Planet Nottinghack

28 August 2015

Martin Raynsford hackergotchi for Martin Raynsford

LRP Safe Pipe Wrench

Things were a bit hectic last week before Vale so I don't appear to have any construction photos of this item but it's 5 layers of lasercut LD45. The nut was made by wrapping a detailed piece of foam around the bar. The whole thing was plasti dipped instead of latexed so it came out a bit harder than desired but it's not like I actually get into combat at these things anyway.

by (Martin Raynsford) at 28 August 2015 04:23 PM

27 August 2015

Martin Raynsford hackergotchi for Martin Raynsford

Large Stellated Dodecahedron Corner Test

Andy from Travelling Light Circus saw my stellated dodecahedron at Manchester Makefest and he decided that he wanted a much bigger one. So I got to work straight away proving that I could make a corner joint for a star that was 4 times bigger. I used a 3D model to figure out what the angles should be and I used button hex bolts to reduce the amount of tinkering members of the public could do to it.

I used a T-Slot joints to hold the stars onto the framework. One thing that has always bugged me about T-Slots is the way the nut can fall out of the slot, to overcome this issue I made the nuts captive with another piece of wood. The nut outer is glued into place in the T-Slot so there is no way the nut can fall out, particularly useful when the joints are going to be at all sorts of funny angles in the star.

by (Martin Raynsford) at 27 August 2015 10:52 PM

26 August 2015

Dominic Morrow hackergotchi for Dominic Morrow

rustic apple boxes – making laser cut things

For too long I’ve thought and talked about doing some posts of things I’ve made. After all my blog IS Continue reading

by chickengrylls at 26 August 2015 05:36 PM

24 August 2015

Martin Raynsford hackergotchi for Martin Raynsford

Vale Resource Storage

This is the third iteration of resource storage for Vale LRP. This time round I built enough storage for all 4 types of material and added some extra space for coins and mana. The 4 large trays are specifically designed to hold each type of resource, each with 5 columns because there are 5 different resources of each type. They all sit on top of a tray which has a lip to hold them all together, also in the tray are 15 separate compartments which can be used to hold the different kinds of mana and coins (crystals) which are used in the game. 

I initially wanted to build them all into their own box and while I'm not ruling that out at the moment the box would need to be sturdy enough to have someone sitting on it and that's the part I'm worried about.

by (Martin Raynsford) at 24 August 2015 03:09 PM

23 August 2015

Martin Raynsford hackergotchi for Martin Raynsford

Card Sphere Sculpture

I was inspired by George Hart to make some kind of large sculpture that could be assembled at a maker faire maybe with half a dozen people helping to build it. I designed this one on a 3D model, it's made from 60 identical pieces that all interlock. The main issue is that it doesn't take photo easily. We went to Manchester Makefest and made one from corrugated card that was 5 times larger, it took most of the morning to assemble, we made a second one that was a mirror image but then we lost all the photos we took of it. If you were at Manchester Makefest and you happened to get a picture then we would love to see it, otherwise this is destined to remain a single dull post.

The sphere itself was pretty easy to build (even with a hangover), I'll happily share the file if people are interested. If I were to do it again I would try to find away to add another linkage between the parts, this whole thing feels a bit like a ball within a ball and it could do with a few more structs between the inner and outer sections. 
Due to requests I've now added files and pictures, I've included the PDF too because this thing could be cut with scalpel and scissors. (svg here, pdf here)
60 of these go into a full sphere

by (Martin Raynsford) at 23 August 2015 10:04 PM

20 August 2015

Martin Raynsford hackergotchi for Martin Raynsford

Vale Maps

These were very handy at the weekend just gone. It's a map of the quarry we play Vale LRP in, we added named locations so that everybody looking at the map was talking about the same location. It was actually really handy and I'll be making some more of them in the near future.

by (Martin Raynsford) at 20 August 2015 07:11 PM

18 August 2015

Martin Raynsford hackergotchi for Martin Raynsford

Pendulum Test

This was a quick test piece I made for a pendulum. A project I'm working on requires an easy to assemble free swinging pendulum of a fixed length so I did away with the string and put a pin in as the pivot joint. It's pretty free swinging but I'm not sure if it's good enough yet.

by (Martin Raynsford) at 18 August 2015 08:25 PM

14 August 2015

Martin Raynsford hackergotchi for Martin Raynsford

Scale Mail gauntlet

A non laserable in preparation for an upcoming Vale Event. This Scale mail gauntlet is made up of 200 individual metal scales all weaved together with 400 smaller split rings. It's a pretty cool piece especially considering I had the bits floating around in the garage for several years now. Scale is definitely harder to make than chain but looks prettier.

by (Martin Raynsford) at 14 August 2015 07:33 PM

13 August 2015

Martin Raynsford hackergotchi for Martin Raynsford

Clarkcade Keyrings

After the cabinets came the keyrings, neither of these was the winning design but they're both pretty close. As I didn't take a photo I guess you'll have to see Simon at an event to find out what the final design looked like.

by (Martin Raynsford) at 13 August 2015 07:25 PM

12 August 2015

Martin Raynsford hackergotchi for Martin Raynsford

Don't forget your knifebed

Most laser cutters just come with a honeycomb bed, the honeycomb offers lots of support to the material you are cutting but numerous vertical slats offer lots of chances for bed reflections also if you cut right to the edge of the honeycomb you're cutting on sheet metal which can leave a sticky residue under your work.

All Sharks machines come with a honeycomb and a knifebed; the knifebed is usually stored under the honeycomb because lifting the honeycomb up prevents smoke from being trapped under it. While I was cutting some more Clarkcade gaming cabinets I realised that I should be using the knifebed instead of the honeycomb. It's perfectly suited for this kind of job where the panels are much bigger, All the shrapnel falls through the gaps allowing me to put the next sheet on without even cleaning up and the cuts were all much cleaner due to the reduced number of reflections.

6 new Clarkcade Cabinets ready for postage

by (Martin Raynsford) at 12 August 2015 07:19 PM

11 August 2015

Martin Raynsford hackergotchi for Martin Raynsford

Mother of Pearl

Just Add Sharks gets a lot of new material requests, the result is usually the same, send us some material and we'll try it. So this weeks new material is Nacre, better known as Mother of Pearl. Like leather it makes quite a smell while cutting but I was able to get through 1.5mm relatively easily. I think it's going to be used for guitar inserts.

by (Martin Raynsford) at 11 August 2015 10:44 PM

09 August 2015

Matt Little hackergotchi for Matt Little

RPM sensor

Monitoring the rotational speed of the wind turbine blades can help with power performance measurements.

This post shows various techniques to measure the rotational speed of a 'wild AC' output small wind turbine. In this system, the wild AC is rectified into DC and either delivered to a battery or to a grid-connected inverter.

The wild AC output of the turbine can be used to give us the rotational speed.


by (Matthew Little) at 09 August 2015 10:46 AM

Derby Silk Mill - Maker in Residence

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From November 2014 until May 2015, I have been one of four "Makers in Residence" at Derby Silk Mill, in the UK.

This has been a slight change of activity for me, as I usually focus on renewable energy systems, but has been a great opportunity to encourage Science, Technology, Engineering, Art and Mathematics (STEAM).

I hope to encourage the younger folk (and all ages!) to get involved with future engineering and technology issues.

I kept a separate blog of my work at the Silk Mill, but here are some details of the work I have done here.


by (Matthew Little) at 09 August 2015 10:45 AM

06 August 2015

Martin Raynsford hackergotchi for Martin Raynsford

Amazeballs at Makefest

Manchester Makefest is going to be running this weekend and one of the collaboration projects they're attempting to run is Amazeballs. Several people build modules that contain marble runs for 27mm pinballs, the modules are brought together at the faire and the machine all works (in theory).
Marble machines being kinda my thing and a desire to help people with interesting ideas Just Add Sharks ended up signing up to make 2 modules for the machine. Dominic has made one and here is my module.

My first attempt to make something fancier failed completely, the balls are pretty big and heavy and sheer momentum was smashing the machine apart during testing so I went back to the drawing board and came up with this passive machine. The 68mm drop between start and finish isn't a lot to work with but it is possible to make something interesting that can run that length.

by (Martin Raynsford) at 06 August 2015 01:54 PM

03 August 2015

Martin Raynsford hackergotchi for Martin Raynsford

Superman Cosplay Belt

A quick item I managed to squeeze in amongst a busy week. This foam piece is destined to become a belt buckle for some superman cosplay, possibly to do with the new supergirl series starting soon. 

by (Martin Raynsford) at 03 August 2015 10:19 PM

02 August 2015

Steve Barnett hackergotchi for Steve Barnett

SpeedTwin Update

Recently I’ve been focussed on finishing off my radio controlled model SpeedTwin ST-2. This guy is not the biggest model I’ve built in terms of wingspan, but it wins in terms of chunkiness and complexity. I started it in 2012, but it stalled at some point because everything was blocked by scary “one shot or it’s ruined” style tasks. I recently dug it out and decided to get these things over with so I could get it back on track.

This thing is pretty huge!

The fuselage was stalled as the servos and radio receiver needed fitting before any progress could be made, as they would soon be difficult or impossible to access. After fitting the servos I coated a sheet of 1/16th balsa with epoxy and stuck it to another block coated with tape, shiny side out. Once the epoxy was dry the taped sheet was removed leaving a perfectly smooth surface which the receiver could be stuck to with double sided foam tape. I glued this mounting to the side of the fuselage with a few balsa rails so it could be easily removed if necessary but was still securely fitted. This was mounted behind the canopy area in a spot that was still accessible while being as far as possible from interference from the battery and speed controllers. This location also provided a convenient spot to mount the antenna vertically.

Receiver and Antenna Mounting

With the servos and receiver installed the decking on the rear of the fuselage could be added. This is designed to form a skin over the formers and spine of the fuselage and give it the correct final shape without having to use excessive material or sand material away. To fit this I first figured out the best way to have the grain match the curvature of the surface and cut some 1/16th balsa to shape. After a few test fits this was glued where it meets the fuselage sides and left to dry. It was then curved around the formers and glued a bit at a time to avoid overstressing the material. Despite this a crack formed at the very rear. I was able to fix this by glueing and pinning it in place and sanding it smooth later. Once this was glued on I cut the sheeting down the centreline and repeated the process for the second half.

Fuselage before decking Glueing the decking Decking half finished

With the rear of the fuselage essentially finished I moved on to the front end. The nose was built up from blocks of 1/2 and 1/4 inch balsa which were glued on and then sanded to shape. This process requires a lot of sanding allows for nice curves to be shaped easily. The canopy was built in a similar way but from a block of blue foam glued to a balsa base. The foam was shaped to the correct profile with my hot wire cutter and then sanded the rest of the way. A 1/64th ply windscreen section finishes it off. The canopy base has some rails glued to the bottom which locate into the opening on the fuselage. The canopy is then held in place with a dowel at the back and will eventually have a catch installed at the front.

Nose blocks and canopy base Canopy foam Nose after sanding

At this point the fuselage was basically finished except for the covering. I decided to use a lightweight fibreglass technique for this with 25gsm glass cloth and water based polyurethane instead of epoxy resin. An internet search will provide plenty of good instructions on this process so I won’t expand upon it here.

Glassing the fuselage

With the fuselage out of the way there still remained a lot of work to be done on the wing.

Unfinished wing and fuselage

First the leading edge of the wing (formed from a strip of pre-shaped balsa) was glued on to the front of the wing and sanded to match the wing’s taper. With this in place I was able to locate the wing in the fuselage and measure from the tips to the rear of the model. Once these measurements and the measurement from each wingtip to the fuselage matched I was convinced the wing was aligned correctly. I drilled a hole for a locating dowel into the front of the wing through a hole in one of the formers and another hole through the wing so it can be held in place by a nylon bolt. The dowel and bolt will provide a secure and repeatable fit for the wing (but hopefully the nylon bolt will break instead of the wing in the event of a crash).

Wing locating gubbins

The next part of the wing that needed attention was the engine nacelles. The original has huge engines hidden inside bulbous nacelles which needed to be recreated (even though my motors are relatively tiny). I chose to use the designer’s recommended method for this which is to plank the nacelles by glueing strips of wood over formers, with some foam parts where the curvature made this impractical. I decided to build these in two parts with the upper part permanently attached and the lower part removable in case access to the landing gear mounting points was needed later.

Strengthening the nacelle structure The planking begins More planking Upper nacelles before sanding Lower nacelles Lower nacelles with foam parts Cutting foam nacelle parts New hot wire cutter More filling and sanding needed Before and after sanding Finished upper nacelle

During this process I ended up making a second hot wire cutter for making parts that needed square edges (at least before sanding) and for parts that needed a consistent thickness. This consisted of a frame made from an old speaker cabinet with a hole drilled in the centre. A screw inside the hole mounts the bottom of the hot wire which runs to a similar hole at the top. The top of the wire is mounted to a spring (for tension) attached to a block which can be moved about and clamped in place. Spacers under the block that holds the top of the wire allow adjustment of the sprint tension. A thin strip of wood attached to the table with a smooth shank screw makes a fence which can be clamped in place to cut parts to a consistent thickness.

The planking was slow and tedious but performed in short bursts – adding a few strips and leaving the glue to cure while doing something else. Unfortunately I wanted to build the upper nacelles first, so the removable section could be built to fit them. I learnt partway through that using softer wood was better for this process and the lower nacelles came out nice and smooth with just sanding. The upper nacelles made from harder balsa required quite a bit of filler and some reinforcement from beneath to get them nice and smooth.

Landing gear mount Landing gear Nacelle front block

My motors will fit on the front of the part of the nacelles shown above, with an extra bit of foam that will be sanded to shape to hide the motor and provide a nicely shaped front section to the nacelle.

Once the nacelles were built I installed the landing gear struts using some P shaped clips made from brass. These were made by folding brass strip around the landing gear wire using a vice, drilling a hole in the correct place then trimming them to size. This allowed the struts to be bolted to plates attached to the underside of the wing. A hole had to be cut into the lower nacelles in a suitable place for the strut to fit through, with some clearance to avoid damage if/when the wire flexes. Cutting these holes was a bit nerve wracking after spending so much time on the nacelles, but after measuring several times I was able to hit the correct location first time (with some extension of the holes to fine tune the fit).


Finally the wing tips were cut from from blocks of balsa, roughly shaped and then attached and sanded to their final shape.

Once the wing was complete I did several passes to check for dents and other issues (which were fixed up with filler) before glassing it in the same way as the fuselage. The nacelles were glassed first followed by the rest of the wing, with cut outs around the upper nacelle area to avoid the extra curvature causing problems.

Glassing the fuselage added about 30g to the fuselage (which originally weighed about 235g) and 50g to the wing, which originally weighed about 495g. This is not a problem and well worth it for a sturdy finish. As the numbers show, most of the weight and complexity of this model is in the wing since it’s a twin engine design.

This brings the project pretty much up to date, and all that remains is the last 10% which will probably take 90% of the time!

by moop at 02 August 2015 07:59 PM

01 August 2015

Martin Raynsford hackergotchi for Martin Raynsford

Family Tree Paper Cutout

It wasn't just bunting I made for Nan, I was also encouraged to make a present too, Kim pointed me towards nice family trees, went out and hunted a picture frame and even bought me black card. I just drew and cut and assembled. The black silhouette is a fairly standard card cut out, but I replaced the mdf backing found on most frames with a perspex backing to make the frame see through and the whole thing pop out.

by (Martin Raynsford) at 01 August 2015 08:45 PM

31 July 2015

Iain Sharp

Fixing the cutest proper scope – Sincair/Thandar SC110A

When doing some research on the web about my Philips X.40 electronics teaching kit I found out about the contemporary Philips EE2007 kit which had a battery operated CRT for the teenage nerd to play with. Just how cool is that? Even as an adult I immediately wanted something similar. The schematics of the EE2007 CRT module are easily available and I thought about building a clone using modern components but, to be honest, I am a bit of a scardy -cat when it comes to high voltages and I didn’t fancy getting to grips with the HT supply. Like so many others the project went on the back-burner.

SC110A Photo

The original eBay photo – looks OK

Recently though I was thinking about upgrading my boat-anchor oscilloscope (it’s a 1980s(?) high-spec Hitachi hybrid analogue/sampling scope which is a joy to use but massive and very limited by today’s digital standards) and I thought I might be able to get a second hand modernish digital scope on eBay without spending too much. I didn’t find the ideal match there, but I did see a Thandar SC110A miniature analogue scope. It was love at first sight – a battery powered scope in a small, smart enclosure that matches my function generator which is always on my electronics bench. Some people find kittens cute but, for me, this dolls-house scope with its tiny 4cm diagonal screen just makes me feel all squeeeeeeeeeee. In XY mode I could use it like the EE2007 CRT but with added convenience of calibrated amplifiers and a timebase (no intensity input though).

The scope was described as working but I was always sceptical because eBayers are often economical with the truth and anyway not many people would know how to test it properly. Without being cheap it was at a price that I was prepared to spend for a bit of fun so I bought it expecting I would have to do some remedial work. When I got it there was good news and bad news. Good news was that you could get a “bright line” trace with no signal and most of the functions seemed to do vaguely the right thing. Bad news was that the display had awful distortion and freaky interactions between the X and Y axis. Also some of the input ranges on the Y axis didn’t seem to work. Time for fault-finding and recalibration using the handily supplied service manual.

To do the calibration you turn the scope upside down and take the bottom half of the case off which exposes the main circuit board and calibration controls. Once inside you see that the circuit board is actually branded Sinclair so you will understand if I was suspicious that it could ever be made to work properly at all. In fact Thandar and Sinclair seemed to have cooperated on several test instruments. Sinclair seems to have picked up the case mouldings from Thandar and Thandar sold several Sinclair instruments under their own brand (brave decision). This design seems to have originated in Sinclair and the CRT, as we will see, was custom made for Sinclair for their microvision pocket TVs.


Ready for repair

Ready for repair

The mark of the devil


When I powered the scope up to calibrate it I realized that it had a fault that I had never seen before in any device. It worked, to an extent, the right way up but when you turned it upside down the trace disappeared and the whole thing seemed dead. I spent a long time turning the machine one way and then the other trying to find out where the thing stopped working and where the fault might me. Eventually I heard a little tinkle that seemed to come from inside the CRT which alerted me to the real cause. Sometimes electronic debugging involves all your senses. Removing the screening foils and looking inside the CRT I found that the glass supports holding one of the Y axis deflection plates and place had broken it the electrode was just flopping around – coming in to contact with other electrodes when the scope was turned upside down. Humm – eBay seller was dodgy on that one IMHO. Still, at least we have a plausible explanation for many of the problems.

Now, where do you get a custom made Sinclair CRT from in 2015? A few specialist shops had them listed at silly prices and were out of stock anyway. Then I had an inspiration – my searches had told me that the Sinclair Microvision TVs used the same tube so perhaps I could get one of those and cannibalize it. Back to eBay and, yes, there was a suitable Micovision for sale at not too high a price.

While waiting for the Microvision to arrive I did the best to fix the other problems working with the dodgy tube. To do this I had to strip the case off completely so I could run it the right way up and still access the controls. As a matter of routine I decided to replace all the polar capacitors (tants and electrolytics) in the design. It has a switching power supply which is nice and compact and gives it a very wide tolerance of supply voltages. In my experience switching power supplies were pretty rare at the time so this might have been a brave design. Normally in test equipment you see a lot of effort going in to conditioning the power supplies with great big capacitors to smooth them. In a sign of classic Sinclair cost-cutting the biggest supply capacitor in this scope is 47uF. It seems to work well enough though.

Next I turned my attention to the dead ranges on the Y Axis. . I spent a long time investigating possible faults with the switch or problems with the Y input buffer. In fact I should have checked the obvious. There is a “DC Offset” trim which needs to be set right to get the input buffer working correctly on all ranges. RTFM applies here.

After a few days my Microvision arrives in the post. I have to say it does look like a proper gadget and must have been quite a cool thing when it was new. As far as I can tell, with no suitable source for a modulated analogue TV signal available, it worked fine. Inside it’s in good condition and there is a surprising amount of space in the case. I feel a bit bad about whipping its tube out and swapping it for the broken one from the scope but I reckon it’s better to have one useful device that works than a TV that is no longer usable in the digital era.

My Sinclair Microvision

My Sinclair Microvision

Interior of Sinclair Microvision with the precious tube

With the new tube in and the polar capacitors replaced the scope is working a lot better. Almost everything seems fine except that the Y signal is still very distorted. My fear at this stage is that the shorted electrode in the old tube has damaged some components in the Y amplifier and it’s going to need a lot of debugging and component sourcing to sort it out. In a moment of inspiration I wondered if looking at the lissajous figure from feeding the same signal to X and Y might be useful to understand what was going wrong. Instead of the expected straight line I saw a very definite knee – like some part of the amp was saturating. It turns out that setting up the calibration for the Y amplifier involves two interacting gain controls. The previous person to set this up had set one way too high and the other way too low forcing the amp in to saturation and clipping. Once both had been reset to near their midpoints the amp worked just fine. To be fair the service manual doesn’t explain how to set these controls very well and it requires a bit of electronics experience to know what you are supposed to do.

Aren't they cute?!

Aren’t they cute?!

With the Y amplifier recalibrated everything now works very nicely. Technically it’s certainly not a great scope but its simplicity is lovely. The tiny size is very practical. I like the immediacy of analogue scopes. You interact with them much more by intuition rather than digital scopes where you have to think. For answering the eternal electronic engineering question, “do I have a signal here?”, on my audio circuits it will be very handy. As I nice final touch I made a lead so I can use a USB battery booster that I got as a freebe from a trade-show as a power supply. It should run for about 10 hours on a charge. It’s just a really nice thing! I’ll maybe think about whether I can add an external control for the intensity and perhaps do a DIY TV on it.

by Iain at 31 July 2015 09:21 PM

30 July 2015

Martin Raynsford hackergotchi for Martin Raynsford

Armour Tiles

I had these leather panels that I strung together for a hint of armour on a character. I decided to engrave them with fancy pictures to add a slight element of mystique and flavour. They're only mathematical diagrams about the forces exerted by various linkages but they came out quite well.

by (Martin Raynsford) at 30 July 2015 09:48 PM

29 July 2015

Martin Raynsford hackergotchi for Martin Raynsford

Project #7: Lego Lack Coffee Table

I hadn't intended to do another coffee table for some time but we had Lego spread all over the coffee table and I was getting bored of rummaging around the bottom of deep storage boxes so I decided we needed some real Lego storage and lots of shallow trays to make it easier to find the parts. There was also a convenient gap under my Escher coffee table so I figured I would base it around another Lack coffee table.

The table consist of six trays that slide neatly between the legs of the Lack. The top four trays have six sections, the fifth tray has four sections for slightly larger parts like long beams and the bottom tray is twice as deep with four sections so that assembled models can be stored. Each tray is lasercut from 3mm mdf and faced with 6mm poplar plywood. The rack is made from 6mm mdf which has proven to be strong enough to be leaned on by small children. The sides of the lack were turned into extra storage for really big base plates and instructions, the sides are hinged at the bottom and held shut with magnets at the top.

We started to fill the trays up with Lego and we realised just how much Eli has already, once I get my Lego into the mix I think we might need a second storage system. At least I have a happy customer for the time being.

by (Martin Raynsford) at 29 July 2015 09:35 PM

28 July 2015

Martin Raynsford hackergotchi for Martin Raynsford

Gaming Tokens

I cut these test tokens from sign makers HIPS. You cut through the top layer to get to the layer beneath it making for very high contrast signs. 
Below I did the same with clear plastic, the etched letters will be filled with black resin to make it stand out more.

by (Martin Raynsford) at 28 July 2015 09:24 PM

27 July 2015

Martin Raynsford hackergotchi for Martin Raynsford

Improved Manufacturing Jig

The new useless machine design has a PCB which allows it to be assembled easily, it also allows me to sell machines preassembled. The MAD museum are selling the 'No Soldering' version of the machine which means I end up soldering the boards myself. I remade this jig to hold all the boards in place, this post is mostly about the continual improvement though. The last iteration of this jig had round holes which let the PCB's twist in place, this one has square holes that key into the switch and hold them tight. The joy of having everything laser cut is that you can refine these things over and over again with minimal cost and effort until it is exactly right for the job.

by (Martin Raynsford) at 27 July 2015 09:26 PM

26 July 2015

Martin Raynsford hackergotchi for Martin Raynsford

80th Bunting

While I was busy making useless machines in the garage today the rest of the family was inside making bunting for Nan's 80th Birthday party (the kids loved it). Not wanting to be totally left out I rolled in at the last moment with half a dozen laser cut flags to be added to the mix. Clearly a lot more effort and love went in to the hand crafted flags but I guess we all have our own skills and Nan will appreciate the thought.

by (Martin Raynsford) at 26 July 2015 09:18 PM

19 July 2015

Kate Bolin hackergotchi for Kate Bolin

"Have you noticed that the more frequently a particular open source community tells you to RTFM, the..."

“Have you noticed that the more frequently a particular open source community tells you to RTFM, the worse the FM is likely to be? I’ve been contemplating this for years, and have concluded that this is because patience and empathy are the basis of good documentation, much as they are the basis for being a decent person.”

- Rich Bowen (via roomthily)

19 July 2015 06:24 PM

16 July 2015

Martin Raynsford hackergotchi for Martin Raynsford

Signs in Action

With the style decided upon but me headed away on holiday, I made a final tweak of the artwork and sent it up to Dominic at Just Add Sharks. He did the actual cutting for me and delivered it to Totally Brewed in time for their event. It looks great on their bar.

by (Martin Raynsford) at 16 July 2015 07:51 AM

15 July 2015

Matt Little hackergotchi for Matt Little

ACS758 Current Measurements

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I've been designing a breakout board for the ACS758 hall-effect current sensor. The first few prototype boards came in and I decided to give them a quick test. The results were not quite as I expected so I thought I'd put write about them here, for others that might be using this IC.

These current sensors come in a number of ranges (50A,100A, 150A and 200A, all with uni and bi directional variants). They use the hall-effect, which measures the change in the magnetic field to measure current. This means you do not need to install a shunt resistor, with its associated power loss and voltage drop.


by (Matthew Little) at 15 July 2015 03:18 PM

Martin Raynsford hackergotchi for Martin Raynsford

Totally Brewed Sign Styles

Our new unit in Nottingham is right next to a micro brewery :) Totally Brewed are pretty cool neighbours and they're vaguely interested in the potential of laser cutting so when we were presented with an opportunity to make a sign for their mobile bar we jumped right on it. The logo featured above looks great but the vectors were far from ready. The design couldn't easily be vinyl cut so I made a few prototypes that could be laser cut to show what we could offer as an alternative.

by (Martin Raynsford) at 15 July 2015 07:58 AM

14 July 2015

Kate Bolin hackergotchi for Kate Bolin

communiststephenharper: My new aesthetic is KNIT GOTH


My new aesthetic is KNIT GOTH

14 July 2015 09:05 PM

07 July 2015

Martin Raynsford hackergotchi for Martin Raynsford

More Meeples

I've had a lot of requests for smaller batches of meeples with different tokens in them, so I made some :) I'm selling these and the original packs in the shop now (or meeple svg here)

by (Martin Raynsford) at 07 July 2015 10:51 PM

06 July 2015

Kate Bolin hackergotchi for Kate Bolin

Why Do TV Characters All Own the Same Weird Old Blanket? A Slate...

Why Do TV Characters All Own the Same Weird Old Blanket? A Slate Investigation.

Or why a granny square crochet afghan is ubiquitous.

I can’t crochet a granny square, but I do keep on meaning to do something like this.

06 July 2015 09:03 PM

05 July 2015

Martin Raynsford hackergotchi for Martin Raynsford

Massive Heredox

Ed Saperia, inventor of Heredox and a million other cool things asked me to make a large version of the Heredox tile game for garden parties. It's made from 12mm exterior ply that was cut at B&Q on their big saw. The symbols however were laser cut from 3mm poplar and affixed to the top of each tile, with laser cut markings on each tile to show where the symbols should go. The whole game was then strapped up into a carry case which has the rules engraved on it. As a project it took way longer than expected but it's a really cool item I got to make so that's pretty rewarding.

by (Martin Raynsford) at 05 July 2015 08:41 PM

01 July 2015

Martin Raynsford hackergotchi for Martin Raynsford

Gaming Markers and Tokens

I just cut a batch of gaming tokens for Tree, these are apparently for the game "Guild Ball"

by (Martin Raynsford) at 01 July 2015 11:43 PM

29 June 2015

Martin Raynsford hackergotchi for Martin Raynsford

Signs and Premises

Just Add Sharks moved a few weeks ago, we are no longer in with Kitronik and we now have our very own unit in the wholesale market in Nottingham. It's great to have our own space to work from, we've already filled it with laser cutters and I'm now beginning to fill it with laser cut thing too. You're all welcome to visit us at any point just drop us a line first to make sure we're in.


by (Martin Raynsford) at 29 June 2015 09:13 PM

24 June 2015

Martin Raynsford hackergotchi for Martin Raynsford

Baymax Birthday Cake

It's not only laser cut stuff that gets made in our house, although you'd be forgiven for thinking that. Eli turned 5 this week (where does the time go) and he wanted a Big Hero 6 cake so I knocked up this Baymax head and shoulders. It's all cake based and then iced with ready roll icing (sugar paste), internally I used Cake Frame, left over from my Fraggle Rock adventures, this just holds the head in place. My first attempt at real baking and the Madeira cake was super easy to make and very tasty. 

by (Martin Raynsford) at 24 June 2015 04:15 PM

19 June 2015

Martin Raynsford hackergotchi for Martin Raynsford

Project #6: Minecraft coffee table complete

The Minecraft coffee table is now up and visible. There are lots of pictures and a detailed description of the build process available over on the Kitronik Blog. This project idea lingered for a good 12 months and having the support and backing of Kitronik really made it possible to put it together in super fast time. Go check it out now

by (Martin Raynsford) at 19 June 2015 11:40 AM

14 June 2015

Martin Raynsford hackergotchi for Martin Raynsford

Carcassonne Coasters

This drinks coaster is made up of 4 Carcassonne tiles, they've all been cut as one tile and then varnished (to provide some drink resistance). I accidentally recut the edge when I flipped the tile over so there are excessive burn marks around the front. I'll be making these up as a set of 6 (each coaster different) if anyone is interested drop me a line, customer interest tends to get things made faster :)

by (Martin Raynsford) at 14 June 2015 08:12 AM

09 June 2015

Martin Raynsford hackergotchi for Martin Raynsford

LED Clock

I wanted an LED clock for the garage so I ended up making one. I bought a kit from China, it went together easily although there is a little gotcha with one of the LED segments going in upside down. It was a little bit bright and hard to see the red segments against the unlit segments but that was easily fixed with a layer of masking tape over the front. Goes well in the garage.

by (Martin Raynsford) at 09 June 2015 09:36 PM

08 June 2015

Martin Raynsford hackergotchi for Martin Raynsford

Winged Heart Remake

I very long time ago I made this winged heart using stacked veneers (can't believe it was 2.5 years ago). It's been to most maker faires with me and it's received a lot of love but I was finally asked to remake it at the recent Halifax Mini Maker Faire. With all remakes I took the opportunity to make some improvement, most of the feathers are now stuck on the backboard which made it easier to assemble and the heart is now made flat because the stacked veneers were too awkward last time. I'm also sharing the files this time around. (svg here)

by (Martin Raynsford) at 08 June 2015 11:36 PM

06 June 2015

Martin Raynsford hackergotchi for Martin Raynsford

Linbin System

There are laser cut linbin files available online already so this wouldn't be much of a post if I'd just made some of those. This is a modular stackable/rackable linbin system. Contained in the files is a series of parts for making linbins, you can add 5 middles and put a cap on either end to make a really long or wide linbin or any combination you want. Oh yeah, it also has a living hinge to make up the front lip which means it's really easy to scoop the contents up the front lip and out of the box

The bins all stack on top of each other and a small overlap locks them into place so they won't fall off. The racking system is also versatile because it can be wall mounted or free standing, it can accommodate any sized bins in any position.

I've got the whole Linbin system (svg here)
I've also prepared a file with the 3 bin racked system shown. (svg here)

by (Anonymous) at 06 June 2015 10:35 PM

03 June 2015

Matt Little hackergotchi for Matt Little

Wind Empowerment Development Week

No image

A few weeks ago I headed down to rural France, near Toulouse to take part in a week-long Development Camp working on wind turbine measurement for the group Wind Empowerment.

About 10 people came from all parts of Europe, along with people joining via Skype from all parts of the world.

We discussed ideas and specifications and prototyped equipment for monitoring wind resource and remote monitoring and managing wind turbines.


by (Matthew Little) at 03 June 2015 01:41 PM

Mini Amplifier Kit

No image

This is a simple, low-cost amplifier kit based upon the LM386 amplifier IC.

It has a maximum output power of 1W, which is good enough for amplifying mp3 players, phones and also the beeps and sounds from microcontroller projects.

Please note: This kit has one surface mount component, the LM386, which is good for those learning to solder surface mount components, but not best for people new to soldering. The rest of the parts are through-hole.

It is available for just £6 (including delivery within the UK).


by (Matthew Little) at 03 June 2015 09:14 AM

01 June 2015

Martin Raynsford hackergotchi for Martin Raynsford

Project #6: Minecraft landscape coffee table prototype

May seemed to pass by so quickly, it's not as though I forgot to do a monthly project I just ended up leaving it quite late and I'm playing catch up with the documenting of it. For a long time people have been admiring this landscape at maker faires and I've been promising to make one coffee table sized. This time round I decided to pixellate the contours and turn it into a minecraft themed environment. There will be more to follow in the next few days but for now here is the half sized, non plastic prototype.

by (Martin Raynsford) at 01 June 2015 08:55 PM

27 May 2015

Martin Raynsford hackergotchi for Martin Raynsford

The return of the Stellated Dodecahedron

The Stellated Dodecahedron is back, there was a lot of interest in it at the maker faire and someone even went as far as buying a kit so I figured I better get it working properly. Last time I only cut one but I couldn't really sell it because the material was wrong. I had some 1.5mm ply which was clearly exterior ply and not interior ply so the edges were so horrendously burnt and sooty that it smudged everything. This time around and Kitronik is now stocking 1.5mm Birch that is definitely laserable. So with the right material this thing makes a decent kit, I even managed to make the finger joints so snug that it doesn't need glue to hold together.

by (Martin Raynsford) at 27 May 2015 07:14 PM

25 May 2015

Martin Raynsford hackergotchi for Martin Raynsford

Graham of Thrones

By request I was asked to etch an A4 sized stark wolf with a 'Graham of Thrones' caption. I used my prior artwork which is pretty to the picture sent to me which sped things up a lot. Having a nice clean line drawing allowed me to quickly raster it, to get a version without overlapping tufts and then re vectorise it (the updated 'trace bitmap' in Inkscape is incredible). The image was first engraved but it didn't pop enough for my liking so I put it back in (I hadn't moved the surrounding frame) and outlined the engraving as well. I took the decision to not etch the teeth and to only outline them which I think makes them stand out a bit from the picture. Anyway customer is happy and so am I.

by (Martin Raynsford) at 25 May 2015 10:26 PM

23 May 2015

Martin Raynsford hackergotchi for Martin Raynsford

Relief Photo Frame Pair

I've been wanting to use this landscape depth technique thing for quite some time now, I have a monthly project in progress right now that uses it but while I was doing that I thought it would be pretty cool to make this pair of frames with the positive and negative images in them.

The perspex is often labelled as Glass Green which gives a slightly false impression. The backing sheet is green and it gives the whole thing a lovely green tint. In reality this is the clearest perspex sheet I've ever seen and all the green tint goes away when the backing is removed. It's really good though if you want a Glass like material. I got it from Kitronik (again)

by (Martin Raynsford) at 23 May 2015 09:36 PM

22 May 2015

Martin Raynsford hackergotchi for Martin Raynsford

Lego Mad Max - Fury Road

I must confess that I got a little bit distracted and carried away when Eli asked me to make him a Lego car yesterday. In case you haven't seen Fury Road I recommend you go and see it on the big screen it's weird, cool and it'll lose a lot of impact on the small screen. I fiddled and faffed with a few Lego pieces and was reminded of the film, from there I ended up making 6 vehicles based upon the ones in the film.

It gets a little bit image heavy from here on down so to save my regular blog readers I'm hiding it below the cut
Read more »

by (Martin Raynsford) at 22 May 2015 07:44 PM

Oak Board Game

A ye olde board game board for a game called Gluckhaus, this was cut on request for a LRP game.
The material is an oak veneered plywood that is now available from Kitronik, it worked really well for this. There are a few knots and lumps and bumps that are a bit tougher to get through but as I'm only going to be making one of these that's fine. 

by (Martin Raynsford) at 22 May 2015 10:44 AM

21 May 2015

Martin Raynsford hackergotchi for Martin Raynsford

Rubber stamp

Another simple rubber stamp, the more I do the more I learn about what not to do with these things. I should probably write something useful about how to do stamps. As much as I like having a full square background it's probably time to concede that the excess rubber should be cut as close to the stamp as possible.

by (Martin Raynsford) at 21 May 2015 10:34 AM

20 May 2015

Martin Raynsford hackergotchi for Martin Raynsford

Line Art - Varying Densities

The last of my line art experiments from last week. For this one I varied the densities of the lines radiating from the centre. The effect is much more significant than I imagined. Again I failed to cover the centre of the pattern so it burnt a hole in the middle. Maybe a sun circle in the middle of this patter. No I just need to find time to write the instructable for it.

by (Martin Raynsford) at 20 May 2015 03:18 PM

19 May 2015

Martin Raynsford hackergotchi for Martin Raynsford

Line Art - Names

This one uses the same process as the others but I tried to vary the etching pattern. There are a series of wavy lines which produce an interesting pattern around the shape. The mistake I made on this one (and the next one:) was not covering the centre of the pattern. The very middle of the etch was cut about 100 times during the process which obviously added up and put a hole through the middle of the design. "Eli + Hazel" would be been a better choice with the "+" over the centre of the pattern.

by (Martin Raynsford) at 19 May 2015 03:16 PM

Line Art - Heart in Heart

Another attempt at some fancy line art. This time I left the ends of the lines on which gives a much more defined outline to the heart shape and is also much faster to prepare.

by (Martin Raynsford) at 19 May 2015 07:12 AM

17 May 2015

Martin Raynsford hackergotchi for Martin Raynsford

Line Art - Bird in Tree

While I was busy last week I had some ideas to make something pretty for Kim. She likes birds and I wanted to try more of this line art style so I drew this Bird in a tree for her. I do intend to write an instructable about this but for now I've just attached the svg (svg here)

by (Martin Raynsford) at 17 May 2015 09:58 PM

16 May 2015

Martin Raynsford hackergotchi for Martin Raynsford


I wanted to make a little Baymax to go into Eli's birthday party invites. This is cut from 0.8mm white polypropylene. The details were coloured in with a black fine liner pen. (svg here)

by (Martin Raynsford) at 16 May 2015 10:44 PM

15 May 2015

Martin Raynsford hackergotchi for Martin Raynsford

Medium sized Empire map

By request I made a medium sized Empire Map, it's pretty much the same deal as the big one but with a few tweaks. This map is intended to be taken too and from the events so it's a bit smaller at 1000mm x 900mm. It has some extra Otkodov regions at the top and also the barrens just to the right hand side. The regions are one of three different heights instead of four different heights. The main difference is that each region is removable, this was achieved by placing two pegs under each region. The regions line up and with the pegs and sit in the right places on the board. Finally I added a little celtic flourish in each corner, you might recognise these as the Celtic knot dice. It turns out that having the six basic sides of the dice allows me to quickly and easily construct flourishes for decoration.


by (Martin Raynsford) at 15 May 2015 10:06 PM

12 May 2015

Martin Raynsford hackergotchi for Martin Raynsford

Clarkcade Gaming Cabinets.

One of my 12 projects this year was/is going to be a retro gaming cabinet. While I was at the UK Maker Faire I met Simon and I saw his awesome Clarkcade cabinets and in particular 'the fighter' which is exactly what I envisaged for my cabinet. These machines are top notch quality have all the right features and finishing touches, so I was keen to get some hints and tips. After a short discussion it turned out that Simon was keen to try getting a some parts laser cut which was very convenient, now just two weeks later I've cut my first cabinet for him and there will hopefully be many more on the horizon as we try to figure out the best way to laser these machines (such as yesterdays hidden joints). My cabinet will still be put off till slightly later in the year but what a head start I'll have when I finally get round to it.

by (Martin Raynsford) at 12 May 2015 07:19 PM

11 May 2015

Martin Raynsford hackergotchi for Martin Raynsford

Hidden Finger Joints

The weeks just fly by and it's weird because I was busy making things last week. I made a quick prototype for a hidden finger joint. The item in question is intended to be made from 12mm mdf which is something I can't cut on my 80W laser so the next best thing is to cut it in 2 pieces and stick them together. If the inner layer is hidden away though you can add these kinds of fingers to make the assembly really easy.

by (Martin Raynsford) at 11 May 2015 09:20 PM

04 May 2015

Steve Barnett hackergotchi for Steve Barnett

CNC cut control horns

I was at a loose end during today’s bank holiday so I decided to do a mini-project (with bonus recycling features) and make a set of control horns for my radio controlled SpeedTwin ST-2.

Control horns in DraftSight

After deciding on a sensible size for the control horns I drew them up in DraftSight. These ended up being 25mm tall and 12.5mm wide at the base. I designed them on a sprue so that when I come to etch the remaining copper off they don’t get lost in the etching tank. The horns are shaped so that the holes for the linkage can lie on the hinge line with plenty of material around them for strength.

The DraftSight file for the parts can be found on GitHub in my rc-parts repository, which also contains drawings of various bits of radio control hardware that I’ve designed parts around. Please feel free to use any of it or to contribute drawings of parts.

The victim

The PCB material I used comes from a nice FR4 board onto which was otherwise unusable due to a design mistake. The board was intended to be used as a 2 player version of Charlie’s ‘Minigun’ miniature SuperGun project. Unfortunately after etching I noticed I had messed up the pinout of the JAMMA connector when transcribing the design from Eagle to KiCad. Rather than throwing it away this project is allowing me to reuse the material for something useful. My 2 player ‘MiniGun’ will eventually get finished and written up too.


As a quick aside, the SpeedTwin has made some progress since I last posted about it. The fuselage is nearly finished, except for sanding the canopy to shape and some more work on shaping the nose cone. The wing is also coming along, with the top half of the engine nacelles planked and mostly sanded to shape. The remaining work on the wing is to install the tips and build the bottom half of the nacelles, which will be removable for access to the landing gear.

Once the control horn design was ready I used CamBam to convert it to G-Code. Unfortunately some manual editing was required on the output to get Grbl to accept it happily. The main problem was a G17 code, intended to signal that arcs should occur on the XY plane, which caused Grbl to error after any subsequent G3 (arc) code. This setting was default anyway so the line was removed with no adverse effects. I also tend to remove comments from any code that is passed to Grbl – the parser can choke on lines over 50 characters so comments at the end of lines are best removed. If I find an open source CAM program that will provide Grbl compatible G-Code out of the box I will probably switch to it, I just need to put in the time to find one. :)

Cutting the parts

This is the first time using my eShapeOko since I rebuilt the controller so I had to spend some time setting up again. Once I’d calculated the appropriate steps/mm settings for each axis everything went fairly smoothly and after a few ‘air cut’ test runs I cut the parts. Since this part is all made in one cut I simplified things slightly by removing all of the Z axis movement from the program. I manually plunged the bit into the work from GrblController and then set the program going.

I decided not to drill the holes on the CNC to save setup time and because I don’t have a suitable drill bit that fits my eShapeOko’s rotary tool. They will be quick and easy to drill accurately on the drill press at NottingHack at a later date.

Mostly finished parts

All that remains is to etch the remaining copper off (and sadly lose the current futuristic look), drill the holes and cut off the sprue.

by moop at 04 May 2015 07:35 PM

02 May 2015

Martin Raynsford hackergotchi for Martin Raynsford

More Leather work

More Leather work for Marcus. I was trying to align the etch to the middle of the leather that he sent me but it didn't really work. Clearly I should have used the laser to cut out the leather as well.

by (Martin Raynsford) at 02 May 2015 10:58 PM

01 May 2015

Martin Raynsford hackergotchi for Martin Raynsford

Custom Useless Machine

The new useless machines are a lot easier to assemble, this means I'm now happy to assemble them myself and sell them as finished units. This also means I'm happy to customise the machines by request. This one was coloured red before assembly and then had a name engraved on the lid.

by (Martin Raynsford) at 01 May 2015 06:59 PM

30 April 2015

Martin Raynsford hackergotchi for Martin Raynsford

Project #5: Smart Useless Machine

I thought I would close out this month with another new product and finishing one of my monthly projects. This is the 3rd and final kit that I was calling Project #5: a complete revamp of my useless machines.

This kit is a smart useless machine, there is an arduino inside the box which allows you to program in different behaviours based upon how many times you flick the switch (or anything else you can dream of). Currently the box gets miffed if you turn it on too many times. Full sample code is provided and being based around an arduino there are dozens of amazing libraries already written for all sorts of functions. There is a small power circuit which allows the arduino to turn it's own power on and off, the only power consumed in the off state is the leakage current of the transistor. In testing the circuit ran for a whole week (2-3 tests a day).

Here are just a few ideas of things you could add:
  • Add some character to your box, with a real time clock chip make it come out slowly after midnight or once every hour.
  • Add some neopixels to make the inside of the box glow.
  • Add a second motor to make it wave the flag of surrender or run away when it gets annoyed.

by (Martin Raynsford) at 30 April 2015 10:17 PM