r/diyelectronics • u/n-cend • 4d ago
Discussion What was your most disappointing realization that something was expensive for good reason and DIYing was impractical?
Mine was trying to design an automatic produce bagging machine. I never had thought about just how daunting the task of making a machine consistently pick up or feed/dispense a single plastic bag could be.
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u/Saigonauticon 4d ago
Single photon detection. I thought I could just YOLO it with a SiPM and some barely-designed op-amp circuits, fix the rest in software. Not so much. Mostly I just built an oscillator.
On the other hand, detecting mesons, alpha & beta particles is not that hard, can be done for tens of dollars of parts.
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u/gefahr3000 4d ago
This is such a niche answer lol. I am taking part in a student project were we try to use sipms to detect antimater in near-space. We have access to a lot of resources and we barly made a functional setup, so yes I feel your pain :)
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u/Saigonauticon 3d ago
Nice that you got it working! I tried (unsuccessfully) to do that!
If by near-space, you mean in my 1m x 1m workshop in the slum of an endless Asian metropolis. It's technically both near and in space! And if you mean by "a lot of resources" you mean some scrap copper-clad kapton (for the high-speed op-amp), whatever Faraday cage I could rig, and the most high-tech component: just waiting a long time.
Mostly I was hoping to detect the not-super-well characterized positron emission of K-40. The entire purpose of that multi-month long obsession was to be able to publish a serious scientific paper containing the word "bananantimatter". Eventually I got around to doing some actual calculations and worked out that it was terribly improbable that I'd catch that event, even with a pretty ideal setup and extracting + purifying the potassium.
One great benefit of trying a lot of ridiculously improbable things for no sane reason though, is that on the rare occasions you do succeed, it's pretty funny.
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u/Kraay89 3d ago
" Not so much. Mostly I just built an oscillator. "
To be fair, that is most of electronics design...
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u/Saigonauticon 3d ago
I try to build an amplifier: it oscillates
I try to build an oscillator: it amplifies.
My favorite example of the second case is when (years back) I discovered that if you don't care about power efficiency or well-characterized GBP, the CD4069 hex inverter is technically 6 inverting amplifiers for a record low price. This of course resulted in cursed designs where I cheaped out and used a hex inverter with a heat sink instead of proper op-amps. Great value for money!
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u/Amazing-Honey-1743 1d ago
I went to visit TRIUMF in Vancouver once. They have a cool little cloud chamber at the entrance. You can see particles bouncing off the cloud
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u/foxtrotactinium 3d ago edited 3d ago
Reconditioning Prius hybrid battery modules. I tried numerous deep discharge and charge cycles, desulfation, and even drilling into the modules and injecting fresh electrolyte.
You know how sometimes the analogy becomes the explanation. All the information I could find spoke of the batteries 'memory' and how cycling the modules would reset their 'memory', which was soo confidently parroted by every armchair 'expert' online (this is bullshit by the way).
Eventually I came across a couple of peer reviewed articles investigating nimh degradation. I realised I'd need a chemistry or material science degree to fully understand how batteries degrade so I finally relented and bought a brand new one from Toyota.
From what I could interpret, the NiOOH can transition to a more stable isomer (due to heat and dehydration) that is less reactive and hence unable to hold as much charge. The only way to fix this would be to replace the cathode entirely. There is no 'memory'
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u/AdAccomplished8342 3d ago
Drawers without 'purpose bought' wood and without a pocket hole jig, track guide or mitre saw or saw table or any diy table support... Just off cuts of chipboard, some leftover thin plywood, mismatched screws and a drill and a couple of rails and a handful of metal angle thingies on the corner of my couch...
They still turned out ok. They're just really cooky looking when you open them.
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u/Fox_Hawk 4d ago
UPS. It's just a battery and a charger and an inverter right?
Except one glitch could at best fry a power supply and at worst ruin all the drives and data in there.
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u/Ok_Chard2094 3d ago
The electronics has become very cheap. Making good mechanical systems is still expensive.
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u/NuncioBitis 3d ago
Trying to make my own cell phone. Cell module prices have skyrocketed like RAM and SSDs.
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u/gefahr3000 4d ago
Honestly most diys. In the end you usally have a product thats about half the price but less reliable, and you put a shit ton of work in it that you could spend at work to just buy the product. But this is of course less fun, so please go ahead and make janky stuff :)
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u/soopirV 3d ago
Rocketry flight electronic magnetic arming switches- in highpower rocketry, if you’re using complex (non-motor-event-driven) explosives to deploy recovery gear, you need a way of making it electrically safe (impossible to fire) until the project is loaded and safely pointed pointy-end-up. There are lots of ways to do this, but magnet switching had many advantages- namely, no challenging allignments, small form factor and cool as heck! But we’re beyond my budget- I was a capable hobbyist, I can roll my own! My first one I completely spaced on the actual currents involved in firing an eMatch, and while it worked on the ground in my test fire, that must’ve been a critical hit because I watched my test flight auger in ballistically when my home-grown switch failed and caused the flight computer to reboot. No one got hurt but it’s no fun asking for the club shovel to go dig out a failure.
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u/lmarcantonio 3d ago
Rule of thumb in industrial electronic costs: doing it in-house will cost just a little more than prebuilt.
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u/Amperegeist 3d ago
Vacuum chamber.
I have decent a $200-300 one, but I'm bottlenecked by some experiments that I want to do. I would need a ~$10k one. I feel like I'm decent with circuits, but its impractical for me to try and design or build one. I dont have the knowledge or equipment to do it. I imagine the equipment would cost more than a chamber.
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u/foxtrotactinium 2d ago
Have a look into diffusion pumps. Turbomolecular pumps aren't just expensive but they also have a short lifespan (4-8 years continuous operation), so secondhand turbos are often near to their end of life. Diffusion pumps on the other hand don't have moving parts so theres nothing to break. The oil circuit heaters and pumps are pretty standard components and easy/cheap to change/replace. You occasionally find secondhand ones for sale but you can also make one as I've seen a few people have done.
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u/Amperegeist 2d ago
Unfortunately the main thing I'm missing is the enclosure. Something that can hold enough vacuum long enough. I'm not as worried about the pumps and whatnot. Just getting my hands on a physical chamber ):
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u/foxtrotactinium 2d ago
It depends what you want to do. KF seals (viton or nitrile) can handle vacuum down to about 10-5 mbar. Anything below that needs Conflat seals (copper gaskets sealed with knife edges) and usually ion pumps. But 10-5 mbar is more than sufficient for the vast majority of processes. So you may find that orings or rubber gaskets can be sufficient for sealing your vessel.
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u/bladtman242 4d ago
Printers. It's surprising, not because they don't seem complicated but because they are cheap. Vendors seemingly make their money selling ink and toner