Monday, 21 July 2014

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 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.

(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!

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