Drilling holes in my flowerpot.

The other week I had also made a little grating that sits in the bottom of the furnace and stops charcoal blocking the air flow. I just used some scrap steel I had handy.

Grating.

To make the crucibles I got two sections of 80mm diameter pipe cut to 140 long. I also got some 8mm plate from which I will cut the bases for the crucibles and will MIG weld these in place. I also picked up some 8mm rod from which I will make the lifting and pouring tools.

Crucible.

I attached the blower to a length of steel pipe I picked up when I got the crucibles. That was sitting in their offcuts bin so I grabbed it and used it as is. I attached the blower with some rubber sheet and two hose clips. I put some polymorph plastic into the cut off handle to hold the wires in place nicely.

Blower.

At Bunnings today I also picked up some nice Elmo gloves which might be wise dealing with hot, molten metal. You need to keep fully covered up including gauntlets and full face shield.

I also got a bag of charcoal but resisted the urge to fire things up yet. I was busy working on the car and I also want to make sure the cement is really set before heating things up.

Today after work I went for a walk to the City Mission shop and there I was able to buy an old hair dryer (the only one), a muffin tin and two spoons. The lady in the shop thought it most odd collection. All up $14.

Hair dryer.

The hair dryer worked so the first thing I did was take it apart. Inside are some heating coils and a small motor. The motor is obviously not mains rated so I figured it was powered using the heaters as a big resistor to drop the voltage. Measuring it with a meter confirmed this. 14 volts to the motor at high speed and 10 volts on slow. I simply removed everything form the housing, soldered two new wires to the motor with clips on the end to attach to a 12 volt battery and chopped off the handle. I was left with a compact, 12 volt blower.

A tube can be inserted into the unit then into the hole in the furnace to blow air into it. That’s a PVC pipe above but obviously I will use metal when it is running. I have an old vacuum cleaner tube or some old exhaust tube I can use somewhere. Will mount the blower onto a small wooden base to lift it to the correct height.

Ingot pan.

The pan I got should be suitable for making ingots if I can work out if it has a non stick coating or not. I think it doesn’t. It feels enamelled rather than non stick and there are traces of muffin stuck to it making me think it’s not! I might give it a sand blasting to make sure.

Spoons.

The spoons will be attached to metal rods to be used as slag skimmers. I might drill drain holes in one of them and see how well that works.

I still need to get some steel to make a crucible but I might do a trip to the steel place in the weekend anyway to get more steel for the Austin 7 so I can see what’s on their cut off table there.

The site that really put me onto this was http://www.backyardmetalcasting.com/ which has a ton of information and projects. Hours of very interesting reading there. The owner of the site has produced two small starter books which I ordered that arrived last week.

Today I went to Bunnings to get the materials needed to make my own flowerpot furnace and I spent the day happily putting it together. It’s pretty rough and ready but it should work. I won’t put all the details here, you should really buy the books yourself for those, but here are the basics.

Starting point.

I started with a clay flower pot, a steel bucket and some cardboard tube. I also bought a small masonry drill bit, needed to make a hole in the pot later on. I also bought a bag of mortar cement. Everything came from Bunnings (cost about $40NZ). The cardboard tube I got from a vinyl sign place. I just popped into a place I knew near somewhere I used to work and asked if they had any old cardboard tubes since the vinyl they use comes wrapped on them. They gave me a couple of short pieces for free.

Next I worked out where to drill a hole in the bucket. The furnace is basically the flowerpot sitting in the bucket surrounded by cement. A hole goes though the bucket into the bottom of the pot (hence needing to drill a hole in it) though which you blast air. Inside the pot you have a steel crucible for melting aluminium in and that is surrounded by, and sitting on, a  bed of charcoal. You blast air into the bottom of the pot to get the charcoal burning very hot. The whole thing is covered by a heavy lid to keep the heat in.

I marked where to drill the hole on the bucket with tape and cut it out. Since the top of the flower pot sits flush with the top of the bucket you make the hole at the correct height to be right at the bottom of the pot.

Hole in my bucket.

After making the hole you cover over it with thick cardboard and tape to keep the concrete in when we insert the pot. Next I started on the lid. I cut a piece of steel to fit over the bucket.

Lid and vent tube.

In the middle of the lid you make a hole to hold the vent tube. The tube is just there to act as a former around which more concrete is poured. On the first firing of the furnace the cardboard will be burned away. To make the concrete lid we obviously need some sides to our lid. I would have preferred to use steel but I didn’t have any (well I did but I dodn’t find it till later). Instead I used some scrap aluminium. Part of the original body my little Austin 7 came with that I ripped off it.

Aluminium scrap.

I cut a strip and marked out tabs so I could bend those over, using some welding pliers as a mini metal bender, and rivet it to the lid.

Lid making.

The two metal strips are steel used to make a lugs that I can attach a handle to to remove the lid. I took the handle off the bucket and will use it on the lid.

Now pop riveting aluminium direct to steel really makes me cringe.  In the car for example I will go to great pains to make sure the aluminium skin doesn’t directly contact the steel frame. This is due to what’s called dissimilar metal or galvanic corrosion.  But I figure in this it’s not going to matter. It’s just a quick and cheap way to get melting stuff so it should be fine and it will probably wear out from the heat long before it corrodes away!

Finished metalwork for the lid.

With the aluminium wrapped and riveted I welded on the steel handle supports (I also riveted them to the aluminium sides) and then I used some wire threaded side to side to provide some reinforcement for the concrete I would pour into the lid.

Mortar.

First I mixed up some brick mortar to go between the pot and the bucket. I used the child’s spade I found working on the car the other weekend. It worked very well! You slop some of the mix into the bucket the push the pot down into it. You need lots of weight on top of it to keep it down as it keeps popping back up!

Steel and lead weights.

Next I mixed up some different cement I happened to have left over from garage restoration. This contains gravel as well as sand and cement. This I used to fill the lid.

Lid.

It was quite fun being out in the sun today playing with my bucket and spade. Really takes me back. Doing the lid was a lot like icing a cake!

Well, so I imagine.

Next I need to wait 6 hours or so until the mortar is starting to set. Then I can remove the cardboard from the side of the bucket and carefully dig a tunnel through to the pot. Then the bucket and lid are left to cure for a few weeks. Once that’s done I can drill out the hole into the pot and, after adding a piece of angle iron to the bottom to stop the hole being blocked by charcoal, fire the thing up.

Before doing that I will need to make a crucible and some tools for handling things. I also need a small air blower. My shop vac is too powerful. A hair-dryer or small squirrel blower should do the trick though.

When I start doing the aluminium body on the car I am sure to have many bits of aluminium left over. It will be good to be able to melt it down and turn it into something else.

Update: Next morning.

I went out this morning to see how things were going. The concrete hasn’t set as much as I thought but it is drying out I think. I removed the cardboard over the side of the bucket and dug out the inlet tunnel down to the clay flower pot.  Next I leave it to set properly (if it does!). When that’s done I can drill out the hole in the side of the pot, sort out a blower then test it all out.

Waiting to set.

The basic  premise was simple, port the classic game Taipan! to the Arduino.

If you are reading this you probably already know what Taipan! is but for those who don’t Taipan! is a classic, turn based computer game from the early 80s, most famous on the Apple 2, where you try to make your fortune as a trader. It is based loosely on the  novel Tai-Pan by James Clavell.

Why this came about all takes a bit of explaining. It all started with my workmate Grant find a copy of Taipan for our Android phones. Unfortunately that port isn’t too accurate. To play the correct version I went off on an Apple 2 retro thing that lead me to eventually making my Apple in an Ammo Tin which I wrote about here. One of the games I used to test it on was Taipan!

Testing Taipan! on the ammo tin.

There is a very good Apple 2 emulator available for Android which also lets you play Taipan! once you find a copy of the original ROM.

Grant had in the mean time been looking into Taipan! and found a C port of the original source code online. He started porting it to C#.

We dug about a bit and came up with the original Apple basic code online as well as a very well done web based version created by Jay Link who did the original C code.

That got me thinking if I could somehow make a portable version using an Arduino. I didn’t get very far with this until I was contacted by Farnell/Element  14 though this blog and asked if I would like to be part of their Road Test programme. Basically, as I understand it, I can choose something off their site under a certain value, they’ll send it to me and I can use it in a project and blog about it saying I got it from them. I chose a small 128×64 pixel graphical LCD as I have been wanting to play with one for a while.

So far nothing has come of that (am waiting to hear back from them if that is OK to get) but I couldn’t wait so I started on my port. I took Jay’s C code mentioned above and started porting it to my Arduino. Instead of using the screen I would first just send all output to the serial port. Taipan! is, for the most part, text based. Later on I could write all the gLCD handling routines.

The first issue was how to do input into the game. Taipan! is mainly numbers based with some simple multiple selections. A full keyboard isn’t needed so instead I decided to use a small numeric keypad. These little matrix based keypads are cheap and easy to find. I decided to use one for my version of Taipan. Sparkfun sell them and have some good information about them available here. I got mine locally though from Surplustronics.

Getting a keypad to work with the Arduino is trivial. There is a keypad library already available. However that library requires using seven digital inputs to connect up the keypad.  I didn’t want to do that since then I wouldn’t have enough pins left over to drive the gLCD. It occurred to me I could do it with some kind of voltage divider type set up using one analogue pin. A bit of searching showed this has already been done! This is one of the great things with the Arduino. Whatever you want do do, someone has probably already done it and there will be a library available or else you can follow in their footsteps.

I simply copied that method described above and got the keypad working here on a breadboard. With a bit of tweaking that method works very well. It will get confused if you press multiple keys at a time but then it is easy enough to say ‘don’t do that’. Unfortunately I could only get it working well with the 12 key keypad. The 16 key pad would require another resistor in the divider matrix and then the difference in analogue value between key presses became too small to reliably detect.

Detecting what button is pressed on the 12 key pad is easy but I wanted away to enter letters too. The main place you need this in Taipan! is to enter your firm name and for selections later in the game. The selections I could cheat with and use number options instead of using the letters of the selection. For example instead of having options F)ight R)un T)hrow I could use 1) Fight 2) Run 3) Throw meaning I could use the keypad to enter the number of the choice.

The original Taipan! uses this method when the user selects which destination to go actually. I guess because they don’t have unique starting letters!

I did however want to be able to enter letters via the keypad for when the user enters the name of their company. The name isn’t actually used for anything. It’s just displayed on the screen so I could have left that out but then it wouldn’t be an accurate port! The method I use is similar to how some mobile phones work. Each key is assigned some letters. To select a letter you hit the key the appropriate number of times then stop. After a small delay whatever letter you last selected is the one chosen. I also wrote routines to allow the user to do a single key press as well as enter long numbers.

This method work well. Unfortunately the 12 key pad doesn’t have the letters marked on the keys as the 16 key pad does. The keys however are the same physical size. I simple took both keypads apart and swapped the buttons over.

12 and 16 key pads.

The keypads are very simple. Plastic buttons press on a rubber diaphragm that has conductive pad that contact the traces on the PCB. They are held together via plastic stakes that are melted over on the ends. To open them up you can use a scalpel to slice off the top of the stakes then carefully price the housings apart.

Keypads apart.

Then you simply swap over buttons as you like.

I put the keys with letters on them into the 12 key pad. I also replaced the ‘*’ and ‘#’ keys with ‘D’ and ‘A’ from the 16 key pad. I decided I could use the A and D buttons for yes/no choices as they can stand for A)ccept and D)ecline. When entering numbers or strings they also work well as D)elete and A)ccept keys. The bottom row also now spells out ‘DOA’ which appeals for some odd reason!

New keypad.

To hold the back on I simply made up an aluminium backing plate that is held in place with some small machine screws though the keypad mounting holes.

Aluminium backing plate.

With the keypad entry done and the ability to press single keys, enter number and enter strings I started working on porting over the C code. I simply started by porting code in the order the user encounters it in the game,  i.e. enter your company name, choose the staring conditions, etc.  This went very well as the language is fairly standard between the two. Any text to the user I simply output to the serial port using the standard Arduino Serial.print() functions with literal strings.

When I got half way through though things went wrong. All of a sudden nothing worked right. Odd things would happen. It would work for a while then I would get rubbish in the output. After much head scratching I worked out what had happened.

The Arduino uses what’s called a Harvard architecture. It has three different types of memory as described here. Basically your program code is stored into what’s called flash memory. So as your sketch gets bigger and bigger you use more and more flash memory. This is the memory mentioned when you compile your code in the Arduino IDE and it says at the bottom:

Binary sketch size: 28584 bytes (of a 30720 byte maximum)

When your program is run any variables it creates are created in what’s called SRAM.

The Arduino I am using (the Duemilanove) uses an Atmel ATMega 328 microcontroller.  This has 32K of flash memory but 2k is taken up by the Arduino bootloader. It also has 2K of SRAM.

When you have literal strings in Arduino code they actually end up being stored in both flash memory and SRAM. This is all described here in detail but basically by having a lot of strings in my code I was running out of memory. SRAM memory that is. Think of SRAM as the memory needed to run the code while flash is the memory needed to store the code.  The trick is to use PROGMEM to only store them in flash then pull them out as needed. This worked well and I was able to port almost all of the code and get it running.

The key word there is almost. Next I started running out of flash memory!

You end up seeing the dreaded out of memory error when you try to load your code to the Arduino:

Binary sketch size: 32484 bytes (of a 30720 byte maximum)
processing.app.debug.RunnerException: Sketch too big; see http://www.arduino.cc/en/Guide/Troubleshooting#size for tips on reducing it.
    at processing.app.Sketch.size(Sketch.java:1651)
    at processing.app.Sketch.build(Sketch.java:1570)
    at processing.app.Sketch.exportApplet(Sketch.java:1610)
    at processing.app.Sketch.exportApplet(Sketch.java:1578)
    at processing.app.Editor$DefaultExportHandler.run(Editor.java:2314)
    at java.lang.Thread.run(Thread.java:619)

This is a problem. Every line of code you write and every library you include uses up flash memory. I went through and did some optimising but this wasn’t enough. I hadn’t even included the libraries for driving the gLCD yet!

I then looked at all my strings. It seems there is about 5k worth of text strings in the game of Taipan! If I could take those out the flash memory it would free up some space.

So I looked at storing the strings externally. Luckily it is dead easy to add external storage to the Arduino. I bought some EEPROM chips from Jaycar, the 24LC256. This is a 256kbit chip meaning I have 32k times 8 bits of storage, more than enough for all the strings. Hooking this up is dead simple. It is an I2C chip so all I needed to do was add the I2CEEPROM library from the Arduino playground and I was off.

I wrote a separate Arduino sketch to load the data onto the EEPROM chip. This works in the following way.

The strings are all written to the flash memory sequentially. Strings are null separated. I write all the string starting from memory location 1024 on the chip. From location 0 to 1023 I have a lookup table. This table consists of integer values (each taking up 2 bytes) where each value is the address of a string stored in memory.

So basically on the EEPROM chip have a 512 element array (2 bytes per element using 1024 bytes means 512 elements) where each element points to a string in the table.  The first strings address gets written into element[0], the second string into element[1], etc.

The strings can me any length as long as they have only one null terminator. I can store the address of up to 512 strings. Of course you can tweak these parameters as needed but for me that is more than enough to store all the strings for Taipan! ( currently 177).

I keep a record of what strings are referenced by each element and when I want to print out a string I simply fetch the appropriate element off the EEPROM and print it, e.g Serial.println(GetStringFromTable(121));

From the table I know that means: 121: Aye, we’ll fight ‘em, Taipan. : 4507

That line is taken from the output of the string writer sketch. 4507 is the actual address that string is in the EEPROM but the user doesn’t need to know this. They just need to know it is string 121. Element 121 in the element array contains 4507 and that’s where the string is fetched from. The good thing about this system is any changed to the text of the strings won’t affect their index. So the existing code will work. New strings are only ever added to the end of the table and assigned a new index as needed. You don’t need to change any existing index.

After doing all that I saved about 3k. Not much but enough that all the code would fit on the Arduino and I had a fully playable game where all the game logic worked.

I should note here that the C port I was using isn’t 100% accurate. It is very, very close though. By examining the Apple basic code I was able to make my port closer to the original Apple version. I think I have my logic almost exactly like the original Apple version but I keep tweaking and finding ways to make it closer.

I should note that all this has taken a week or more of progress in the evenings after work. My poor car project has been woefully abandoned while I work on this. One setback was when I bought the memory chips. I also bought a new breadboard from Jaycar.  Earlier in the week I had bought one from Surplustronics but it turned out to be utter rubbish. The connectors on the board were far too tight to even push components into without their legs bending. I tried opening the connectors out with a sharp pointed object but doing that meant the connectors lost their spring. Was cheap, useless rubbish so I threw the whole breadboard into the bin.

The Jaycar one should be better. I bought a large board and when I got home transferred my keypad to it. I was only using a small part of the board. However after that nothing would work! It seemed like the keypad wasn’t working. After about an hour of puzzling over it I finally worked out that two of the strips in the board were shorting out. I’ve never seen that before and it was unfortunate that in such a massive board I happened to plug my 7 pin keypad across the 2 rows that were shorted!

Once I sorted that out and went back to the original tiny board everything worked fine again.

Breadboarded.

The last bit of code I had to get working (apart from graphics) was concerned was the code to output numbers in a screen friendly way. The original Taipan! will output numbers more than 1 million in a ‘friendly’ format. It will say things like 1.2 Million or 23.6 Billion. The Apple code to do this is shown below.
For some reason getting my head around that took me forever. I was sick at the time and so it took a day or more to get that working accurately in the Arduino. I still don’t fully understand how it works!

10  CLEAR :WK$ = "*":CH$ = "*":C
     H% = 0:WU% = 0:R1% = 0:I = 0
     :J = 0:K = 0:II = 0:IJ = 0:I
     K = 0:T = 300:LT =  LOG (10)
     :T$ = "Taipan": GOTO 10000
.
.
.
 600  IF WW < 1E6 THEN WW$ =  STR$
     ( INT (WW)): RETURN
 610 II =  INT ( LOG (WW) / LT):I
     J =  INT (II / 3) * 3:IK = 1
     0 ^ (II - 2):WW$ =  LEFT$ ( STR$
     ( INT (WW / IK + .5) * IK /
     10 ^ IJ),4) + " "
 620  IF IJ = 3 THEN W$ = "Thousa
     nd"
 630  IF IJ = 6 THEN W$ = "Millio
     n"
 640  IF IJ = 9 THEN W$ = "Billio
     n"
 650  IF IJ = 12 THEN W$ = "Trill
     ion"
 680 WW$ = WW$ + W$
 690  RETURN
.
.
.

With that in place the game is logically complete. You can play it as a fully text based game and it seems to be the same as the Apple version (including the infamous bug). The problem now though is there is now more room to add the graphical LCD libraries or extra code to it! I am currently using up 28584 bytes (of a 30720 byte maximum).

This is where I am at now but I have a plan for how to continue.

The plan now is to use a second Arduino as a slave just to do the graphics output. And instead of the gLCD I may instead use the Arduino TV-Out library. This allows you to hook your Arduino to a TV via the video in and display on that. I tried the demo and it seems to work very well (just two resistors and an RCA cable needed!). If I can get that working I will use a second Arduino as a graphics slave and talk between them using I2C (as I am already using that to talk to the EEPROM). I can output the game to a standard TV.

The plan is to put the whole thing a small, portable housing using a tiny LCD monitor such as this one.

For the housing I got this:

Tai-pan, the book!

And yes, it’s a first edition! Suppose I better read the thing before I destroy it.

I searched on-line for some I could copy with no luck. I tried drawing my own, also with no luck. In the end I just grabbed a piece of printer paper and some scissors and simply cut out bits that weren’t cricket shaped until I had something close. I had to trim some bits off then stick them back on in other places but in the end I got this:

Cricket cut-out.

Not too bad! With a little imagination.

Next I needed some metal suitable to recycle to make the cutter. I decided to use a large 5 litre mini beer keg I had left over. It was a special release for some rugby game or something last year.

Mini Heineken beer keg.

Now these little kegs are interesting. They are pressurised and have a tap on the top. When you open the tap the beer comes out. Was real imported beer too so not too bad for a lager.

I had to cut the can open so I hacksawed a slot into it then cut off the top. Inside it was a surprise. Instead of being a simple pressurised can there is a fancy gas pressurising system inside them.

Glued to the inside of the base of the can is an aerosol can. The sort of thing you get lighter butane gas in. On top of that was a plastic apparatus.

Cannister inside can.

The plastic top of the cannister pops off revealing a small metal bracket on the nozzle of the cannister.

Metal clip on nozzle.

The plastic thing turns out to be a piston and cylinder. The piston pushes down on the metal clip opening the nozzle on the cannister letting gas out of it.

Piston and cylinder.

I had assumed at first that cylinder contained a spring since if you pressed down piston the cylinder it would then pop back out. On taking it apart however I found it was simply a sealed cylinder and the piston has an o-ring seal to make it air tight.

Piston and o-ring.

I cut the top off the cannister (it was empty of gas) and found that inside it was full of black pellets (that look like mouse poo).

Mouse poo pellets.

Despite what some people think of the taste of Heineken I suspect it isn’t actually mouse poo but instead pellets of charcoal.

What I think happens is the piston and cylinder act as a valve to keep the pressure inside the keg at a constant. When the pressure drops the piston pushes on the cannister nozzle releasing more gas – CO2 I guess.

Turns out there is a whole web site for this thing here. Although it is much more amusing in Espanol being called El Barril!

Anyway, with the keg dissected I wrapped some tape around it in a long strip so I could cut out the metal I needed. From the paper pattern I knew approximately the strip needed to be. I had to wrap around the tin about twice.

Tape cutting guide.

With the strip cut out I used a hammer to flatten it then trimmed up the edged with a straight edge.

Hammering the strip.

I marked down from one edge to give me a fold line then using some angle iron clamped to the bench folded that over to 90 degrees. I then hammered the rest of it down flat. This stiffens the strip and provides a safe top edge to press down on.

Yes, that’s an MGB starter motor in the background.

I then simply bent the strip by hand for the smooth curves to the paper pattern. For the straight bends I used my welding pliers as a small metal folder.

With the metal folded to the pattern (more or less) I traced around it on some paper and cut it out to see how it looked.

Traced outline.

With that looking mostly like my original cut-out I continued on.

I made a small insert to make the cut-out of the rear leg. This is simply another piece of strip but cut so that the part holding it to the outside of the cutter is cut away so that doesn’t cut the biscuit dough. This was held in place with pop rivets. These same rivets hold the ends of the cutter strip together too.

Rivets.

Finished cutter.

To test the cutter is used some Play Doh. Not having a proper rolling pin I used the nearest handy roller shaped thing – a 37mm Chinese artillery shell. I cut it out and poked a pen in it to make an eye! The edges are a bit jagged since I didn’t want to press down too hard on my wooden table top. The thin (0.26mm) metal  actually cuts quite cleanly with a bit of pressure without it being sharp or dangerous.

Rolled out.

It works!

I am not sure it is really cricket shaped but it is something. I can’t bake so I can’t test it properly myself. I need to find someone who can bake and can ice well (I think suitable icing will help A LOT) to really test it out for me. If only I knew someone suitable.

Generally I have been working on my little Austin and I tend to update that blog more. That’s where all the cool kids hang out.

Today I added a new project there, since it is Austin related, but really it’s an Arduino project.  I made the old phone in my garage play old 1930s music when you lift the receiver. You can see that here.

Musical garage phone.

As well as that I am throwing myself into my other projects. They are good and distracting from the real world.

I have been working on Steed a little. I made him a new jacket which took multiple attempts to get right. I am getting better at sewing though. I need to make him a shirt and a waistcoat next. And an umbrella of course (with a sword in it).

Steed’s new jacket.

I am also working on the railway again. Now the track is all ballasted I am starting on the scenery. Tonight I finally started laying down the cardboard mesh over which you put glue soaked tissues. This will make up a very stiff but light shell for the base scenery. It is also easy to change later. Have moved on a lot from when I was 10 doing it all with plaster of paris!

Starting the scenery mesh.

I also, some time ago, bought some small models for the railway. I need to get more.

Models.

I also worked out how to make my own tiny people to put into dodgy situations. They are made from thin wires soldered together then layers and layers of paint added on to bulk them out. Each figure is only about 10mm tall. This is the one I love the most. She’s pole dancing around a pin.

My tiny, curvy dancer.

Apple 2 in an ammo tin.

This was a follow on from my Tardis MAME console. The idea was to build a small portable MAME machine. My idea, not an original one it turns out, was to build a PC into a .50 cal ammo tin. I bought a tin from Kiwi Disposals on K Road, the local army surplus place. Apparently this was some time in about mid 2008 but I can’t be sure. I know I took loads of pictures of things but I can’t seem to find them!

Ammo tin.

Ammo tins are made from steel and they are very solid. They are also waterproof, have a solid catch, a carry handle and the lids can be detached. They make great tool boxes (I have one in the back of my MGB) and they have been used in the past for making other ammo tin computers. I think mine cost me about $25NZ. Apparently it heldM728 artillery shell fuzes not actual .50cal rounds.

To go inside it I wanted an older motherboard. I specifically wanted one with a joyport, the old 15 pin D ones. The idea was that I would use this machine with my ancient but excellent Thrustmaster F16 FLCS joystick. I had a look on TradeMe and came across an older motherboard for sale. It was a Gigabyte GA-8LD533 with a 1.7GHz Intel Celeron processor. I had to look in my TradeMe history to see I bought this back in June 2008 which is how I dated when I started the project!

To fit the computer into the ammo tin I made a metal sub frame to mount everything too. I am sure at the time I took pictures of all this but I can’t find them at all now. I did get everything finished and I think it was all working but I never actually used the machine for anything so it is been sitting on the floor under my computer desk for the last 3 years gathering dust. All the pictures here are new ones. I can’t remember if I actually got the thing running. I think so?

You’re probably wondering why I dug it out now. Well, that is my colleague Grant’s fault.  I know several Grants. The first is old beardy from my Zeacom days. He gives me old engines to play with. The second is artist Grant who helps me with car things. The third is author Grant at my current job. He got me addicted playing Taipan on our Android phones. It turns out this isn’t a great port. So I started looking at the original versions. The one I remember is the Apple 2 one.

Now the Apple 2 is a computer I remember very fondly. It wasn’t my first computer, that was a Commodore Vic 20. The Apple was my second computer. At first I had an Apple 2 plus, bought by my parents second hand from the computer shop that used to be over the road from the old Farmers building on Hobson street in Auckland. Oddly enough I now work less that a km from there – doing computer stuff! We eventually upgraded that to an Apple 2E enhanced.  Recently I discovered at my parents house my old Apple 2 folder. In 1986 that computer cost my father $1864! And that was at a discounted price since he worked at the university so got an educators discount. I was 13.

Original 1986 receipt.

That was a lot of money then. Still is now! I guess it paid off, computers is what I do and now it pays for me to be able to spend money to recreate what I had way back then.

It’s kind of circular really.

Anyway, Grant got me into Taipan and we both fondly remember the Apple 2 version. Grant has an idea to build a PC into an old Apple 2 disk drive. I remembered my old ammo tin project and decided to turn that into an Apple 2 emulator. I had previously tried out the AppleWin emulator and knew that worked well. The latest version is now here. I decided to try Taipan on the ammo tin.

When I tried to run it the damn thing wouldn’t boot. It seems that somewhere along the line the 120GB drive in it failed. I found it wouldn’t boot up and I wasn’t able to reformat the drive to reinstall Windows XP on it. I did find an old 1.2GB drive and was able to get the machine up and running on that. Unfortunately 1.2GB is far too small for an up to date XP installation. But it was enough for me to get the machine running and AppleWin installed to make sure it was going to work.  Once I confirmed that author Grant came to my rescue with an old 20GB drive I could use.

So I set about rebuilding the machine.

In the original box I had made the basic fame and mounted the motherboard, power supply and hard drive. I had bought a small PC power supply to fit inside the tin. I am not sure what the wattage on it is but it is tiny. I am using the on-board video port and have no peripheral cards at all so I should need too many watts.

Basic box.

The basic fame is made from aluminium sheet with aluminium extrusions in the corners.

Front panel.

The front panel is another sheet of aluminium with appropriate cut outs. I used two drawer handles on the front to provide an easy way to pull the chassis out of the ammo tin.

The motherboard is mounted with four brass screws fitted through the bottom of the chassis. To keep the screw heads flush I used countersunk screws. I drilled the holes for them then put the screws into the holes and hit the heads with a hammer. This indents the aluminium to fit the screw head so they fit flush with the chassis. I used a plastic sheet under the motherboard to ensure it wouldn’t short and used rubber power cord grommets cut in half as rubber spacers to hold the board off the chassis.

MB mounts.

The motherboard was mounted into the chassis. The front panel provides cut-outs for the connectors on the back of the motherboard, the power supply and for switches, LEDs and USB ports.

MB and supply installed.

The MB sits in the base of the chassis. The power supply sits above it attached to the front panel. The hard drive, in this case a 5 1/4 drive, is attached vertically to the back of the chassis.

I used a missile switch as the main power/reset switch. I added two LEDs for power and HDD indication. All of this was basically how the box was as I built it in 2008. The front panel had a large hole in it which I was going to use as storage. I never actually got around to making a liner for the hole so I made up a new aluminium panel which isolates the motherboard from the rest of the tin. This panel, forming a neat cubby hole, is held in place by the LED bezels and provide useful storage space.

Cubby hole.

With this in place the chassis was finished and it ould be slid into the ammo box. It is worth nothing that if you need to reinstall Windows or need the use of a CD/DVD ROM drive you can simply slide the chassis out and temporarily attach a drive. All the cables are present in the chassis already.

DVD drive.

You can see how when the chassis is slid into the box the cubby hole is separated from the rest of the box.

Chassis in box.

If you look carefully you will see the third USB socket is upside down. This is one I added with the update to the build. I had two spare USB cables floating about inside the box so I made one available on the panel. I put it upside down since I have found you sometimes come across some USB accessories that won’t fit into the socket in a sensible orientation. They need to be inserted upside down! This way I have all bases covered.

Well, that’s my excuse anyway.

Everything is very snug in the box. After running it for a while. I discovered several thing. 1) it gets very hot and 2) it would be handy not to need to connect external speakers.

For the first problem I added in a second (well third) fan. The CPU already has a fan as does the power supply. All the air was being blown out of the holes on the front of the power supply and this seemed rather hot. I added in a fan to the side of the cubby hole to blow air through the box. This made a massive difference to the temperature of the box and now it runs very cool.

  Fan vent in cubby hole.

I also decided since all I was trying to emulate was very simple Apple 2 sounds I should add an internal speaker. The Apple 2 used a simple, small, single channel speaker. I added one inside the case held to the side of the power supply with industrial strength Velcro. I added a switch to the front panel that switches the output from the internal speaker (wired so both channels are going into the one speaker) to the normal rear (in my case front) line out socket. I did this using the front audio output socket on the motherboard. This way I can plug external speakers into the box if needed but most of the time the Apple sounds are sent to the internal small speaker, just like in an original Apple 2.

Front panel with speaker switch.

With those in place I slide the chassis into the box.

Chassis in place.

The cubby hole is used for storing the cables and mouse. I am currently using a wireless mouse with a large receiver that I got when I originally started the project in 2008 . I modified the receiver by opening it up and hot gluing a rare earth magnet into it. I can then stick the receiver to the outside of the steel ammo tin.

Storage and magnetic mouse receiver.

I will probably replace the mouse with a modern Bluetooth one to save some space. I also had a USB folding keyboard that would fit into the cubby hole. Unfortunately that broke so for now I am using conventional keyboard. I have bought a new folding one that will hopefully fit into the case.

And that is the box basically finished. Even though it is an old motherboard and CPU it is easily enough to run the Apple 2 emulator. So far every single game runs fine.

I can attach the box to a external monitor or, through an interface box, to my old tellie (yes, will get an LCD one day). Everything (hopefully including the keyboard soon) fits into the cubby hole when the box is being carried. It is all pulled out and set up to run the machine. The cubby hole is left free then so the fan is unobstructed although it does provide handy storage for temporary items.

The toggle switch is used to power the box on and off. Flicking it off will cause the box to shut down nicely rather than just killing the power.

AppleWin allows you to run the screen either windowed or full screen as well as simulating colour or monochrome screens.

Next is to download as many old games as I can. So far all of them seem to run well. It’s a real trip down memory lane for me. All the old games: Below the Root, Wings of Fury, Captain Goodnight, Rescue Raiders, Choplifter, Loderunner, Conan, Drol, Bolo, Dungbeetles! We got ya!

I also need to build the equivalent of an old Apple joystick. AppleWin allows the use of a PC joystick but I want to build a PC compatible joystick in the style of the old Apple 2 ones. I have a plan to build a small one using the analogue stick from an old Playstation controller and a couple of buttons.

I started building up a small collection of cufflinks (I also have a collection of salt and old 1950/60s Gillette razors but that’s another story). Cufflinks are ridiculously overpriced in NZ (what isn’t?) so I tend to order mine from overseas. You get better quality ones at better prices if you hunt about.

Favourite cufflinks.

Above are some of my favourites. Yes, I am something of an Anglophile and a train-spotter. The Dalek ones are very cool and I always had it in my mind that the TARDIS would make a nice cufflink. It is possible to buy some but I never got around to it. The London Underground ones a friend of mine got for me when he and his wife visited London from their home in New York and I then had to wait till they visited New Zealand to bring them to me. Those are well travelled cufflinks!

One of my other (many) projects is an N scale model railway I am building to go into a dining table. That is a 1930s British themed layout and when looking around at what buildings I could get for it I discovered you can buy a tiny N scale Police Box.

Hornby Police Box.

This is one of the Hornby Lyddle End range of resin models. I bought one, as well as some buildings, online since they don’t seem available in NZ easily. Oh, if you’re a retailer in NZ (and elsewhere actually) and have an online shop here is a hint – listing products you don’t actually have in stock and not telling people until they get to the checkout is not good!

The Police Box arrived and it is very cute. Perfect for my railway but also perfect to make some cufflinks from. The model is about 22mm high.

Lyddle End Police Box model.

It looks just like another TARDIS I happen to have here at home! I didn’t want to cut up my railway one so I ordered another from the UK. I got mine from Celestial Games and Books on eBay who were excellent. It’s interesting that ordering things from the UK is much easier than ordering from the US and shipping takes far less time than getting things sent from America.

I also bought some brass cufflink bases from a local online jewellery supply shop called Beadaholic. They, by the way, have an excellent online shop!

Model and brass cufflink base.

Next I used a modelling razor saw to carefully cut the model in half. This unfortunately results in the loss of the lamp from the top of the box but that is easily fixed later. After cutting I flattened the back of each half by rubbing them on some wet and dry paper.

Model sawn in half.

To attach the model to the bases I made some small brass backing plates. These were cut and filed from 0.9mm thick brass. I first made one then used that as a template to make the second. They are a little rough but at this scale they don’t need to be perfect and I like the hand crafted look. A quick clean up with some wet and dry and a final clean with steel wool finished them off.

Brass backing plates.

I was then able to solder the cufflink bases to the backing plates and later I could glue the model onto them.

Bases soldered on.

Next I repainted the model halves. I used small tins of Humbrol enamel paint – matt number 25. I love the smell of that stuff, reminds me of childhood and making models. Unfortunately I couldn’t recreate the fine lettering that was on the original models. These were actually stickers stuck to the model. Again the loss of detail doesn’t matter too much as these will be seen from a distance usually. I didn’t have a brush fine enough so I used a toothpick to put on tiny dabs of paint. White for the “Police Box” signs and white for the “Pull to Open” sign with some black lettering.

Painting.

I also made a replacement lamp using a tiny piece of styrene plastic glued on with superglue.

Replacement lamp.

Finally I superglued the painted model to the brass backing and gave the whole lot a coating of satin varnish, Humbrol 135, and I was done!

Little TARDIS in front of big TARDIS.

TARDIS cufflinks completed and ready to wear.

Right, where was I? I stuck the templates for the letters and the direction arrow onto the remains of the steel case.

Templates glued to the steel.

The letters and arrow were then cut out using the jigsaw and a hacksaw then filed and sanded smooth.

I then worked out how to make the pivot. I have no idea how real weather vanes do it. Looking online all I could find were silly toy ones. I found people online who make and sell real weather vanes but none explained how the pivots work. Perhaps it’s a trade secret? So I invented my own.

I am using a tube sealed at the bottom with a ball bearing at the base as a pivot and a bush near the top to stop the vane flapping about. The vane itself is attached to a straight steel shaft that slides into the sealed tube part. The whole thing is full of oil so it shouldn’t rust or wear out and it should provide a smooth rotation without being too sensitive due to the damping effect of the oil. Pictures should make it clearer.

Pivot parts.

The main body is simply a piece of steel tube.  Into the bottom of this is brazed a bolt, the head of which was turned on the lathe to make it fit into the tube. I put a small countersunk hole into the head of the bolt to locate a small ball bearing to work as the pivot. The ball bearing I got from inside an old spray paint can. These are what you hear rattling when you shake the cans. Now some cans have steel balls and some glass marbles. How do you tell which has which sort? Stick a magnet to the outside of the spray can and gently tip the can so the ball inside rolls past the magnet. If it is a steel bearing it will stop when it reaches the magnet whereas a glass marble will just roll past. Actually it makes no difference to me, I cut them ALL open and rescue what’s inside before putting the steel can out to be recycled! I have a jar full of the damn things.

Anyway, the bush at the top of the tube is just a nut I turned down to fit. The main shaft of the vane was some rusty old 1/2 inch steel rod I found in my old garage. The bush is pushed into the tube then held in place via a small hole in the tube I then plug welded through to hold it all in place. The picture above shows the relative positions. The whole tube is eventually filled with oil so the bush is actually totally submerged meaning it won’t rust or wear out in a hurry.

The pivot ball bearing.

You can see above how the ball bearing sits on the bolts at the base of the tube. The bolt is brazed into the bottom of the tube as shown. Later that bolt thread is used to screw the pivot into the main mounting bracket of the weather vane and it allows it to be turned to accurately position the direction markers.

To this pivot base (which doesn’t turn) the direction indicators are attached. I brazed the letters to lengths of 6mm diamater steel rod then welded these to the base.

Direction letters.

Once the base was done I brazed the direction arrow and locomotive to the main 1/2 inch steel shaft. I changed the rear of the arrow from my original design to one with more surface area based on this original LNER sign from Briglington I found online. I also added a small water shield made from a piece of tube and a washer. This gets welded to the weather vane shaft and it forms a cap that goes over the top of the pivot base to stop rain getting into the tube. This needs to be welded on very carefully so it is concentric to the main shaft so it won’t rub on the pivot base as the vane turns. I also added some balance weights to the front of the arrow head to balance the main vane.

A weather vane needs to be balanced with equal weight each side of the main shaft, so it spins easily, but has to have more surface area on the rear half than the front so it points into the wind.  I didn’t get this quite right (hey – it’s my first try!) so I needed to add weight to balance things out.

I then made the base which is simply a section of tube welded to a steel base. PArt way down the inside of the tube is a nut that matches the thread on the base of the pivot. This nut is welded inside the tube. I drilled a hole in the tube at the point the nut needs to sit then just plug welded the nut in place from the outside of the tube. For some reason I didn’t photograph this! The base was just some scrap 3mm steel plate I had that I cut to what I felt was a pleasing shape. The tube is welded to this.

Mounting plate.

This mounting plate is in turn screwed to a wooden base that is bolted to the eaves of the garage. The wooden base was made from some scrap marine ply I had about the place.  I needed to know what angle to cut the wood but since I didn’t have a ladder tall enough to get up to measure the angles I made a little measuring jig. This is just a long piece of wood with a T piece nailed to to top arranged so, with some force, it can pivot. To the pivot I hung a plumb line. I then took this contraption to the front of the garage and held it up making sure it was vertical using the plumb line. I then pushed it up onto the eaves. This moved the T piece to the correct angle.

Contraption for measuring roof angle.

I then transferred that angle (turns out it was 20 degrees) onto the wood. Simple! The steel mount is simply screwed to the wooden base which is in turn bolted to the garage eaves. I turned up a pointed plug from a piece of dowel to fit to the bottom of the mounting bracket just to finish it off. The steel base was primed with a zinc rich primer.

Wooden base for steel mounting bracket.

Another detail I didn’t get a picture of was the spacer used between the base and the mount. It goes on the threaded part of the base and is carefully cut to the right length so that when the base it turned fully into the nut in the base the direction pointers point in the right direction. I used a pice of 1/2 inch copper water pipe. Using copper means the spacer has some give in it. You can snug the base up very tight into the mount, the copper distorting a little for the last part of the rotation so you can get it in the exact right place. I got the idea from the crushable spacer used in an MGBs rear differential to set the differential pinion gear.

Oh, about now I discovered I could buy online some really nice locomotive cufflinks that happened to be almost the same as my weather vane. So I bought some! $30NZ shipped from the UK, arrived in 4 days! Cheaper than buying locally.

Locomotive cufflinks!

With everything done it was just a matter of painting it all. I painted the steel with black satin paint. Obviously I used the right stuff since the spray can has a picture of a weather cock on the front! Who wants a giant cock on their roofs?!? I painted the wooden base white and I used carriage bolts (appropriate for a railway themed vane) to bolt the whole thing to the eaves. So the vane sits into the base which is filled with oil to cover the ball bearing and steel bush. The base is in turn screwed into the mount via a spacer and a into nut welded inside the base shaft and the whole thing is bolted to the garage.

Finally painted.

Finally with everything painted and finished I just needed to bolt the whole lot to my garage roof. Luckily my father had a ladder long enough and he came over to help me by holding the ladder while I clambered up to bolt it all in place. Once done we stepped back to inspect it all and this is how it came out!

Finished weather vane.

Now if you wondering why the N-S letters are backwards in this view there is a good reason for this. As my mate Dave pointed out to me weather vanes will have one correct orientation. From other views the letters will be backwards. I was to busy making sure I got the N-S-E-W order the right way round to notice! Mine is the right way round when viewed from inside the house!

Yep, that was totally planned, not lucky chance at all…..

View from indoors.

Finally, to prove it works, a little film on YouTube.

Works at night too!

So in light of all that I decided to start a new project – a railway themed weather vane to put up on my spare garage. Currently my house and spare garage (I have two – doesn’t everyone?) are being painted and they are looking really good. The peak of the spare garage roof is the perfect place to put a nice weather vane which should be a fun little project to build.

Spare garage soon to be painted.

I seem to be going through a railway phase just at the moment. Reading everything I can about old British railways, locomotives, stations, etc, etc. I’ve always been a bit of a trainspotter I guess. I decided to make this weather vane with a railway flavour. I knew I needed some suitable steel and looking through my junk cupboard I found an ancient PC whose case I could cut up. It is a 486SX-25 so slightly past it’s best. The top cover of the case is nice thick steel – 1.2mm thick to be exact.

Nice steel case.

I decided to reuse this steel to make the bulk of the weather vane. I hunted online for a suitably representative locomotive that would look good as a sillouette. In the end I decided on a LNER J83 tank loco. The Hornby model railway provided me with a nice clear side view of one so I copied the image and put it into a graphics program, turned it into a black image and printed it out. I used that image to take measurements from which I then scaled up 3x to transfer onto the steel cover.

Outline drawn onto the cover.

I did tweak the design a little to make it clearer and easier to cut out. I just drew the design onto the steel with a Sharpie, some of it freehand, some with a ruler. The wheels I made slightly oversized. A screw jar lid made a useful template to trace around for those!

Once drawn out I drilled holes in strategic places then, using a metal cutting blade in my jig saw, I started cutting it out.

Holes drilled to allow the pattern to be cut out.

It took a lot of careful cutting but eventually I removed most of the bits that aren’t locomotive.

Shape roughly cut out.

I then started filing, grinding and cutting the edges to clean up the shape. I found that was well as using the bench grinder and hand files I was also able to use my joggler, a panelbeaters tool used for bending and punncing holes in steel for plug welding through. I used it a lot when restoring my MGB. With it I was able to nibble close to the line in some tricky spots which then minimised the amount of hand filing needed.

Joggler tool.

After about an hour and a half of mainly hand filing the main cutout was done. I gave each side a quick once over with the random orbit sander to smooth off the rough edges.

Finished cutout.

About now I was felling pretty pleased with myself when I suddenly realised ‘Bugger, the damn thing looks a lot like Thomas the Tank engine‘. Bah!

<trainspottervoice> Oh well, everyone is sure to realise my locomotive is based on the LNER J83 where of course Thomas was based on an LB&SCR E2. Obviously completely different locomotives! </trainspottervoice>

There is just no way I am going to paint the thing blue and red now though!

Next I need to make a direction arrow in the style of the old station Way Out signs and make the letetrs for the direction pointer. In preperation for that I used an online font sampler to print out the cardinal directions. The font is Gill Sans which is the font used by the LNER railway back in the day for all their signage. Since I am using their loco it seems fair I should also use their lettering! I will glue the letter onto the steel then cut those out.

Gill Sans font for the cardinal point markers.

More updates soon.

Part two is now available here.