Blog update 2020

1 May 2020

Due to an unfortunate server accident last year my blogs were lost and I have been unable to recover them. All of the original content up to a point is available here on the Internet Archive's Wayback Machine.

All the original photos of all my projects are here Gallery

All new updates are being put here on my Asciimation YouTube Channel.

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Demodex eyelash mites under the microscope.

January 3rd, 2019

A funny little film I made. You probably don’t want to watch if you don’t like the idea that there are things that live on you…

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My eyes have been quite sore lately. Initially I put it down to hayfever but the sensation is more odd than that. More a kind of crawling, twitching sensation in my eye lids. They all look ok but felt funny. Like something was crawling about in the edges of my lashes.

Turns out something is…

I’d vaguely heard of these things before, small mites that live inside the bottom of your eyelashes. They are called Demodex Mites. So being a big geek I decided to pull out my microscope (an old Cooke, Troughton and Sims) and go mite hunting.

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I tried pulling out a lash with some tweezers and accidentally managed to get two. So I put them on a slide with a drop of water and a cover slip then took a look through the scope. You can see the eyelash hair and the root.

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And I found two mites! And yes, you can see them crawling about. The film isn’t great but gets better at the higher magnifications. I was simply holding my phone camera to the eye piece. Initial magnification was 24x, then to 60x then finally 240x. I should really 3D print some sort of adapter to make attaching the phone possible.

Once I am back at work next week I will go see my optometrist to see what can be done about it. Apparently they are quite common and I don’t think it’s anything to worry about. I wear Ortho K contact lenses so I am always very careful about keeping my eyes clean. The crawling sensation is really quite unpleasant but I feel better now knowing there really is something crawling about in there!

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Enigma machine pocket watch update.

December 18th, 2018

An update on the watch. I decided to make it into an actual watch. It was a comment on Hackaday saying they didn’t even care that it didn’t tell time…

Well, that got me thinking. Why couldn’t it? I spent so much time getting the Enigma machine part to work I never considered the watch part. So I did some investigation. Turns out there are many cool little RTC (Real Time Clock) ICs available that can talk to a micro that you use to set and get the time. The RTC runs independently from the micro with its own power supply and it keeps very accurate time. You set the time to it then it basically sits there and keeps counting the time up. Later on you can read back what the current time is.

You can buy modules to do this of course, like this one from Sparkfun. Or this from Adafruit. Both quite tiny by themselves but far to huge for my pocket watch. I did some hunting about and came across the STMicroelectronics RTC chips, one of which, the M41T62, comes with a built in crystal in a 8LCC package. That whole thing is tiny – 1.5mm by 3.2mm.

And they do free samples! So I ordered some. They are incredibly small.

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All I had to do was solder 4 wires to it, power, ground and the two I2C wires. I managed that with 0.15mm wire after having stuck the chip to a popsicle stick with some wrapped over to make it double sided aluminium tape. That was to hold it in place as well as be a heatsink when soldering it. Then I had solder it using a jewellers loupe to see the bloody thing.

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I then breadboarded it up to see that it would work with the Enigma hardware (using my damaged screen). You also need two pull up resistors for the I2C but I knew there was room for a couple of standard 1/4 ones.

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Turns out space in side the watch physically wasn’t an issue at all. Space on the Arduino micro program wise was! I found a library for reading and writing to the chip using the wire library. It’s relatively simple. You simply read and write to registers on the chip. I found someones library to use but it was a bit messy and rather large and since I am only using the hours, minutes and seconds (so didn’t need to worry about any of the date or alarm functions) I just wrote my own simplified library with the functions I needed. The Arduino Pro Micro is pretty full:

Sketch uses 27,340 bytes (95%) of program storage space. Maximum is 28,672 bytes.
Global variables use 1,046 bytes (40%) of dynamic memory, leaving 1,514 bytes for local variables. Maximum is 2,560 bytes.

 

The RTC chip is wired direct across the battery. The current is less that 100uA, probably far less when the chip isn’t doing anything. On startup the Arduino in the watch reads the time from the RTC and displays the hours and minutes, in 24 hour time (it is a military device after all) in the bottom corners of the splash screen. It read it once then the internal Arduino clock handles updating the time on the display. You can manually change the time by holding the left and right buttons and clicking select. That simply increments the hours or minutes. When you hit the select button alone to exit the splash screen the time is saved back into the RTC if it has been changed.

And that’s pretty much it. Start up is instantaneous so the time is available as soon as you open the lid. It makes the device far more practical.

Putting it into the watch wasn’t too bad, just fiddly. I wrapped the chip and wires in some Kapton tape as strain relief on the wires themselves as the pads are so tiny any mechanical stress will rip them off. To sleeve the resistor legs I used a trick learned from plastic model making. You take a cotton bud with the hollow plastic tube and heat it over a lighter flame then when it starts to melt pull the ends apart. It stretches out into a thin tube. I then used that as small sleeving over the wires.

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And it all goes back together as before. I am not sure how accurate it will be. It should be fine given the batteries probably need replacing monthly and you need to reset the time then. If it is usable day to day I am perfectly happy with it. It doesn’t need to be hugely accurate. I am just pleased it is now practical and it’s name is accurate! It will be interesting to see 1, how well it keeps time in real use and 2, how long the batteries last!

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Enigma machine pocket watch.

December 2nd, 2018

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This is a follow up project to the Enigma Machine Wrist Watch I made a few years ago.

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I’ve been taking a break from my 3D printed Enigma machine as I am up to the tricky wiring stage. I have for years worn a pocket watch but unfortunately my last one got broken when it fell onto a tiled floor on an overseas trip. These days pocket watches are cheap and plentiful but the issue is finding people who can repair them. Even if you do it si so expensive it is not usually economically feasible. I often carry a little music player watch I made which you can see here.

http://www.asciimation.co.nz/gallery2/main.php?g2_itemId=6122

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I thought well, why not reuse the electronics and code from the Enigma wrist watch and put them into a pocket watch. The electronics and software are almost identical. I did upgrade from using an Arduino Pro Mini to an Arduino Pro Micro. I also added in better button debouncing using the bounce 2 library. The user interface on both watches is identical.

The first thing I had to do was find a suitable old watch case. A chunky one like the music player would have been good but I wanted what is called a hunter style watch. It is one with a little hinged lid on it. I ended up with a half hunter, one with a little window to show the hands.

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The watch was a broken one so I didn’t feel bad about destroying a working watch. The case is gold plated. In the picture you can also see the little 0.96 inch OLED screen and the pro micro that is the main processor. You can also see how there isn’t much room available. The curved nature of the casing makes things tricky too of course.

The first thing I did was remove the window and etched a new plate to cover the hole. I did two, on in copper and one in brass to compare them. The design is based on the outline of an Enigma machine rotor. I used the brass one in the end.

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I also bread-boarded up the circuit to make sure it was all still working and to play with battery configurations. I also tested using a bare bones Atmel chip but in the end decided the pro micro was the better way to go (and much easier to program since it has onboard USB).

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One thought for batteries was using four button cells flat in the bottom of the watch but with only about 10mm of space to play with height wise there wasn’t room for the micro and stacked screen.

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The round shape means there is much less room available than in the rectangular wrist watch. I also thought about using a tiny LiPo battery like in the railway music player but I didn’t have any small enough and then you also have to provide a connection for the charger (or make the batter removable).

In the end I went for three button cells stacked, I am using LR54s which are only a few mm thick. I did thing of using LR44s lying side ways but the casing just isn’t thick enough to have room.

One thing with old watches like this is that they have two back covers, inside the back cover there is a second dust cover. I was able to use this as a way to clamp the circuit board for the watch in place. This watch casing is actually gold plated.

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It took an awful lot of prototyping and messing about with different configurations before coming up with the final arrangement. One of the initial thoughts was to put the buttons on the top plate which would be made from a PCB material. I used that method in the watch but the buttons on that are usually not seen. I wanted something cleaner for this so went with buttons on the base plate and little brass plungers that pass through the top plate to push them.

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3D printing parts to test the fit was invaluable.

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With the basic idea worked out I made the bottom circuit board. This is made from 0.5mm thick board to be thin enough to fit. I use the same method I used for etching the cover plate and the little brass Enigma logo. I print the design with a laser printer onto glossy magazine paper (Hornby railway magazines work well) then transfer the image to the very clean brass or circuit board. You use an iron on the highest non steam setting to heat the press the toner onto the metal. You can then soak it in water to remove the paper. A gentle scrub with an old toothbrush helps remove the paper.

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I then etch it in Ammonium Persulphate used for etching PCBs.

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The battery holder is a piece of brass tube I split so I could open it out. Inside it is a piece of clear acetate to insulate the inside wall. I etched the board so that the lower battery contact si a ring meaning if the batteries are put in upside down there is no electrical contact. This wasn’t strictly needed as the Arduino has reverse protection built in on the raw input pin.

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Shown there is the first top plate I made from thin brass. In the end I needed to remake that from thicker material to allow the screen to fit down into it to give me enough room.

One thing I did have to do to save space was use very small switches. I went for the more tactile push buttons and am using a tiny NC plunger switch for the main power switch. The needed it’s plunger extended so the lid of the watch can turn the switch off. I used a piece of 1.6mm OD copper tube drilled out to 1.2mm and super glued it onto the switch plunger.

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I also turned up little brass standoff and tapped them 2mm for the small screws I would use to hold the top cover on.

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I assembled everything on the base circuit board so the electronics of the watch and switches and batteries are one unit.

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The initial top cover was very thin but I remade it using thicker brass with a hole cut in it to locate the glass of the OLED screen. That let the screen circuit board sit up higher allowing more space inside the watch. I found I needed that because when I mocked everything up I forgot to allow space for the wires. Even using 0.4mm diameter wire made the electronics stack too thick to fit. By recessing the screen into the top plate I gained enough room.

Unfortunately you have to be very careful with the little LCD. I already had to cut it down a lot to get it to fit in the watch. But I wasn’t careful enough when assembling it during one of my mockups and I cracked off the corner of the glass. There must be tracks running through the corners as that made the display faulty.

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It was easy to replace and I also added some white glue under the glass to give it a little more strength.

I decided to paint the top plate wrinkle finish black like the housing of the wrist watch (and the top rotor cover of real Enigma machines). The trick to getting a nice finish si heat and my little toaster oven I found in an op shop worked perfectly. I also used it to bake on the red paint I back filled the little brass Enigma badge with.

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Another issue I found after assembling everything was that the buttons for the left and right switch were’t 100% reliable. They would get into positions where they would stick. This is because the button is not directly under the plungers.

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This is because the buttons couldn’t be too close to the walls of the inside of the casing. In the end I made buttons with fatter bases and then had to file clearance into the casing to allow space for them.

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That fixed the problem. Assembling the watch isn’t too hard. You fit in in from the back and the inner back cover clamps the board in place. You then drop the top plate on. The buttons are held in place temporarily using Kapton tape.

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Two brass screws hold it on, one doubling up as the battery negative terminal holder. That is made from a piece of springy bronze taken from an old WW2 piece of radio gear. So the watch does have a little bit of WW2 in it!

The pro micro seems faster to start up faster than the pro mini (faster bootloader?) so the watch turns on and is ready displaying the splash screen by the top you have lifted the cover. I am very pleased with how it looks and functions. Battery life won’t be great of course, maybe 2 hours continuous use. But that’s plenty for a (100% functional) novelty watch. It has a nice weight to it as well, weighing 90 grams without the chain.

And finally more pictures of it finished and next to the wrist watch.

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I made a film showing how it is assembled here:

And this is the previous one with the wrist watch showing how the interface works:

 


A Van De Graaff generator.

May 6th, 2018

This was a quick(ish) little side project I did as a break from the Enigma and working on my Austin 7 after I had a clutch lining setback!

A Van De Graaff generator is a machine for generating static electricity. You can read all about how it works on the link but basically it’s a long belt running over two rollers of differing materials. The top roller is enclosed in a metal sphere that accumulates a charge on it’s surface. Shorting out the charge to the base of the machine creates sparks. Quite high potentials can be created with these machines.

They aren’t hard to build at all. A search online will find lots of examples, some literally made using tin cans and rubber bands. They all produce sparks. Here I will just describe some of the details of the machine I made and how I made it.

I’ve always wanted to make one of these and in fact did start making one when I was a teenager but I never got it working I think. Recently, while out shopping, I saw these stainless steel bowls that were almost a perfect half sphere for a cheap price. They are 300mm diameter and had a flattened bottom. I bought 3 of them, 2 for the upper sphere and one as the lower cover.

The first thing I did was make the bottom of one of them spherical. I simply heated the base up to red heat then beat the bottom into a curve using a wooden teardrop mallet. I then smoothed the surface using the highest crown anvil wheel in my English wheel and then sanded the bowl smooth.

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For the lower top hemisphere and the bottom one I first drilled a large hole with a hole saw. Slow speed and lots of cutting fluid is needed here.

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I then sat it on top of a large metal pipe and heated the edge to red hot with an oxy-acetylene flame.

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Next I placed onto the red hot hole a wooden bowls ball and gave it several good whacks with a large hammer. This turned the edge over into the hemisphere. A little clean up with a hammer and dolly smoothed things off. The finish isn’t perfect but the important thing is the sharp edge gets turned to be well inside the curve of the hemisphere. The actual curve is covered in the final machine.

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Any sharp edges on the spheres will bleed off charge limiting the voltages the machine can reach. By curling the sharp edge in we make use of an effect shown by Michael Faraday where the charge only exists on the outside of the sphere. You can see how the top of the sphere curls back in here around the 80mm diameter PVC pipe I use as the main support.

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The rollers of the machine are made from PVC pipe. The top roller runs freely under the action of the belt so it contains it’s bearings in the end caps. These were machined from plastic chopping board machined to be a tight fit into the PVC and the bearing press fit into pockets in the end caps. A split piece of PVC acts as a spacer inside the roller to stop the end caps pushing too far into the tube. The bearings are cheap skateboard bearings.

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The bottom roller is a press fit on it’s shaft since it needs to be driven by a motor. So it’s bearings are held onto aluminium brackets by small plastic caps machined to fit the bearings. To accurately drill the mounting holes I printed out a 1:1 template and glued it to the metal so I could centre punch through the paper and then drill the holes.

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The PVC rollers are parallel sided. When trying to run a flat belt over pulleys it helps if the pulley has a slight crown to it. To do this I 3D printed a plastic sleeve that is a tight push fit over the PVC. You can see them in the picture above. To make sure they don’t absorb moisture from the air (moisture and dirt are bad for proper working of the VDG machine) I sealed them with several coats of acrylic floor polish.

For the machine to work you needs rollers of different materials (and different to the belt). We are making use of what’s called the Triboelectric effect. You can read all about that online. For my rollers I am using Teflon on the top roller and aluminium for the lower one with a latex rubber belt rolling over them. One interesting thing is the whole roller doesn’t need to be the material of choice, just a thin layer in contact with the belt. I use Teflon plumbers tape on the top roller and aluminium tape on the lower one.

The sleeves allow me to easily change the material for experimentation without have to remake all new rollers.

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It also allowed me to easily change the crown by printing new sleeves as my first ones were far to barrel shaped, the crown can be quite subtle. The lower axle has a pulley wheel with a groove to take a drive belt pushed onto the shaft. Using chopping board plastic works well here as it is a little flexible so you can drill an undersized hole then push fit to onto the shaft.

The top roller was mounted to a metal bracket made from aluminium. It is shown here on top of the spatter guard I used to make the metal combs later on.

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To make the top and bottom mounts that hold everything to the PVC main tube I used more chopping board cut into rings. To cut the rings I made a simple jig to mount my router too. A base board with a central pin made from a 6mm bolt with the head chopped off. The router is mounted to a board that has holes in it that can fit over the central pin then rotate the router around it. The plastic chopping board has a 6mm hole drilled in it. It is then fitted over the pin on the base board. Then the router mounted on its board is put on top. You can then easily cut circular shapes.

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The top part is made from three circles. The biggest is cut to the same diameter as the inside top diameter of the bowls used as the main spheres. A hole in the middle is slightly smaller than 80mm so the disc will sit on top of the PVC main tube but allow the belt to pass through. The other smaller discs were all machined into rings on the lathe. I had to use the face plate to mount them too as the rings were too large for the chucks. The smaller ring is a sliding fit over the 80mm PVC tube. There are two similar rings to make the base of the machine.

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The rings are joined by 6mm threaded rod. The distance between the upper rings was set so the bottom hemisphere would pus up over the larger ring but so that half of it would sit above the top of the metal. That provides a lip that the top hemisphere accurately fits down onto which aligns the edges of the two hemispheres to make a complete sphere.

The upper roller is mounted on it’s ring and it sits above the larger middle disc and has a copper strip that connects between it and the edge of the two hemispheres.

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The three threaded rods mean the height of the roller can be adjusted and the roller can also be set to be perfectly parallel to the lower roller. When the machine is running you adjust the nuts that set the ring height and you can actually see the belt move across the roller. You adjust the nuts so the belt runs nice and true in the centre of the rollers.

Attached to the top ring is the upper comb. This is just a small piece of the metal splatter screen cut so the sharp points are close to, but not touching, the belt. I made a copper strap to clamp the screen in place. My first ones were nicely shaped using a 3D printed, two part press mould. I simple cut the strip to the right size, put it between the two printed halves of the mould then squacshed it up in the vice. The results were pretty good.

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But then I decided a simple flat strip was better as the comb can poke out both sides allowing for easier adjustments.

The bottom of the machine has two sliding fit rings with threaded rods and spacers made from aluminium tubes. These bolt directly to the wooden base board. That was cut into a circular shape using my router jig again. I am using a piece of oak recycled from old furniture. There is another metal comb at the base of the machine made from simple folded aluminium. And another copper strip to make contact with the lower hemisphere.

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I was going to add a plate to allow me to key the PVC tube when it fits into the base rings but so far I haven’t found that to be necessary as long as you make sure the tube does rotate so it rubs on the lower axle.

The belt itself is made from a latex exercise belt. You can get these are an actual ring and I have some on order (from China of course) but the local ones I got were just a single strip I had to join into a loop. For some reason they felt the need to send me this one small flat package in a giant box. I tried all kinds of glues but nothing really worked that well. So in the end, just to see if the machine worked, I used double sided tape.

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The machine is driven from a small DC motor from Jaycar. I originally tried a mains cooling fan motor salvaged from an old microwave but it didn’t have enough torque. With a pulley ratio of 1:2 my DC motor can turn it fine. The motor can go up to 18 volts but I am using a 12 volt supply and a DC speed controller. I found if you go too fast the belt starts wandering and comes off the rollers. About 10 volts works well on my machine.

The drive belt is a rubber o-ring. For my first experiments, before I had the o-ring, I was actually using elastic hair ties and they worked surprisingly well as long as you didn’t stretch them too much. The motor mounting bracket has a slot in it to allow the motor to be moved into the correct position and with the correct belt tension.

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Actually putting the machine together is a bit fiddly. The main tube is assembled to the top of the machine first. Next on the base you remove the metal comb then remove the non driven side bearing holder and bracket so you can slip the belt over the lower roller. Then you have to turn the whole thing upside down (or at least on it’s side) so you can drop the belt down the main PVC tube as you slide that down onto the base. I find trying a long piece of string to the belt and poking that up the tube so you can pull the end to keep the belt under tension works well. You then slide the PVC down onto the base. The rings hold it in place. You can then pull the string to stretch the belt so you can fit the upper roller. Then you reattach the lower comb and make sure nothing is rubbing. The clearances with the PVC tube in place are pretty small. Cut outs in the PVC clear the axle shaft and provide a window for the lower comb to poke though.

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With everything in place and adjusted the hemispheres are put in place and held with tight fitting rings that slide on the PVC tube. One holds the lower base down and another holds the lower half of the upper sphere up.

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And then it makes sparks!

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There are still things to do. The belt I made isn’t holding up too well. The issue is I joined the two ends of the belt together when it was un-stretched using double sided tape. Double sided tape doesn’t stretch. With the belt on the machine under tension it is stretched so it get narrower. Only the bit with the tape can’t stretch to narrow out so instead it bunches up causing little ridges. These hit the combs and bleed off some of the charge. I think when my continuous belt arrives this will fix that. You also have to be careful not to rotate the PVC tubing in the base as it can then rub on the axles. You notice when that happens pretty easily though. I might add some kind of key to the bottom of the PVC so it only fits in one position.

I want to make a small box that fits under the base to hold the electronics for the speed controller. The base sits up on rubber doorstops to provide a steady base so there is room. The other thing I need to investigate is earthing the base. The power supply I am using doesn’t connect the supply DC negative to the mains earth. The machine seems to work well enough without that connection and some quick tests I did with a clip lead to main earth didn’t seem to make much difference. So I am not sure the best thing to do there.

The machine charges up well. I have been able to get 400mm long arcs from it in a dry room It’s hard to know what voltage that is. You see various figures for the breakdown voltage of air (10kV per 10 – 15mm or so) but I don’t know if that’s valid for a VDG. You can feel physically the electrons flowing off the thing when it’s running and so the breakdown voltage of the air will be different I think. So the voltage isn’t as high as you might think. To arc 400mm it’s probably hundreds of thousands I think. Just how many I am not sure.

Currently my earthing sphere is only 30mm diameter. I have a much larger, 80mm stainless ball on the way from China and I think that should help too. The larger the spheres the more charge can build up. I think I am already near the limit of how much charge my upper sphere can hold. With the earthing sphere more than 400mm away the charge starts leaking into the air. You can hear and feel it doing it.

The other thing I should do it mirror polish the upper sphere. I am not sure it will make too much difference but it will look nice!

It’s certainly been a fun little diversion and it makes a handsome and interesting machine!

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3D printed Polish Enigma – March 25th 2018 update.

March 25th, 2018

So another update. Some good progress but some rethinking and redesign is necessary. This is a complicated project. I don’t think all the people who email asking if I can just send them them files so they can make one themselves realise the amount of work that goes into a project like this.

I made an effort to spend a whole weekend to progress the project. On Saturday I finally got stuck in and machined up all the key shafts. Jobs like this look easy to people who don’t do machining. It’s not a difficult machining job at all to be honest. But in all jobs like this the time is all in the prep and set up. And just making 26 (well, 23, I already made 3) of the same thing just takes time. So I spent Saturday making the shafts. I ended up having to remake the longer ones because I forgot the old maxim measure twice, cut once. I ended up making them 1mm too short! And if I had started making the longest ones first I could have trimmed them down and used them as the shorter ones but I didn’t, I made the shorter ones first. And that’s a trick I know so no excuse for messing that up.

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That actually took most of Saturday interleaved with printing things, model making, washing and housework and so on. Today (Sunday) I started on the wiring of the keyboard.

First I made a common bus from wire links. The way the keys on the Enigma machine work if that in the normal position (normally closed) each key connects it’s matching lamp to the appropriate letter on the plug board. When a key is pressed it disconnects the lamp and connects to a common voltage which is then fed through the rotors. This means one contact on every switch goes to the same place. I bent up wire links to connect all the switches together.

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With the links in place I could remove the switches to add the other wires. This is where things started going wrong. There are 2 wires to each switch of course. So 52 wires all together. In a very small space. I tried running the wires between the cams and this sort of works but there is no clearance so the cams rub on the wires.

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This is probably workable for a machine that won’t be used much but eventually it will cause issues. Also the keys themselves can get stuck on the wires. I went ahead though and finished the wiring and then assembled the keyboard.

One thing to mention here is with so many solder connections to make I ended up digging out my reliable old Weller soldering iron. When I worked at Weta I had to supply my own tools and computer (which I wasn’t allowed to connect to the internal network). When you work there you’re an independent contractor so you have to supply that stuff yourself. So my Weller ended up being taken to work. I ended up buying a cheap chinese iron for home. It’s a bit shit.

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The hot air part actually works fine and I use that for heat shrinking. The soldering iron though is rubbish. I just doesn’t get hot enough and the temperature regulation is all over the place. It’s a Hakko knockoff so maybe replacing the iron with real Hakko spares might work?

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So I dug out my old iron again since I bought it home when I finished at Weta and it was still sitting in a box with a bunch of other stuff I bought home. The Weller uses tips that set the temperature. And I run very hot tips in it. I’ve always found it’s better to use a very hot tip and solder quickly rather than a cooler one that takes longer to get things up to temperature. The quality of the tips seems to have gone down unfortunately in recent years. I don’t know if they changed them to work better with lead free solder (which I won’t use) so normal solder just eats them now but they definitely don’t last like they used to. Still, it was a pleasure to do all the soldering with old faithful, even with a slightly used tip, that the crappy Chinese iron I must admit!

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With the wiring done ti was onto assembling. Each key is sprung loaded and this causes an issue with physically assembling the keyboard. The keys need to be pulled down so they aren’t all wobbling about and so they all line up so they can fit into the holes in the keyboard top. To pull them down I came up with a neat trick. I went out to the garage and found some rubber hose from my car parts that was a tight(ish) fit on the shafts. With a piece of kapton tape to make the shafts fractionally thicker I could push on short sections of tube and these would allow me to pull the keys down and hold them in place. That worked really well actually. Assembling the keyboard was still tricky but not as bad as I though.

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Unfortunately I put in the wrong spacers when I assembled the keyboard meaning the keys aren’t in the right place. And, if you watch the film, you’ll see there is nowhere near enough clearance between the key mechanisms and the wiring. Each key pressed rubs on and moves the wires about a bit. This would be fine for a short time but will eventually cause issues.

So I am going to redesign things to move the wiring out of the way. One step forward, two steps back.

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Still, with all the key shafts made I was able to test the keyboard mechanically and it work very well. I am pleased with how it has come out and the machine is definitely looking more complete now. As a purely mechanical machine it works very well. I will redesign the keyboard wiring and try again. I have redesigned the rotors, entry wheel and reflector so I am ready to start making those now.

Just as soon as I order more wire!

 


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