Planet Nottinghack

23 October 2014

Martin Raynsford hackergotchi for Martin Raynsford

Board Gamingible

I wrote an instructable last night which rounds up a lot of my board gaming type posts.

It was also supposed to inspire people to support my jumpstart campaign for Carcassonne files so consider this a gentle nudge for my blog readers too

by (Martin Raynsford) at 23 October 2014 08:22 AM

20 October 2014

Martin Raynsford hackergotchi for Martin Raynsford

Laser Cutter Comparisons

I'm often asked to offer comparison between laser cutters 'X' and 'Y'. I feel it's important to try and offer impartial advice, we do have our own laser importing business after all so it would be very easy to be biased. The trouble is that I'm not sure what people are really asking when they want two machines compared so I thought I'd write a little blog post to talk about the basic comparison and discuss the most important thing that people always overlook.

Laser cutters are often presented alongside a pretty dull technical spec sheet. This is straight forward list of details about laser power, cutting area and cutting speeds, sometimes it also includes price. I would hope that most people are able to do these comparisons for themselves. Bigger cutting area is better, more laser power is better and often comes at an increased price. 

This is where the question confuses me. The only information I have about the other laser cutter is this dull spreadsheet which is easy to compare and laser cutters are all very similar mechanically. Big metal box to avoid blinding, check. Laser beams to cut through material, check. Extractor fan to keep air breathable, check. In fact it's the most significant item and the most important detail that is often glossed over on the list or ignored completely. I'm unable to comment/compare the Laser cutter controller if the listing doesn't even tell me what controller it is.

The control software is such a significant part of the whole laser cutter experience I'm completely amazed that some listings don't even mention what the controller is. 90% of the time the laser cutter is a black box on the end of a usb cable, you deal with the software interface to prepare the files you are working on. You need software that is functional and straight forward at the very least. I've seen a laser cutter that had Chinese software called 'Printer Driver', that was all we knew about it and it's impossible to Google that for any more information.

If I were buying another laser cutter I would insist upon knowing what controller it came with in advance. If I can't find any useful resources about that software online I would not purchase the laser, it's a simple as that. Life is too short to faff with badly written software, some of these laser cutter controllers are even described as completely unusable by reviewers. I would even go one step further, if a supplier is unable to provide me with a demo version of the control software it would worry me. Are they trying to hide their bad software or do they just not know how to set up the demo? Either case is pretty bad, and this applies to all manufacturers, cheap eBay lasers and UK importers.

These are standards that I hold our own company to. All of our laser cutters use Lasercut 5.3.
I won't lie and tell you it is the greatest software ever written; it is the perfectly acceptable face of cheap laser cutter controllers. We offer a download and demo version of the software so you can check it out before you even get near one of our machines. The community is also pulling together to create some really useful resources for it and are slowly dissecting some of the more complex parts of the system.

by (Martin Raynsford) at 20 October 2014 11:33 PM

17 October 2014

Martin Raynsford hackergotchi for Martin Raynsford


Image tolen from the interwebz because I forgot this blog post was scheduled but not completed
3 years ago today I posted my very first Laser Cut Item, a simple card for Kim. I had bought the laser cutter a few weeks earlier and I had decided to embark upon a crazy project to laser cut 365 things in 365 days. Now 3 years on, I've complete the 365 things, the 52 things, made a job from my hobby and started a laser import company that is really taking off.

Who knows what I'll be doing this time next year but I can tell you, I'm working on some big projects at the moment. I should be displaying more of the parts for you and I can't wait for this first one to be finished because there will be some awesome pictures. I'm also working on open source controllers for laser cutters and some other nifty little tricks you can do with our lasers so it looks like it's going to be another fun year.

by (Martin Raynsford) at 17 October 2014 04:00 PM

16 October 2014

Martin Raynsford hackergotchi for Martin Raynsford

Animitronic Mannequin

Another quick turn around part for this upcoming cake project. You'll have to trust me that there are laser cut parts in there. I used an arduino to drive the 3 servos; head, tail and foot. Power comes from a small 5V brick and it's connected directly to the mains. Believe it or not this will get covered in icing and become a 'cake', for now it's been sent off to the wizards so they can work their magic.

by (Martin Raynsford) at 16 October 2014 10:18 PM

15 October 2014

Martin Raynsford hackergotchi for Martin Raynsford

Massive Cake Stand

This massive cake stand (1200 long) is a small part of the new project I'm working on. I can't give too many details yet but I just built 20 of these sections all of which will be stacked with cake in the near future. Stay tuned because this project is awesome and huge.

by (Martin Raynsford) at 15 October 2014 09:53 PM

14 October 2014

Martin Raynsford hackergotchi for Martin Raynsford

Getting Jiggy with it

It's not just about the things you can make with a laser cutter, the laser can also help you make things to make other things. I've been making these internet boxes for quite some time now, each one has a hole in the top and two holes in the side. I've been drilling them by eye for far too long so I finally got round to building a jig to hold the boxes in the right place for me. The vertical slot lines it up to drill a hole in the top. The horizontal slot is larger than the side of the box, pushing it to the top lines up one hole, pulling it down to the bottom allows the second hole to be placed just above it.

by (Martin Raynsford) at 14 October 2014 09:51 PM

Dominic Morrow hackergotchi for Dominic Morrow

chaosdorf, germany

Martin and I run Just Add Sharks Ltd, a laser cutter company we started in January 2014 to meet what Continue reading

by chickengrylls at 14 October 2014 12:47 PM

James Fowkes hackergotchi for James Fowkes

Renaming things quickly in Eagle

I use Eagle for my PCB design and I generally find it to be a nice piece of software. One annoyance that I came across recently was the seemingly hard task of doing a “bulk rename” of components on a schematic. … Continue reading

by fowkc at 14 October 2014 10:51 AM

11 October 2014

Martin Raynsford hackergotchi for Martin Raynsford

Chaosdorf Bottle Tops

Last night at Chaosdorf we cut a few little samples to see what would work on the laser cutter. This bottle top was a fantastic success. I'm expecting some awesome things when they start engraving their own logos on to the bottle tops for their home brew (and now I'm home again I'm relaxing and thoroughly enjoying one of the bottles we bought home with us)

by (Martin Raynsford) at 11 October 2014 08:54 PM

10 October 2014

Martin Raynsford hackergotchi for Martin Raynsford

Chaosdorf Cutting

Tonight I'm in Germany and more specifically Düsseldorf where we're visiting the Chaosdorf Hackspace. We have just installed a Greyfin laser cutter and they decided to engrave the hackspace logo onto the top of an old IBM thinkpad. They've picked up the software pretty quickly, imported their design and with a few gentle nudges have etched this logo onto the lid of the laptop. After a bit of a cleaning scrub it came out really nicely. 

It'll be a fun night here at their social evening and then back to the UK for Dominic and I tomorrow.

by (Martin Raynsford) at 10 October 2014 04:27 PM

09 October 2014

Spencer Owen hackergotchi for Spencer Owen

RC2014 SD Bootloader Update

Just a quick update to about the SD Bootloader I designed a few posts ago.  Well, the PCBs have arrived and last week I took a soldering iron to one of them and gave it a quick test

One side of the board is effectively an Arduino, so without plugging it in to the RC2014, I connected up an FTDI lead and uploaded the Arduino Blink sketch.  A quick check with a multimeter and one of the pins was altenating between 5v and 0v.  So far, all good!

Next, I uploaded a simple sketch that would count on from 0 to 255 in binary on the 8 output pin and plugged it in to the RC2014

int data_0 = 14;
int data_1 = 15;
int data_2 = 16;
int data_3 = 17;
int data_4 = 18;
int data_5 = 19;
int data_6 = 2;
int data_7 = 3;
int inbyte = 55;

void setup()
  pinMode (data_0, OUTPUT);
  pinMode (data_1, OUTPUT);
  pinMode (data_2, OUTPUT);
  pinMode (data_3, OUTPUT);
  pinMode (data_4, OUTPUT);
  pinMode (data_5, OUTPUT);
  pinMode (data_6, OUTPUT);
  pinMode (data_7, OUTPUT);  

void loop()
  for (int inbyte = 1; inbyte < 255; inbyte++){
    digitalWrite(data_0, inbyte & 0x01);
    digitalWrite(data_1, inbyte & 0x02);
    digitalWrite(data_2, inbyte & 0x04);
    digitalWrite(data_3, inbyte & 0x08);
    digitalWrite(data_4, inbyte & 0x10);
    digitalWrite(data_5, inbyte & 0x20);
    digitalWrite(data_6, inbyte & 0x40);
    digitalWrite(data_7, inbyte & 0x80);

    delay (1000);

A simple BASIC program on the RC2012 displayed the numbers it was reading.


It looked like success at first, but then I realised it was counting up in a very haphazard way.  After jotting down a few of the numbers in order and converting them to binary it became obvious that I’d wired up the analog pins A5 – A0 not A0 to A5.  A quick change of the Arduino code and all was good there!


The Bootloader board has 6 output lines from the Z80, 3 of which go to the Atmel ‘328 and 3 go to LEDs.  A BASIC test using OUT 0,1 OUT 0,2 and OUT 0,4 showed that the LED outputs worked, so I figured the other 3 would do too.  So, next to get the SD card reading.

This proved to be harder than expected! I had designed the SD header on the end of the PCB so that it could be wired up in a few different ways.  One of these was through a “poor mans SD adapter” (Simply a micro SD adapter with 0.1″ header pins soldered on!).  This didn’t work, but maybe it was my soldering – I did melt the adapter a little bit!  I had some cheapo chinese SD boards from eBay, so I gave on of those a go, but still nothing.  Tried the other one.  Nope.

I assumed that there was a problem with the new board, but to rule things out, I tried a genuine Arduino with one of the SD boards.  Still nothing.  Another Arduino… That didn’t work either.  Maybe different SD card?  No difference.


Conclusion is that all the SD adapters are dead!  In the mean time, however, I did discover that using a resistor voltage divider to get the 3v3 needed for the SD card won’t work and that a proper 3v3 regulator is needed.  The eBay boards have this so should have operated fine on 5v.

Then I remembered I had a faulty TFT screen with built in SD adapter.  As far as I know, it’s only the screen that’s faulty, but, hey, it’s worth a try, right!  And, would you believe it, it worked!  About 3 hours had been wasted on faulty hardware – which wasn’t even anything I had built or designed!


So, inspired by this, I worked on getting data from an SD card on to the RC2014.  There are two sides to this; The RC2014 sets an output high, waits a moment and reads an input, sets the output low and reads the next input and so on.  The ‘328 reads a byte of a file on an SD card, puts it on the output pins, waits for the input to change and reads the next byte and so on…


The result is that in BASIC at least, the RC2014 can read from an SD card!

The next stage is to write this in Z80 assembly language and burn it to ROM so that it can read the SD card directly in to memory and start executing the code.

In the mean time, however, I have designed my own Micro SD Card adapter for this which has a built in voltage regulator. This should make things a lot neater!

by Spencer at 09 October 2014 08:59 PM

08 October 2014

Matt Little

The Prediction Machine

No image

The Prediction Machine is an interactive artwork which aims to engage the public with climate change issues via a fortune telling machine.

Created by the artist Rachel Jacobs in collaboration with myself, Ian Jones (Sherwood Wood), Matthew Gates, Robin Shackford, Juliet Robson, Dr Candice Howarth and Dr Carlo Buontempo.

I designed, built and tested the human-power device and electronic and electrical systems.

Here are some photos of the unit in action and the build details.


by (Matthew Little) at 08 October 2014 10:00 AM

Martin Raynsford hackergotchi for Martin Raynsford

More White Knight

My black on white, laser engraving laminate finally arrived so I could sit down and do some more of the White Knight Designs. As a game of thrones fan these two really caught my eye and it was good fun putting them through the laser cutter last night. Jordan has been great about sending me higher resolution artwork than I can steal from Facebook so I cut them in duplicate and will be sending the second set in his direction.

In the meantime don't forget about my attempt to jump start my Carcassonne set file release.

by (Martin Raynsford) at 08 October 2014 08:02 AM

07 October 2014

Martin Raynsford hackergotchi for Martin Raynsford

Jumpstart me Carcassonne

Nearly a year ago I completed my Laser cut set of Carcasonne, it's been up for sale in my webstore but I am continually asked to release the svg file so people can cut there own. I normally share all my files but I have a few problems with this one, it took 160 hours to draw the base tile set and a further 24 hours to draw the river. I haven't been able to justify giving the file away but with the world being the way it is I can't sell it as a file to individuals because it only takes one person to share the file elsewhere and I've lost all control over it. So I've come up with this 'Jumpstart me' idea.

I'm asking for just £500 (not a lot of 200 hours of work) and when I reach that amount I will release the files to all the people who have contributed towards the total, including the tile backs. 3 months later I will release the files publicly on my blog without tile backs. I will keep this page updated with the running total so you can see how close we are to reaching that total. I have set up a paypal link so you can purchase the files as many times as you like  (I'll try to figure out an easier way to send more money), but also because that gives you protection and the right to a refund at any point (although please just ask me because I'll happily return the money without paypal intervention). Let's see if this can work

Purchase the Carcassonne Files here

Current total £190 / £500

The small print
  • This is not a good way to recreate your own Carcassonne tiles. This is a deluxe version of the set and will cost far more than buying the basic set. 
  • If we do not reach the full amount by the 7th Novemeber, I will make the decision to cancel and refund everybody or accept the amount reached and release the files anyway.
  • The tiles are done with 3 cut operations, an etch, a low power cut and a high power cut. The low power cut can be very tricky to get right without cutting through the wood.
  • The files will come as svg, pdf and dxf. There were made in inkscape so svg is the native file type. pdf actually works as a universal file, the dxf imports into Lasercut 5.3
  • Lasercut 5.3 files can be supplied upon request.
  • This is not a full game it is a board game accessory, you should still buy an original copy to ensure you have the complete game.
  • Klaus-Jürgen Wrede, Z-Man Games or any other publisher please don't sue me for using your artwork, we just love your game and want to make our own awesome versions of it.

by (Martin Raynsford) at 07 October 2014 02:08 PM

06 October 2014

Martin Raynsford hackergotchi for Martin Raynsford

Foam Sword Blanks

This is not the project it should have been. I was supposed to be engraving this design onto the side of a blank sword (A 3 layer foam sandwich with a carbon fibre rod in the middle). I was supposed to mark the outline ready for cutting. The problem is that with the rod sticking out the end of the foam there was just no way to make the sword fit inside the 1200mm wide hole to get it under the laser head. It was really the wrong combination of thickness and size.

Plan B, I cut and engrave the swords as 3 separate panels and they get turned back into a sword when they are returned back to Eldritch. This was an option, right up until the moment I left Nottingham because even just foam blanks were 1100mm long.

Plan C, I cut the each layer in 2 parts, small enough so they fit inside my laser. 

As you can see, not everything works out as planned, This has left us with an interesting sandwich arrangement but I'm sure Simon will be able to work his magic in it. I shall post an update photo when the sword is completed.

by (Martin Raynsford) at 06 October 2014 03:41 PM

05 October 2014

Martin Raynsford hackergotchi for Martin Raynsford

Foam Sword Templates

I hadn't really thought about to before but when you're making a dozen similar LRP weapons at once it pays to have a template to trace around. Simon asked me to upgrade his lino templates to perspex ones which. There are 4 sizes, the longest being 1.1m long so I took a trip up to Nottingham hackspace to use their larger laser cutter. These were cut from 6mm perpsex and came out rather sturdy 

by (Martin Raynsford) at 05 October 2014 03:15 PM

04 October 2014

Martin Raynsford hackergotchi for Martin Raynsford

Wood Veneers

If you'll indulge me for a quick moment I'd like to follow up from the last materials post with a quick message about the joy of wood veneers. They're cheap, versatile, effective and with a bit of imagination you can put them to great effect. I've used them on some of my best projects. You can buy small single sheets of veneer for marquetry style pieces, they're typically 0.7mm thick.

What makes them great is that they'll fit in any size laser cutter, and even the cheap 40W Chinese imports can cut through them at a sensible speed. This makes the whole technique accessible to anyone with any laser cutter. I just restocked this week and picked up these 60 sheets of wood for 30 sheets (30 Great Britain Pounds for anyone not in the know).

So go buy some, you won't regret it. Also don't forget to pick up some magnets because the veneers often take on a slight warp and you'll need them to hold the work flat

by (Martin Raynsford) at 04 October 2014 02:54 PM

27 September 2014

Martin Raynsford hackergotchi for Martin Raynsford

New Materials Page

It's a bit of a work in progress but I've started to list the places that I buy my materials from. I get asked a lot about the poplar wood ply and I guess a blog post is only relevant for a week before it disappears off the bottom of the page (much like this will). So you'll note the new materials page in the header which will take you to the ever changing/growing list of materials I'm working with.

I'm actually still looking for laserable bamboo if anyone knows where to get some

by (Martin Raynsford) at 27 September 2014 04:16 PM

26 September 2014

Martin Raynsford hackergotchi for Martin Raynsford

White Knight Design

Every so often (OK quite often) I do things 'just because'. I saw Jordan's Facebook page for White Knight Design pop up on my feed the other day and I thought this material would work well for it.

What I really like about this project is the complete overkill. I started with a silver sheet and etched all the background away, leaving the logo proud. I love the matt surface left behind by a high resolution etch. It took an hour to etch 288x114mm so it's completely impractical and for that I love it.

by (Martin Raynsford) at 26 September 2014 10:39 PM

Pen and ink owl

Ed Saperia (of Heredox fame) introduced me to the wonderful pen and ink artwork of Iain Macarthur with the best of all questions, "can it be laser cut?". Move forward 6 weeks and while I was exhibiting at the rather quiet Leicester Creator Faire I finally found the 2.5 hours I needed to devote my laser cutter to engraving one of his pieces in sufficient resolution. I love the way the wood grain shows through on the etched patches giving it some extra depth amongst the intricate details. Sadly I fear that the stark black and white of the original does this piece far more justice than the cream and burnt colours of the laser but it was a fun piece to etch and the visitors enjoyed seeing the laser do all of the hard work..

by (Martin Raynsford) at 26 September 2014 07:46 PM

24 September 2014

Martin Raynsford hackergotchi for Martin Raynsford

Rocket and Groot

I loved guardians of the galaxy and I was inspired to make this veneer portrait of Rocket and Groot. I used layered veneers on Groot to make the different sections of his body stand out. If I were to remake it I think I would add a little more definition to Rockets gun to make it seem a bit more 3D (svg here)

by (Martin Raynsford) at 24 September 2014 10:58 PM

Quartz Fail

I'm always happy to try new materials that people send me to see if they can be engraved and this time it was the turn of Quartz crystals. Slate, Sandstone and Marble all engrave so there was always a chance this could work and as you can see from the image it wasn't a complete failure but the quartz was chipping away under the laser beams so it makes for some very rough edges to the engrave. It's not good enough to warrant doing again but at least it has been tried now.

by (Martin Raynsford) at 24 September 2014 09:52 AM

23 September 2014

Matt Little

Pedal power for Nottinghamshire Healthcare

No image

There has been a spate of pedal power projects in the re-innovation workshop recently.

This post shows one recently built for Nottinghamshire Healthcare. The pedal generator was designed as a challenge with a twenty second test to see the amount of energy the cyclist can generate. It also needed to be relatively portable (to fit within the boot of a car).

The systems consist of:

  • a shunt regulator (rated at 400W) to dump any excess power
  • a LED bar graph display as a visual read out of power generated
  • an LED display which shows the actual power output in Watts
  • a 20 second test display with an output in Watt-seconds


by (Matthew Little) at 23 September 2014 03:17 PM


No image

Its very difficult to explain the concepts of power and energy. People often ask me "Can I power my kettle with that?".

So to try and put the energy in a cup of tea into perspective I built the 'Cuppa-meter'.

The 'Cuppa-meter' shows a cup of tea which lights up as the energy required for a cup of tea is generated. This can be plugged into a pedal generator and people can 'feel' the energy required to make a cup of tea.

They can either pedal slowly (and hence low power) for a long time, or they can pedal hard (high power) for a shorter time. The end result (the energy) is the same - a nice hot cup of tea (or rather a lit up image of one).

 This post gives a few images of the cup of tea and also the calculations used.


by (Matthew Little) at 23 September 2014 02:22 PM

22 September 2014

Mouse hackergotchi for Mouse

I love Crow T Robot

Crow is the best

by Mouse at 22 September 2014 11:55 PM

21 September 2014

Martin Raynsford hackergotchi for Martin Raynsford

Bring forth the Galleries

Over the next few days I'll be making some changes to the blog and adding some content to the bar at the top. I'm starting with the galleries. Underneath the blog I've been storing all my images in several picasa photo albums (they tie in nicely with the blogger interface). Now that the blog has grown to 700+ posts it's hard to randomly browse it all to see all of the things. This way you can browse the galleries directly and more easily find your way to the good stuff. Happy browsing.

Oh and btw, having just browsed all the galleries myself, this Iron Man wood veneer is my current most favourite item of all time (subject to change of course)

by (Martin Raynsford) at 21 September 2014 09:48 PM

Teacups Follow Up

This is the cake that dinkydoodle designs made, on top of the cake stand that I made. In a rather disappointing twist the stand worked perfectly during testing but failed when it was fully loaded up with cake. The customer was unaware of the rotating potential so nothing really hurt except a bit of pride. More photos of this wonderful cakey creation can be found on their FB page.

by (Martin Raynsford) at 21 September 2014 08:31 PM

20 September 2014

Kate Bolin hackergotchi for Kate Bolin

Kara Stone and Gabby DaRienzo made Knitting Simulator, a game...

Kara Stone and Gabby DaRienzo made Knitting Simulator, a game that uses a Makey Makey, a tilt switch and some knitting needles to knit your way to awesomeness.

I just wish it wasn’t just for Mac, because OMFG let me virtually knit!

20 September 2014 08:56 PM

16 September 2014

Spencer Owen hackergotchi for Spencer Owen

Chromecast to VGA


When Google first launched the Chromecast, I wanted one as it seemed like it would solve a lot of viewing problems for me.  The trouble was, my “TV” (technically, it’s a 42″ monitor as it has no tuner) doesn’t have any HDMI sockets, so it would cause more issues than it would solve, and I figured it would be £30 wasted.


When the price was dropped to £18 recently though, I figured that was within the realms of wasteable money I was prepared to spend.  My TV didn’t have HDMI, but it did have composite, RGB, SCART and VGA connections.  Surely something would work…

I remembered that I had got hold of a HDMI to VGA adapter for the Raspberry Pi which worked quite well (both times I tried it!), and although I couldn’t find any definitive answers on line, I thought I’d give it a go.


These are plentiful on eBay for under £5, although there are several variations, and I can only vouch for the ones that look the same as the ones shown above.  eBay listings update more often than this blog post will, so I won’t link to a specific one, but search for “HDMI VGA Raspberry” and you should find some that looks like the photo above.  Some of them do not have audio out though, so watch out for those as they’ll be a problem.

The first problem I found, however, was that the Chromecast had a male HDMI plug.  So did the VGA adapter.  I had my doubts, but a female to female HDMI adapter (£2 from eBay) worked a treat!  Add in a 3.5mm jack to twin phono adapter (your audio set up might be ok with the 3.5mm lead that comes with the adapter – alternatively, you might need to buy an amp and speakers!) and I was good to go


It might look a bit gangly, but the point is, it works!  Google Chromecast to VGA TV for under £27! (And most of the ganglyness is hidden in normal use anyway)


Generally, this works perfectly streaming 720P to my TV.  The only slight niggles I have is that I lose about an inch of picture down the left hand side (but not really noticable), and when the power is removed from the Chromecast the speakers make a funny popping sound (probably the caps in the VGA discharging).  But otherwise, all is good.

So, if you want a Chromecast but don’t think you can use it, think again. 

by Spencer at 16 September 2014 05:11 PM

15 September 2014

Spencer Owen hackergotchi for Spencer Owen

RC2014 Bootloader for SD Cards

So, the RC2014 is great.  I can run Microsoft BASIC and program it from there, and as long as I am using a terminal emulator, I can copy & paste to save and load programs.  Alternatively, I can write Z80 code using an online compiler then download it, copy it to USB stick, move it to my old Windows 2000 laptop (which has a parallel port) so I can burn it on to EPROM to see if it works, make adjustments and repeat with another EPROM.

I will be the first to admit, however, that this is probably not the most efficient workflow.  Not to mention the time and effort involved in wiping the limited stock of aged EPROMS.

So, I am in the process of designing an SD Card based bootloader.

i (2)

Interfacing a Z80 to an SD card isn’t totally straightforward though.  For starters, the Z80 runs on an 8 bit parallel data bus, but SD cards use a Serial Peripheral Interface (SPI).  The Z80 is 5v, the SD card us 3v3.  And as for using the Z80 to address a particular memory location on the card… well, forget it!

[Sometimes I seriously wonder just how Zilog expected their Z80 to address things like 512GB of SD card when they designed it back in 1975!]

So I’ve decided to use a modern ‘cludge’ to provide the glue to stick the two parts together..  An Atmel ATMEGA328 (Arduino) speaks SPI and has enough pins to provide an 8 bit signal.  I will use the same interfacing technique as I used with the LED Matrix displays so that there’s a buffer between the Z80 and ‘328

IMG_20140911_210721 (2)

I hooked up a rough and ready breadboard & Arduino test to prove the concept, but initially I had lots of Odd Things™ happening, and all but came to giving up.


At the last moment, I spotted the school boy error.  The power rails of my breadboards are divided in to two halves, and despite having things connected to both sides I didn’t have anything to connect the two.  So the decoder chip was being back-fed through the SD card adapter.  Ooops!  In my defence though, it really is bloody stupid for breadboard manufacturers to not join up the power rails all the way through.  It is bad enough that the two sides aren’t linked – although I can appreciate you might want maybe a 5v and a 3v3 volt rail… but splitting it down each side too, well, this has now become a more of a rant than a blog.

Screenshot from 2014-09-14 22:15:22

So, with the Arduino able to put characters on the Z80 data bus that I could read with BASIC, I decided it was time to take it to PCB level.  I’ve got 8 bytes of data input from the ‘328 to the Z80 via a 74HC245 and 3 bits of output from the Z80 to the ‘328 via a 74LS374 selected from a 74LS138.  (There is also 3 output lines going to LEDs for status monitoring).  The hardware should be easy enough, so I’ve laid out the PCB and sent it off to OSHPark to be manufactured.  It is, however, the largest and most complex board on the RC2014 so far.

The software will be the tricky bit for me.  Firstly, I need to write a boot loader in assembly language and burn it to an EPROM (wasn’t this what I was trying to avoid???).  Secondly, I need to write an Arduino sketch that will read an SD card and write it out to the 8 bit parallel bus.  From a timing perspective, I have assumed that the Z80 will write to it’s output so the ‘328 will know to put the first byte of the SD card on the bus.  The Z80 will then read this, write it to RAM and signal to the ‘328 it wants the next byte.  And repeat until done then set the Program Counter to the address in RAM to execute the code.

I have deliberately chosen a request/send model so that timing issues are avoided – partly because I don’t know if there would be timing issues, and partly because one of the things I would like to do is run the Z80 very very slow (so I can see what is going on), and this should still work.

Initially, I will gloss over the issue of file size and memory location by assuming a file size of 1k (with the ‘328 padding with FF to make up the balance) and that all programs are run from 0x8000.  I can, if needed, add in a file on the SD card that defines these parameters that the ‘328 can send as a preamble… but we’ll cross that bridge when we get there!


by Spencer at 15 September 2014 07:06 PM

Martin Raynsford hackergotchi for Martin Raynsford

EMF Camp - Vodka Roulette

I thought I was at the end of the 'things made at EMF camp' but then I remembered I actually cut some stuff for myself while I was at EMF camp. It's probably because I prepared most of the things in advance but they were cut and assembled at EMF camp so that counts right?

I've made flavoured vodkas before by dissolving boiled sweets into vodka and coming up with some pretty tasty flavours. This year I thought I would go one step further, I made 5 sweety flavoured vodkas and 1 nasty flavoured vodka and being a field full of tech geeks I figured they would appreciate a mechanism to automatically select a flavour for them. In brief, an arduino uses the random function to pick the appropriate bottle. A row of surface mount LED's illuminates the bottle selected and these are driven simply with a ULN2008 driver chip. The LED's spin round in a circle and fade in and out as they are selected. The rotation slows down and picks one bottle to end upon.

I'm not sure the random seeding from the A->D is particularly effective and I was basically resetting the power each time to make it spin again so it had this weird habit of picking the nasty, Horse Radish, flavour every time but that just all adds to the fun.

by (Martin Raynsford) at 15 September 2014 01:31 PM

14 September 2014

Spencer Owen hackergotchi for Spencer Owen

RC2014 with ZX Printer interface

My original plan had never been to design and build my own computer.  I had, however, planned to build a clone of the Sinclair ZX80, which has been on my bucket list of things to own for year, and which I had found plans for online.  Whilst collecting the parts and reading up on simple Z80 computers I got kind of sidetracked and ended up with the RC2014.

The print out shown was what was left from the last time this was connected to a ZX Spectrum!

The heart of the RC2014 is a Zilog Z80 CPU, which is the same one that Sinclair used in the ZX80, ZX81, ZX Spectrum and Z88.  If the ZX81 and ZX Spectrum can run a ZX Printer, then surely it follows that the RC2014 will be able to too?

The RC2014 backplane brings out nearly every signal that the ZX Spectrum has on it’s edge connector, so a simple adapter from the 0.1″ pin header to an appropriately laid out edge connector should suffice.  The only signal the RC2014 doesn’t have is 9V which is used to drive the original ZX Printer, so I added a connector for that to be injected in.  (For my use it isn’t strictly needed as I’ve got the Timex/Sinclair 2040 (also sold as Alphacom 32) which takes it’s power from a mains adapter, not the edge connector, but is otherwise totally compatible)


i (1)

So, I soldered the connector on, plugged it in and expected things to work.  But, no.  I had Odd Things™ happening, and couldn’t get much sense out of the serial interface.

It turns out that the ZX Printer uses very very minimal address decoding.  Basically, if the IO address line A6 is low, then it has the data bus.  The only thing I had connected to the IO of the RC2014 was the serial interface, which although it only had a small amount of address decoding, it did use A6 in a low state.


So, a little bit of thinking later, I realised that the easiest solution was to put some decoding on to the ZX Printer adapter so that it would only respond to a more specific address.  Luckily the design of the RC2014 backplane meant that cards can be easily extended with a bit of Verobaord.


Here’s the modified board with a 74LS10 that brings A6 low only when A0, A1, A3, A6, A7 are high.  Therefore I can address the printer from port 203 (0xCB)



The control of the printer is very low level indeed (ie ever so simple, thus complicated to do!).  Early tests have shown that I can print lines of different lengths though!  I consider that a #WIN but will see if I can get a dedicated print driver written for this.

by Spencer at 14 September 2014 07:34 PM

Martin Raynsford hackergotchi for Martin Raynsford

MSRaynsford Gift Cards

"Alex Bailey requested a laser cut gift voucher for his dad, Adrian" ;)

So that was basically it, but I realised it was a good idea and agreed to make him a little laser cut item to represent a gift card. This all happened weeks ago but given the recent spate of catapult fiddling you can see how the two get connected. You get some instant gratification in the form of a mini catapult which you can assemble while you wait for me to ship the item you pick from my blog (this includes customised items).

If you would like a giftcard simply copy the file I shared last week, change the wording at the bottom and return it to me

Both giftcards and catapults are available from the same listing

by (Martin Raynsford) at 14 September 2014 02:10 PM

13 September 2014

Steve Barnett hackergotchi for Steve Barnett

eShapeOko Part 3 – Tidying up

Having had the ShapeOko for over a year now I’ve used it for quite a few projects, but nowhere near as many as I intended. Part of the reason for this is that the controller for the machine was still rather jury rigged so setting it up was a hassle. To solve this problem I’ve been working on integrating together a permanent version of the controller.

Finished Product

I started by designing a pair of custom PCBs with a bus to connect them together while allowing for expansion. The first board is essentially an Arduino with custom pin out. The second board mounts the stepper controllers. At some point I may add a breakout board for limit switches and a board to interface with a pendant for manually controlling the machine.

Arduino and Stepper Boards

Having built the boards, they all work fine, but there are things I’d do differently if I made another. First off I’d probably stick with a standard Arduino pinout, both for reusability and because the 24 pin DIL socket I used turned out to be expensive. Additionally, the layout for the (single sided) boards would have been much simpler without the DIL socket to consider.

Arduino board underside with horrible routing for the DIL connector

With the boards made I decided on using an FTDI module I had lying around for USB to serial conversion, replacing the Minimus that I was using previously. I designed a very simple breakout for this module to expose the Power, Reset, Ground and Serial Tx/Rx signals in a way that matches the Arduino’s FTDI header. The main benefit of the breakout board, however, was that I could give it appropriate dimensions for mounting in a case.

With all of the boards made and (a few months later, once a burst of motivation turned up) assembled, I needed to build a case to keep the parts together. I decided to laser cut the case from perspex in order to get it made quickly—and because I thought a clear perspex case would look cool.

Due to my earlier experiences with fried Stepper Controllers I decided to use locking connectors to prevent accidental disconnection while the machine was powered up. After some searching I found that 4 pin gx16 aviation connectors seemed to do what I want. I ended up ordering some from China through Amazon as it was the cheapest source, though thanks to the seller incorrectly filling in the customs form I paid more than expected for them. Regardless, they work nicely and look good. I also used one of these connectors for power, with two pins acting as 12v and ground and spare pins for signalling. Should I choose to power the machine from a PC power supply at a later date, one of these lines will be used for the PSU’s power on line.

Locking Connectors

With the connectors and some switches chosen and measured, I began work on designing the case. I settled on a fairly simple tabbed box design. The box is split into two sections to match the two widths of board: narrow USB to serial breakout and wide Arduino and Stepper Controller boards. The sides of the box have slots into which various mounting plates can be bolted. The boards locate into slots in the mounting plates, allowing for quite flexible arrangement of the boards.

Case Parts

Runners for board mounting

With the case parts cut, I found it fairly fiddly to assemble, but once together it was quite sturdy. Some of the wires to the connectors had to be soldered with parts of the case in place. This makes maintenance slightly trickier, but will reduce the chance of intermittent connections to the steppers which could exist if I’d used a second set of connectors on the board.

Assembling the controller inside the case

The layout of the connectors and switches was mostly determined by the shape of the case and the space taken up by the boards. I ended up with the stepper connectors on the top of the case in the same section as the USB to serial adapter. The connectors are quite deep, so they required a lot of space behind their mounting plate.

Stepper connectors

On one end of the case there is a cutout for the USB to serial board and a reset switch for the Arduino in the form of a big red button. It’s not exactly an emergency stop button but should have a similar effect.

USB connector and reset switch

On the other end is an extra gx16 connector for power and a switch that will act as a power switch if a PC PSU is used. The switch is designed to connect or disconnect the ATX PS_ON line instead of being directly in line with the 12 volt input, which would require a sturdier switch. There is space for mounting a much smaller alternative switch, but I went with a large toggle in the end.

Each end of the case has a grille and mounting holes for a 45mm fan should extra cooling be required.

Power switch and connector

In order to keep the cables for the steppers tidy, I slipped on two pieces of heat shrink over the paracord sheaths I added. These keep the ends of the paracord neat at each end of the cable and provide a bit more bulk so the strain relief in the connectors has something to grip.

Finished Product

by moop at 13 September 2014 10:53 PM

Martin Raynsford hackergotchi for Martin Raynsford

Cheats Parametric Design and Catapult download

Parametric Design is the generation of files from an initial series of variables. The pattern is described in terms of these variables and when the values are changed the whole design is adjusted. These variables can typically be used to store things like the material thickness and object size. Something like this tabbed box maker offers true parametric design but it's an extension that is written in python so you require some programming skills before you can write your own. For something like this mini catapult design where we only want to change one variable a full blown extension would be overkill so there is an easier way.

I spent a lot of time working on the variants of this catapult so forgive another post centred around it. When I scaled it down to half size a lot of the press fit joints no longer fitted together because the material was a little bit more than 3mm so I realised there was a quick and easy solution to changing thickness.

When the design consists of entirely laser cut parts you can cheat the parametric design process. When the catapult is scaled all the parts stay sized relative each other, so I created a version of the file where the material width is considered to be 1 unit. Any tab or slot that relates to the material width is 1 unit wide (in my case mm's). When I want to cut the item in a new material I take this base file and scale it by the material width. When I have 3mm ply I scale it up by 300% and I'll save that file and run with it, but if I get some thinner stock, say 2.9mm, I can go back to the base file and quickly scale it by 290%.

This trick only works for items where most of the parts are laser cut. It wouldn't work with something like my marble machines because the marbles are a fixed size and the holes to mount the motor need to have the right spacing, but it will work for some designs and it is a lot quicker than recreating the whole thing parametrically.

Here is the catapult file scaled and ready for conversion to your own material thickness if you would like to give it a try. I recommend something like 0.5mm nylon chord for the string to go with it, you can work out exactly the right length of the string by wrapping it around the notches in the edge of the board. (svg here)

Catapults, large and small can be bought from my shop

by (Martin Raynsford) at 13 September 2014 01:19 PM

12 September 2014

Martin Raynsford hackergotchi for Martin Raynsford

Catan Disks

Both children are elsewhere and I'm sat waiting for someone to arrive so I thought I'd have a look at my inbox. I had a request asking if it was possible to make some wooden disks for a catan game (I have to admit I'm not sure which one it is) because the game now ships with plastic tokens instead of wooden ones. A quick download of the desired tokens from Board Game Geek, a doodle and 10 minutes later, I now have the appropriate disks, 25 in diameter and 6mm thick. In fact it's taken me far longer to reply to the emails and blog about it than it did to make the tiles. Lasers are awesome (methinks I could sign off many of my posts like that)

by (Martin Raynsford) at 12 September 2014 01:09 PM

08 September 2014

Martin Raynsford hackergotchi for Martin Raynsford

Vale Group Symbols

A batch of group identifying tokens done as a custom job for Vale LRP

by (Martin Raynsford) at 08 September 2014 08:48 PM

Matt Brailsford - Barnsley IO keytags

Matt Brailsford wanted to cut some keyfobs for Barnsley IO. AFAIK he had some assistance cutting a sample wooden one and then came back to cut a bunch of plastic fobs. After we left him hanging round the village for an age waiting for assistance I let him play on the machine on his own, with a few little hints he came up with these nice green key fobs.

by (Martin Raynsford) at 08 September 2014 06:29 PM

07 September 2014

Martin Raynsford hackergotchi for Martin Raynsford

Tilda Badge Case

The Tilda Badge is widely regarded to be one of the most technologically advanced badges given out at any conference. It was only a matter of time before someone turned up in our camp asking for a case to go round it. I think the files were already online somewhere but the case wasn't quite thick enough so the battery had to be taken off the back of the badge before it would fit.

by (Anonymous) at 07 September 2014 09:25 PM

06 September 2014

Martin Raynsford hackergotchi for Martin Raynsford

Ciaran O'Connell - EMFM Signpost

Ciaran O'Connell, on behalf of the radio station at EMF Camp, EMFM, wanted a sign that would distinguish their marquee from the ones on either side of it. Queue the laser cutter. Cut from 3mm perspex and backed with 3mm of fluorescent perspex, this made the text really stand out.

by (Martin Raynsford) at 06 September 2014 09:13 PM

05 September 2014

Martin Raynsford hackergotchi for Martin Raynsford

Dan Nixon - Google Cardboard

Dan Nixon spent a fair bit of time on the laser cutter trying to cut a first draft version of his google cardboard design, made from wood. The unit spent most of the weekend on the bench full of laser cut items and was a definite favourite with visitors to the village. I think there is a bit of market for these if he could be persuaded to sell them.

by (Martin Raynsford) at 05 September 2014 09:05 PM

04 September 2014

Martin Raynsford hackergotchi for Martin Raynsford

Mark Phelan - Twitter Ticker

Mark Phelan was one of the first to come to us in the laser cutting village and ask for an item to be cut. He wanted a holder for a roll of ticker paper that was going to be fed through the ticker. This machine was printing out all the tweets sent to @emfcamp over the course of the weekend. 

by (Martin Raynsford) at 04 September 2014 09:02 PM

03 September 2014

Martin Raynsford hackergotchi for Martin Raynsford

Laser Cutting Village Sign

The first thing we needed at EMF camp was a sign for our tent. A bit of a group effort and cut on multiple laser cutters we cut this fancy font using a range of different materials for each letter. The line spacing on the etch was massive to get them done quickly. All the letters were hot glued to the base plate (in slightly wonky fashion) by myself before it was hung from the side of the tent with bungy cords.

by (Martin Raynsford) at 03 September 2014 08:50 PM

02 September 2014

Martin Raynsford hackergotchi for Martin Raynsford

EMF Done

Images Stolen from Dominic :)
So EMF camp came and went over the weekend and was a fantastic success. We set up the Laser cutting village and with the help of Ian and his laser cutter we demonstrated laser cutting to the masses, giving them the opportunity to play with our laser cutters all from within a field. The weather couldn't have been any better and despite some fairly hefty 15 hour days in the laser cutting tent I really enjoyed the whole thing. 

Over the next few days I'll be posting up some of the things we made at EMF camp on the lasers (this is partly to fill the gap while I install the new laser in my garage and build up stock for the upcoming mini maker faire in Brighton)

by (Martin Raynsford) at 02 September 2014 11:33 PM

Matt Little

USB reprogramming lead

No image

Lots of the kits sold here require a programming cable to program the ATMEGA328 micrcontroller.

These kits use a bare microcontroller and do not incorporate a USB-Serial IC on them (unlike the actual Arduino UNO and others).

This reduces the cost of the circuit as, once the project is complete, you do not need to reprogram the IC and having the USB-serial IC is a waste.

Here are some reporgramming cables which work with our kits.

They are available for £9 (inlcuding P&P within the UK)


by (Matthew Little) at 02 September 2014 02:05 PM

28 August 2014

Martin Raynsford hackergotchi for Martin Raynsford

Laser Cutting in a Field

So this weekend I am decamping from the garage and recamping in a field. We are setting up the laser cutting village at EMF Camp, which basically means we'll be running our laser cutters for all and sundry to use in the middle of a maker festival. One of the best descriptions I've heard is that it's like a maker faire but without the public. I'm taking everything from tools and lasers right down to my workbenches and while this seems a tad intimidating it's actually going to be good for me. Now that I have a blank canvas to work with it should be much easier to fit my new A1 laser cutter into the garage when I return with it.

by (Martin Raynsford) at 28 August 2014 09:36 PM

Kate Bolin hackergotchi for Kate Bolin

Take some Avatar: The Last Airbender iconography. Take some...

Take some Avatar: The Last Airbender iconography.

Take some fluorescent perspex.

Take a laser cutter.

Create your own phone charms to show your Air Nomad or Water Tribe affiliations.

28 August 2014 03:00 PM

26 August 2014

Martin Raynsford hackergotchi for Martin Raynsford

EMF Camp Mini Catapult

I scaled down the catapult kit to half the size, the catapult still packs the same amount of kick presumably because the projectiles are half the size too. We're intending to give these out as business cards at emf camp so head on over to the laser cutting village to pick one up.

by (Martin Raynsford) at 26 August 2014 10:04 PM

Kate Bolin hackergotchi for Kate Bolin

This is an utterly ridiculous knitting project. I bought an LED...

This is an utterly ridiculous knitting project.

I bought an LED plant pot from Lidl. And I knew I wouldn’t put an actual plant in it, because that just seemed pointless - I’m rarely outside at night, it would never be on.

So I knew I was going to EMF Camp this year, and I knew that having little random lights is always a lot of fun, and I had a small collection of fibre optic hair clips from The Glow Company because of my Teddy Lupin doll project, so I started goofing around and here you go, a cactus with fibre optics in the flowers.

I did think about putting the fibre optics throughout the cactus so that it would have “spines”, but I knitted them in the round, and it would’ve been impossible to properly get it all sorted.

I think that I might do it again, with one knitted flat, so that I can fit the fibre optics into the spines.

26 August 2014 08:53 PM

25 August 2014

Martin Raynsford hackergotchi for Martin Raynsford

Sheriff Style Badges

It's definitely LRP season, these tax official sheriff style badges were made for a group at the gathering. I also made a batch of the mage guild badges for another group (although I've left them to colour in their own stripes)

by (Martin Raynsford) at 25 August 2014 08:53 PM

24 August 2014

Martin Raynsford hackergotchi for Martin Raynsford

Teacups Cake Stand

As a bit of a rush job last week I was asked if it was possible to make a cake stand, capable of rotating 6 individual cakes, like the teacups ride you'll find in a theme park. Because I'm a sucker for punishment and I was enthused by the idea I decided to take it one step further and have the teacups rotate around the central cake while they in turn were rotating.

I fired up the trusty gear generator program and designed myself a planetary gear mechanism that would achieve the desired motion. The layers use the turntable mechanism I like now, there is potentially a lot of weight going through these things so it's nice to know that the load is not transferred to the motor.

If I had to do it again I would change a few things to make it run smoother and definitely put in a large motor. In fact I would really love to make another one of these and perfect those minor issues so if anyone else wants a turntable cake stand then please speak up.

by (Martin Raynsford) at 24 August 2014 07:30 PM

23 August 2014

Martin Raynsford hackergotchi for Martin Raynsford

Afternoon Ambilight project

I recently purchased a couple of RGB addressable strips for play and potential future projects. While I had one handy though I thought I would make up a DIY ambilight system for our TV. Eli was also very interested so we actually turned it into an afternoon project while Hazel was napping. I drilled the holes in the board while Eli threaded them with cable ties, we then put the LED's in the right places.  I overkilled it with an Arduino Mega control board and a 5V 4A power supply also hung from the board. I used Prismatik to drive the ambilight system. It was a fun way to spend the afternoon and the effect is pretty good but these LED's weren't bright/angled correctly enough so it's been taken down again already awaiting a V2, with a proper laser cut and angled frame.

by (Martin Raynsford) at 23 August 2014 09:47 PM

22 August 2014

Martin Raynsford hackergotchi for Martin Raynsford

3060 gone

The 3060 now has a new home, Ben came to collect it yesterday. Hopefully at some point he'll have a web presence of all the awesome things he's made with it and I'll be able to point you guys over to it. It fit nicely into the back of their vehicle.

It's been a hectic week trying to get the machine ready to go as well as do a dozen other things. I don't have an 'after' photo but the before shot shows you just how much elbow grease was required to get that machine back to a clean state. Now the machine has gone it's left a rather big gap in the workshop but it's still going to be another 10 days before I get the new machine in there. We're taking it with us to EMF camp first. I'm quite excited now, I'll post about the new machine asap.

by (Martin Raynsford) at 22 August 2014 09:45 PM

Spencer Owen hackergotchi for Spencer Owen

The Future I AM IN YOU

As a child growing up in the 1970s, I had no idea of what the future held.  I didn’t know if Mr Benn would be able to get back from his adventures, or if Scooby Doo could catch the Evil Swamp Monster, or even if we were going through the round or square window in PlaySchool.  But there were some things about the future that was pretty certain.  We would all have robot butlers, go on holiday to the moon and drive electric cars!

2014-07-13 13.31.18

So, as I drove to work this morning in my electric car, wondering when my moon tickets would drop through the letterbox, I realised that maybe, just maybe, I am already in the future

2014-07-13 13.31.27

The car itself is a 2013 Chevrolet Volt Extended Range Electric Vehicle (E-REV).  There is quite a large choice of electric vehicle on the roads in the UK right now, and, just like petrol cars, come in a range of sizes, styles and prices to suit different people.  They don’t all work the same way, or use the same technology, and what may be perfect for one person might not work at all well for someone else.  For example, a Nissan Leaf is battery only, quick to charge but only has a range of 80 miles or so.  Hybrids like the Toyota Prius, have a engine and a motor and can run on either and will charge the battery when running on petrol.

I have covered almost 2500 miles in just over 2 months, and most people I talk to seem  interested in how it works both technically and practically for me, and why I went for this kind of car.  It is an excellent car that suits me well, but it does have limitations and downsides that mean it might not be for everyone.

Firstly, it is an Extended Range Electric Vehicle.  That is, it runs on an electric motor from battery power, but it also has a petrol engine that can run a generator to keep the battery from running flat.  Unlike a hybrid, the petrol engine does not drive the car.  Normally, the battery is charged up from home which gives me range of about 40-50 miles before the engine needs to kick in.  As my daily commute is around 18 miles each way, and I’ve not been on any long journeys since getting the car, the engine has not been needed, or even started.

(Except once.  I got in the car and a message on the dashboard informed me that due to the infrequent use of the engine it needs to be run for a 10 minute maintenance schedule.  I guess that makes sense to ensure nothing seizes and all the fluids are pumped around a bit.  And 10 mins of petrol use over 2500 miles (so far) still seems very low!)

Charging the car is very easy.  It comes with an adapter that will plug in to any UK 13A plug socket.  This runs at 6A by default and will fully charge the battery from flat in around 8 hours.  It can be overridden to run at 10A, or 6 hours to charge.  Thanks to a government scheme though, I have had a dedicated charge point fitted free, and this runs at 16A, taking about 4 hours to fully charge.

2014-07-13 13.31.36

There are electric charge points dotted around all over the place, most of which are free, some are cheap and others less so.  These range from most IKEA branches, some supermarkets, city car parks, motorway services, hotels and other places.  They are often run by different companies and have one or more of the common 4 charging sockets and charge at different rates of power.  Although I have free access cards for a couple of companies charging posts, so far I have not used (or needed) any.

Some other electric vehicles, particularly the battery only ones have much more powerful charges built in to them, so can charge at 32A, 63A or 125A.  This makes sense for en-route charging if you need to drive somewhere beyond the limit of your battery.  The Chevrolet Volt, though, takes too long to charge for this to be practical.  Effectively, you get a maximum of about 12 miles range per hour of charge, which makes it suitable for destination charging.  Unless, of course, I wanted to stop for 4 hours every 40-50 miles!

As I said earlier, though, my daily commute is about 36 miles round trip, so that has been covered on battery only since getting the car.  Some evenings I pop out, and some weekends I take much longer trips.  So far, plugging in when I get home for an hour or so has covered all the evening trips, but sooner or later I will be heading down to Essex or further afield.  For a trip like this, the first 40+ miles will be purely electric, with the remainder of the journey having the engine running.

As you can imagine, the engine is a small efficient unit.  Because it is not driving the car, the speed it runs at is controlled for efficiency of charging, and I can expect to get over 50mpg from it.  Still not too shabby for a big car like this.

2014-08-21 17.07.33

So, how much does it cost to run then?  Well, I’m glad you asked.  It has worked out around 3.4p per mile based on the cost of electricity to charge it up.  That is around £1.25 per day to commute to work and back.  By comparison, the same journey in my LPG PT Cruiser (which wasn’t too efficient, but the fuel was cheap) cost around £7 per day.  If I’d been running that car on petrol, it would have been over £13.  Then, of course, there’s the car tax which is zero!  And, because of less engine wear and less break usage (regenerative breaking used whenever possible) services costs are lower too.

But I bet it is slow.  What is it like to drive? Actually, it’s quick. Amazingly quick.  I mean, really quick. Even in “normal” mode, it takes off from the lights quicker than most cars out there, and in “sport” mode, it can outpace a rocket!  And, unlike a convention engine that has a gearbox to make use of its sweet spot of power, an electric motor has torque available to it whatever the speed.  And with the exception of a little bit of tyre noise and wind noise at higher speed, it is completely silent!  It is so quiet actually, that I am beginning to listen to the background noises and interference in most of the pod casts I listen to!

Oh, and don’t get me started on gadgets.  Well, ok, yes, it has gadgets.  Lots of them.  Sure, regular stuff like CD \ DVD player, electrically heated seats, sat nav, Bluetooth etc.  But also touch screen display, DAB radio, rear view reversing camera, hard drive for MP3s.  My favourite one, however, is preconditioning; Before you leave in the morning, whilst the car is still plugged in, the heaters and window demist can be  triggered.  So, not only do you come out of the house to a nice warm car (or a cool car in the summer), but it doesn’t affect the electric range as this was done from the mains supply!  Genius!

Despite the fact that electric cars have been around for years (If the Toyota Prius was human, it would be getting its GCSE results next year!), things have still got a long way to go before everyone drives an electric vehicle.  The infrastructure isn’t yet as commonplace as it needs to be.  The range of all cars except the Tesla S will mean compromises for most people.  Initial purchase price is still too high compared to a dinosaur fuelled equivalent.

But, one by one, we will all get to the future.  For me personally, I am really pleased that I am living in the future already, although just a little bit sad that my robot butler must have hidden my moon tickets!


by Spencer at 22 August 2014 01:55 PM

17 August 2014

Spencer Owen hackergotchi for Spencer Owen

Man Cave 2.0

Recently I’ve read a few posts about other peoples working environments, office setups, man caves or work benches.  I’ve also had a couple of people ask about mine, since I tweeted about the redecoration and overhaul of my old “spare room” as it transformed in to “Man Cave 2.0″.  I had intended to write it up when it was finished anyway, although, even now, 9 months later, it is still not finished, I am begining to realise that it will never actually be finished but will evolve and morph over time.


So, this is a look at the overall design and some of the finer detail in to my Man Cave 2.0 as it stands in August 2014


So, obviously the PC is at the heart of things in here.  Well, actually, the PC itself is tucked right away in the furthest corner under the desk as I hardly ever touch it.  Instead, though, I have the power switch mounted just below the monitor screen shelf and have a selection of USB ports wired in to convenient locations.IMG_20140815_204630

Under the monitor shelf is some LED lighting – nothing too fancy, just white, along with an 8-way extension socket.  I’ve not filled them all up simutaneously just yet… but I’m sure I will do one day!  Under the desk itself is the same set up of LEDs and power sockets.


Above the shelf is the cable modem, router, external hard drive, speakers.  That corner of the desk is just far enough out of reach that I wouldn’t want to use it for anything I need to get to regularly, but just close enough to reset a router or plug in a new cable on the occasions I need to.


The desk itself is HUGE!  2.4m by 1.2m at its widest, although most of it is 800mm deep due to the shaped cut-out that was flipped over to make the shelf.  The key to it though is versatility.  The centre section is multi-use, depending if I just need space to spread out, or add an Ikea breadboard for soldering or messy stuff, or add a cutting mat for more delicate things.


No good workbench is without a power supply.  This one is a converted ATX PSU for 3v3, 5v, 12v, -12v, and USB power output too.  Thanks to re-innovation for that.


Storage solutions help me fill this small room with just soooo much crap.  Of course, Really Useful Boxes help with this storage!


A couple of Ikea units, a shelf, and what appears to be randomly placed drawers, boxes, cupboards and display booths are all within handy reach behind me.  I’ve tried to keep similar things together and labelled, and so far that seems to be working well.  Can you see the little HP Micro Server lurking there?


This is where new electronic projects are born.  And old ones go to die.  And unfinished ones go to sleep.    There’s a good selection of components, PCBs, prototyping stuff


Every couple of years I need to update my Cisco certifications, and over the years I have managed to get myself quite a reasonable collection of hardware for building my own labs.  Before the renovation I was limited to only a few devices per lab.


The old Toshiba Satellite laptop is about 15 years old, but still great for connecting in to the Cisco colsole ports and running a few basic applications.  It is also the only machine I still have with a parallel port, so it’s still needed for my eprom programmer.  I have a 12U floor standing rack on casters which holds all the heavier Cisco equipment…


And another 14U of rack framework built in to two support legs.  When the wiring is complete there will be a 24 port patch panel in each one as well as one under the monitors so I will be able to connect anything to anything.  It will also come in handy for keeping me warm in winter :-)


Oh, and no Man Cave would be complete without a Leggy Lampshade for providing optimal lighting just where it’s required!

For bigger, more mechinical stuff, there is still my garage, and that might feature in a blog post at a later date.  Surfice to say, there’s most of the tools I need in there, but for anything else, Nottingham Hackspace is open 24/7!


by Spencer at 17 August 2014 06:42 PM

15 August 2014

Matt Little

Low-Cost Wind Datalogger

No image

Wind speeds are very site-dependant - with topology, ground roughness and other factors affecting the local wind speed. Knowing the wind speed and frequency of the wind speed at a particular location allows us to make a more accurate resource assessment.

An accurate resource assessment is required for ensuring the wind turbines are sited correctly - in locations where they will generate the maximum energy.

This project was to develop a low-cost, low-power wind speed monitoring unit. This has mainly been developed for use in remote rural locations with a specific application to small wind turbines for international development projects.

This project is open-source and PCB design, software and hardware designs are available on GITHUB.


by (Matthew Little) at 15 August 2014 02:36 PM

Spencer Owen hackergotchi for Spencer Owen

Linux support, upgrades and headaches

Some of you may remember that last year , after a regretful decision to ‘upgrade’ from Windows 7 to Windows 8 I decided to jump ship and switch over to Linux.  Ubuntu 13.04 to be precise.  I blogged about the install process here, and my first thoughts after a week here, with the intention of regular posts whenever something goes really good or really bad.

So, it’s 14 months later, and basically things have gone pretty good.  Sure, there’s some things that aren’t just how I like them with Windows, but other bits that just seem to work really well.  In defence of my lax blogging, I’d just say that I got on and used the computer as I expected I would.  I got tripped up a couple of times, but Google and always seem to put me back on the right track.

I have expanded my Linux network too.  I was donated an old netbook last year that now runs Ubuntu 13.04 for an hourly Twitter job.  The plan had been to test it on the netbook then set up a Raspberry Pi to run it, but the netbook is surplus, capable, cheap to run and it works – so why change.  I have also bought myself a little HP server which I put Ubuntu Server 13.10 on, along with OwnCloud.  This works like DropBox, and synchronises files between my main PC, phone, tablet, work computer and is available to me (albeit slowly) anywhere on the internet.

All in all, things have been ticking over quite nicely.  Life has been happy in Linux land… until recently!

I’ve been off work this week recovering from an operation.  This has given me more spare time than I normally have, although it also limits how long I’ve been able to concentrate on things.  I know that’s probably a bad combination, but, hey, lets go with what I’ve got!

So, a few days ago I thought it would be cool to “upgrade” to a retro looking terminal like this nice Swordfish90 one.  Seems fairly straight forward, but I quickly came in to troubles when some of the required packages were unavailable or were untrusted.  Lots of 404 errors.  Oh well, just one of those things that looks easy on the internet but is actually more involved.  Never mind, it would have been nice, but isn’t really required.

Later, I SSH’d on to the netbook and noticed that it said there were security updates to be applied and a new distro was available.  I didn’t really want to upgrade the whole distro, but would feel happier knowing the security stuff has been applied.  Sadly, I was unable to install the security patches as the same 404 errors were occurring.  Ok, maybe it’s time to upgrade the distro then.  This actually went very smoothly. “do-release-upgrade” quite happily took me from Ubuntu 13.04 to 13.10, and after a reboot, it tells me there is another new distro – 14.04 – that I can upgrade to.  Yeah, well, in for a penny, in for a pound.  I run that and all seems good.

Well, it seemed good.  The hourly task was still running.  For a while.  A reboot got it going again.  The following day I woke up to find that my broadband was down, so it had missed a few more of these tasks.  Can’t blame the upgrade for that though.  A restart got it back online, and in the last couple of days it has only missed a couple or so tasks – compared to missing none for the previous 4 months.  Seems like too much of a coincidence, but I suspect there’s something in the upgrade that didn’t go too smoothly.

I guess the OwnCloud server should really be running the latest release of Ubuntu too, so last night I did a “do-release-upgrade” on that machine.  This was already running 13.10 so only 1 upgrade was needed and this went really well.  The only problem was that afterwards OwnCloud wasn’t running.  Seeing how this is the whole raison d’etre for this machine this was a bit of an issue.  It seems like the upgrade overwrote the Apache config files that tell it where the OwnCloud web pages are served from.  Random poking about and looking at files made me appreciate just how little I understand about what makes this box tick.  My data was still there though, so eventually I decided to download and install the latest release of OwnCloud.  Something clever in it realised an older version was already installed, so it asked if I wanted to upgrade, I said yes, and suddenly everything works just as it did before! Hurrah!

So, this just leaves my desktop PC running Ubuntu 13.04.  When I installed this last year it was the latest release and all was good.  I could have installed an older version, 12.04, at the time which had come out a year earlier, but had Long Term Support (LTS).  I didn’t appreciate the difference at the time between a LTS release and a non-LTS release, but this has been hammered home to me in the last couple of days.  My version, 13.04, was released in April 2013 (see how the version numbers work now?), and had 9 months support.  In October, another non-LTS release, 13.10 came out, which I should have upgraded to between October and January.  Then, after the LTS release 14.04 came out, I would have had 2 months to upgrade to that.  This page shows the Ubuntu releases quite nicely

But I didn’t.  I have missed 2 upgrade cycles, and upgrading isn’t looking like a viable option for me right now.  I certainly can’t run the upgrade online as all of the repositories are unavailable.  I could download and burn myself a 13.10 DVD which I think will give me the upgrade option, and then do the same for 14.04 – However, with my experiences so far on the other 2 machines (which only have 1 task each), I worry about breaking 14 months worth of getting this computer to just the way I like it.

Probably the sensible option is to back up all my stuff and do a clean install to 14.04.  Copy back all my data and reinstall all the programs I’ve got used to.  But I know that adjusting to a “new” computer can be a slow and painful experience, and I doubt I’ll be able to find half the stuff again.

If I’m doing a complete reinstall, there’s a strong temptation to go back to Windows 7.  Life seemed simple then, and I knew what I was doing.

Alternatively, I procrastinate, put off the inevitable, and carry on with 13.04.  It works, and pretty much does what I want.  Ok, I would like to add a pdf printer and a cool retro looking terminal program, but without the repositories being available that isn’t something I can do.  Over time this is going to become more and more of a problem.

Hmmm… to be continued

by Spencer at 15 August 2014 12:50 PM

14 August 2014

Kate Bolin hackergotchi for Kate Bolin

Announcing the shiny things!


Every year people build amazing things and install them all over the site. Here’s a rundown of some of the projects coming to EMF this year.

Bar Arm

Behind the bar you’ll find a robotic barman in the form of an ex-laboratory robot arm mounted on a mobility scooter. It’ll try and serve you drinks, but we can’t promise it won’t throw them at you instead.

A Tune On A Stick

Somewhere on-site you’ll find a lighthouse-like structure making strange noises. It plays a tune while spinning around - what it plays depends on who is nearby. Find some friends and try standing around it in a circle.

Giant Pixel Sign

A giant interactive sign made up of 900 RGB LEDS controllable from your web browser, lurking somewhere in the dark. Upload your own artwork, or your favourite gif!


Desperate for some Club Mate but don’t want to move? Call the Robobutler! He’ll trundle across the site and deliver you a tasty beverage, hopefully without destroying tents in his rush to do your bidding.


A large forest of radiant “trees”. As you move through the·grid it senses your presence and initiates a ripple of light & clicks, however it will be used in several ways - expect a multiplayer maze amongst other things!

Giant Ride-on Duck

The folks from Tog in Dublin have built a giant duck you can drive around. We don’t know why, but we want a go anyway.

ISS Tracker

This giant arrow will spend all weekend tirelessly pointing at the current location of the International Space Station. Unfortunately there will be no visible ISS passes during EMF, so (time permitting) an interface is planned to allow pointing at other astronomical points of interest.


The buggy that almost self-destructed hauling things around EMF in 2012 has been repaired and is better than ever, with a new trailer for hauling your equipment around and a smattering of ridiculous addons. Internet-connected golf cart anyone?

Retro Gaming

Back by popular demand the retro gaming tent has ballooned in size! Expect to find full-size arcade cabinets, pinball, and every retro console you can think of.


Adding to our list of autonomous vehicles is BigHak, a giant ridable version of the Big Trak toy you may have had as a child. Either drive it manually, or program it Big Trak-style with the accompanying phone app - we have a prize for the first person to successfully program it to navigate to the bar from their tent!

Cocktail Barbot

Somewhere in the Nottinghack village you’ll find a two meter long automatic bar. Choose a drink from the menu, insert a glass at one end and get a cocktail down the other - even down to the tiny umbrella and slice of lemon.


Balloons floating high above the site listen for noise and tell one another how loud it is. As the pings move between them they pulse with colour, lighting up colourfully in waves across the site.

Giant Hammock

In 2012 we had a giant hammock made from fishing nets - in 2014 we’ll have an even bigger one!

Kite Arch

24 kites mounted on a long cable - once the wind gets up the arch takes off! As the weekend progresses they’ll be being decorated as an ongoing workshop.

The LHS Bikeshed

The LHS Bikeshed is a 3 player starship disaster simulator in a caravan. Players are trained to fly the ship and then given a short scenario that inevitably ends up with them being exploded, burned, suffocated or smeared across the surface of a planet. Find three friends and set off into the galaxy!


An amazing sea of fish that respond to touch. Individual fish light up and move, before spreading colour, light and motion through the entire SHOAL. The fish tell their friends what’s happening and a motor means all the fish can swim in the same direction, or turn to face someone who has come to play!

Pacman! On a Sphere!

A version of Pacman that is played on an actual real-world sphere. The pac-man player must run around the projected sphere trying to find all the pills, whilst up to another four players play the ghosts trying to hunt him down!

The Nuclear Poker Bunker

A half-size Hexayurt Quad Dome, within which people play Nuclear Poker, a card game designed to teach Generals too young to remember the Cold War about Mutually Assured Destruction.

The Kinematocinegraph

A chance to sit out in the night air and quietly enjoy flickering images from the past. A small antique box contains a projector filled with silent films from - sit, be calm, and watch films for as long as you like.

Pedal Power

Two pedal power generators powering a small sound system, a bubble machine and LED lights in the evening. Get some exercise!


Hidden in the villages is a large umbrella adorned with meteorological equipment, generating a weather-related soundscape and light show for those standing underneath.

The Marvellous Booze Fogger

A device for the turning of alcoholic spirits into the most inhalable of mists, pleasing to the tongue and satisfying to the mind. A very certain panacea for the ills of the soul and a solution for those tired of the sorrows and trials of day to day living. It is most shiny:

Are you bringing an amazing project to EMF this year? Let us know!

So, um, I’m doing the Kinematocinegraph.  I’ve done a lot of work on the recipes for Cocktail Barbot.  And I’ve been there for the Marvellous Booze Fogger.

I’m not saying that EMF Camp is going to be awesome, but it is TOTALLY GOING TO BE AWESOME.

14 August 2014 08:06 PM

12 August 2014

Martin Raynsford hackergotchi for Martin Raynsford

HyperQBS by Geobender

I saw these HyperQBS from and thought they were very cool so I decided to make one. A 3D model was made, flattened using Pepakura and Laser cut for quick assembly, then it was glued and taped to turn it into a hexaflexagon thingy, I even wrote an instructable about it if you'd like to make your own.

by (Martin Raynsford) at 12 August 2014 09:28 PM

HPC 3060 for sale

So I need to make some room for the next laser which means getting rid of the 3060 machine. It's served me relatively well and with the few improvements I've put on it the extraction works relatively well and you can see what you're cutting. So it'll be going for £2800 hopefully, it's listed on ebay but just contact me directly and we can discuss it.

by (Martin Raynsford) at 12 August 2014 07:58 PM