About Me

I've been taking things to bits, and making things ever since I can remember, starting with dismantling knackered alarm clocks and watches and helping my dad fix the car. Now I have a well-equipped workshop and have aquired lots of new skills, so I can make better stuff. When they first appeared, I became involved with personal computers, and these and developments in electronics have increased the scope of the things that I can do. Just recently retired, so O yes, now I can make all sorts of stuff.....

Monday, 29 May 2017

May 2017 update

Well, as usual, there have been a whole bunch of things going on in these here parts, so roughly in date order, here we go.

Automatic mechanical for Jon
I was busy with watches again at the end of last year and the beginning of this - an automatic mechanical one for Jon;  a quartz one that Owen helped to make, and which he took back to Oz with him; and a very challenging one for The Boss.

... and the 'exhibition back' window
The mechanical one was easier than I thought it would be, the usual agonising over measurements and tolerances, but it went together well and looked pretty good - I especially like the window in the back which shows all the oily bits whizzing round inside. This one, and Owen's, both used a new idea for the dial - a printed water-slide transfer on a plain light coloured background. 

Both turned out fine, although the transfer material is not completely clear so it gives a slightly mottled look to the dial which I quite like.  I have also played around with using a transfer like this on a light silver background, and then spraying over with a coloured transparent 'candy' paint, which looks very good (the colour conceals the mottling) but you have to be very careful when spraying as the thinners eats the transfer if it is laid on too thick.  How did I find this out, I hear you wonder.

Owen's watch was a similar case style, but with a different dial setup, different hands, and a quartz movement.  Not much point in an exhibition back, as there are no oily bits or whizzy things to watch. I cunningly left the difficult part of putting the whole thing together for Owen to finish off, and last time I saw them both it was working like a charm.

Owen's watch

Decorative back, but no window

Orange or what?
The third watch was anything but easy.  This was a completely different style to the other two, very modern and bright, and almost everything that could go wrong, did. We started with a long process of deciding what colour to paint the dial: it was destined to be a bright colour, using candy paint - transparent colour over a silver base coat - which gives a brilliance and depth to the paint.  We must have tried 15 different colours before deciding on a bright pink/purple, only to find that it looked rubbish when actually in the watch, so a late switch to a bright burnt orange candy which looked great.  In the process of making the case, I managed to strip the thread on the back three times, each time requiring a new back to be made, but finally got the watch assembled.  Left it on the kitchen table while looking for a suitable strap, and a few days later noticed that the hour hand had somehow picked up some of the paint off the dial, and smeared it all round.  Ah, I thought, I'll just make a new dial and all will be fine.  Except that when I took the back off to take it apart, the thread in the case stripped, so we ended up with a new case, and a new back, and a replacement dial and re-painted dial ring.  

Finally got it finished a couple of weeks ago, made a cream leather strap to go with it, and it looks pretty good - very noticeable and striking, though I guess not to everyone's taste. 
Its quite hard to capture the colour in a picture, if the light is too bright the colour just glares, and if its too dark it looks flat and washed out. Trust me, though, it is very definitely ORANGE!.

On the subject of devices to tell the time, I mentioned in my last blog that I was building a Arduino-based clock.  This now finished, and it does exactly what I wanted it to do - it tells the time in large, bright numbers, so that my dodgy eyes can see the time from across the room; it automatically dims the display after dark; and best of all, it takes power failures (we get probably two or three every month) and spits them out because it has a battery powered module on board that will remember the time for around ten years of no power.  As soon as the power comes back on, the time automatically shows correctly. Oh, and it automatically deals with the annual silliness of moving the clocks forward and backwards for reasons that probably made some sense in 1503 but is just a nonsensical waste of time and money now.
Now, some more Arduino fun stuff.  I have an amplifier attached to the main PC in the house, and to play music I have to lean over and switch it on - nothing too difficult about this, except that it often gets forgotten about after the PC is shut down, and ends up sitting there warming the room and doing nothing until someone notices and switches it off. This needs automating, without a doubt, so a cheap Arduino Nano and some programming produced a pretty respectable result.  The Arduino monitors the incoming audio line, and if it detects a signal it switches a relay to turn the amp on. It keeps monitoring the audio signal, and if it stops for more than a couple of minutes, it switches the amplifier off. A couple of extral LEDs on the front of the amp tell everyone what is going on, and with very few tweaks it works perfectly.  Hooray!

A bit less of that hooray! malarkey when I tried to apply the same treatment to the amp in the kitchen. This has two possible inputs, one from an iPod and the other from a Chromecast Audio jobbie, so the Arduino needs to monitor two different audio inputs and decide which one is live and switch the amp input accordingly.  This all worked perfectly on the bench, so with great ceremony I re-installed it in the kitchen and waited for the applause. Still waiting......  It turns out that I tested it using the iPod running on its internal battery, which worked fine, but I have discovered that the same iPod makes a very faint signal on the audio line every time the power supply.charger kicks in - about every five minutes - and although the noise is inaudible, its enough to switch the amp on.  Disconnect the power, and its fine. I have changed the power supply at least four times, tried different cables, added a ground loop isolator, and altered the Arduino audio threshold and the best result I can get is that it now only does the phantom switch-on around twice a day. Unfortunately, this does not impress The Boss too much.

She's also not too gruntled over my current Arduino project, which is an automatic watering system for a planter box that I recently built.  She was even less gruntled when I told her it was called "Watermation". I thought that this would be an easy project, but it turned out to be more complex that that.  It has a pair of moisture sensors that monitor the dampness in a couple of the plant pots, and when one or other of them decides its too dry, a pump switches on for a short period and pumps water from a reservoir onto the plants. I was a bit paranoid about leaks on my solid wood floor, so I installed another moisture sensor in the bottom of the box to act as a leak detector, flashing a LED and sounding an alarm it it detects water.  Then of course its necessary to monitor the water level in the reservoir, so a cheap ultrasonic module watches that and another LED turns on if it drops too far.  The pump came out of an ancient Toyota screen washer, but the Arduino can't handle the juice it needs on its own, so there's a relay module to do the switching, and another module that allows the pump speed to be controlled by twiddling a knob. Most excellent.  I still need to finish off the pipework to each of the plants, and a bit of trial and error is needed to ensure an adequate supply of wet stuff to each one without having so many holes in the pipes that there is not enough pressure left to feed the ones at the far end.
Ultrasonic level sensor
 The reservoir is a 5 litre screenwash bottle, salvaged from the bin

All the 'lectrics strapped to the water reservoir
Next time:  a report back on the kart, with a new steering wheel and angled boss, and a new footrest - lets see if that makes it any faster, plus another watch or two no doubt. And here's Jacob, playing with the most expensive toys in the house: a box of clothes pegs :-)