrical container I found laying in the kitchen, and for my electrolyte, as much as I would have loved to have some Copper Sulfate on hand, I had to make do with a concoction of apple vinegar, salt, and a tad bit of lemon juice. I set the whole system up, and plugged it into my bench suppply. Cheap? Yes. Crappy? Yes. Would my senior year chemistry teacher be proud? Possibly.
I tested my method first with a scrap piece that was left over from the water jet cutting, on which I had also tested the surface sanding. This meant that at least one of its faces was polished and bare, like the diamonds.
To my surprise, it worked great! Electroplating with arround 30Watts, for about 30 minutes yielded the following result: (The section that was submerged in the solution and plated is clelarly visible in contrast to the section that remained outside the liquid)
It adopted the grey tone typical of tin plating! With my hopes restored, I repeated the procedure on the lower halfs of both diamonds, attaining simillar results. (Shown in darker light to make it easier to see the difference between the plated half and the bare half)
The parts were of course rinsed with water after the procedure, and the entire thing was done with plenty of windows open and proper airflow. I also refrained from touching, smelling or tasting any of the substances involved.
REmarks, conclusions and other thoughts
This one had to go first: Even though doing the almost all of the assignment in one day and setting up a clandestine electrochemistry lab in my room sounds like a solid plan, I really have to get a grip on my time management. I hope that in this class I will be able to consistently produce quality results, and I cannot do that if I do not properly organize my time.
That being said, the whole ordeal, although stressful, exhausting and sleep-depriving, it was also interesting, and dare I say, fun! And I have to say I really like how the diamonds have turned out. I kinda hope we are allowed to keep one of the two diamonds after this is over.
Cost of Production
Keep in mind that I am only considering the cost of the techniques which eneded up actually being used to finish the part. (I am not counting the cost of any tools or techniques which had no effect on the result)
Material cost:
Aluminum sheet: (Since I didn’t know what alloy it was, assume it is Alloy 6061, the most common)
Price = 22.50$/sqft
Used = ~30sqin = 0.20sqft
Cost = 4.50$
Tool time cost:
WaterJet: (1.5 hours) at (~35$/hr varies depending on what abrasive you use) = 52.50$
Sandpaper and file: (0$/hr they don’t get more expensive the more you use them, and the price of the used piece of sandpaper is negligible) = 0$
Electroplating setup: (1 hour) at (Between cost of chemicals ~9$, and electricity 30W for 1 hour, I estimate it costs ~9.01$ to run) = 9.01$
LabouR Hours cost:
The average pay for a workshop (similar conditions to the OEDK, not a factory) seems to be 25$/hr
Not including the time wasted on methods that did not work, I spent about 4 hours actively working on the pieces, which totals to 100$.
The average pay for a graphic designer (Think up and design the Illustrator pattern) seems to be 27$/hr
I spent arround 3 hours designing the pattern I wanted to cut, which totals to 81$.
TOTAL:
Adding up all the individual costs brings the total up to:
247.01$
Which means each diamond individually costs:
123.50$
If we ignore the graphic designer’s pay, as it is a fixed cost, not a variable cost, (The design is only designed one time, after that we can use it indefeniteley) it brings the final cost of a single diamond to:
83.00$
Kinda pricey to be honest. Although I guess I could call it modern art and sell each for at least 12,000$. After all, there are only two in the entire world…
