Late August update

As usual, the work of the retired person is never done, and there's been lots occurring this month.  Lets look at some of it:-

First, a bit of a rebuild of my ancient air compressor.  I originally built this the best part of 30 years ago from an old compressor unit from a scrap fridge and an air tank off a lorry, and even had the build featured in one of the Model Engineer type magazines.  Given that the compressor unit is probably around 40 - 50 years old, its done sterling service - it blows up the tyres; blows dust and gunk off; and has done a huge number of spray painting jobs (including a set of kitchen cupboard doors; large parts of the old Morris van, and a complete Vauxhall Astra).  After all these years, its leaking a bit and the pressure switch - made from various junk including a piece of an old truck inner tube - was looking a bit sad. Time for a freshen up.

The main reason for looking at the compressor was because I have also ordered myself a new airbrush (yes, from China) and I will need a decent adjustable air supply for that.

It quickly became apparent that a new pressure switch sourced from the UK was going to cost £30 plus, so off to China to buy the same item for around £6 including postage.  Inspired by this find, I also ordered a new moisture trap for the princely sum of around four quid.

New moisture trap

Delivery was around 3 weeks, so in the meantime I set to work dismantling the old girl. For those that don't know, the back heavy lump in the bottom of a fridge is a steel bottle containing a motor driving one or two pistons.  Air is drawn into the space inside the bottle through a pipe, and is then sucked into the cylinders, compressed, and forced out through a narrow pipe. The bottle also contains a small amount of oil which lubricates the pistons via a crude pump arrangement, but unfortunately this also produces a fine mist of oil which gets sucked in with the air and which is guaranteed to ruin any freshly applied paintwork unless its removed first.

The rebuilt compressor

I took the top off the bottle by sawing through the weld seam with a hacksaw - if you choose the right spot, no metal filings will find their way into the innards.  My plan was to run the intake of the compressor directly to the outside of the bottle, thus stopping the oil from being sucked in with the air, but the contraption of pipes that I had to create to do this made the air intake much smaller than before and the compressor ran massively hot after only a few minutes, and it was clearly struggling to suck the air in fast enough.  So I reverted to the original design and will deal with the oil mist by means of the new moisture trap.  Topped up the oil a bit and tack welded the lid back on the bottle.  A bit of a tip here if you do this - after tack welding, make sure that you cover the joint around the bottle with tape or silicone sealer, if you don't the air gets drawn in through the joint instead of through the filter, and the noise it makes resembles the sound of a thousand centipedes farting.

.. and from the front, the string operates the drain valve on the tank

Earlier than expected, the new pressure switch arrived, a bit of hacking about of the pipework and its up and running.  Unlike the old home made switch, the new one is adjustable and also has an unloader valve which releases the pressure in the compressor itself when it switches off so that when it turns back on there is no pressure in the cylinders - a good idea to save wear on the compressor, and a very satisfying blast of air every time it switches off.

I plan to use the new airbrush on the bench, so I will need to run a long hose from the compressor and mount the moisture trap on the wall above the bench.  The moisture trap also has a pressure regulator, so it needs to be close to where I'm working.  Pacing up and down now waiting for  the postie to deliver the airbrush, and from then on anything remotely flat that stands still long enough will end up with an assortment of flames, skulls, dragons and flags.  Can't wait to get stuck in, though there is a lot of dark muttering from the kitchen every time I mention it.

Next, I've finally finished the water alarms.  When we built the house, I planned for these to be installed in both the utility room and the kitchen, as a water leak in a timber frame house with solid wood flooring would be a complete disaster. Over the years we've had occasional explosions in washing machines and I've become a bit paranoid about them, so a couple of weeks ago when the washing machine stared leaking and it turned out that the rubber seal on the door had a tear it prompted me to finish off the alarms.

The rubber seal was fairly easy to replace - you need to remove the top and the front of the machine and its pretty easy after that - although the genuine Miele spare cost the thick end of £90 plus postage.  Gulp.

Indicator panel in utility room

as well as the blow-your-head-off siren

The alarm is a simple Velleman kit which I installed inside a standard double wall box, with a trailing wire to connect the sensor - two stainless steel plates held around 3mm apart with a block of plastic and laid on the floor under the machine.  In the utility room, the box is in the wall behind the washing machine and connects to an adjacent CAT5 wiring point with a short patch lead, as well as a second lead that goes up inside the wall to emerge in a single wall box above the worktop.  This box contains a set of indicator LEDs and a fly cable to a siren mounted underneath the high level cupboards, as well as a kill switch for the siren and a test button. The test button has already given me endless entertainment at the expense of unwary visitors :-)

The unit in the kitchen

The CAT5 connection provides 12 volt power for the sensor, LEDs and siren, and also has a feed back to the Arduino to tell it when an alarm is triggered. I plan to rig up another central siren fed from the Arduino to kick off not only when the water alarms go off but also when any other alarming event occurs - for example, if the back door should open after 1 am.
The alarm unit in the kitchen is set up in much the same way, although its mounted in a cupboard which unfortunately muffles the siren a bit, but its still loud enough to trigger a change of underwear when it goes off unexpectedly.

Then there's the brass clock. Since last month, I've stopped drooling over it and made a ring face from 3mm thick aluminium sheet, mounted on to a satin black steel carrier plate and a small bracket for mounting.  I plan to mount it to a seriously chunky block of timber, then encase the clock proper in a glass-panelled shallow box - hard to explain, but you'll understand when I post some pictures hopefully next month. In the meantime, its been running more or less continuously, driven by the Raspberry Pi for now, although it will be eventually driven from another Arduino hidden inside the timber chunk. 

I've started writing the software, a bit tricky as the clock will need to know what the real time is without any feedback from the mechanism, and if there's a power failure it will need to automatically adjust its own hands to bring it back to the correct time. The plan is for it to continuously count the number of pulses it has delivered since 00:00 and convert that into time which it will compare with its own internal real-time clock. 

The glass panels will all be engraved with some suitable text, and I'm going to try edge-lighting the glass with high brightness LEDs in the hopes that it makes it look as if the lettering is hanging in mid air. Its gonna be a pointless beast, but a beautiful one


Last month I attempted to play chess with my grandson, OB, but failed as I had a set of pieces but realised we didn't have a chessboard. So this month I made one, and when OB and Charlotte came to stay last weekend we tried it out a few times.
As usual, its made from scraps, starting with a square of 18mm MDF.  I already had some offcuts of yew and some left over maple from the flooring, so I cut these into strips and planed them down to around 3mm thick.  Trimmed the strips to the correct width on the radial arm saw, and then set up a stop on the same saw to cut 32 squares of each colour.  I also had some left over strips of dark imbuia which I planed to around 3mm thick. 

Starting from the centre, I glued the first square and let the glue dry, then added a strip of imbuia and the next square pressed against the first.  Long strips of imbuia in one direction, and short bits the other and fairly quickly I had a board.  A final strip of imbuia all around the four edges, a strip of light wood salvaged from some venetian blind slats glued on all four sides, and we're done.  It took some fairly brutal work to sand the top flat - first took off the big sticky-up bits with the angle grinder, then the big plate sander with 80 grit paper, and finally the small plate sander with 240 grit wet and dry (much better than sandpaper, o yes). Three coats of danish oil, final rub down with a fine scotch pad, a good whack of beeswax and some serious elbow grease polishing with one of those micro-fibre dusters, a set of stick-on felt feet and it looks pretty good.

I'm pleased to report as well that the kart race in August went a lot better than the previous month.  The weather was perfect, warm but not too hot, and spending the money on a new set of tyres made a massive difference.  (Note to self: replace tyres every two or three races in future, instead of trying to make a set last all year.) I ended up having a couple of close runs with one of the many guys who are always faster than me, went quicker than him on two of the four races but never managed to pass him.The new tyres helped, of course, but I was a lot better at braking a bit later and not as much, as well as trying to resist the inevitable elbowing in the first few corners.  All in all, a good days racing.

Some movement on the medical front this month at last as well.  Rather than just opt for the standard radio therapy treatment from the local hospital to fix my prostate, I wanted to explore whatever other treatments might be available as well, so I persuaded my GP into referring me to the Royal Marsden in London.  This is a world-renowned cancer centre and one of only five hospitals in the UK to have a Cyberknife machine.

Standard radio treatment bombards the tumour with low power beams over a period of around seven weeks - it takes this long because the beams can damage healthy tissue, so the dose has to be strictly limited.  The Cyberknife (great name, eh?) fires multiple beams at the target from all different angles, so the tumour gets the full dose, but the surrounding pipes don't get damaged.  It was originally developed for use on brain tumours where surgery was not possible and standard radio therapy would cause too much damage.  The machine is very accurate, and automatically adjusts for the body moving as you breathe.

Well, we saw the Marsden last week, with good and not so good news.  The less-good news is that the Cyberknife treatments are only being done as a series of strictly controlled clinical trials and I don't qualify because of my previous colon cancer and my ongoing lymphoma.  The good news is that although they have a variety of more conventional radio treatments available, the one they recommend happens to be exactly the same as the one that is provided at the local hospital.  No point in trekking to London for that, so I've started the wheels moving here with the expectation of radio treatment starting late September and finishing around 8 weeks later, some time in November.

And finally:  busy flying the whizzcopter the other day down on the playing field when I was approached by a lad of maybe 10.  "Cor" says he, " that's great, can I have a go?"  "No" says I, "its too dangerous".  Lad thinks for a moment, then says "did you make it?", and when I told him 'yes' he says "Are you a scientist?".  "No", I says, "I'm a genius".  "Oh, right" he says and tootled off home, presumably to tell his mum that he'd just met the village idiot.

And next month?  If the airbrush arrives there will be lots on that, plus I should be well under way with the clock.  Vroom, vroom

July news

A bit late this month with this update, lots going on as usual.


Last month we had some sad news about Sergei the meerkat. This is a further update from Alexandrei Orlov, Sergei's friend:
"Peeples. Am wanting to thank all who send letter with sorry for Sergei, very kind, but waste of timing. Am also here to tell that I am very angry.  As all know, Sergei found hanging in workshop of Meerkovo Airways and everybody think he too stressed with new job and hang own neck. But when Vassily go to cut body down, he find that it not Sergei at all but just stupid meerkat toy!

Big searching by Meerkovo Security Agency (MSA) have discover many thing:  first, Sergei have pilfer many rouble from accounts over long time using IT skill.  Second, new stewardess Tanya have disappear, and three: new Meerkovo airplane have missing also.  MSA have follow airplane to Moscow airport and are believing that Sergei and Tanya are hide with american spy, Snowdon Edward.

This all very bad. Many rouble is gone, and Sergei having much cheap vodka and all kind of duty-free game with Tanya while I am bite furniture with angriness. MSA is on case, will catch stealing meerkat and bring back, hanging in workshop will not be joke this time."

Ooops.


Brass clock mechanism

This is one of my favourite pieces of silliness ever and I am childishly pleased with it. I have had a gear cutter for my little milling machine for a long time, and finally decided to try it out by making a clock mechanism.  I started by making a mock up, then amended the bits that didn't work properly and produced the final article. The pictures are a bit pants, but give the general idea (the black lump is the stepper motor).

Cutting an alloy gear on the mill

Its a pretty simple gear train, as the clock only has two hands (minutes and hours) and a simple 12 to 1 train between the spindles.  The smaller gears are turned from brass rod, with the bigger ones made from aluminium, and then the teeth are cut using the rotary table stood on its side. I made all the gears with numbers of teeth that can easily be counted in whole degrees as I don't have a dividing head. The smaller gears were cut from one solid rod and then parted off on the lathe. Each set of gears was then mounted on to a brass spindle and a silver steel shaft pressed into each one.

The front and back plates are made from 2mm thick brass, with the gear spindle holes carefully drilled to the correct centre distance on the mill using the rotary table to get the correct angles between them. The original prototype was marked out with dividers and drilled from centre-punched marks, but the spacing was not accurate enough and the gears didn't mesh properly.

Stepper motor and controller

The clock is driven by a small stepper motor - less than two quid each from my friends in China - and the drive from this is geared up 9 to 1 so that a large number of motor steps provides a small movement at the minute hand.  I've had it running off the Raspberry Pi and it chunters away happily.

The plan is to drive the motor from an Arduino (I already know how to program this; its a bit simpler than the Pi and there's only so many different languages I can be arsed to learn).  There will be a position detector on the hands so that the Arduino knows where they are and it will automatically compensate for time drift by adding or subtracting a few steps each hour.  The hardest part is going to be setting the time - 'real' clocks have a clutch on the spindle so that you can just whang the hands round but I would like the Arduino to do it automagically.  My plan is for the Arduino to go through a setup routine each time it is powered up, so it needs to turn the hands to a point where is knows where they both are; then calculate the number of motor steps required to get to the 'real' time, and then crank the motor as fast as it can (either forwards or backwards) to set the hands correctly.  If this works as planned it should look really cool, and  you should never need to touch it, although compensating for summer time/GMT is going to be a bit of a chore.

Anyway, the end result is that the mechanism looks pretty good and works a treat so far, I just need a cheap Arduino and a few days spent in the programming room before fitting it into a case.  I was originally planning to use it for the garden, but it seems a waste to hide those luverly gears away inside a housing so I'll get the programming working and then decide where to put it.  Non-rude suggestions are welcome.



Metal storage in the workshop has long been a problem.  The raw material comes in a variety of sizes, and once some of a length has been used, the remaining stumps end up swilling around the bench and getting in the way.  Time to resolve this, and it turned out to be much easier than I had thought.

The long pieces - up to around 1 metre long - are all now stacked neatly on a rack which is fixed to the wall.  The rack is simply two strips of slotted angle from the junk pile with steel rods welded on at around 45 degrees, and once the angles are screwed vertically to the wall the metal bars are just laid loose on the angled rods.  Works a treat, the pile of spider-infested metal that used to live in the corner is now a neat and easily accessible stack on the wall and the spiders need to find some place else to live.

The shorter bits provoked a bit more head scratching.  They come in all sizes, from a couple of centimetres up to 40-odd cm.  The solution was a couple of lengths of plastic waste pipe, sawn into various lengths and gooed to a piece of MDF with that excellent 'No More Nails' stickum.  I also gooed each piece of pipe to its neighbours and the end result is a pretty solid cluster of tubes.  The shortest pieces of metal are too small to fit into a tube - they all jumble around in the bottom and you can't get 'em out - so they ended up in an old plastic storage box.

All in all a neat and easy solution, and the workshop looks heaps better for it. Oh, and I can now find stuff as well :-)

A couple of months ago I mentioned the cows painted on the wall of the house in the village.  I recently bumped into the artist and he told me that a couple of other people had asked him about painting cows on their walls, and the first of these was finished a couple of weeks ago.  I can't explain why, but I really like this idea, if we had a painted wall I might ask him to do it here.

We took the kart out for its second outing this year last weekend with disappointing results.  It was one of the hottest days of the year, certainly the hottest we've seen at the track - announcements over the tannoy all day reporting on the ever-rising temperatures and pleading with everyone to drink more.  There was racing the day before, so the track was full of grip, but man, was it hot in the full race overalls, hard hat, boots, gloves, rib protector, phew! My driving performance was rubbish, though - braking too early and too much; too slow into the corners; leaving too much space in front at the start (just asking for someone to drop in there), the list of errors goes on.  I was better at this last year - not good, but better - and it seems that not racing for around 9 months means that I have completely lost any track skill I once had. As the day went on, all the drinking started to take its toll with water sloshing around in my bilges, and the old neck started to give out in the same way as the month before and the last few laps of the final had me flopping about like a rag doll.

I do have a bit of an action plan for next month.  A new set of tyres to replace the old five race set, and a bit of effort to move the seat forwards slightly to increase the grip at the front to make the beast turn in a bit better.  I also plan to follow Jon's advice and exercise the old neck by working it against a weight as well, and then its just a matter of not being such a wuss when out on the track.  Get a grip, man.

I've also been doing some deck repairs, a bit warm for clambering about under there but I need to make the most of the fine weather.  A couple of the deck boards have rotted and needed to be replaced, and over the ten years that the deck has been there some of the foundation posts have subsided and pulled it out of shape.  Replacing the rotten planks was easy enough, and I re-levelled the rest of it by pulling out three boards in the middle, unscrewing the joists from the supporting posts and jacking the whole thing up with as selection of car jacks until it was level, then replacing the screws.  A lot of huffing and puffing, but its done and already looks better.  The last remaining job is to pressure wash the whole thing and then paint it with some non-slip deck paint - unfortunately the rain water tank has gone dry with the lack of rain, so this will have to wait until its filled up a bit, the old pressure washer consumes water at an astounding rate.

The fine weather also means that I have been flying the tricopter quite a bit, and I am very slowly getting better at it.  Not had a crash for some time now, but panic still very quickly sets in when the thing suddenly sets off at speed towards the village hall or a passing pedestrian.  I can now do the banked turn thing, but the flight controller obviously thinks that more power is needed for this and it comes out of the turn at supersonic speeds.  I'm still having trouble working out which way its pointing when it is a distance away, and when its a long way off I'm still having trouble deciding if its high, or distant, or both, making it hard to judge where its going to come down if an emergency landing is required. Still, onwards and upwards.

And finally, the latest medical news.  I'm still in good shape, in spite of the hormone injections adding around 5 kilos to my weight and giving me a dull headache most of the time.  The good news is that the PSA reading is now down to 0.3 (the closer it is to zero the better).  We saw the oncologist  a week ago, and he agreed without a fight to refer me to the Royal Marsden in London, we should hopefully get an initial consultation with them by around the middle of August, then see where that takes us.  More forwards, please.

Next month:-  Charlotte and OB came to stay with us a few days ago, and we were going to play chess only to discover that we had the pieces but no board to play on, so I've started making a rough board, progress report next month.  I've also agreed to build some picture frames for them both, and hopefully I'll have some better results to report from the next kart race meeting. I was going to attack the Arduino temperature sensor that is misbehaving, but the fine weather has meant that I have spent most of my time outside so this will have to wait for some cooler weather.

June update

Loads been going on this month, a quick summary as follows.

First, the Whizzcopter.  I'm pleased to say that updating the fimware on the flight control board has made a massive difference to the flyability of the tricopter.  During this fine weather, I'm flying every couple of days or so, and havn't had a serious crash yet, although I managed to fly it completely out of the village playing field and dropped it gently into the farm field beyond.  The field turned out to be waist-high with nettles and other savage plants, and it took a while to find the machine - perched vertically on the edge of a ditch with around two feet of water in it.  Lucky or what?

I still havn't mastered flying it towards me, nor the execution of banked-turns-with-simultaneous-altering-of-throttle, and the dropping into the field escapade highlights the fact that when the beast is high and far away its impossible to tell height from distance. Its also surprising how much even a light wind can blow the thing about - changing the propellers for a smaller size made it better, but its still a handful in anything but almost still air. If the fine weather continues, I'll keep flying.

Then there's Sergei.  After last month's exciting news item of him piloting the whizzcopter, I've had a message and picture from Alexander Orlov from Meerkovo with some sad news.  The message reads as follows:-

Sergei RIP

"Am having to tell bad news about Sergei.  I know him all my life, and until recent he was in charging of IT department, but wanting more adventuring.  After much training (almost ten minute) he is put in charge of Meerkovo Airways first airplane.  However, flying performance was not good, mainly because he spend much time in cabin playing 'hide the sausage' with funky new stewardess Tanya instead of pulling stick at front.  After too many crash landing, we have suspend his fuzzy ass, and he taking this rejection much badly. Picture show how we find him in workshop. Still, he never good at IT, and worse at piloting, so no great loss.  Am more concern that new airplane can not be found, and Tanya so upset about Sergei that she have disappear too."

Grandfather clock wood pen holder

A few small things built this month.  The first is a pen holder for my desk, made from the remaining fragments of the ancient grandfather clock carcase.  Once all the woodworm, dry rot, nail holes and bullet wounds were cut out, there wasn't much wood left that was usable and this little item finishes off all that remained, while all of the left over unusable stuff has been given a chance to serve again by providing light and warmth in the fire pit.

The fire pit in action

I'm still doing some low-level background work on the Arduino to make it deliver information to a 'status screen' to be driven by a Raspberry Pi.  The Arduino has been working fine for a long time now, turning things on and off and monitoring the status of door locks, lights, and other stuff, but the temperature sensors I used never worked properly.  These were LM34s, bought to match some sample code that I found on the web, but only later did I discover that they read temperature in Fahrenheit which required the software to then convert readings into Centigrade. A bit more research, ordered a couple of TMP36s which read directly in Centigrade, hack the software about and bingo! she works. Well, sort of.  The original sensors gave readings that floated all over the place, and one of the new ones does the same.  Playing around with things leads me to the conclusion that the sensor works fine and that the fault is in the wiring somewhere, so the Arduino box has to come out of the rack to trace the dry joint or bad crimp.  This is a bit of a trial because of all the wiring in the engine room, so I'll do this next month.

Power supply from PC PSU

I've also made a general purpose power supply for the workshop out of an old PC power supply that I've had kicking around for a few years that I am never going to use for a PC.  This conversion is pretty easy to do, loads of information on the web on how to wire it up, and the hardest thing was trying to connect and bundle all of the hundreds of wires that need to be tidily crammed into the enclosure.  I managed it without any blinding flashes or other incident and the picture shows the end result - the only problem is that the blue LED is so bright that it nearly sets your hair alight if you get too close:  "don't look at the light, Mary..."  The box dishes up pretty tightly regulated voltages of 3.3v, 5v and 12v, and I've already used it a few times to test various things to see if they work.  Useful things made from junk again :-)

Table with umbrella

Last month I built the garden table which has been a big success, especially now that the plants are getting a grip and flowering.  Its also just the right height to put your feet on while sunning, excellent.  With the recent fine weather it seemed a good idea to add a stand for the umbrella that has been home to several generations of mice and spiders in the shed for the past couple of years, so a bit of work with a boring bit, some scrap wood, a few screws and my little hammer produced this result.  Looks good, works well, another successful junk conversion.

Workshop floor paint job

I've also just finished painting the workshop floor an attractive battleship grey.  It nearly killed my back and knees, but its much easier to sweep up the wreckage and it brightens the place up a bit as well, and it should also stop the rain from soaking into the concrete and creeping under the door.  Since I've had the paint for the best part of five years I thought it was about time I used it - of course, it ran out after around three quarters of the floor was finished, so I had to buy more, and you can only buy it in 2.5 litre cans even though I needed less than a litre.  Ah well, I've got some spare in case I need to paint some other floor some other time.


Last Sunday was race day, the first time I've raced the kart since last October.  Near-perfect weather conditions, and a track with plenty of grip should have made for a great days racing.  However, my driving was pretty poor, with whatever skills I possessed last year completely forgotten, and by the last race my neck muscles were so knackered that I couldn't control the flopping of the old bonce against the g-forces.  Good fun for all that, but I need to build up the muscles a bit before next month's outing - Jon says I need to tie lead weights on my helmet, but I'm pretty sure the scrutineers will have something to say about that.

Last, a health update.  Just had the third of the hormone injections and done loads of research on the best place to get the radio therapy - probably in London, and I suspect I will need to get the local wallahs in a Kytherian death grip to persuade them to refer me.  I'm currently waiting for an appointment with the local oncologist to kick off that discussion:  'round one, seconds out!'...  

Next month: I will have the Arduino home control box to bits and sort out the temperature sensors properly, and I'm working on some storage solutions for the various piles of metal and other important stuff in the workshop, as well as planning a clock for the garden (probably driven by an Arduino and  stepper motors).  I have also been thinking for some time about building a 'thousand year clock', o yes: more on this later.

May update

Well, here we are in May already, another month and some more new stuff occurring.

First, a progress report on the Whizzcopter.  The early flight experiences, all quite a long way south of 'good', have resulted in a number of changes to the design.  The original frame was a fine engineering piece, immensly strong, but quite heavy as it was made mostly from aluminium, although I was pleased to see that the motors and props were quite happy to hoist its considerable weight into the air with ease.  My plan was to practice in the garden to aquire at least some rudimentary skills before heading for the airfield, but this didn't work out too well.  For starters, what seems like quite a big open space suddenly shrinks when the 'copter starts swerving about, and then there are all sorts of obstacles that it seems to find as if with a magnet - flowers, trees, fences, houses, people - and most of these result in broken propellers. I struggled on, but soon began to see the real problem with the weight - not with lifting it up in the air, but instead with the considerable impact when it hit the ground and the resulting damage to the metal frame.  Slowly but surely, the alloy arms became bent; the motors started to lean in different directions and the rudder became less and less useful, all of which made it more and more erratic and hard to fly.  Eventually a very substantial prang onto the tail boom trashed the steering servo, and it was back to the workshop for repairs.

Bent alloy arms

Only when I had it in pieces did I realise how much of a hammering it had taken, and it was clear that a reduction in weight was necessary.  Off to that nice Mr Ebay, and a couple of days later some lengths of 10mm square carbon fibre tube arrived.  Easy enough to make some new arms, mounted the motors directly to them instead of using the metal mounting plates, ordered a new servo (mounted above the arm and out of impact range) and we're back to the garden.  Flying skills still much the same, but the much reduced weight means that the crashes no longer woke sleeping children in the next village, so off we went to the playing field just down the lane.

Broken carbon arm :-(

With more space to work with, things were a lot better, although of course the higher you fly the more the wind affects it and the harder it hits the ground when it comes down:  however, the carbon fibre arms took the punishment pretty well until one of them snapped off at the root.  I had some spare material, so replaced the arm but a few flights later the steering servo sheared all the teeth off one of its gears and it was back to the workshop again.

Sergei ready for taking off

As an aside, we did try a couple of flights with Sergei the meerkat strapped to the top.  His extra bulk made the copter very unhappy in the brisk breeze, and he didn't enjoy the landing much so we let him get off.

Close examination of the arms showed an interesting thing.  The carbon tube is immensly strong across its section - ie, left/right and up/down - but the landings rarely hit the ground straight on, and instead the impacts apply a twisting motion to the arms.  The tube is 'pulltruded', which means the fibres are arranged longitudinally, and twisting the tube makes the fibres crack apart. This then makes the arms very rubbery, and as the craft swings wildly around the sky the force of the propellers twist the arms which then confuses the flight controller board  and results in even more wild gyrations and the eventual crash.  Hmm, unless I can guarantee to only land in a controlled manner (unlikely any time soon), I need to modify things a bit.

Revised steering servo mounting

More carbon tubing duly arrived, as well as some alloy tubing of the exact diameter of the hole in the carbon tube, and I epoxy glued the alloy tube inside.  It adds a bit of weight, but not a great deal, and the arms are now much more rigid and twist resistant. I also replaced the servo, deciding that the cause of the gears stripping was probably the weight of the motor jerking to the side when crashing and applying considerable force to the servo gears.  I've re-made the motor mounting and the steering pivot to make the whole thing smaller and mounted lower, and fitted an old 'servo-saver' that I had in the old RC car racing junk box - these devices are intended to absorb the shock of car wheels hitting a rock or a kerb, so I'm guessing they should work here as well - if not, I also have some model shock absorbers in the junk as well, so I can fit one of these to the motor mount.

I've only had a quick test flight, but the inevitable heavy landings don't seem to have had any effect on the arms, even though one of the crashes was hard enough to jerk the motor connectors apart.

The other thing which will almost certainly help matters is an upgrade to the firmware on the flight controller board.  All the experts on the web tell me that the automatic levelling is much improved, and I have to say that the early test flights are much more stable and predictable.  Woo hoo, if the weather improves from today's wind and rain I'll be off to the field to try it out proper like.  Watch this space

'Copter battery charger PSU

The 'copter needs batteries, so I bought a cheap charger which only runs off 12 volts DC - ideal when on an airfield where you can charge from the car battery, but no use in the house.  So I knocked up a simple power supply using a transformer, some capacitors and a 12v voltage regulator all mounted in an old metal case and it works a treat.  Solved the problem, and reduced the quantity of unused spare parts in the workshop, good result.

While playing with this I tried to use an old PC power supply, but although it supplies the required 12 volts, it couldn't handle the current and kept tripping out.  I tried a second one in case the PSU was faulty, and that one was worse.  Presumably the charger is asking for more juice than the PSU can provide without getting upset. This does present another opportunity though, as these PSUs supply well regulated 12v and 5v outputs, which are very useful for a whole host of things, so I plan to modify it slightly to give it proper plugs and sockets, and then mount it underneath the top cupboards and above the bench in the workshop.  Another triumph of turning junk into something usable, hooray!

Now for something more simple, a windshield for the camping stove.  This little stove has been invaluable for brewing tea, coffee, soup and other stuff on karting weekends and out other travels.  However, it suffers badly from wind (stop giggling at the back) so I decided to make a simple folding windshield.

The windshield under test

I unearthed some stainless steel sheet left over from the chimney of the hob extractor fan unit and cut it into four equal squares with the jigsaw, then carefully rounded the corners and took off all the sharp edges with a file.  I need the thing to fold up, so I drilled the side edges of all four sides and hooked them together using some strong wire split links (made from an old coat hanger, wound round an 8 mm rod and split with a Dremel).


 

... and folded flat

The end result is pretty good, I think.  Its heavy enough to stand solidly on its own, but not so heavy that it will be a pain to cart around, and it folds up into a neat flat arrangement that will be easy to stow.  Another triumph of turning junk into useful stuff, so another hooray.






Next up, the deck table - no, not a deck chair, a table.  This is a simple design that I've been thinking about for some time, so I fetched the timber a couple of days ago and yesterday decided to start preparing it.  Before I knew it, around 4 hours later, and the thing was finished and in position on the poop deck at the back of the house.

This is a Serious Table.  The top is made from four 6 inch x 4 inch sleepers, and the legs cut from another one, with various chunky bits screwed up underneath to hold it all together. I've left a gap down the centre to fit a pair of plastic planting troughs which will eventually be packed with exotic blooms (or pansies if the exotic stuff fails to grow). The sleepers weigh around 25Kg each, so the whole thing weighs in at around 140 Kg:  the wind that's been tossing our garden chairs all over the village for the past couple of weeks is going to have a bit of a struggle moving this puppy.

Last, there's the happy story of the cows on the wall. Before we moved into the village, an elderly gent who lived in a cottage at the far end decided to paint the side wall of his house with pictures of cows.  He may have been slightly deranged, but he painted huge cows and flowers in the style of a five year old all over the wall and although the traditionalists probably recoiled in horror, I liked it.  He was a nice enough chap, if slightly eccentric, but unfortunately he died a couple of years ago and the house was sold.


A few weeks ago I drove past the house and a local decorator was up a ladder repairing and re-painting the wall:  a bit sad, I thought, the old boy had been a bit of a character and the cows were a bit of fun.  Ah well.

Fast forward a few more days, and hooray! - the decorator is also an accomplished water colour artist and here he is painting a new set of cows on the wall.  Not the cartoon ones of the original, this is a proper true to life painting, it looks absolutely great and its also a nice tribute to the old boy who originally lived there.

And finally, an update on my medical situation which is looking much rosier, I'm pleased to say.  I'm well under way with the 3 months hormone injections for the prostate, and expecting the radio therapy to start probably sometime in June or July.  The lymphoma is apparently a very slow growing type, and may end up being treated with chemo or just left alone and closely monitored - I'm having a bone marrow sample taken tomorrow which will provide some more information and seeing the specialist again next week to work out what happens next.  I've stopped tae kwon do training while we work out what is going on, so I need to start a regular excercise programme to keep me fit until I return to the dojang.
Must go, the workshop is waiting....

March update

Its been a mixed time over the past month or so with other stuff getting in the way of me making things.

The main 'other stuff' has been some medical issues.  Long story short, in January I went to the doc for my annual medical for my racing licence, and while there he suggested a PSA blood test.  Various biopsies and scans later and it is confirmed that I have prostate cancer, not particularly surprising in someone my age, and treatable in a number of ways - the general view is that people die with prostate cancer rather than from it, so this is a Good Thing.

One of the scans also showed some enlarged lymph nodes, so a couple of weeks ago I had surgery to have them removed and taken away for questioning.  We got the preliminary results back yesterday, and more good news - its neither the colon cancer making a return visit, nor is it the prostate, since both of these can be pretty nasty.  Instead, its apparently a non-Hodgkins lymphoma which is described as 'very treatable' by the nurse who called. Treatment seems to be chemo of various sorts, so we're waiting on an appointment with yet another specialist to find out whats in store, but the overall view is that outcomes are generally good, so hooray for that.

So in between hospitals and doctors, what else has been going on?  Not a great deal, but some progress.

The parts for the whizzcopter have been ordered and are expected to be delivered by around the 24th.  I already have the batteries, which turned out to be bigger than advertised, so I've had to remake the battery tray gubbins to make it fit.  The battery charger came with no instructions whatsoever, and a non-intuitive user interface, but fortunately there are loads of videos on YouTube showing how to set it up, and in spite of all the horror stories about exploding LiPo batteries mine charged up without a hitch.

Once the rest of the bits arrive, all I will need to do is to install the flight controller and set it up, get the radio working and we're off.  Except that Sean got his quad running a few days ago and it seems to be a bit of a handful, and there's no reason to believe that mine will be any easier to fly.  Good thing I ordered the spare propellers, methinks.

On the karting front, we had a test run a couple of weekends ago to try out the changes made to the front end to cure the turn-in understeer.  It was pretty cold, so not a great deal of grip, but opening up the front track by 15mm each side seems to have made a considerable difference with a big improvement in the way it turns in to and progresses through the corners.  When we set up the alignment, the camber on the offside was a bit out, probably due to some minor twist in the frame or a bend in the stub axle.  We altered the camber by one notch on that side only to bring it roughly correct according to the lasers, but on the track it was an absolute pig - very heavy to steer, and lots of jacking of the rear wheel on the corners.  We reset it to the neutral position and its much better, astonishing that the smallest possible adjustment made such a difference to the handling.  Hopefully, the next race meeting in May will be warm and dry and we can check it out in anger.  In the meantime, the rear bumper has snapped (a vibration induced fracture, common on these parts), and the battery is showing its age and needs to be replaced.  Time to get the credit card and the welder out.

Which neatly brings me to the next item.  All those who know me agree that my welding skills are legendary - ie, I score maximum points for the amount of weld, but nil point for the quality and appearance. When I was a boy, this style of welding was known as 'bird shit welding' which describes it rather well.   Well, I've had to make a new hinge arrangement for the lift-up hatch in the decking that covers the underground gas tank, and because my old welding mask was broken, I decided to splash out 35 quid on Ebay for one of they new-fangled automatic jobbies. Hoo boy! Its great - easy to use, none of that 'flash the weld and shut your eyes' malarkey, and no more painful arc-eye.  Best of all, because I can use both hands and see what is going on at all times, the welds are much smoother and better in every way.  Obviously I am actually an excellent welder, let down by my poor equipment in the past.

The hinges as a result are a great success.  The old arrangement was a set of biiiig steel hinges, which worked ok for a couple of years and then rusted up solid, with the result that the next time the lid was opened it tore the screws out of the wood.  Not good.  The new arrangement will be marvelled at by archaeologists in future centuries - it has two massive tubular steel brackets which hold 55mm diameter ball bearings, with a 25mm shaft between them, and the whole thing mounted to the frame and lid with 8mm bolts. Thanks to that nice Mr Ebay, the bearings cost around 3 quid each, and the steel tube another fiver or so, so the whole thing came in at under 15 quid.  Not bad.  The down side is that the lid is supported by a pair of gas struts from a 1983 Vauxhall Astra, and one of them has given up the ghost - this is pretty poor, especially as I used the last of my spares to replace the one on the side gate only a couple of months ago, so I'm going to have to find a scrapyard and get some more.

I've also re-started work on the Raspberry Pi stuff.  I've simplified the stream of data coming out of the Arduino box, since the software that was interpreting it seemed to get confused after a while, and I'm in the process of re-writing the PC software to grap the data stream and put it in a file that can then be read by a web page and displayed on the Pi.  However, this unearthed another problem that has me completely banjaxed.

I'm using Visual Basic 6 to do the programming, because I have used this a lot and it just works - I have the VB.net as well, but its hugely more complex and I'm only doing simple stuff for which VB6 is fine.  So, I open up the code for the old version of the software - lets call it version 1 - and hack it about to suit the new data stream, then save it as version 2.  After a few attempts, it becomes clear that version 2 has lost its way and I need to start again, so I close version 2 and open version 1 again.  Except that now version 1 opens with all the new code from version 2, and nothing I can do will change that.  The original version 1 file showns that it hasn't been altered, but I can't get the original code back.  I remember this cropping up in a past encounter, but I never found a way round it, and googling doesn't seem to pop up loads of other punters who have had the same experience, so maybe its something to do with the way I've installed it, or because I'm being more than usually stoopid.  Either way, I'm screwed, and the only way to move forwards is to start a new project from scratch - this might be the best way to go anyway, but I'd like to know why VB won't let me load any older versions of the code - if anyone has the answer, I'd be very interested.

Last, I did some work on the idea of watch boxes, and made a sample to test out the new hinges and ways of holding the watches in place.  Although there seems to be a surprising number of people who collect expensive watches, I'm not sure how many of them are prepared to spend a wedge of folding money on a handsome box to put them in, so I think I will build a new jewellery box with the new hinges and see how that turns out first.  I still need to solve the problem of getting by boxes in front of the customers, still looking at that.

Onwards and upwards.  The next update will have an extensive report on the flying experience of the whizzcopter, and the Pi software should be pretty much finished.

February 13 update

Managing to loosely keep to the monthly updates, so this is what has been interesting me in the last month or so.

First, I've made some progress with the Whizzcopter.  It now has the motors and speed controllers installed, as well as the servo that steers the back end of the beast and I have to say that wiring the thing up was probably the fiddliest thing I've done in a long time. I also made the mistake of ordering wire for the motors that would happily carry the power from Hinkley Point which didn't make the wiring any easier.

Motors, ESCs and wiring completed

It seems sensible to cover the flight controller and the otehr electronics to protect against water when landing upside down in long wet grass, so I thought about making a fibreglass cover - however, its a bit of a performance to make a master model, then a mould, then the actual cover so I've temporarily opted for an industrial strength egg box instead.  I initially thought that this was a bit daft until I saw that Jon had a margarine tub on his....

Direction finding lights

I've taken note of other people's experiences when flying and fitted the brightest LEDs that I could find to each of the three legs so that I can tell which way its pointing when its in the air - get it wrong and left means right, forwards is backwards and... you get the idea. The front two legs have green lights, and the back ones are red, no idea if this is going to help or not as I suspect that when its more than twenty feet away it will just become a black blob against the sky.  I'll report back later.

The supplier is presently out of stock of some of the remaining bits I need, and I want to order everything in one go as the postage is a bit steep, especially if it has to come from Honk Honk.  All I need now is the propellers, batteries, flight control board (this is the brains that should prevent those 'uncontrolled flights into terrain' moments) and the radio gear, plus a few odds and ends.

In the meanitime, Jon has finished his and has had several flying expeditions at the cost of several propellers and some damage to the landing gear.  He foolishly offered me a drive with it, and I have to confess that a fair amount of the broken bits were the result of my near-death experiences.  It does get easier with some practice, and a day with no wind would be a massive help I suspect.  I'm told that a tricopter like mine is easier to fly than a quad, but I suspect this is a story for the fairies.

Second thing is that I have finally got round to re-building my web site for the woodwork projects that I like to do.  Check it out at www.grizelli.com

I've spent a bit of time looking at ways to sell my woodwork stuff, and drawn a bit of a blank.  Galleries in general deal in paintings and sculpture and seem to turn their noses up at wooden things - not arty enough for them I guess.  Then there are shops that might consider selling, but their commissions are outrageous, with some as 'low' as 30% and the all time highest one at 95%.  The trouble is that massive markups like this make the pieces so expensive that they are never going to sell, so the shops will draw the conclusion that wooden things are non-sellers and refuse to stock them.  And then there are the many shops and online outlets who have very impressive web sites but who can't be arsed to reply to a simple email enquiry, and the online marketing people who make their money out of charging you to post on their web site and who thereafter have no further interest in promoting you.

There must be loads of people like me who make well-designed and well-made items but who can't get them in front of the public at a sensible price.  The obvious thing is of course a web site, but a simple google for 'jewellery box' results in a gazillion hits for cheap tat from China and there's no way a poor man's web site is going to get noticed in all that dross unless you pay Mr Google a wad of dosh.  There must be another way, I'm just not sure what it is, so if anyone has any ideas I'd be delighted to hear them and give a suitable reward for any that I use.

Third piece of work this month has been a long-overdue overhaul of some stuff on the kart. I've had this machine for around 4 years now, and although it has performed well its becoming obvious that a bit of TLC would be a good idea, so I've tackled these things:-

- new steering column bearing, and straightened the column which was bent in a fairly spectacular crash a while back (that was the one that gave me the tyre marks on the steering wheel)
- straightened the front bumper support bar, bent in a different excursion into the scenery
- new rear axle bearings and a new sprocket
- took off the undertray (can't get the steering off without) and hammered ou all of the various off-road inflicted dents and replaced all of the very battered bolts
- re-aligned the steering geometry and checked the front to rear weight distribution (currently around 59% rear/41% front, ideal should be 57/43 apparently)

I need to cure a bad case of 'turn in understeer', which I have always assumed was the result of my crap driving style, but having talked to various peeps and read up on the web I've concluded that at least some of the problems are setup related and not self inflicted.  Accordingly I've pushed the front track out by 10mm each side and we'll try that out at a practice day planned for the 22nd.  The other option is to shift the seat forward a bit to improve the weight distribution, but thats a bit of a pain to do and hard to work out whether it needs to be moved by a little or a lot, so I might try just moving some of the bigger weights off the seat and onto the front to see what difference it makes.  Who knows, I may have exceptional talent which is being held back by poor setup.  On the other hand.....

What else?  Well, I've done some more work on a web site for the Raspberry Pi, and am now probably going to include a set of pages which will be 'how to fix it if it breaks' for all of the slightly odd stuff that lives in this house.  I've roughed out most of this and next month will see some more work on this.  I should also get the Whizzer finished, and the results from the kart test session.  Oh, and I'm doing some design work on a watch box as well, and I feel the need to get stuck into the novel that I've been thinking about for the past five years, so its unlikely I'm going to be bored any time soon.