Can you feel the breeze? The “Breath Of Air” Kites

So still and serene are the Kites. A delicate design hanging from a sturdy structure, that with just a gentle movement of  air turn into a dancing delight.

The Kites created by Def-Proc creative director and founder of Red-Violet Made Jen Fenner collaborated with Def-Proc design engineer Patrick to bring together two fields of expertise, a combination of Textile Art and Engineering  and create an interactive installation. They were made as part of an annual exhibition in conjunction with Re-View Textile Artist group in Birkenhead Park Visitor Centre. The exhibition theme and title being Breath of Air called for artists to create works inspired by the feeling of being in open spaces,  outdoor landscapes, things that fly including birds and kites and even some fish.

Jen’s Kites were inspired by wind chimes and mobiles. The kite motif fitted in perfectly well with the interactive installation she wanted to create. Using an air sensor combined with an illusion of weightlessness the Kites reflect how they would look in flight.

Hanging daintily on 42 awg copper winding wires from a 6ft high wooden frame looking akin to a chandelier, the installation is made up of 42 Kites, each with their own individual LED light.

Using a  very sensitive  heated diode anemometer  which are triggered when the kites move from just as little as a gust of air from walking past the installation, the LED lights turn on inside the white cotton kites in a randomised sequence of flashes similar to a flickering candle, these continue to flash until the kites come to a stand still again.

The suspended kites hang from a circular clear acrylic girder using laser cut method that was designed to slot together and support itself without glue and also to keep the wired parts of the creation neat and unobtrusive.

Unsuspecting spectators were politely surprised by the installation coming to life and upon realising how it worked had much fun trying different ways to create a wind effect and make the kites dance.

Oggy! Oggy! Oggcamp 2015!

This year Def Proc were apart of the Oggcamp 15 team.  It took place over Halloween weekend at LJMU Art Centre opposite the Liverpool Metropolitan Cathedral.

If you are wondering what it is… Oggcamp is a technology based cultural community event that is growing in size each year. The “unconference” is supported by Entroware, Ubuntu, Fedora and Linux Voice and it all began, once upon a time, in 2009, when two podcast teams joined forces.

The event features new exciting products from makers for you to play with and stare at in awe, live podcasts and talks from the event attendees themselves, sharing information on their passions and interests.

The great thing is, it’s not just for techy types. Its for the whole family. The talks aren’t just about laptops and advances in podcast communication, no, they are there in the first place as a sharing platform of knowledge provided by people like you, with backgrounds in similar or different veins to you that could take your fancy and if you felt like sharing something of interest you just had to sign up. Leaf Liverpool was also on hand to supply you with tea, coffee and cake.

And finally… the best part…there was free pizza!!! Always a great incentive to peak your interest into checking out something new and different.

Our creative director Jen was on board team Oggcamp to help plan the event and create all the fabulous fluorescent Ogg-artwork for the posters, signs, t-shirts and mugs, as well as designing the look of the website. You may have seen the bright orange crew t-shirts, even purchased a slime green memorabilia t-shirt  or mug but either way they could not be missed!

Another great part of Oggcamp, if we do say so ourselves, was our collaboration project with DoES, The Made Invaders foam dart gun range.

We managed to provide great entertainment for many kids and adults alike, as well as create competitiveness between parents, offspring, siblings and friends.

We were offering a Grand Prize for our highest twitter recorded scorer, so the competition was on to win one of three Nerf gun prizes. Top score of 429,496,896 (via a well explored zero day exploit!) won the Nerf Zombie Strike Slingfire and for the runners up there were two other Nerf Doublestrike pistols for second and third place.

The DoES Liverpool Tower was also on display at the entrance greeting the attendees along side the RedViolet Kite Installation. Other DoES exhibitions included a Knitic circular knitting machine, Boomstand and RFcrafting (a DefProc client’s project) – remote control Minecraft buttons.

All in all it was a fantastic unconference full of gadgets and games. Albeit it was still work, but it was a very fun weekend filled with everything we like most. We hope to see more of you here with us next year as the event continues to grow in the future.

See below for a collection of photographs from the weekend taken by DefProc Photographer Lu Lowe.

The DoES Tower – a misuse of trust and a 3D printer.

At Def Proc we were excited to hear that as a part of the Build Your Own exhibition. DoES was lent an Ultimaker 2 Extended 3D printer to kick start a 3D prosthetics group where people who needed prosthesis could build there own as part of the exhibition.

Primarily whilst working on the Build Your Own projects, we took the chance to play with a very big printer and misused the trust to do something cool with it. We were slightly worried how the Ultimaker people would feel about this, but everything worked out ok in the end.

The DoES Tower was a collaboration between us, the CAD Monkeys and Brett Lempereur who did the rest. We decided to create a 1m scaled representation of the Liverpool “Radio City” Tower /St Johns Beacon, but to be quite frank, we just wanted to create something tall and then ideas grew from there.

Brett Lempereur  coded the lights around the outside of the beacon that displayed DoES Liverpool  and connected them to the internet where the down lights where controlled by twitter. The idea in practice was so you could tweet @Doestower< a colour> which would change the colour of the tower lights, take a photo, and send it back to you with a message that is randomly chosen from pre-selected assortment.

The message sent back as a result of the tweeters tweet.
The message sent back as a result of the tweeters tweet.
Watch as participants enjoy the fun of the towers internet enhanced capabilities
Watch as participants enjoy the fun of the towers internet enhanced capabilities






The tower is also a radio podcast player. During Liverpool and Manchester MakeFest the tower would play randomly selected podcasts including transmitting live podcasts that were currently being recorded at the Liverpool event.

The Tower was created in several different parts and then later assembled. The main stem is made up of 3 parts then the cornice is made up of two parts, one which is created as a support system and the other is indented with holes to show off the led lights, a ring for the windows and then the letter ring which individual letters that have been printed and then attached to a track of neopixel RGB LED’s which light up the letters from inside. The cupola, essentially the mid section of the head of the tower is also the container for the arduino and wifi sheild. The tower is completed by ventilation chimney and the advertising board and is all held together by gravity nails and a weighted base.  See here for more information of the process:

Shows the Cornice support structure in detail as well as the tower in whole and from above.
Shows the Cornice support structure in detail as well as the tower in whole and from above.


This took a total of 5 days and nights to complete the full printed parts.

This is the largest 3D printed product we have created. It was, in the end a fun and creative project that held many challenges such as creating the sloped hollow pieces as they needed support during printing to avoid any post processing and cleaning. The tower as it stands despite assembly, is how it came out the the printer.

Tower 02 Tower 05Tower 03



DoES Tower

Photo taken by Chris Huffee, using a pinhole camera created by himself at DoES

Other links to the project:

Krate & Co. approached DefProc looking for someone to laser engrave client images into their clear acrylic trainer boxes which would later be used for commercial purposes.

@Krateandco originally asked for 100 crates to be laser engraved, but due to the clients quota changing in total 140 crates where required. Def Proc was able to adapt easily to the new requirements.

Each crate was carefully produced in the same way for uniformity. Firstly the product was engraved with a specific image required by Asics, followed by a thorough vacuum to remove any traces of acrylic dust, wiped over with acetone and repacked in to Krate & Co’s protective bags.
You can watch the production of the laser engraving in the video below:

The initial product was to be used as a part of Asics Naked, Copenhagen in-store launch as a limited edition shoe box to encase the trainers.

Kate & Co were essentially pleased with the completed work and the samples were well received by all involved.

2D laserable outlines from 3D CAD solids


I’ve been creating in Onshape much more recently, even creating 3D models of items to laser cut. At some point though, I have to export the outline of the sheet shape, so the laser can cut the outlines, and I need to extract that from the model some how.

This is possible to do, depending on what software you’re using. While I’m sure the massively expensive commercial CAD programs have a workflow to support outline export directly, I mainly use either OpenSCAD or Onshape at the minute.


If I was using OpenSCAD, then a `projection()` of the model can be saved as an SVG to open straight into Inkscape, or as a DXF to import to the cut-file preparation program of your choice.

see also:


Onshape and FreeCAD

Onshape doesn’t have a projection tool that I’ve found at the time of writing, but it’s possible to take a model into FreeCAD that can be projected and exported to 2D.

While I’ve done this a couple of times, I don’t do it regularly enough to remember the steps, so this process is largely a reminder for me too…

  • export the part from Onshape as a STEP model,
    • Parasolid should work too,
    • but STL files are mesh, not solid, so they won’t project,
  • open the STEP model with FreeCAD,
  • switch to the Draft module,
  • select the solid that you want to project and choose the “Shape 2D” tool, this should make the actual projection,
  • hide the solid (right click in the menu and “Toggle Visibility”) to see the projection,
  • select the projection and “File” → “Export”
  • choose “Flattened SVG” and choose the name and location to “Save” to,
  • open the resulting file in Inkscape to check you have what you expect.

It still has the tendency to explode the lines, instead of keeping chain of lines for the outlines, so these might need recombining in Inkscape:

  • `Ctrl + A` to select all,
  • `Ctrl + Shift + G` to ungroup until the bottom bar shows all “objects” and no “groups”
  • `F2` to change to the Node tool,
  • `Ctrl + A` to select all the nodes,
  • click the “Join selected Nodes” tool.

Then all the overlapping nodes should be joined together.

Continue reading 2D laserable outlines from 3D CAD solids

Nerf Range and MFUKLC

Aside from the smaller “5-minute projects” that I do, I also like to do a bigger, display project each year to take to shows like MakerFaire UK and MakeFest Liverpool and Manchester. Last year’s was the internet connected train set. This year, it’s a full blown foam dart range, with scoreboard, countdown timer, RFID registration and a build-your-own lasercut challenge on top!

Outside of those events, the range and the train set are available for installs elsewhere. Please contact me if you’d like to see either at your event.

I’ve previously seen piezo sensor based approaches for hit sensing. Similar to knock sensors; but foam dart sensor specific such as Reactive targets for Airsoft and NERF™; which uses an earlier signal conditioning design ( link)

While I had been planning on doing a smaller range as a DoES Liverpool project (a makerspace filled with freelancers seems to do fewer group projects compared to hackspaces peopled by hobbyists), it all got a little out of hand after two symposia in one day.

With a lunch time UK Maker Belt Association (UKMBA) lunch (in a pub) and an Open-Source Hardware User Group (OSHUG) event in the evening, followed by going to the pub afterwards, and it all culminated in a challenge to build laser cut device to fire foam darts, ping pong balls or ball pool balls called the Mega Fun UK Lasercut Challenge (MFUKLC) where all the entries had to be open source.

That gave me both a deadline to finish, and a challenge to create a range that could cope with recording up to 10 hits per second, per sensor for a 30 second period.

Designing the Hardware

This might give you a nice idea of how we approach a project normally. As a first step, I needed to break down the big goal of “make a nerf range” into a number of smaller areas and tasks that I can do one-by-one to build up to the whole at the end.

First up was outlining the electronics and control structure.

You might notice chief noise-maker of .:oomlout:. with me in the video!

The result of this planning was then a series of modules communicating by serial, which would be controlled by a central, control module.

  • Control Module — Arduino Mega (for multiple serial ports) listening for the RFID reader, start button press, and running the status light in the button, sending commands out to the others, and reading results.
  • Target Module — An Arduino Mega (for the number of ports) that makes quick scans across the 16 piezo sensors to count any hits, record the data locally to SD card for analysis later, and count the score to return to the control module.
  • Timer Display and Scoreboard — 3-digit and 6-digit LED displays respectively (using Matt Venn’s big-7-seg displays) that will display a countdown or show the score. Using almost identical code, these displays can display static figures or 1/10 second countdown depending on how they are instructed.
  • USB Serial — to allow the control module to report the score (and RFID identifier) back to an external computer at the end of each go, so that can be sent automatically tweeted to the competitor.
Controller Layout
]7 Controller Layout

Open Source

Unlike some projects that claim to be open source “at some date in the future”, the files for the range and the entries for MFUKLC are all available right now at under MIT licence. You can recreate any and all of the parts of the range, control module, enclosures, circuit boards, entries, etc. as you like.

Just to point out that although the range was specifically designed to use Nerf products (and we use Nerf Jolts for competitors) it is not affiliated with Nerf or Hasbro in any way, and is not limited to Nerf products. It works equally well for any foam dart weapon, for even ping pong ball or ball pool balls!

SSL certificate and CSR generation

SSL certificate and certificate signing requests have been causing me some trouble over the last few days; and as I have it all sorted, but will need to do it all again in a year’s time: here’s the process I used.

I’m just looking to generate a certificate for a single subdomain at a time, from the linux command line for use on a server (actually a Digital Ocean droplet), where I have root access. This means I can generate private keys locally, and not have them leave the server where they’re generated and used.

For SSL you’re looking to make three files:

  • A private key that your server will use to make the https connections This should not be disclosed.
  • A certificate signing request csr that you generate from the key and send to the ssl certificate provider. This includes the public form of the private key.
  • A certificate crt back from the ssl certificate provider that will respond with. This is used by the server to ‘prove’ that the private key comes from the entity that it claims to.

Continue reading SSL certificate and CSR generation

Hire us to Make your Project

We proudly work with mostly small businesses, individuals, artists and designers, making prototypes and small run productions of their ideas. While established businesses may have contracted many times before, it can be a daunting thing to present your idea to someone else and ask them to make it.

So, to try and make it easier, here’s the steps we’d expect to go through when you contact us:

  1. talking through your project,
  2. offering tangible outcomes,
  3. accepting the contract and initial payment,
  4. production,
  5. presentation of the result,
  6. final payment.

Continue reading Hire us to Make your Project

It’s a Cracker

It seems like a kind of tradition to do a 5 minute project for Christmas. Last year’s cheertree is back up in DoES Liverpool and has now been extended by MCQN to draw pictures on the front of FACT. And it’s also running the christmas tree lights in my house. This year it’s crackers, and inspired by cracker’s already being die-cut from flat sheet, and there being no designs ready for me to download and cut my own crackers, I’ve created one.

laser cut cracker
It’s a cracker

While I’ve included laser scores along the length — to make it easier to roll across the grain of the craft card I used in testing — they can be removed to give a circular cross-section (although it does give a slightly low-poly, new æsthetic look). Because the crackers are still completely flat after cutting, they’re ideal for decorating for completely customised decorations. They could even be cut from pre-printed card; the world is your bivalve.

I’ll be cutting a number of these this year, and printing some low poly christmas trees from Faberdasher (and maybe a polar bear or two), and perhaps printing jokes in the style of to go inside them for the DoES Liverpool Christmas party this year. Cut files available at: Some assembly required, and some cracker snaps:

  1. Place a cracker snap along the length and stick down at each end. Depending on the length, this might need trimming to fit inside the cracker, but should lie flat.
  2. Roll the cracker and push the tabs through the respective slots.
  3. Tie one end with a ribbon.
  4. Fill with your cracker prizes (bad jokes, plastic tat and a paper hat are traditional).
  5. Tie the other end with a ribbon.
  6. Profit.

A Fully Parametric Hob Knob

It’s a user generate-able knob to operate a stove-top hob, rather than a fully configurable biscuit — sorry!

When you move into new rented accommodation, there are all sorts of challenges that aren’t obvious from the initial viewing. But one that I did know about from the offset was that my new cooker and hob were devoid of knobs to turn them on and off! “No worry,” I thought, “I’ll just 3D print some at DoES Liverpool, surely there’ll be some on Thingiverse that I can just print and fit.”

Cooker fittings seem to be an area where there aren’t any engineering standards whatsoever so in the spirit of rapid prototyping, I printed a selection of 4 knobs to find out what things I didn’t know that I didn’t know about cooker knobs. As none of them fitted exactly and there wasn’t one I could easily modify, I set about creating my own, and as I had 2 different fittings to design for, the easiest approach was to make it a all fully parametric model so one file could generate both the shapes I needed.

round knob
Rounded oven knob with 2 scollops

This design should fit any D-shaped shaft, so it could be used for any hob, stove, oven, grill, range, volume, potentiometer or rotary encoder knob.

If you want to make your own Hob Knobs, you can visit Thingiverse to customise your own, or download the latest hob_knob.scad file from Github and adjust the measurements according to your installation:

  • the required height of the knob from the surface (height),
  • the diameter (shaft_diameter) and distance across from the flat of the D to the rounded side (D_width) of the shaft (printing clearance is added for a tight sliding fit(clearance)),
  • the outer diameter of the knob (outer_diameter),
  • the inner clearance diameters of any seals that it needs to clear up and over, and set the wall thickness of the knob (wall_thickness) so that \(outer\_diameter – \left( wall\_thickness \times 2 \right) \ge inner\_diameter\)
  • the visible height of the shaft (shaft_length),
  • any plunge depth (plunge_depth) if the knob centre should drop below the fascia.
  • the height required for the internal structure to clear any seals (clearance_height)

You should also choose:

  • the number of sides to the outside of the knob (no_sides) ­— the default is a low-polygon style 9-sided design, but 250 sided will give you a very circular knob,
  • the size of any chamfer on the top (top_chamfer)
  • if you want a pointer to show position on a dial (with_pointer)
  • the size of the pointer (point_size)
  • the number of degrees clockwise that the pointer should be away from the normal direction of the flat of the D (point_angle)

Extra features:

  • if you want extra features (extra_feature) such as scolops around the edge, tap-like extentions or a cutaway view
  • the number of those features (number_of_features)
  • the number of degrees offset anti-clockwise for those features to rotate them round into a good position (offset_angle)
4 hob knobs in situ
Selection of hob knobs