I’d like to see us upgrade the electronics lab into something useful for targeting modern PCB type projects aka surface-mount dominated instead of through-hole dominated.
That means the addition of some things to the space.
This is probably the most important consideration. Leaving aside whether the old analog scopes work, modern systems all have interface buses like UART, SPI, I2C, etc. That requires a digital scope to decode.
There are lots of options: standalone, USB-based, tablet-based.
In my opinion, the two key features on a scope to be useful for hobbyist work are 4-channels and 100MHz. SPI decode requires 4 channels. 100MHz bandwidth barely captures 33Mhz signals (3x the fundamental frequency) but 33MHz is normally pretty fast for hobbyist signals. 5x would be better, but the jump to 200MHz is a significant enough price bump that you could buy a second scope.
I’m a standalone snob. However, the standalones have several points that I consider advantages in that they don’t require a paired computer, and they tolerate slightly higher voltages and misconnection better. If you tie a USB-scope ground to a solid 20V source, probably the scope and the computer are dead. If you tie a standalone ground to 20V, your circuit will likely vaporize instead.
I would probably go with a Instek GDS-1104B. That’s about $650-$750 and some places offer EDU pricing which we might be able to get. They hit the specs I laid out, and they transfer to PCs faster than most of the other choices.
However, I’m not wedded to this decision and am happy to discuss with people if they think there is something that meets our needs better.
- A Metcal soldering station (at least one)
Yes, we have Hakko’s. They’re okay. I used them personally for a lot of years.
And then I got a Metcal and my soldering got WAY easier. Don’t get me wrong, my soldering still sucks, but at least now I could at least make tiny 0402 components functional if not pretty. And I could solder big transformers because they finally got enough heat at the tip.
I can go into why Metcals are better technically if people want (careful … I will bore you to tears about curie points and power transfer), but the Metcals have two particular advantages for a hackerspace: the tips interchange easily without tools and they never need calibration. The tips are about $20 each and people who really care would probably purchase and carry their own.
The power brick (MX-PS5200) new is $600, but they regularly pop up on eBay for various prices and used is generally perfectly fine. The handpieces (MX-H1-AV) are about $140 new and do also pop up on eBay–used is a mixed bag. Someone with more patience than me at dealing with fleaBay and returns on suboptimal stuff could probably score something good.
We already have a microscope and it’s optics seem fine, but the ring light needs to be repaired or replaced. We need to refresh some basic materials/chemicals (see #5)
That would put the lab in a state that people could do stuff like hand solder up single boards ordered through OSH Park or hand solder up kits from Adafruit.
To be able to do multiple boards, we need a touch more tooling:
- PCB Solder Paste Stencil Printer
Those are generally in the $300-$350 range depending upon phase of the moon. They work. That’s about all you can say.
- PCB Reflow Oven
Whoo boy. In the middle of a hackerspace this is likely to be contentious.
At work, we bought a Qinsi QS-5100 from Alibaba. Those appear to no longer be made or all appear to be counterfeit, now. The difference between that one and the T-962(A,B,C,whatever) was the number of heating elements.
It appears that the T-962C is the closest equivalent nowadays-and it appears to be total garbage. So, it’s back to the venerable T-962A which has had a couple of upgrades. $350 and change.
As hackers, though, there is another option at about the $500 price point. You can build a decent one of these out of a convection oven and a controller:
That’s quite a bit of Reflect-a-Gold and Hi-Temp insulating blanket. Both are quite annoying to work with.
Can you go cheaper? Sure. But then you’ll spend more time piddling with your oven than building your boards.
There is also another really hacker option. It’s called “Vapor Phase Reflow” and it uses a thermal transfer fluid called Galden (I use Galden HS240, if I remember correctly–I’d have to go look up the receipts). At some point after Covid I may shoot a video about that. It has the downside that you now have a per batch cost to your boards (about $10-20 per batch), but the upside that your boards come out fantastic, and you don’t have to dork with the Chinese reflow oven profiles.
- Small refrigerator
Solder paste in particular needs refrigeration, and you don’t want people putting food in with it (eating metal–even if it’s Tin-Silver-Copper solder–generally isn’t exactly healthy). A small peltier thing is probably the right size and wouldn’t have the capacity to risk someone stashing their beer and getting it contaminated.
- Chemicals and sundries
These surprisingly add up more quickly than you expect.
- Flux Remover
- Paste Flux
- Basic Solder
- Solder Paste
- Lint Free Kimwipes
- Acid-free brushes
- Canned air
- Desoldering braid
- Aluminum plate scrap to solder things on
- Wire strippers
- Magnifying lenses
With that set of equipment, you can produce multiples of boards for classes or small production runs for businesses. For example, this would let you run a 10-20 person class on some Arduino project. Stencil the boards for the class, let the students populate them with tweezers and magnifiers, and reflow a bunch of them in single batches.
Feel free to suggest anything I missed.