Vaudeville halloween

Me and my friends Jowan Sebastian, Tom Brimson and Liam Dennis wanted to organise a night that could double as a showcase for fun interactive things that we wanted to make. Halloween seemed like a good night for that.

With the help of Jack Williams, we put on the night at 5 below. My addition was to help create some sound effects buttons that were placed around the bar and fed through the main PA and help create a big LED filled crucifix.

The sound effects were made using a board based on Lady Ada’s Waveshield, similar to the board I made for my Mario Lamp. It consists of an Arduino shield that reads WAV files off an SD card and plays them out through a 3.5mm jack. There are 6 buttons that trigger 6 different sound effects. I made it using SMD components so I had to rejiggle the original design around a little in Eagle. Here is the board and the schematic.

This is the audio player, housed within a wooden box. 3 of the 6 buttons are mounted in the lid, for the DJ to operate.

The remaining 3 were placed inside dolls and attached around the bar.

As well as the sound box, we constructed the cross. We made MDF boxes to house the lights and covered them with tracing paper and perspex to diffuse the light.

Here is the crucifix assembled in the bar with an automatic RGB sequence.

As every halloween party needs, A spooky rupert the bear poster.

Embossing stamps

I was asked by Robin Mackay and Paul Chaney, who work in the workshop next door to me, whether I would be able to produce a set of embossing stamps for an upcoming issue of Robin’s philsophical journal, Collapse. I had never done this before, but I’m pretty interested in printing techniques, so jumped  at the opportunity. This next post kind of catalogues the stages I went through if anyone is interested in doing the same.

Robin wanted a sheet, almost A6 (100mm X 170mm), that contained the text of a recipe. Before I went about cutting this out, I wanted to do some smaller size experiemnts. I had heard that nylon is the best material for making the stamps, so using the little CNC mill, I cut out a male and female block from some blue Nylon we had. To start with I made the cut paths in Illustrator by outlining the text I had, then offsetting the outlined path. When making the female block, the offset needs to be inside the text to account for the angle of the engraving bit.

The engraving bit I was using was 30 degrees from vertical, which meant that if I wanted to engrave 0.2mm deep, I had to offset by (0.2 * tan30)=0.115mm. I repeated this offset until the middle of the thickest part of the text was reached. Once this was done, the text needs to be flipped for the female.

Here you can see it once it was milled out. I found that Nylon was less than ideal because of the amount of swarf that gets left attached to the block.

Here’s the male piece, where the cut path has been offset around the outside of the text.

Here you can see the results of the first stamp test. The final piece was to be on this thick matt black paper as it was part of the artwork.

I then decided to use Acetal rather than Nylon, which macines a whole lot better. I made this test block, with varying engraving depths.

Here the results using the different depths. As you can see, the shallowest engraving produced the most detailed emboss.

To achieve this fine a detail, I had to trace over each letter in the font to create a special variation for engraving. Because if you just offset the path, where there are really thin bits of the letter, the path just dissappears. To get around this, I traced a line along the centre of each letter. Evil Mad Scientist made an Inkscape extension for doing this with a tutorial on how to use it here. I use Illustrator so I did it manually, which took a while, but I prefer most of the features that are with Illustrator.

This shows the outline of the font itself.

Here you can see the actual cut paths, created by ofsetting the outline.

The plate sizes needed were slightly larger than the maximum size of the bed which is 152.3mm X 101.6mm, so I had to construct some jigs that I thought would hold both the male and female plates in the same position.

Unfortunately I was unable to get the surface of the plate flat enough to get an even engraving. In the photo above, the upper right corner is engraved OK, but the bottom end hasn’t engraved at all.

I thought I’d be able to get round the problem by machining a male and a female that were slightly smaller, to fit onto the machine bed so I could fully flatten them on the machine before cutting, and I managed to make to plates well enough, but the finished sheet had lines accros it that weren’t wanted.

On this example, you can see that the press wasn’t even from left to right. Also you can see offset lines around the text, towards the top on the left, that is from imperfect cutting of the male piece of the stamp. On top of this, the stamps don’t fully reach the top and bottom of the paper, which had all been guillotined to that size.

In the end it worked out OK. The reason that the original stamps weren’t flat on the cutting surface is because there was a jig in place so that both male and female plates were aligned, but this jig was pretty precarious. I realised that if I didn’t use the male stamp, I could just cut the female part flat on the macine bed. The press has enough pressure to flatten all the paper apart from the recesses engraved into it.

This had the added benefit of making the text easier to read because the flattened part of the paper took on a much smoother, almost glossy surface, but the raised text was left with it’s original matt finish. This made the contrast much higher.

The text of the emboss is for a recipe for a pretty gluttonous cake that is a artist commision for the Collapse journal.

Here is a picture of the press. It consists of 2 thick aluminium rollers, with the top free-rolling roller being height adjustable, and the bottom roller being connected to the handle. It is very beefy and sturdy and could easily handle the high pressures needed for the embossing.

I thought it might be nice to use this press to emboss some business cards.  engraved a little block with a nice geodesic sphere pattern.

I used the same black card used for the recipe, but when I ran them through the press, I spray glued an inkjet printed piece of white card that contained the details on. So the front of the card is a normal white business card and the back is this nice embossed geodesic pattern.

Here you can see both sides of the card. Big thanks to Alan Clarke for helping with the graphics and also for the photo.


So if anyone has an interest in trying to emboss their designs, I hope this might help. Using the female only stamp method is good in that it is simpler to create the stamp and improves the contrast between the embossed part and the pressed part, but if you want to keep a consistent texture of the paper, you’ll need to have a male part.

I’d highly reccomend using a roller press like the one above, because it makes it quick and consistent. I did try some presses using a bench vice and G-clamps but it took much longer to do each pressing and they tended to be more patchy.

If you’ve got any more questions, just contact me.

LED card

I’ve been thinking about making an SMD LED card for a while and as my friends Ky and Jenny were departing from Falmouth for Brighton, I though it would make for a good present. Here’s a video of the finished thing.

I started by drawing out the circuit schematic in Eagle. I based it around the videos I’d seen for making a LED knightrider circuit using a 4017 decade counter and a 555 timer. Here’s a link to the page I used.

A basic explanation of how it works is that the 555 timer is set up as an astable pulse generator, so the ouput of the 555 oscillates between 0V and 5V(low and high). This is routed to the decade counter. The decade counter has 10 outputs, 9 of which stay low and 1 is high. Each time the 4017 input goes from low to high, the output pin that is on moves to the next pin. This basically cycles through the ouputs, which are in turn connected to groups of LEDs.

Each ouput pin of the 4017 drives between 1 and 5 LEDs. This requires between 20 and 100mA of current. The 4017 is only rated to give 20mA so I had to put a MOSFET inline with each ouput. This acts as a switch that only uses a small amount of current to turn on or off but connects the LED groups directly to the main power lines.

To adjust the frequency of the 555 output, which changes how fast the 4017 cycles through the LEDs, I added in a very small potentiometer and also a surface mount slide switch.

Below is a schematic and parts list which includes Farnell order codes.

Part Device Value Farnell order number
BAT1 AA battery holder 908733
BAT2 AA battery holder 908733
C1 0805 capacitor 1uF 1828853
C2 0805 capacitor 10nF 1414662
C3 0805 capacitor 10uF 1833812RL
IC1 CMOS decade counter CD74HC4017 1739754
IC2 SMD timer NE555D 1737167
LED1 0603 LED pink 1685073
LED2 0603 LED orange 1710526
LED3 0603 LED orange 1710526
LED4 0603 LED orange 1710526
LED5 0603 LED green 1226372
LED6 0603 LED green 1226372
LED7 0603 LED green 1226372
LED8 0603 LED green 1226372
LED9 0603 LED white 1716769
LED10 0603 LED white 1716769
LED12 0603 LED white 1716769
LED13 0603 LED white 1716769
LED14 0603 LED white 1716769
LED15 0603 LED blue 1686063
LED17 0603 LED blue 1686063
LED18 0603 LED blue 1686063
LED19 0603 LED blue 1686063
LED20 0603 LED blue 1686063
LED22 0603 LED blue 1686063
LED23 0603 LED green 1226372
LED24 0603 LED green 1226372
LED25 0603 LED green 1226372
LED27 0603 LED yellow 1226417
LED28 0603 LED yellow 1226417
LED29 0603 LED yellow 1226417
LED30 0603 LED yellow 1226417
LED33 0603 LED white 1716769
LED34 0603 LED white 1716769
LED35 0603 LED white 1716769
LED38 0603 LED white 1716769
LED39 0603 LED white 1716769
LED40 0603 LED pink 1685073
LED44 0603 LED pink 1685073
LED45 0603 LED pink 1685073
LED49 0603 LED pink 1685073
LED50 0603 LED pink 1685073
Q1 SMD transistor MOSFET-NCHANNELSMD 1758065
Q2 SMD transistor MOSFET-NCHANNELSMD 1758065
Q3 SMD transistor MOSFET-NCHANNELSMD 1758065
Q4 SMD transistor MOSFET-NCHANNELSMD 1758065
Q5 SMD transistor MOSFET-NCHANNELSMD 1758065
Q6 SMD transistor MOSFET-NCHANNELSMD 1758065
Q7 SMD transistor MOSFET-NCHANNELSMD 1758065
Q8 SMD transistor MOSFET-NCHANNELSMD 1758065
Q9 SMD transistor MOSFET-NCHANNELSMD 1758065
Q10 SMD transistor MOSFET-NCHANNELSMD 1758065
R1 0805 resistor 82k 1100327
R3 0805 resistor 120R 1738947
R4 0805 resistor 39R 9334467
R5 0805 resistor 30R 9334297
R6 0805 resistor 24R 9334181
R7 0805 resistor 24R 9334181
R8 0805 resistor 120R 1738947
R9 0805 resistor 39R 9334467
R10 0805 resistor 30R 9334297
R11 0805 resistor 24R 9334181
R12 0805 resistor 24R 9334181
U$1 0805 resistor 50k 9608257


Once I had the schematic sorted, I went about laying it out on the board in Eagle. After spending a while laying it all out I printed the design to a PDF using CutePDF to ouput it as a vector image to do some graphic editing.

I could then open it up into Illustrator and play around with the lines. I added in some text and made a few of the signal lines curved.

At this stage it could be used as an etch resist pattern for use with the toner transfer method or similar. I use a little Roland MDX15 CNC machine. It uses a print driver that I have to create the cutting lines. I did this by using the offset path function.

Here’s some images of cutting it out

I then had to do some of the most fiddly surface mount soldering I have done, but it turned out OK in the end.

Corian printing blocks

So being slightly less than gleeful about my cash situation for christmas towards the end of a recent holiday in Morocco, I decided to make some olive tapenade as a gift for friends. Olives are plentiful, cheap and very tasty in Morocco and I really like homemade tapenade, so I bought a few kilo’s back, got some Kilner jars off Ebay for them and made it up. It was completely tasty which was good.

I have made lot’s of produce at home in the past and bottled it or put it in jars to preserve, but one thing I always leave out, to my annoyance, is the labels. This time I decided I’m gonna make some nice ones, so I made a vector design in Illustrator, then converted it so I could mill it out on the MDX-15 milling machine at work. We had some Corian lying about so I used that very succesfully. I think Resinboard might have worked as well but we didn’t have any, even though I think it’s a lot cheaper. Once I had the board I went about printing with it. I did this in a similar way to lino prints, by rollering ink onto a tile and then onto the block, then pushing it onto the paper. This worked well for the small block I made but I think if you made a bigger block, you’d need a press.

I started by designing a label for the round Kilner jars.
I then merged the shapes into one and offset them a couple of times to a distance of 0.1mm which is roughly the radius of the engraving bit.
Next I offset from the original line by 0.5mm each step for cutting with the 1mm chip breaker.
The first thing I tried cutting was a piece of birch faced plywood. As you can see it doesn’t allow for very good resolution at all.
After trying the wood I tried Corian. It is an artificial stone made of acrylic and stone dust that machines very very well.
Here is a closeup image taken with a macro lens. You can see the pretty fine detail. This text is about 8pt font. One problem though - it's been cut the right way round so the print would be the wrong way round.
I made a final version in reverse with all the surround cut away as well as just around the pattern.
I then went and lost the nice stamp that I had made. Dang. Anyway I made another and decided to leave the bit surrounding the design there, so that when I rolled the ink on it would be rolled on flat.
To get ink only on the top layer of the corian, it is rolled out flat on a tile or piece of glass.
After trying a few different colour variations I settled on black ink on gold paper.
So I had my labels sorted but I couldn't just give them as they were, so, after the success of the process, I decided to make some tiled wrapping paper. I drew a 3D tree then made a sort of icicle pattern from it.
Here's an image of the block that I made from it. If I was to do it again, I'd probably make the design a little simpler and blockier.
Here is the finished wrapping paper. I went for a black and red chequered tile design. I found it was quite hard to align each tile to the next one but I think the print effect makes up for it.

How i learnt to knead time, or my arduino intervalometer

So I made a Intervalometer for my Canon 400d camera at last. It’s another one that’s been in the endlessly long pipeline for a while. I based it on the wonderful Arduino and got a bit of code off the person that made the Intervaluino whic can be found here.

It was an excersize in how to design a PCB in Eagle and then mill it out on the Roland MDX-15 milling machine at work. At first I did a version of the Intervaluino, but one that all fit onto one board that was a shield that fit onto the arduino. I didn’t realise how cool making shields for the Arduino is before. They just clip together like lego and you can just stack them one after the other. Anyway I found that the 20mA or so that the Arduino gave out wasn’t enough to trigger the relay. After a brief lesson in transistors from Sam I put together a circuit that would definately trigger the relays and had an LED for both the focus and shutter lines.

Above is the schematic of the final circuit. Basically what happens is the Arduino pins 8 and 11 go hi to 5V, making the circuit around the realy. This puts out about 20mA, which isn’t very much,  so they turn on a transistor which allows the relay to access the current it needs to turn on. There’s one relay that connects the camera’s focus trigger to ground, which makes the camera focus and one relay that connects the camera shutter triggger to ground to take a picture. When taking time lapse movies it’s best to use manual focus so the focus pin is slightly redundant, but just in case….

I went through a few versions before I got the final working one.

I milled out 4 boards and populated and soldered 3 before I had one that finally worked. Frustrating!!!!

This is the first one. This is just cutting out the tracks with an engraving piece and not cutting away the unused copper. This makes it harder when your soldering, in case you make a mistake.

As you can see on this version, I had set the tracks too thin and hadn’t left enough room at their sides to mill away the unused copper.

This one is almost there, apart from I forgot to flip the pattern over. To make the components be on the opposite side from the Arduino, so they would fit on, I would have to solder every one onto the top side of the copper, whic is WAY too tricky for my patience.

Here’s that final version, with the bottom photo showing it connected to an Arduino and a 9V battery pack with the 2.5mm jack that connects to the camera coming out.

Message me if you want any of the files or if you know how I can upload them here.

Finally here’s a video made using it