I have always loved maps, and have been interested in topographic maps. I had purchased a laser cutter from china which saw no use for about a year. On my drive back from Bear mountain, a friend of mine had a brilliant idea: take the contour lines, cut each layer on a laser and stack them to create a 3D topographic map. So I decided to give it a shot. After countless hours in the garage and many prototypes, I finally developed a process that produces some really impressive results. I have decided to share my experience here, so do read along and build yourself one of these wonderful looking maps!
Also i have put them up on Kickstarter, and if the project gets funded we hope to start producing them for the public.
Step 1: Getting Started
So you want to make one of these? Here is what you'd need to gather
- Decide on an area, it can be anything from a city to a continent
- Decide on how big, personally i like the 18in x 24in size for a first map
- Download and install ArcMap, it's the GIS program we will use to create and export contours. There is a 60 day trial that you can utilize
- Obtain a DEM (Digital Elevation Model) file for your area. UGIS NED (National Elevation Dataset) is a great source, as they aggregate elevation data from various sources. Obtain the best resolution you can get for your area.
- Obtain a vector graphics program like Adobe Illustrator/Corel Draw for post processing the ArcMap export.
Step 2: Preparing the DEM Files
The goal here is to create vectors representing contour lines at certain elevations. These vectors can then be sent to the laser cutter and later the layers can be stacked to obtain a 3D contour map. DEM files are rasters representing elevation data. They encode elevation through a grayscale gradient. We will use ArcMap to generate these contours at specified intervals. Fire up ArcMap, choose your map size (22x29 here) and select a basemap. Here I choose OpenStreet Map.
Step 3: Preparing DEM Part2
Import your DEM into ArcMap by dragging it in from the folder onto the application. It should appear on top of the basemap of your chosen location.
Here the DEM for Africa appears above the Open Street Map for Africa. Layers appear on the Table Of Contents window to the left, they can be turned off/on using the check-mark.
ArcMap lets you choose various symbologies to represent elevation data. I found it best to use a classified function to map a range of values to a single color, where previously it was a continuous gradient. This lets us draw contours at specified intervals. I choose to use a non-liner interval here as it creates more uniform contour intervals rather than bunching them up at steeper elevation changes.
My goal was to create six layers, as I was planning on using 1/8" birch for a total height of 7/8" (6 elevation layers + base layer). This is a decision you will have to make based on how thick you want the map to be, taking into account your layer and frame thickness.
Right click on the DEM layer and select Properties. Select Symbology -> Classified. Select Six classes and a color scheme. Now your DEM should be classified into six color intervals.
You can further refine your classifications by clicking on the classify button, this will influence how your contours will look, as you can choose between a liner/non-linear/custom binning. The optimal binning will depend on how varied your area's elevation is. The graph in the classify window represents the distribution of your elevation points. Click on the images above for details.
Step 4: Smoothing DEM
Before generating contours you might have to smoothen your DEM, as LASER cutters do not like jagged lines, these lines create burns and will increase your kerf. Fortunately there is a Focal Statistics tool in ArcMap which averages groups of pixels and smoothens the DEM. The amount of smoothing depends on how complex your DEM features are. The goal is to obtain smooth contours, so you will have to play around with your Neighborhood settings option in Focal Statistics.
The Focal Statistics Tool can be found(as with all other ArcMap tools) on the search box to the right(See image above)
Step 5: Generating Contours
Contours are generated from DEM files using the Contour tool. Select the Contour tool (See Images Above) choose your base elevation, interval and let it do the magic of converting the DEM image to contour vectors. You might have to reclassify the elevations into a linear interval before doing this if you choose a non-linear step during the classify operation. This is because the contour tool only accepts a linear interval. The reclassify tool can also be found in the search bar.
Once the contours are generated you might find that some of the contours are too small, pick the smallest acceptable contour and get its length by double clicking on it. Explore the attribute table, sort by shape length and delete all shapes smaller than the smallest acceptable (see images above). Tiny contours will not cut out cleanly on the LASER. They will essentially be burnt out holes, or be too small to handle. The smallest possible contour will ultimately be a factor of how small the kerf is on your LASER.
Step 6: Adding Lables, Country Borders Etc
ArcMap has a database of country borders, roads, rivers etc. which can be added for engraving to give your map a cooler look (See Images).
Here we add country borders, rivers and city names. Labeling options for each of these features can be found by right clicking the feature layer and selecting Properties -> Labels.
ArcMap offers extensive labeling options including hierarchies and rules for where the labels can be placed i.e. allow on top of lines etc.
Step 7: Add Other Map Elements and Export.
ArcMap has other map elements you can add including a scale, a compass etc. You can find these options on the inset menu, here we choose to add a scale and a compass.
Once you are happy with your map on ArcMap, export it to Illustrator using the export option.
Step 8: Illustrator Prep
Once exported to illustrator prep your files for laser cutting. Export each contour elevation to a separate layer as we will be cutting each contour from a separate sheet of wood. Also export the engrave layers such as roads, labels, rivers, borders etc. to a separate layer for engraving.
Step 9: Off to the LASER!
We decided to use 1/8" birch plywood which takes a stain well for our map. Experiment with various wood stains to achieve the look you want. We are cutting each contour interval on a separate sheet to make assembly easier. engrave first, then cutout the contour one layer at a time.
Step 10: Assembly...
Once you have the layers cut as separate sheets, assembly is simply a matter of aligning each sheet and glueing the contour sections. You can choose to minimize the wood used by masking each layer in illustrator, and only cutting out the required areas. We find that cutting out the entire sheet for each layer method to be vastly easier to assemble. As aligning small contours by hand is a pain when it comes to gluing. Super glue is best here because it sets in about 10 seconds and you can move on to the next layer instantly.
We used a Red Oak balusters from home depot for the frame.
Voilà!, you now have your own 3D Topographic wood map