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This is a question Home Science

Have you split the atom in your kitchen? Made your own fireworks? Fired a bacon rocket through your window?
We love home science experiments - tell us about your best, preferably with instructions.

Extra points for lost eyebrows / nasal hair / limbs

(, Thu 9 Aug 2012, 17:25)
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Arcade madness
I make things. I particularly make things from my youth - probably trying to hold on to it I guess! I have a particular fondness for 80's arcade games like Defender, Track & Field etc...
I've made a few MAME cabinets over the years, but as life dragged on, kids, pets, etc... made having full size machines a little impractical, so I set about making a table-top cabinet of my own design.
I broke apart a USB keyboard and shorted the switches into a veroboard that I could wire the arcade buttons into.
After a few evenings of bad soldering, I finally had it finished.
It looked like a rats nest....but it worked. Of sorts.
I'd forgotten about the bouncing you get from analogue switches, so if you pressed 'Fire' once you'd get three or four presses of the button sent to the keyboard controller.
I realised that putting a capacitor across the bridge would solve the problem, however the wiring and soldering were far to fragile to take apart and fix...so I started enquiring about printed circuitry - turned out to be far too expensive, so looked into making my own.
You need a UV oven and a whole host of other expensive crap.
So....I found that if I printed the design backwards on a laser printer, then ironed it onto copper board (just about the only time I've ever used a clothes iron for anything), I could use Ammonium Persulphate to etch away the copper leaving my newly pressed imprint on the copper. Get a brillo pad and it should leave the copper underneath intact.
...I asked the electronics engineer at work if this was viable, and after he stopped calling me names and laughing told me in no uncertain terms that, no...it would not work.
The fool!
It bloody worked perfectly, however, the fumes from the Ammonium Persulphate probably guarentee that my lungs no longer do!
(, Fri 10 Aug 2012, 11:39, 7 replies)

Get some sodium persulphate, much nicer to etch with.
(, Fri 10 Aug 2012, 12:31, closed)
That's pretty much how we made circuit boards as school.
Except we used a waterproof pen to draw it out and then dunked it in an iron solution of some sort to etch the copper.
(, Fri 10 Aug 2012, 12:45, closed)
We had a bubble etcher, that didn't bubble.
So some kid always got the lovely job of spending all lesson jiggling the baskets with the boards in up and down.
(, Fri 10 Aug 2012, 13:35, closed)
Ferric Chloride...
It's messy and stains everything but it's much less horrible in nearly every other way.

The iron-on-toner-transfer thing works just great. Here are some boards I did from some artwork I found on the 'net:

The real problem was that the copier paper was a bit rough and "hairy" so the tracks needed a lot of cleaning up. Glossy magazine paper works well, apparently.
(, Fri 10 Aug 2012, 13:55, closed)
I did use
glossy magazine paper, but found that HELLO 90GSM works far better and is much less hit-and-miss. It's a bastard to get off once ironed on, but once you do get it off it works 100% of the time.
(, Mon 13 Aug 2012, 10:26, closed)
...save yourself all of that hassle and just buy a J-Pac or I-Pac

(, Fri 10 Aug 2012, 14:01, closed)

(, Mon 13 Aug 2012, 10:25, closed)

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