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.

December/January update

Hmm, so much for my plan of writing something on here every month.  Xmas got in the way a bit, so there's no big stuff to talk about this time, but lots of small things occurring

The first is the Raspberry Pi.  I got one of these as a present from Jon a while back, and although very interesting, it had a couple of shortcomings that made me park it for a while.  For those who don't know, its a credit-card sized computer which runs a proper Linux operating system with a proper windows-like user interface - its a bit slow compared with your average desktop PC, but fast enough to be usable.  I planned to use it as a means of running a house monitoring screen.  The intention is to have it display a calendar and task list; a news headline ticker; plus showing the status of various devices around the house - doors open/locked; inside and outside temperatures; whether lights are switched on or not and a bunch of other stuff. The Pi is small enough to be tucked away either behind or inside a PC monitor, which can probably be persuaded to provide it with power as well.

I have an arduino computer running quietly in the engine room which switches lights and the vent system on and off, monitors temperatures, doors, and water controls, and collects all this status data and squirts it into the server.  Up to now, that is as far as it has gone, although my plan was to have the server collate the data and then feed it to a web page that the Pi would read.

The problem was the Pi only has a HDMI video output, or composite video.  The spare screens that I have are all PC monitors, and none of them has HDMI, and although one has a composite video input the picture quality was so bad that text on the screen was pretty much unreadable.  I'm not about to buy a new screen just for this, so the Pi went into a drawer while I thought about it for a bit.

You can buy HDMI to VGA converters - however, they are big-ish, need mains power, and cost the thick end of a hundred quid, so for all these reasons they are a non-starter.  A recent trawl of ebay turned up a cable adaptor for a lot less dosh, and although all the boffins state that its not possible to do the conversion like this (because HDMI is digital and VGA is analogue) I also noticed that a couple of the big electronics sheds were selling what looks like the same thing for around £30.  My chinese pals would sell me one for a little under four quid, including free postage so I thought I would risk it. 

Chinese VGA to HDMI adaptor

Around three weeks later it arrived, a nicely made device in Apple white.  I plugged it into the VGA lead, reconfigured the Pi to speak out of the HDMI port, and hooray! - not only did it work, but the display is crisp and clear with easily readable text.  I have read some doomsayers on the web shaking their heads and claiming that the power requirements of the adaptor will burn out a diode on the Pi if used for long periods ('she canna take it, Captain'), and they may be right, but for now it makes the Pi a usable device again.

In a sudden burst of enthusiasm I dusted off the old visual basic skills, and wrote a bit of code that collects the data from the arduino, displays it on a screen and stashes it in a text file for later access by the web page, which is still to be written.  My copies of VB - both v6 and VB.NET - won't run on the Windows 7 environment, so I tried downloading the latest VB.NET express version from Mr Microsoft.  Hoo boy.  Not only are my programming skills rustier than I thought, but Mr Microsoft has taken the superbly simple and easy to use VB environment and turned it into a programming monster, much more complex and hard to follow, and with online help and examples that make it even more 'ard and 'orrible. I took the easy option and loaded VB6 on to the Windows 2003 server where it runs quite happily and wrote the code on that.

More to come on this next month, I now have to build the web page and find ways to import Google calendars and task lists, and add a scrolling news ticker.  The Pi browsers are more restricted than those that run on Windows or PC linux, so this is going to be another challenge.  Where did I put that copy of Dreamweaver...?

Next:  audio cassette tapes.  I spent a lot of time a few months ago scanning all our old photographs on to the PC, and decided I would do a similar job with the hundreds of cassette tapes that I have collected over the last forty years.  I bought my first Philips portable cassette machine in 1969, had a big Akai open reel machine as my main music generator until around 1980 when I bought a Technics M14 cassette deck.  The quality of the Akai was better, but the cassettes were much easier to use (I've never seen a car stereo that can play open reel tapes) so the Akai was sold and all music from then on was played on the Technics deck.  CDs arrived and blew away the tapes for quality, and slowly the tape deck was used less and less, eventually being consigned to a cupboard with its massive box of tapes.

Rather than just bin the whole lot, I thought I would copy the tapes that were worth saving on to my music server.  To my surprise, the tape deck still worked after a bit of cleaning the dust out of some of the switches to cure a slight hum on one channel, and althought some of the tapes were a bit sluggish the whole thing worked.  Downloaded the most excellent Audacity free software, hooked it up to the PC and we were off.

Amazingly it worked very well, although a bit tedious - have to copy every track in real time, so a 90 minute tape takes errrr.... 90 minutes to copy.  I finished copying all of the tapes I wanted to keep and was idly skimming through some of the others when the deck died.  All the electronics were working fine, but it seemed like a drive belt had either snapped or was slipping too badly to continue.  I briefly thought about trying to fix it, but a) you can buy these machines for a fiver on ebay or at a boot sale, and b) the whole idea was to get rid of the whole cassette tape thing, so why would I want to revive the old girl?

I can't bear to throw away stuff just like that, so I stripped it down for parts and turned the rest into a small pile of of plastic and metal.  That old deck had been a good friend over the years, played endless hours of music in around six houses on two continents, so I was sorry to see it go, but the way forward is digital, so adios amigo.

Next, some new stuff - the Whizzcopter.  Sean introduced me to the idea of multicopters a while back - for those who don't know these are helicopters with several sets of rotor blades, and while flying a helicopter (either real or a model) is fiendishly difficult and requires you to have at least five hands and three feet to keep the thing in the air, multicopters have an on-board computer that takes care of most of the crash prevention gymnastics.  The brains of the device revolves around a set of electronic gyro sensors which detect changes in attitude, and the computer automatically corrects by speeding up or slowing down the propellors.

Sean is keen on a quadrocopter with four rotors, but I have decided to build a tricopter.  The tri is a bit more complex to make, as it is steered by a tiltable back rotor, but it uses less power (so increases flying time) and costs less as there are less bits involved.

The completed frame

I made a start of the build of the frame this month, using mostly bits that I already had in the workshop - 10mm alloy tubing for the arms, 4mm rod for the bracing and some fibreglass sheet for the central platform that hold all the clever bits. Made extensive use of my little milling machine to make the motor mounting plates and to drill holes in the central platforms at exactly the right angles and spacings.

Fly cutting one of the motor mounts

Drilling the centre platforms on the rotary table

The arms seemed a bit too rubbery for my liking, and I assumed that with all the weight in the centre that a heavy landing would probably buckle the arms, so I braced them underneath with angled alloy rods.  It may not be pretty, but its certainly very rigid.  The whole thing weighs in at around 450g, and I reckon the rest of the bits will bring the flying weight up to around 850g.

The steerable motor mount plate - it will be tilted with a servo

I've just ordered the motors and speed controllers and a few other bits, should arrive by the end of this week. The remaining parts are mostly out of stock so I will order them later, watch this space.  Sean has started his build as well, and Jon has just received all the bits for his:  I can see this developing into a bit of a competition.....

Hot news now on the coffee front as well.  We have had a Krups fully automatic bean-to-cup coffee maker for around 12 years, and it has worked hard and been great for all that time.  Recently it started getting very confused, grunting a lot and flashing its lights in ever-more bizarre patterns, and consuming coffee beans without actually giving me a cup of the stuff.  Although it cost a lot originally, the business bought it for us and its earned its keep several times over, so it had to go.

Extensive searching on t'internet to find the best replacement - believe it or not, you can pay several thousand pounds for these machines, but I suspect that mostly what you pay for is the name on the front since the mechanics of making coffee from beans ain't that hard.  We settled on a De Longhi machine at a reasonable price and we've been running it in over the past few weeks.

So far it looks good.  It makes a good cup of coffee, it has adjustments that the old Krups never did, and it seems to be well made.  If it lasts as long as the old one did, I shan't complain.

Last thing this time is some long overdue work on the kart.  I still need to do some more research, but it looks as if my oversteering problem on the way out of corners is actually the result of understeer on the way in - too much steering lock to get the beast to turn results in a sudden loss of grip at the back as soon as the front starts to grip and the inside rear wheel lifts. I've noticed this especially when driving in the wet, where there is absolutely no grip at the front at all even on full lock, followed by instantaneous massive oversteer, followed by a close encounter with the scenery.   It may NOT be my crappy driving after all (well, not entirely anyway).

Fixing the understeer is a bit of a trial and error thing, so I've made a start in the meantime on other stuff that needs doing.  So far I've straightened the front bumper bar (pushed down on the last outing with the sudden arrival of the crash barrier); changed a front wheel bearing that was leaking grease; taken the undertray off and beaten out the many, many dents (another result of too many off-track excursions), and straightened the steering column which hasn't been straight since the major collision some time ago that left tyre skid marks on my steering wheel.  The lower steering column bearing is completely fooked, so a new one is on order, can't put the undertray back on until this is replaced as the tray gets in the way of the spanner.

The other major task is to try to clean all the crud out of the exhaust, which is almost certainly stealing some of the power, especially at full throttle.  I've been told that leaving it full of  caustic soda for a while will do the trick so I'll give that a try first.  If it needs to be scraped out, we have a problem, as the various bends and turns make it impossible to get any kind of scraper inside, and the only other answer I can think of is a wire brush on a flexible shaft with the ol' power drill attached to the end.  Whatever I do, its going to be pretty filthy, so I'm not looking forward to it much, but the only alternative is a new exhaust at over 200 quid, so I'll take the filth, thank you very much.

Next month there should be more progress on the Pi; the whizzcopter should be pretty much finished if not actually flying, and the kart should be back together and we should have done a test session to try out the handling changes. Can't wait!

November update

Blimey.  The last time I posted anything here was way back in June, how time flies when you're having fun :-)

A quick summary of projects during that time follows:  you at the back, please try to stay awake

First up is picture scanning.  I bought a cheap negative/slide scanner from Maplins a couple of years ago with the plan of scanning all our old photographs - the idea was to keep a permanent digital record in case the originals went missing, and also to try to correct some of the colour drift that has affected some of the early stuff.  Good plan, but a couple of evenings of feeding the scanner with negatives soon convinced me that it was a job left for another day.  A few years on and the 'another day' has arrived, so I set to work a couple of months ago.

We have three boxes crammed with assorted photos and negatives spanning the time since 1970, and another with a mixture of older pictures and other peoples photos - I finished scanning the contents of the first three boxes in around 6 weeks, the remaining one may never get done (especially as there are lots of photos where neither of us know who the people in the picture are). Windows reports that there is now around 8000 pictures in my library, with a total mass of around 20Gb, and the whole lot has been backed up on to three DVDs in case the server bursts into flames.

Apart from the tedium, the cheapo scanner worked pretty well and I could probably flog it on Ebay for about what I paid for it.  There's also been lots of 'hey, do you remember this...?' moments, and a lot of fun to be had looking back, especially from when the kids were little.  Not only that, but of course we can now run a continuous slide show on the TV of all these old pictures to bore visitors to death - a bit like getting out the photo albums, but infinitely worse.

I've also been turning some perfectly good wood into sawdust again, with the completion of a small wall-hung jewellery cabinet, and a new jewellery box.

The cabinet is made in cherry with some trimmings made in imbuia, and it turned out rather well - see picture. It has my usual brass hinges with ball bearings to make them work smoothly, and the latching mechnism is hidden inside the central divider and operated by means of a pair of concealed levers underneath the front edge of the base.  It's presently sat in the Dansel Gallery near Weymouth with a hefty price tag and waiting for 'the woman who has everything, and needs somewhere to keep it' to arrive with her credit card.

There's a bit more of a story to the box.  A few months ago, a chap in the village who I know slightly turned up at the door and asked if I wanted some wood - he has seen me floundering about in a cloud of sawdust over the years when he's been out walking his dog.  It turns out he's working on a new school being built in Bridgwater, and spotted some of the chippies about to throw some offcuts into the skip, so he stuffed them into the boot of his car and brought them to me as a little present - very nice of him.  The wood is ash, reasonably easy to work, and with a dramatic stripey grain, so to try it out I built this box.


This one has a couple of other features that are new to my boxes.  The corner joints are made using the jointing jig that I've had for a few years and never had the time or patience to set it up properly, turns out it works pretty well.  I havn't made a box with drawers in before, and this works pretty well too.  Finally, I designed a new style of hinges for this box which make the back edge of the lid partly disappear down the back of the box - no real useful reason for this, it just looks a bit different.

Oh, and the chinese character on the front means 'harmony'.  I've got enough wood left to build another box as well, and it never cost a red cent.  Excellent.

This neatly leads on to a couple of other things that I've been looking at recently.  The first concerns my radial arm saw, a fantastic bit of kit but when ripping timber the blade spins towards the operator and in an upward direction, completely opposite to a table saw where the blade cuts downwards.  With larger chunks of tree this is not a problem, as the weight of the wood holds it down, but these boxes use lots of very thin and/or narrow pieces of wood - its real easy for the blade to catch on a loose edge and pick up the piece and hurl it straight into your face, and even with the lexan face mask it can be a scary experience.  And of course, it completely boogers the piece of wood that I'm trying to cut, which is invariable the last piece of that particular colour or grain...

This has always been an issue with these saws, and I've noticed it much more since having my blades re-sharpened a few months ago - you would think that the sharper teeth would make things better, but I noticed that the sharpener has ground the teeth to a more aggressive angle than before and while they cut a treat, I suspect this is not helping the 'throw the wood at the old man's face' game.  Time to try to resolve this, so:-

I made a featherboard - a chunk of wood with multiple fingers that lightly presses against the piece being cut and holds it down on to the table.  The first attempt worked really well, but had a limited range of adjustment for different thicknesses.  It also had the fingers too far away from the blade, so the last couple of inches of wood was not held down by the fingers, and whoosh; whizz; bang, bits of wood banging off the face mask again.

The new version has a pair of slidey fingery bits that allows the fingers to go right up to the centreline of the blade, as well as a better way of adjusting the whole contraption for wood thickness.  Tested it on a few sample pieces and it seems to work fine, but we'll only know for sure when I feed it with that last-piece-on-earth-like-this irreplaceable timber.  I'll try it out for real and then finish off the metal bits with a coat of paint.

I also thought that it would be a neat idea to have a motorised arrangement that slowly draws the wood through the blade.  Apart from the smoothness of the cut that this would deliver, it also has the advantage of keeping fingers well away from the sharp bits.  Into the junk box, and out with a rear window wiper motor from an Austin Metro (remember those?) and some assorted metal chunks and off to the lathe and milling machine.  On to Ebay for some rubber tyred wheels (£5 for a set of 4, thank you very much), bolt the whole caboodle together and hey - it works!. 

A little too fast though, ok for thin plywood but anything thicker causes the blade to struggle.  No problem, I've built and bought DC motor speed controls before so I can do it again, but lets just check Ebay first....  Ah.  Parts to build a DIY controller is around £15, ready built one is around £25 (but will go backwards as well), but my pals in China will sell me a completely built unit for £4 with free postage.  Ten days later, the unit arrives and works perfectly.


A few modifications later and the unit is finished.  Like the featherboard, it still needs to be tested in anger, but it seems to work fine, although the rubber wheel is a bit slippy especially when covered in sawdust. 


And then the most recent workshop thingy.  I have a little Axminster milling machine, an excellent bit of kit that I really enjoy using.  It has a couple of things that are less than ideal, and one of these is the fine adjustment hand wheel on the spindle feed - the wheel is too close to the machine casing to let my fat fingers get in and reset the dial to zero.  Making a longer spindle for the handwheel would be a bit of a hassle - it has a tiny keyway machined in it for one thing - so I made a new handwheel out of some thick pespex that I happened to have lying around, and machined the old handwheel down so that I could screw the new one on to the face of the old one.  Works a treat.

In the process of doing this I realised why I've had a few problems with using this handwheel for setting the depth of cut.  All of the other handwheels on the machine are graduated with 80 small divisions that give a feed of 2mm per turn of the wheel - slightly unusual as most machines are 1mm per turn, but OK once you get the hang of it.  The spindle handle must have been designed by a chimp on crack, because it has 36 divisions and a feed of 1.8mm per turn.  I've tried to think of a plausible reason for this, and I can't - they must have just had some spare 1.8mm screwthreads kicking about in the junk box and decided to use them up. Ah well.

I also realised that one of the great pleasures for me in doing these things is having the ability and the tools to make the various parts from materials that are mostly junk.  The nut that holds the handwheel on is made from an offcut of aluminium bar, and both that and the handwheel itself were made on the milling machine using the rotary table.  Apart from the improvements in usability of the finished project, there is enormous pleasure to be had from just making a nut.
I will try to update this blog around once a month from now on, its not as if I'm sitting around with nothing to write about :-)  Projects for the near future are possibly a radio controlled beach crawler (inspired by the RNLI launchmobile seen at Burnham a few weeks ago), and a reworking of that old nitro model plane engine that I've had for years and can't decide what to put it in - it might end up with a flywheel and clutch, and an on-board electric starter, and it may finish up in the beach crawler, who knows.  I'm also thinking about ways to flog my jewel boxes - galleries are either only interested in paintings, or want 90% commission, yes, you read it right, 90% - and it seems to me that there must be loads of people like me who can make good original stuff but can't get it to market: time for a 'makers community' effort perhaps.

Toot toot

Miscellaneous ramblings

Been a while since I posted an update, so this is a quick summary of some of the things I've been doing lately.

First up is the new dragon, made from strips of thin copper foil cut with scissors and my wife's pinking shears (shhh! don't tell her!), with each piece glued and/or soldered to a framework made from copper wire coiled round a series of formers to give the different parts of the body.  I don't have any pictures of the work in progress, but this is the finished article in the final location in the garden:-

The present shiny tarty colour will darken to a purple-ish brown with exposure to the weather.  For those interested, his name is Brian, and his job is to scare away the bad spirits who may happen to wander past.

The second interesting thing I've been doing is trying the latest version of Ubuntu Linux. Over several years, I have made strenuous efforts to get linux working sensibly as an alternative to Windows, and every past attempt has been a disaster. 

I really would like to see any version of linux succeed as a viable alternative for mainstream users - Windows just keeps getting bigger and more complex, and Microscrote's obsession with security is becoming ridiculous - so every six months or so I download a couple of different versions and try it out. The one I have grown to like best, mainly for its user interface, has been Ubuntu: however, all of the past versions just would not work reliably with my network - even though other flavours of linux and good ol' Windows all run fine.  Also, I play a lot of music, and all of the media players that I tried would play anything except MP3s, which is what all of my music is.

Then there's my other long-standing gripe against linux, which is that if you want to plug anything in to the box, or find out why the network won't run, or install some software that you got from anywhere else, you have no option but to jump into the command line.  Back when I started in computers in around 1978, this was normal, but the world has moved on a fair bit and we are all used to just plugging in a web cam, or a USB stick, or some such, and it just works. The linux command line is even less user-friendly than the old MS-DOS was back in the day, and questions to various linux forums are generally greeted with incomprehensible comments like " .. you can just use Woodchip using the /fek switch.." while further enquiry seems to invariably result in  torrents of abuse.  Not helpful

My latest attempt uses Ubuntu v12.04.  The news is that: a) it installed and worked without a hitch on my four year old Clereon based Shuttle machine; b) it found and used my network with zero drama, and c) best of all, it seems happy to find and use all the devices I've plugged into it without complaint, and with no reason for me to tackle the command line.  After playing with it for a while, I decided that I didn't much like the latest Ubuntu user interface, so I downloaded KDE instead (again, an easy install), which is much better IMO.  Strangely, KDE doesn't come with a printer module, so you have to find one on the web and download and install it manually - a small bit of command line here to do this, but just type in the words and hit return and it loads and works.  (I later found that there is a version of Ubuntu called Kubuntu, which gives you the same end result as I have, although the downloaded version that I have won't boot the machine from the CD, it just sits there looking at you pretty much for ever)

I'm still playing with it, but I have yet to find anything that doesn't work, or requires a Master's degree in guru to be able to make it work.  At last, this may be the way for me to ditch the Windows bloat and security paranoia - I'm going to set it up on the music machine in the garage (yes, in the garage, I like to entertain the neighbours with a bit of rock an' roll when I'm working out there) and try it for a while on that.

Next item concerns weight.  As a result of my regular fitness training, the old body has slimmed down a bit and I have lost a couple of kilos, generally a Good Thing.  However, this means that I am now under the minimum weight for my kart racing class, and I need to add some more weight to the kart.  I had some scrap bits of lead sheet in the garage, and decided to try melting them into slabs.

My initial plan was to make a mould from damp sand - the same way that iron has been cast for a few centuries - but reading up on the web suggested that this would be a Bad Idea.  Commercial sand is a complex mixture of sand, clay and other stuff designed to both give a smooth surface to the casting and allow the moisture to escape, and  I quickly realised that my original idea of making a dent in some wet sand and chucking molten lead into it was a non-starter - lead at around 600 degrees C turns water instantly to steam, and if it can't escape it causes bubbles in the lead which burst, splattering molten lead all around.

What I did find out was that you can cast lead into a wooden mould.  The wood chars from the heat, but the metal is not hot enough to set it on fire, and the charring on the surface prevents the wood from burning any further.  Also, the lead contracts slightly as it cools, making it easy to get it out of the mould.  Off to the workshop to make a flat open-topped box out of some scrap MDF, which has a smooth surface finish and is easy to work. The dimensions were calculated to give a slab that would weigh roughly 1.5 kilos and was around 15cm long

I then weighed around a kilo of the scrap lead and cut it into strips with some old scissors and put them into an old saucepan over a camping stove. First put on my face mask (lead fumes are generally bad for you), lit the gas blowlamp and played that into the pan, and the lead melted really quickly, developing a thick scum on the surface which I dragged to one side and scooped out with a flat wooden paddle (a scrap bit of apple wood).  I poured the lead carefully into the mould and left it to cool for around ten minutes, then turned the mould over and smacked it hard on the floor a couple of times until the slab fell out.

It worked so well that I did the same thing again, then drilled holes in both slabs to use for mounting on the kart.

The slabs are smooth and professional looking, and the only damage to the mould is the surface charring and a lingering smell of burning fish.  The saucepan won't be much good for making porridge any more, but that's a small price to pay :-)





The last item is a bit of irony.  I have serviced my own cars ever since god was a boy, and always get a hard time from dealers when coming to sell them because the routine servicing - despite being complete - has not been carried out by a main dealer.  I changed my Civic Type R last autumn and replaced it with the same model with a lot less miles and a couple of years younger, and the new car came with a splendid full Honda dealer service history.

I did a service on the car last week, and discovered that at the last service Mr Honda had replaced the oil filter with some cheap and nasty aftermarket crap; the washer on the sump plug had been used several times, and the air filter looked as if it was the original one fitted in the factory back in 2005.  Based on this, there's no reason to expect that the oil was anything other than cheap cooking oil, or that any of the other service checks had been done properly either.

I'll carry on doing my own servicing, thanks.  At least I know the work has all been done, the correct parts and decent quality fluids have been used, and - most important - I won't have to pay heavily for the pleasure.

Arduino and Home Easy problems

Whew!  Just spent the best part of a day and a half working out what was wrong with the Arduino-based  magic box that controls the lights and a bunch of other stuff in the house.

Its been working fine for a few months, but around a week ago it decided to either not turn stuff on, or turn it on and then forget to turn it off. Pretty poor show.  Most of the HE kit has its own switch in the room where it lives, but some can only be operated with the remote control which can be a bit of a pain.

I scribbled a quick bit of code for the arduino to flash the various pins that operate the remote control, and discovered that the one that turns things 'on' wasn't working.  The 'off' and 'unit' worked fine.

I started by checking the remote control which is hard wired to the arduino box with a length of CAT5 cable and a standard RJ45 plug - this lets me move the remote around the house using the CAT5 in the walls to get the best wireless signal for the HE stuff.  Opened up the remote, no obvious signs of wires hanging off.  Checked the voltage on the three pins that operate the control - two at 0v, but one at around 0.6v, no surprise that the odd one out was the 'on' connection.

I assumed that the remote was the most likely place for a fault, because I had to butcher it about a bit, so I replaced the opto-isolator for the 'on' button.  No joy.

So the control box had to come out of the rack, and be opened up.  I plugged the remote directly into the box and checked the resistance in the connections, all near enough zero as you'd expect.  From this I assumed that the problem probably lay in the arduino - a dead I/O pin probably - so I switched the connections on the processor and changed the code to use a different one.  Put it all back together, but no luck.

Out with the control box again, check everything again.  Still no joy.  While I had the bonnet up, I changed the 12 volt power supply that also lives in there - it was a switched mode supply previously and it had a lot of problems delivering 12 volts - sometimes it would drift up to 15 or 16 v, then other times it would drop to 4 or 5, playing havoc with my mailbox detector.  I binned the old PSU and replaced with a conventional transformer/rectifier/capacitor arrangement and bingo, 12.5 volts bang on the nose.

After replacing the original I/O pin and checking the software yet again, I concluded that either there was some strange fault in the arduino, or there was a cable fault.  Searched online for reasons for the arduino to play up without success, so I went back to the cabling.  This time I checked every single connection of every cable between the processor and the remote, including individual patch leads and the cables in the wall.

All still tested good, but then a fluke - I happened to move the end of one of the patch leads while the meter was still connected and lost the connection:  moved it a bit more and it came back.

Much happiness in the camp, the problem was an intermittent break in the patch lead (which is why it worked ok one day and not the next).  Cut up and binned the offending lead, then celebrated by flashing all the lights in the house on and off a few times without leaving my chair, which didn't go down too well with 'er indoors.

Grandfather clock re-build

Well, its taken a solid two months of hard work, but the new case for the family grandfather clock is now completed. The pictures above and on the left shows the new one, and the one below shows how the old one looked before the re-furb.

The clock was originally built in around 1820, so he's nearly 200 years old, been in my family for six generations, and during that time he's taken a bit of a beating.

What's wrong with the old one?

Well, although the clock itself ran OK, the case was in a terrible state. Originally built with a cheap pine framework and veneered with mahogany, it must have looked fine to begin with but the years caused the veneer to split in lots of places and bits have fallen off, to be replaced by various of my ancestors with more enthusiasm than skill.

At some time the whole clock had obviously fallen face down, hopefully not when someone was walking past it, because the front of the case and the lower door had clear evidence of major full-frontal impact. The key for the lock for the lower door must have also been lost at some point, so a chunk had been gouged out of the case so that the door could be opened.

My mother told me that at one time it lived in a house with low ceilings, and it was too tall, so the owners simply dug a hole in the dirt floor and placed it in that. OK for a while, but the bottom foot of the case rotted away, and ended up being sawn off. I guess that was good in one way, as it meant that it would then fit under the low ceilings, but it meant that the weights had a shorter distance to fall and it would only run for around six days instead of the usual eight. My dad solved the problem by making a box out of some rough timber that he had lying around and balancing the clock slightly precariously on top of it.

Apart from the woodworm, last but not least, I found no less than 33 holes in the back panel of the case. These clocks are supposed to be screwed to the wall, but even allowing for numerous house moves I am mystified why it needed that many.

The clockwork bits

The mechanism ran fine, but it was absolutely filthy - my dad used to oil it with a mixture of engine oil and paraffin, liberally applied with an old paintbrush (that noise you can hear is the clock makers of this world screaming in pain), so the whole thing was covered in sticky black goo mixed with fluff and old spider's webs. I thought it best not to dismantle the old chap, so instead I carefully cleaned the whole thing with petrol and carburettor cleaner, and then lightly oiled all the shaft pivots with tiny drops of very thin oil (the same stuff used for my high speed engraver). One of the cords for the weights was a bit tattered, so I replaced it to avoid a 10 Kg lump of lead dropping through the floor in the middle of the night.

Time for the new case

I started with carefully measuring the old one, and working out how to make replicas of all the mouldings that had been used.

Next, with the assistance of my friend and grandson, Owen, we built a timber framework to provide a solid structure for the whole case. Not only did this give it strength, it also made sure that the structure was square and level. These clocks are picky about being level, so the base had adjustable feet concealed within so that we don't need to mess about packing the mechanism to make it level.

The frame was then sheathed in MDF. This may seem a bit non-traditional to the purists, but remember that these clocks were originally made from cheap materials and veneered with more expensive wood, and if the makers were building one today I expect they would have also used MDF. This material also has the advantage of being strong and dimensionally stable, so it should last a fair while.

The veneer used on the original was mahogany, but these days rocking horse poop is easier to get, so I used sapele for the various mouldings and other solid wood parts. Once the mouldings were made, using my trusty router and various modified cutters, the whole case was veneered and the mouldings fixed in place.

I re-used as much of the old case as possible - the brass finials on the front door; the lower door hinges; the lock for the lower door; the glass in the front door; the wooden pillars on the front, and a few other bits. The door which covers the clock face has concealed ball bearings to swing on in place of the rusty nails used on the originals, and a proper catch to hold it closed (the original was just jammed against the frame to keep it shut).

The whole thing was then given a double coating of mahogany stain to even out the colours of the various woods, and to make it look a little older, followed by several coats of danish oil and finished off with beeswax.

Placed it against the wall, used the hidden feet to bring the whole thing vertical in both planes, and screwed it to the wall. Placed the mechanism on the original seatboard, and hung the weights and pendulum, then adjusted the swing of the pendulum to give an even tick - if its uneven, the clock will only run for five minutes and then gives up.

I can hear it ticking reassuringly as I write this, and although its been a monumental job I'm very pleased with the result. Time to pack the tools away, clear all the dust out of the workshop, and start on the next project...

Arduino home control part 4

Made some good progress with this over the past couple of days.

I experimented with getting the Arduino to read the time and date from the PC, but its too 'ard, mum. Instead, I bought a real time clock module (RTC) from a nice man in China for around four quid and hard wired it to the arduino. Searched the 'web for a simple bit of code to set the clock up, and eventually found this -

http://www.glacialwanderer.com/hobbyrobotics/?cat=4&paged=2

its dead simple, even I can understand it. All the other stuff I found was far too complex for my purposes (and I'm too stoopid to understand most of it).

Then comes the programming. I have to say that software is not one of my core skills, but perseverance wins out over my lack of talent. It ain't pretty, but it works.

What it does is the following:-

- reads the time and date off the RTC

- calculates today's dusk and dawn times based on the current month - it will only update these times once a month, but that's near enough for my purposes

- sets up a series of times to switch things on and off. These are either 'real' times, eg 23:30, or a time which is based on the calculated dusk or dawn times. Some lights come on at dusk, others have a delay to turn them on later.

- reports current state back to the server - at the moment, this is a simple VB application which just displays the data on screen, but in future this will find its way into a web page which will run on an Ameo either in the kitchen or by the front door.

- information displayed at the moment is: internal and external temperatures; lock status of external doors; whether there is mail in the box, and which home easy devices are on and off.

The next stage of the plan is to make the arduino control the central ventilation system based on internal and external temperatures (turn it off on a cold night, etc.), and to run a pair of water leak detectors in the kitchen and utility room - these will be automatic, and shut off the water using solenoid operated valves if there is a leak, but the arduino will tell the PC that a leak has occurred and the PC will wind up a bloody great siren. Looking forward to that part :-)

Some interesting times during the development process, where the software kept running in an endless loop, switching things on and off at random, so much so that Mrs G had to retire to the kitchen as the flashing lights in the rest of the house were giving her a headache. There was also a report that the pulsing of the lights on the deck had encouraged a Sea King helicopter to try a landing, but I don't believe that.

It seems to be working OK, its so far managed to turn all the lights on at the right times without any major malfunction, although I will have to fine tune the post-dusk delay a bit on a couple of the lights. Some alarm from MRs G along the lines of 'what happens if it goes wrong and you're not here? Do I have to sit in the dark?', but I still have a spare remote which can be used to turn things on and off, and all of the important bits have their own switches in the room where they live.

More stuff to come, watch this space.