It’s quite impossible for me to read color codes on those blue one so, when I get a kit like the DSO138 oscilloscope, I end up testing every resistor.
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I just keep mine in baggies with labels and put those baggies in bigger bags based on frequency of use. cause fuck reading metal (blue back) resistors.
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@Farabide, in your opinion would it be possible to protect a potentiometer from being damaged by epoxy resin by first embedding it in epoxy putty? Presumably it should be possible to form an impermeable barrier between the body of the pot and the resin, while permitting electrical current to flow along the conductors.
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@Bitnik !!
I take one nap and you do all this! Love it!
Putty would work but seems overkill when electrical tape works. I’ve seen pot covers but they are awful.
(Now opening a sack of cats to toss among pigeons)
You could cast with voids (filled in bits) and drop in a pot afterwards.
Using female headers or ferrules (right word or have meds made it up?) So you can “decorate” a mignon with optional components or patch them to a circuit or another mignon.
Also wondered if adding some inlay like plasticene (ok, you spell it) would make mignons fit together like jig saw pieces or stack.
Sorry im still sleeping. Can’t wait to see what’s next.
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Thanks for the advice on casting and whatnot.
I’ve thought of this too. I’d say that’s a great idea for the second or third generation of mignons.
Your ice cube tray idea was more useful than you probably thought. Most mignons currently in planning can be extremely small in vitrine form so I can use ice cube trays for mass production of those items. As I think you also suggested, I could even make multi-cast vitrines.
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I wonder where you will end with this approach. This reminds me of semantic modelling. In AI quite a while ago people were working on describing an object or concept by listing primitive attributes and an object could be described as having that attribute (+) or not (-). It failed because it turned out that there was not a set of primitives you could describe every object with.
But the components you use are limited in number. I’m curious to see whether you on your quest to create a sub modular system will succeed.
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I don’t want to get rid of monolithic circuit boards. The things I want to pot are, for instance, an audio stage that translates between the line level on a Bela and the much hotter Eurorack audio. Or a Eurorack trigger and a tiny 3V3 trigger expected by or emitted by Bela (or ESP32 or any number of similar computing devices.)
There may be other items that can be usefully potted (such as a high quality external codec board) but I’d be using such items at the prototype stage. The eventual design would likely be a monolithic PCB or stripboard containing all the functions needed.
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I ended up on sdiy.info when looking for some CGS schematics and they say “If you cannot read resistor colour codes […] DIY is NOT for you.” so maybe I should practice a bit more before building more stuff.
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Yeah, you’re a real amateur. Leave the DIY to the pros with 20:20 full-spectrum vision 
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I’m working on a construction technique I call vitrine tripode. You build a tripod out of stiff wire with a three pin terminal block at the apex, solder the components in between the legs, and cover it in resin. I’m going to do a very simple build using this technique, perhaps just some LEDs between the legs of the tripod.
I’m going for a 2cm approx depth of resin (my test sample was just 6mm deep by 2cm square). The manufacturer’s recommended maximum depth is 1cm so I’ll be curious to see whether this works.
Why 2cm? That’s the approximate depth of the cups in my ice cube tray, and it looks roomy enough to solder together the kind of circuit I have in mind.
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People reading this may have realised by now that I’m not the most experienced in soldering. After yesterday’s debacle I worked out that using pliers to put a loop into my copper wire would make it easier to make it grip the terminal block legs during soldering. You just use the pliers to crimp the loop around the leg and it makes the process much easier.
Then I soldered the tripod together and added an LED between two of the legs. Using some basic kit I tested the circuit electrically so I know the terminal block is delivering power to the tripod and the solder joints are good. My disposable protective gloves are also shown here.
The 25ml graduated column made it much easier to mix up the resin and pour it into the mould. I did it in the bathroom again with the window open, and the result was no mess and no spillage. I kept stirring to a minimum (a few seconds gently stirring in the graduated column) and we’ll see if that affects the quality of the finished product.
Neve the greyhound was curious about the unusual smell. I sent her downstairs for her dinner.
And here is the finished pour. I’ll leave it for 24 hours to see if it sets. 20ml is just right for this volume of ice cube tray cup. I may have spilled resin onto the terminal block during pouring and we’ll see if that’s a serious problem when it’s all done.
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Yep, the loop wire round method works like a charm.
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Each time I go through this process it gets easier and less messy. I’m gathering together enough components to seriously try a batch of four or five vitrines at once. The tripod can be made in advance and shelved until I want to make up a mignon à vitrine. The soldered mignon can be tested in circuit to make sure it does what I expect, and again I can shelve it until I have a batch of resin to pour. Once poured I just wait a day or so and then I can test the finished vitrines.
The basic idea here is that the finished products can themselves be used and reused just as one reuses Lego bricks. As each vitrine design is built to a standard circuit, a faulty vitrine can just be replaced with a new one.
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Love the progress. Seriously, start the book!
I’ve glued smd parts to terminal blocks and pots and it works well. You may be able to add minor passives like resistors for your led or different caps to headers for jumper pins.
Sorry, heavily medded and not making sense.
In essence, gluing male headers to the side of the terminal block gives to a switchable wiring loom to build many variations of variable circuitry. For example a bank of caps or resistors you can switch from serial to parallel or simply create a bespoke value using the header pins as jumpers.
Keep going!
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As ever, even heavily medicated you’re a fountain of great original ideas. Mignon poilu.
I took a look at the vitrine this morning. It was rather cloudy, presumably due to insufficient stirring during the mixing process. It had a gelatinous appearance. I’ll check again in about five hours from now when it will have had a good day to set.
Edit later: it’s been over 21 hours now and only a thin crust has set so far. I’ll leave it alone for another day, but I think I need to find a different kind of resin for this thickness of vitrine.
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Meanwhile I’m keeping Neve company on the bed while I get on with preparing 15 5cm lengths of copper wire for production of trépieds by making loops in the end with a pair of pliers.
Neve is slowly recovering from the amputation of an ingrowing non-weight bearing claw. We’re not allowed to take her on her usual long walks, so she does a lot more sleeping than is normal even for a greyhound.
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After that, Neve needed some attention.
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Jebus is she ever a pretty, sweet girl! Is it difficult getting the resin blocks out of the ice cube tray?
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I don’t know yet. I’ve got a spare tray so if I get time this evening I’ll try a similar pour but this time paying much more attention to the mixing process.
The ice cube trays were advertised as silicone but are actually something called TPE. The stiff top part is polypropylene, I think, but the lower bowl is TPE and ought to have flexibility similar to silicone. I can’t remove anything until the resin sets.
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Here are a couple of videos. Excuse the mumbling. Recent dental work.
To summarise, it hasn’t set properly. I suspect the problem is inadequate mixing.
Examination.
Result of attempt to remove it.
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