New PCBs for electronic board sections

After getting our multiplexed hall sensor array working last week - and failing to demonstrate them at a Unity meetup in Brighton recently after wiring the one working prototype up incorrectly! - we made up some smaller sections, this time in a 7x7 grid.

This means we can use a single input port (PORTB) with pull-up resistors (since the hall sensors pull to ground when activated) and a single port to activate each transistor individually to turn on each row of hall sensors at a time. This means loads of discrete components:

For prototyping (and because of space restrictions on our breadboard) we've only actually wired up five of the seven transistors, but after proving the concept worked, went on to use all 7 in a test (we went on to wire up two of the SMT transistors at the top of the board).

Ok, not exactly loads. But quite a few. Enough to make wiring up each controller circuit for each board section quite fiddly. We etched up a few different circuit boards, using a variety of different mcus, surface-mount and through-hole components.

Even after making as many components as possible surface mounted, there were still a lot of discrete components to stick down on each PCB! Enough to make it worthwhile investigating an alternative, all-in-one integrated (IC) chip to do most of the work for us...

The A2982 may be relatively expensive, at about a quid a time when bought in bulk, but it does simplify the circuit a great deal.

The A2982 is a source current driver. It includes resistors on the transistor bases, to allow them to work at 5v logic levels, and each channel can source up to 500mA if needed. So all those discrete components are gone - and the entire circuit is now just two IC units: a single PIC 16F1829 and a single AS2982 chip.

Each panel is now much simplified from our earlier 12x12 design - both in terms of hall sensors and the controller PCB. Here we're using some thin hook-up wire just to get the board working (the final version will use ultra-thin magnet wire)

We're using 3.5mm stereo jack sockets to connect our PCBs to power/ground/data. So here's the final PCB design all soldered up and ready for the new firmware.

Right now we've got a couple of panels soldered up and working individually - so we're in for a marathon etching session tonight, to make up half-a-dozen or more controller PCBs for all the other panels. A few more like this and some updated firmware and we can create one, big, playing surface....

Creating electronic board game sections

Having sorted out the electronics for our electronic board game panels, we've tried a number of ways of building the hardware to embed them in. After lots of aborted attempts (using mixtures of card, foamex/foamboard and laser cut acrylic) we've settled on routed MDF.

Creating a consistent template for routing the channels, such that the pre-built PDBs will fit perfectly into the grooves, was a real pain, so we've come up with a simple router jig, out of offcuts of wood and scrap metal runners.

The rails are placed parallel to each other, at exactly 420mm apart (in truth, we used a piece of 420mm square cut wood to line up the rails, only to find they're about 420mm apart at one end and 418mm apart at the other, occasionally binding on the wood as it passes through!) But it's good enough for a first try.

The base is marked at 35mm intervals, so that we simply push our board through, under the router, then line up the leading edge with the marks. Set the router head spinning, plunge, then run the router from left to right. As our cutting head is 6mm wide, and the plunge depth set to 3mm, this makes 12 channels for our hall sensors to sit in.

Then we rotate the wood through 90 degrees and use a 16mm cutting head to create wider grooves for the PCBs at 70mm apart (though in the image above, our first board was cut exclusively with a 6mm bit, making the wider grooves with multiple offset passes).

We made a bit of a mess of the first offset (at both ends) for the PCB channel - but once we'd worked it out, the rest of the channels were cut quickly and easily.

The end result is a piece of MDF into which we can easily drop our pre-populated circuit boards. In practice, it may be easier to connect the wires between the boards before fitting (as we did with our earlier jig-based soldering) but we're still ironing out the exact manufacturing process!

The nice thing about this process is that the boards can all be routed independently of the circuit boards, which are then fitted quickly and easily into the grooves. All that then remains is to fit the main controller (that is used to connect multiple boards to each other) on the underside, and a thin cardboard layer fitted to the top, to cover the currently exposed circuit boards.

Getting jiggy with it (see what I did there?)

Using a jig and a stencil for applying solder paste has been quite a revelation for churning through our PCBs for the electronic board game sections - far more so than getting a rudimentary pick-n-place device working.

After just a few hours this evening, we had soldered and assembled a chain of eighteen boards for testing.

And with just one dry solder joint across all the boards, it was very encouraging indeed, to see each one responding the placement (and removal) of a magnet above each of the hall sensors

There are a few things come up with work today that may take a little time to resolve, so it's likely to be the weekend before we can get to the workshop and rout out some mdf boards to embed these in. But already things are looking very encouraging indeed. Can't wait to get a few sections daisy-chained together and actually see one of our board game apps responding to the  hardware for real!

More laser cutting 28mm terrain, wild west buildings

We've decided to have a bit of a push with our wild west terrain (if only so we can get it done and move onto the next massive laser-cutting project, a football stadium, but more on that later!)

We've already got a few "standard" building shapes, which can be mixed-and-matched to create a variety of different buildings. But if we simply repeated our few building designs over and over, we'd end up with a pretty boring looking wild west town! So we've been getting a little bit more adventurous with our designs.

All of our building designs start out like this - a reference photo and lots of overlaid, overlapping parts, drawn to try to give some idea about how they all fit together. Then we produce a "cleaned up" version of the drawing, and send it to the laser cutter:

Given we've had such a miserable "last-bank-holiday-before-Xmas" and the summer seems to have deserted us even before August is out (thanks, Hurricane Bertha) we've spent a bit of time stuck indoors. But it's not all been watching New Tricks and Great British Bake Off. No, we've been busy designing loads of "interesting" looking buildings for our wild west town.

And last night, managed to spend a good few hours at the laser cutter, cranking out kits for our miniature buildings. As yet they're untested, so it's likely that we'll have to amend the final designs. But so far, things aren't looking too bad....

(what's with the half-uploaded files, Google? There are more than just a couple of photos turned out like this in recent weeks)

As well as our standard, 3-inch-wide buildings (tall and short) we found a photo of a tobacconist, squeezed between two larger buildings, so set about creating a super-small building that we could use as a trading post, a telegraph office, tabacconist and so on, by simply changing the top part used to display the signage.

To add a bit of character, we even created a windmill and a water tower for our miniature town.

We've got a jail building on the maker-table too - made entirely from lollipop sticks, to simulate a log cabin (it's hard to create an interesting looking textured surface out of flat, laser-cut planes) so we squeezed some jail bars onto the relatively small windmill section

After cutting out the pieces, we thought that the windmill blades looked far too "chunky" for the model (in truth, the uprights don't look quite right carved out of 3mm mdf, when the design was built for 2mm stock, but it'll do, as a test piece). So we quickly transferred part of the design onto some 0.8mm birch

As we'd run out of "laser-friendly" mdf, we started using some cheap-n-cheerful 3mm mdf from Wickes. Unlike the laser-friendly stuff we got from an online supplier - which has an almost fluffy, untreated surface - the Wickes mdf was really nasty to work with. Both sides are really smooth and shiny, and left a sticky yellow film over everthing - the surface of wood being cut, the cutting bed, the insides of the laser cutter - it got everywhere!

Just before finishing up for the evening, we quickly hacked out a toilet/dunny from a piece of scrap!

With about five "structures" (a few of buildings, a windmill, a water tower and a dunny) bagged up (to keep the different parts separate) we set about cleaning up. The sticky yellow film took quite some removing on its own, so we ended up resorting to some Mr Muscle.

Hopefully this hasn't leaked under the bed. And if it has, let's hope it doesn't do anything drastic like make the belt perish!

After about two and a half hours of lasering almost non-stop, it was time to give the laser cutter a rest and bring our home-made Airfix-a-like model kits home. As each one takes anywhere between 30 minutes and an hour to assemble (including glue drying time) there's probably a full day's work in putting them together. So, softly, softly, over the next few nights, we might actually make some progress....

More 28mm wild west terrain buildings

Inspired by examples of laser-cut buildings, and given the (relatively) quick results we've had from cutting our own wild west themed buildings, and decorating with stickers (rather than modelling and painting them from scratch) we're going all out to produce a "town" of about eight different styled properties.

Which means, given that it's the bank holiday, more laser-cut goodness!

Our buildings are quite small, compared to some of the "proper" manufacturers out there (like 4Ground or Sarissa) but there's a reason for that: since we're building boards which are 6" x 8" and each playing square is one inch, we're trying to keep our buildings to about three inches across, and only sometimes going as large as four inches across.

This means that a board placed "long-ways" could have two buildings along it's long edge, separated by a single or a double square. Or we could place a 4" wide building in the middle of the short edge, leaving one square either side of the building (or two squares between buildings, if two playing surfaces are placed against each other, and a 4" wide building placed in the centre of the short-edge of each).

While not exactly huge, our buildings fit quite nicely with the 28mm scale that most miniatures manufacturers produce. We're not looking to make a massive playing surface - we just want a few buildings to make an otherwise plain-looking playing surface look a bit like a town from the wild west.

With all this in mind, and using various online sources for inspiration, we've managed to design, cut and assemble another western-style building in less than a day. This time, it's a hotel-like building, with a balcony around the second floor.

As ever, all the drawing and layout was done in Inkscape:

Our trusty LS3020 made short work of buzzing through some 3mm mdf (ideally we'd like to make the buildings from 2mm mdf, but we have a stock of 3mm so that's what we're using!)

We've decided to go a stage further this time - although we've no plans to use our buildings for anything other than a showcase game for our generic electronic board gaming system, a few people have already asked about having some of these buildings made up for their own gaming. And if others are likely to want to use these plans, then it seemed sensible to add in some extra little features:

Like a detachable roof, and removable interior floor for the two-storey buildings. It's a bit late for our early single-storey "stores" building (since the roof has been glued on) but we can always retro-fit a removable roof to our "hotel" building (and even add in some supports for a removable second storey floor). For this building, we've planned for them from the start.

When assembled, the lip going around the inside walls will allow us to drop a 3" square floor in through the roof - effectively creating two accessible, interior rooms where players can place their miniatures to indicate that a player is inside the building. It's not something we've coded for in our electronic games, but the if the buildings are used in any other game ruleset, at least we can accommodate this, should anyone need it.

Here's our latest creation (above) alongside the previous buildings, just awaiting some stickers to jazz it up a little. Since this building is in the style of a wild west hotel, we're probably going to have to change the signage on the other building!

Both of the two-storey buildings have been designed with detachable fronts. This will allow us to make a range of different building styles using a basic template for the building construction. It also means that, when used in a tabletop game, getting access to the miniature playing pieces placed around the buildings can be made a little easier, by removing the front canopy of a building.

An unexpected benefit to this approach is also the ability to "mix and match" different building fronts, onto different building styles

We're getting a little impatient to see our wild west building actually appear on the tabletop, so we may yet just cut another of each of our buildings to date, and have a simple, small town of just six or so (very similar looking) establishments.

Sure, laser cut buildings don't have the same detail as scratch-built ones. And stickers will never give the same impressive appearance as a properly built, painted, inked-and-drybrushed piece of terrain. But they are a pretty easy way of building a relatively large playing terrain, quickly. And for that reason, we need to focus on getting our wild west town finished, rather than worry too much about them not being "real hand-built terrain"!

Laser cut terrain buildings - 28mm wild west contd

Steve had a great idea about our laser cut wild west buildings - CraftRobo stickers. We'd forgotten all about our trust little blue-and-white cutting machine; it's been sitting in a box in a corner for a while now.

Luckily it can import .dxf files as cutting lines, and accurately place these over a pre-printed image. So all we needed to do was create a series of jpegs (one for each section of the building) and place the cut lines over them (the same cut lines we drew in Inkscrape for the laser cutter, though modified slightly in places).

The most difficult part is resizing the jpeg images in the CraftRobo software; the only information we have about the jpegs is the height and width, as measured in pixels. The CraftRobo software, RoboMaster, only uses only millimetres as units for resizing images, so we had to do some quick conversions.

Our bitmaps/jpegs were created at 600dpi (to get the best quality printed output). So the size of the image in millimetres is: size of image in pixels / 600 * 25.4

Creating the A4 sized sticker sheets was a relatively quick process: create a jpeg and import into RoboMaster. Import a dxf with the original cut lines as sent to the laser cutter. Resize the images in Robomaster to their actual size (using the formula above). Place the cut lines over the correct parts of the images. Each sheet took less than half an hour to produce:

Our CraftRobo is the old-style blue model - one of the very first imported into the UK a number of years ago. As a result, it doesn't have particularly good downward cutting force - it struggles with anything more than even just thick paper. But for sticker inkjet paper, it cuts just fine.

Each cut goes cleanly through the sticker side of the paper, while leaving the backing paper intact - perfectly cut stickers every time!

Some of the stickers needed to be adjusted slightly to get them to fit onto the building, but for a first try, the results were surprisingly effective.

The 28mm playing piece shows the overall scale of the buildings in relation to a board game playing surface.

We're not quite sure how the buildings will work with stickers on the walls and our laser-cut roof shingles (and a mix of painted and non-painted parts) but the stickers seem to work well enough to use on other parts of the building - the roofs and sides of wooden planks on the building fronts, for example.

The plain wood coloured shingles look quite nice on the single-storey building. And the etched planks on the double-storey building canopy could be left as they are - the colour of the 0.8mm birch contrasts quite nicely with the wood-effect patters on the stickers

We'll have to try painting and dry-brushing the "textured" parts of the buildings, and see how they look with the stickered walls. But so far, things are looking very encouraging.

The overall scene will look all the more convincing once we've got a proper floor down, and maybe a few more buildings around the place. But, of course, the whole point it to furnish our electronic board game - so perhaps it's time to park little wild west buildings for a bit, and get on with actually manufacturing something!

Laser cut 28mm terrain buildings - wild west

A while back, we made some simple 28mm buildings for a wild west shoot out miniatures board game. Having turned our backs on the laser cut buildings that seem to be flooding the board gaming market in recent months, we decided to "scratch-build" our buildings from lolly sticks and coffee stirrers.

The results were quite nice, but the overall process took far too long. So we tried a half-way house - laser cutting rows of shingles for the roofs and cutting planks to make the walls of the buildings. Again, a successful trial, but still making a complete building - even a relatively small, single storey one - was tediously slow.

So now it's time to give laser-cut buildings a try. We know that scratch-building gives impressive results. Shingle roofs and plank-built walls look great when painted up and drybrushed, but - to date - we've nothing to compare them to. So we thought we'd at least put some buildings together, and compare them to our scratch-built ones.

Using photos of existing models on the 'net as "inspiration" we got busy with Inkscrape

We designed and cut a small, single story building (with 3 inch sides, 3 inches deep)...

...and a larger, two-storey building, again with a 3 inch square footprint:

Being impatient, we cut the doorframes and windows from regular 3mm mdf - ideally these would be cut from 2mm, as the 3mm gives them a slightly cartoon-chunky look

The pieces fitted together easily. Unlike a lot of mdf laser-cut buildings, we tried to keep the number of interlocking tabs to a minimum. We're using PVA glue to assemble our parts, which means putting a few sections together, then leaving overnight to dry before further assembly.

Superglue (the real stuff, not the nasty knock-off clone from Poundland) does a pretty good job of gluing mdf together, with the advantage of not needing to be left for a few hours to try before putting more pieces together. But it does suffer from "instant grab" which means you need to be pretty accurate when placing each piece.

Because we hadn't yet tried a full fit of all the pieces, we decided to stick with PVA - to give us time to slide pieces around if they didn't quite line up, first time.

The finished double-storey building looks pretty good. There are a number of first-time design faults that need to be addressed in the second version, but for a first time try, it looks ok.

For a start, things like the top plank isn't wide enough to sit on top of the decorative false-roof parts. This can easily be corrected in the next iteration. The window frames are too chunky, and we designed the canopy supports to line up when cut from 2mm mdf, not the thicker 3mm stuff we had to hand. But these are simple design problems that are easily fixed. The actual, finished building looks quite nice - and even though it has a relatively small 3" footprint, still looks a decent scale for the "heroic 28mm" (i.e. 32mm high) miniatures from Black Scorpion.

Unfortunately, it still looks like a flat, laser-cut building. We're going to try drawing (heavily) on the wood to create a grain effect, before painting over the whole thing with a primer and base coat, to give it a little more character.

 Perhaps a computer-printed sticker for the canopy sign and some posters to go along the sides of the building are the finishing touches it needs? According to some sources, advertising was just as prevalent, garish and clever as today's efforts to get people to part with their hard-earned. Except instead of pasting adverts all over the internet, they just pasted them onto their buildings!

Laser cut planks for Wild West 28mm terrain buildings

Here at Nerd Towers we love 28mm board gaming - and making up and painting the terrain as much as the miniature playing pieces and playing the games themselves.

A quick (but not-so-cheap) way of getting a really impressive looking gaming table up and running is through the use of laser-cut buildings, from companies such as 4ground.co.uk or Sally4th etc. These buildings are, as often as not, lovely detailed, atmospheric pieces which look great when painted up.

The problem is, being familiar with laser cutting, and seeing how these buildings are made, they're a little bit "lacking" for many in the "Nerd Club Gaming Club". It's hard to say what it is, but scratch-built terrain, complete with little imperfections and slight errors always seem to have a little more "character" and (dare we say it) "realism".

I, personally, haven't played and enjoyed a video game since about 1989, when Jon Ritman and Bernie Drummond released Head over Heels on an affordable label. Not long after that came out, when I discovered that ZX Spectrums were not actually coded using a ZX Spectrum, I started writing my own software and simple games - and most computer games become exercises in moving sprites around a screen. I still don't play videogames, even 25 years later on, even after all the advances in technology. At the end of the day, I'd rather be making simple games than playing even the most immersive multi-player dungeon crawler.

Head over Heels - the last decent video game ever made?

And laser cut buildings on a board game terrain leave me cold for the same reason - rather than marvel at the periodic detail, things like finger joints and how the cutting kerf has been disguised catch my attention more than the model; I'm looking more at how it was put together, rather than enjoy the finished product.

And this is mostly, I feel, because most laser-cut buildings have very little construction needed - they're essentially flat-pack, prefabricated miniature houses. They have lots of large, flat surfaces, with some textures laser-engraved onto the surface to make them a little more interesting.

This is partly why we recently spent so much time hand-assembling a scratch-built roof for an Old West building from plasticard - to give the final model a little more texture and character. The problem with that approach was that it was really (really) time consuming. So we came up with a compromise of laser-cutting rows of slates and assembling them to create a textured roof, with overlapping tiles, but which took a fraction of the time to put together.

After successfully making our rows of roof tiles, we look the plastic-wooden-planking idea to the laser cutter to see how that would translate too. Instead of carving the card with a knife and then scratching woodgrain into the surface, we drew some slightly wobbly planks (to simulate them being warped and worn in the sun) and drew some free-hand lines over the surface (in Inkscrape) as grain.

Woodgrain Planks for laser cutting 28mm terrain by chris_holden2495

(A variety of different worn/weathered planks; to create a straight edge, simply turn the plank upside down - so the wobbly bit is at the top - and overlap with another plank above. The two straight pieces at the bottom are for edging the sides of a "lapped plank" wall)

Our LS3020 laser cutter can etch and cut at the same time (or, rather, one immediately after the other) but the driver isn't as easy to use as the BuildBrighton white laser - you basically need to create a bitmap for etching (the woodgrain) and a vector image for the cut-lines. The NarlyDraw software that our LS3020 uses can only handle engraving from bitmaps, and cutting from vectors.

So this is where the fun starts:
It's easy to import a bitmap followed by a vector image, and line them up by eye. In fact, because our wood grain isn't critically placed, we could have done this. But we wanted to try out (and document) how to go about lining up the cut and etch images. So here goes....

Firstly, create the cut and etch drawing in Inkscape on two separate layers (one for the etching, one for the cutting). Place the etch layer above the cut layer, and make each layer visible and invisible, one at a time, to check that all the lines are on the correct layers!

Now draw a little cross (we used a 2mm x 2mm) and place it in the top left corner of one of the layers. Copy the entire cross and paste-in-place on the other layer. We now have a marker that we can use to align the two images in NarlyDraw. (If you're not confident of important the images to the same scale, you can always put another cross in the opposite, bottom-right corner, and use this as a guide to get both images to scale).

Hide everything except the etch layer, select everything and export the selection as a bitmap (Inkscrape exports to .png so we had to load this into Paint Shop Pro to turn it into a 1-bit bitmap: the one bit thing isn't necessary, but it's handy to do, to keep the file size down!) Now delete everything except the cut lines (or copy the cutlines and the cross to a new document) and save as .dxf.

With a .bmp (for etching) and a .dxf for cutting, simply import the two files into NewlyDraw, zoom in and make sure both layers line up on the same cross.

Lining up the cutting guide on both the etching and cutting layers. When both are perfectly lined up, the final result can be previewed easily in the NewlyDraw application

It was with some trepidation that we hit the "go" button, but shouldn't have worried!
NewlyDraw did a great job of etching the bitmap image first...

...before cutting out each plank from the surrounding wood:

Each set of planks takes only a couple of minutes to complete. They overlap nicely and sit quite flat, to create a realistic, weathered wooden wall for a shack or a shed

After a few of our sample offcut sheets had been fed through the laser cutter we had enough planks for the walls to build a small building

Another couple of goes through the laser cutter and we had plenty of roof tiles too

All that remains is to assemble a building using the bits and paint it up, so see whether the wood holds the grain pattern after a layer of acrylic has been applied and drybrushed  (etching it would be pointless otherwise!) or whether we need to use something more like an ink or a stain, and just keep the grain lines darker.

After all this messing about with laser cutters and trying out different approaches to etching and cutting on the same piece, it was actually quite late when we finished last night; so the build and paint begins in earnest this evening!