Friday, 3 June 2016

Sometimes you should just give up and watch telly

....just switch off your TV set and go out and do something less boring instead.
So shouted the kids from Why Don't You as I settled down on a Saturday morning, in front of the telly, to watch other kids going out and doing something less boring instead.

But it's become something of a by-line for nerd club. Maybe we should bring it up-to-date and make it "switch off your Xbox" or "shut down YouTube" or "put down your phone" or something. But the idea is the same - actively making stuff and doing something is far more interesting than gawping at a box in the corner of the room, passively taking in what is beamed into your living room.

I don't understand gamers. I don't see where people get the time to devote hours and hours to playing games. I don't watch much telly. If I were left alone in the house for three days (as sometimes happens when my missus goes away to visit family) there's a very real chance the telly won't ever get switched on. I'm too busy making stuff, planning stuff, designing stuff.... just getting up to stuff (although a large proportion of that time is spent browsing the interwebs for ideas or information).

But sometimes you might just need a break from being all creative - especially when things start to go wrong.

For me, it happened when I tried printing some large-format PCB designs on the cheap press-n-peel alternative paper. It wrinkled up, so instead of mounting it onto a backing paper, I shoved the press-n-peel straight into the laser printer paper feed.


With the paper wrapped around the imaging drum, and the paper so super-thin and fragile (it rips so easily if you try to ease it out of the rollers) this was going to be more than a five-minute fix.

Normally I can dismantle a printer in about three minutes. But that's using hammers and hacksaws, and assuming that I'm after the stepper motors and not wanting to use the printer as a printer again, any time in the future. This was a much longer drawn-out affair!

After about an hour of (careful) dismantling, it took about an hour to re-assemble the printer and get it producing pretty pictures on paper again. So this time, I made sure to always use a carrier sheet for the press-n-peel, no matter how large it was.

It took me three goes to get a good etch on my pcb.


Because of the large areas of black, the boards were heavily pitted in places. Not much of a problem. But that I was using 0.3mm thick traces for the various SMT parts meant some of the traces were fractured or completely broken throughout the board. It probably wasn't helped that I left one board in the heated ferric and forgot about it while I went for a brew and a biscuit.




When I finally got one decent board, tested all the traces for continuity and made sure all the components would be electronically connected, I did a dry fit using a mixture of SMT and through-hole (though surface mounted) components.


That's when it became apparent, I'd designed the board using the wrong sized SMT pads for the circuit. An entire five-hour day effectively wasted.

And I'd missed Bargain Hunt on the telly.

Today's life lesson:
Most PCB layout software has a "proof" print option.
Use it.