Wednesday, 30 December 2015

Ghostbuster's Gigameter LED display

Thomas Lemieux (aka The Iron Man of Maine) asked me if I could help with the electronics for the Ghostbusters Gigameter. Video of it from the film is hard to come by, but it looks like this:

There is not much documentation about it on the web.There is a a 3D printable version at:

The electronics are pretty hard to come by though.

Thomas was a big help with my Proton Pack Design and helping him out was no problem.

I'm a Microchip PIC guy by trade. But these need access to limited compilers and proprietary programming hardware to make them work, and so I decided to go with a cheap (<$4) Arduino Nano clone. This is my first Arduino project.

I'm driving a pretty specific common anode display that I got from AliExpress. But the software is designed to make changing the pin drives very easy.

As it was a rush job, I never formally built it up, but tried it out on a breadboard:

The software picks a target value from 0-999 (unless its the same as the current value) and rapidly displays the current value as it seeks towards the target. As the current value approaches the target value, the count rate slows.

Here is a video of it in action:

And the software is available at:

Sunday, 29 November 2015

I shall call him: Mini Me

I was at Oldham Library and Lifelong Learning Centre with Hack Oldham for the monthly 'Hack the Library' meet up.

Basically, it's a geeky get together to show the public what the Oldham Makerspace is about.

We got to use the library's Vex IQ robotic system.

And we used the Hack space's Cubify Sense 3D scanner to introduce local kids to the technology.

As the owner of a Mendel90 it seemed rude not to get a scan of myself. One of the members decided it would be a good idea to film the process:

This results in a .ply file which contains the 3D information and textures:

It can be viewed in Meshlab, and exported as a .STL file for printing:

I normally use Skeinforge to slice .STL files, but I always seem to have trouble getting it to create support material. For this print I use Slic3r which I set to use a layer height of 0.2mm. My Mendel90 has a 0.4mm extruder nozzle and I have never used such a small layer height before, but I was not disappointed:

Sunday, 15 November 2015


I have been thinking about getting a quadcopter for some time, but I didn't want to spend too much money. After doing some research, I decided upon the JJRC H12C. I ordered this from the UK via EBay for £48.29 delivered.

Being a total novice flying these, I was worried how long I could keep it in one piece. I was amazed though how easy it is to fly, after a few practice runs on the local playing field I was totally at ease controlling it.

Included in the price are: 1) The quadcopter. 2) The remote control. 3) A 750mAh battery. 4) A 1080P still/video camera.

I was very sceptical about the quality I would get from the camera, considering the total price of the package. But it completely exceeded my expectations. It is very susceptible to rapid changes in lighting, but for the money it is amazing. Here are some shots I took whilst flying around Foxdenton Park in Chadderton.

The controller allows you to remotely take a still photo or start a video at the press of a button. The videos with the camera fitted out of the box suffer from 'jello'. Wobbly lines on the picture. This is caused by the camera shaking about on its mount:

The simple fix for this is to force a small piece of foam between the camera body and the quadcopter. Doing this almost eliminates jello, as this shot with a DJI Phantom in the air at the same time shows

The remote control is not of the highest construction quality, but for the price it feels great. I bought a First Person View (FPV) kit from BangGood. This is a 720P still/video camera with a live feed to an included LCD display. Allowing you to view in real time what the camera is seeing.

As supplied, the LCD monitor does not fit to the remote control. So I designed a 3D printable clamp to allow it to fit:

This is available for download on Thingiverse.

Although I have no prior experience flying quadcopters, I cannot recommend the H12C highly enough. I've had loads of fun flying it, and even after a few rough landings it's going strong. If you want an outdoor quadcopter, seriously consider this one. It is easy to fly, spares are available and for the price it is superb!

Tuesday, 18 August 2015

On the range

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Just spent a couple of hours on the range at Arkansas Armoury.
A really friendly place for inexperienced shooters such as myself. I particularly enjoyed the Glock 17 and Springfield 1911.

Tuesday, 21 July 2015

Arcade Club

I joined Hack Oldham last week which is only 15 minutes drive from my house. After chatting to a few of the people there I found out about Arcade Club.

It's 40 minute drive away, and is a video arcade with 100+ video and pinball machines from 1979 ish onwards. There is a flat entrance fee of £10 (£5 for kids) and all games inside are free to play, with a drink and a cake are included in the price.

If you are in the north of the UK, definitely worth checking out the Arcade Club website. I dragged my kids along and exposed them to the games of my misspent youth. 'But there's no story!'. L1tt13 5h1t5.

Pyro Box

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Some weeks ago I completed the 'Pyro Box' for Steve at Operation Lasertag.

It's more like a 'defend the hill' than the normal DomTube 'king of the hill' style game.
The box is assigned to one team, whilst the opposing team needs to attack the box. A digital display shows the box 'health' and a clear, 3D printed light bar is used to indicate hits.

Each opposing team hit reduces the box health by the shot power, and when it reaches zero an explosion sound is played. In addition, there is a wired output to drive a squib so a pyro can be activated. This is connected via the push terminals at the front. Internally, a radio transmitter sends a signal to a remote receiver that can also drive a pyro, allowing a safe distance between players and effects where required.

In addition, the box can be configured so that the defending team can 'repair' the box by shooting it, which adds their shot power (or half their shot power as a switched option) back to the box health.

The control panel is formed from laser cut 6mm acrylic and is mounted in an IP65 box with a carry handle.

Don't have a video of the complete unit, but here is a proof of concept run on the bench:

Sunday, 26 April 2015

Maker Faire UK

This year I was lucky enough to take my family to the Maker Faire UK in Newcastle. My local hackerspace (Hacman) were exhibiting there.

There were many more exhibitors than my local mini maker faire. With some big name shows:

The Humane Machine by Johnny White was a definite crowd puller. I particularly liked the way he made gears out of ice:

I was assuming he had used a prime number of cogs to mininise wear when I realised that this was an art installation and had probably not considered longevity:

There was a stand with a vac forming machine that had a long queue of people assembling their messages from letters:

A jewellery making booth allowed visitors to twist copper wire into strands and add beads to make their own gear:

A barbot dished out (none alchoholic) drinks. I need to make myself a (modified) version of this.

Pretty much something for everyone. Sewing for the girls:

And Robot Wars for the boys:

Beauty by the geeks had a popular stand where the kids could mush stuff up and find out about DIY beauty products

I got to play 1D pong with my oldest which was much more fun than I expected:

A 3D printer with a chocolate extruder brought on excited questions about modifying my printer from the wife:

A remote controlled hexapod robot:

Which shot foam darts into the audience:

This stand had a digital zoetrope with individual LCD panels for each element of the animation. Of course they could be uploaded with different images to allow the animation to be changed:

This guy had made amazing bearing runs from hand soldered copper wire. I failed to get video of this, but goodness knows how long it took to perfect:

Much to the delight of my 7 year old there was a chap doing a bubble extravaganza...

This stand had some kind of analogue audio system that sounded quite good:

My local Hackerspace (Hacman) were exhibiting. An unrepeatable shot of my proton pack with a Dalek in the background,,,,,,

Bertha made a guest appearance on this stand..making me realise I need to dig out the DVD and show it to my youngest.

Most kudos go to 'Litre of Light' who showed that a simple soda bottle filled with water could be re-purposed into a practical interior light:

And inside....

Saturday, 4 April 2015

New Toy. 50W laser cutter.

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I've had one of these in my sights for a while now. And I came into enough cash to allow me to buy one. I ordered from AliExpress rather than ebay, as the price seemed better.

It arrived last week via DHL. Well packed but delivered by Mr. Grumpy himself:

It's slightly bigger than the cheapest that can be bought with a cutting area of 400x300mm. As a 2015 model, it comes with accessories that would previously have to be purchased separately:

An air assist laser head and air pump. This helps to extinguish flames and generally blow unwanted smoke away from the laser head:

A digital control panel, thoughtfully worded in Chinese and English:

A Z adjustable cutting bed.

A honeycomb bed. This reduces the amount of heat transferred away from the underside of the work piece during cutting, and also allows the extractor fan to draw down any smoke:

In typical cheapo Chinese fashion, the honeycomb was not flat, with about an 8mm delta from corner to corner. I solved this by drilling M4 holes in the corners that were raised, and drilled a 9mm holes on the upper side of the frame to allow screw heads to pass inside the frame. I then drilled and tapped the Z bed to M4. This allows me to screw the corners onto the Z bed, forcing it to be flat.

It's also supplied with a water pump to cool the laser tube. I got a 32L box from Wilkinsons and drilled two holes in the top and filled it up with 25L of distilled water from Halfords.

Distilled water is required to stop any impurities in tap water from depositing inside the laser tube. This could cause hot spots. I also added some propylene glycol to act as an anti bio/freeze agent.

Included with the package was a rotary axis to allow the engraving of cylindrical pieces:

Most impressive is the laser tube itself, glass with a helix! Covered in cautions written in Chinese. No doubt recommending not staring into beam with remaining eye.

The software was supplied on a DVDR with a USB dongle. Not entirely sure if this is legitimate or not. However, once installed, it works as expected. There is a plugin for CorelDraw included on the disk which seems to be the most useful of the bunch, providing direct access to the laser cutter from CorelDraw.

The main issue with these budget laser cutters is the alignment of the mirrors. This image from LensDigital shows the laser beam path:

At assembly, they only seem to centre the laser tube on mirror 1. The user is expected to align everything else. I followed this video, and got everything aligned in about 40 minutes.

So with a day of tinkering behind me, I've managed to create a gear with the excellent, free Gear Generator and import a SVG file of a gear and cut it from 6mm acrylic. This has some random lines on it due to my inability to set the feed rate correctly, but still impressive:

A really nice feature of the cut is that it leaves no blemishes on the edges. A cut with a jigsaw would require treatment with a solvent to get this clean: