This map is pretty easy to make, requires no CNC machinery, and was a great excuse to make a mess.
I originally wanted to get one of these made via CNC, either cut out or laser cut, but every one I looked at was way too expensive and the finished product always seemed way too small. Prices seemed to vary from $300-$1300 depending on size and scale etc. I asked a local artist about laser burning the image on to a single piece of wood and I was quoted 843 bucks for a 2'x3' picture! Nope.
I then started looking at building my own 'Maslow' CNC to do the job (totally worth checking out btw) but I serendipitously ended up getting a new Ryobi speedsaw as a gift which changed my priorities.
Total cost of the project was just over $120, and I could've done it much cheaper if I used a cheaper wood and only bought the paint I needed. I probably took me a total of 10-15 hours to make including shopping etc and I've never done anything like this before and don't have a machine shop with a zillion tools. This is my first instructable too.
-Rotary tool - free/gift - (I used a Ryobi Speedsaw, but would recommend using something with speed control)
-Wood mill bit - $15.00
-Medium paint brush - $5.00
-Some kind of projector - free - I used a Moto Z play projector I already had, but you could borrow a regular projector hooked to a laptop or even an old overhead projector for the nostalgic types.
-1x 4'x8' sheet of red oak plywood, around $65.00 I think
-Acrylic Paint (I messed around with a cheapo variety pack, but ended up using only two colours: black and cyan) - about $15.00.
Step 1: Get a Topographical Image
The first step is get a topographical/sounding image of your chosen lake/body of water/topographical feature from the interwebs. A quick google found the lake I was going to make. If you can't find your map, try calling the local city hall/municipality, they might have something. The more gradations that are on your image will translate to more layers of wood you'll need, so consider skipping layers to make it easier to make.
Step 2: Get the Materials, Project Image
There's a lot of different types of plywood to choose from, I had no idea. Visit a few lumberyards, as home depot probably won't carry anything remotely exotic. You could theoretically make this out of anything that comes in sheets such as ABS, clear or smoked plexiglass too.
I used a single sheet of 1/4" 4'x8' red oak plywood, and had it cut into four 3'x2' pieces at the store, as my image has 5 layers, one of which is really tiny. I used a piece of the scrap for a final bottom 5th layer. It's worthwhile talking to staff, they know which woods are more durable and easier to work with, and if they warp with temperature etc.
One thing to consider as well is how many layers you will have, and how thick this is going to make the finished product. This one turned out about 1"" thick which seemed manageable to hang on a wall weight wise.
You then project the image of your lake using a OHP or a multimedia projector of your choosing onto each layer and use a pencil to transfer the map to the plywood. You could even use vellum to transfer an image from a printout like Indiana Jones if you really want to punish yourself. Remember you only need to draw each depth once per sheet.
Step 3: Cut Out Your Layers
This step is pretty self explanatory, but go slow. The speed saw tended to try and skip off, so I would recommend using something with a speed control. You'll notice I tended to burn my image in, which was because I was going too slow with too fast a tool. I had to go this slow to avoid skips, so learn from my mistakes!
I kind of dug the burned in effect and would've kept it if I was staining and not painting.
When you are cutting out a layer, keep in mind round tool marks. They'll pop out and be obvious. You can use a small file to unround some edges, but I didn't bother, I just enlarged small tight sections to be less circular as needed. Some artistic license is required, no? Nobody had better google to see how accurate it is... haha. I tried using an eraser to remove burrs, which worked ok, then I switched to a file which worked a lot better.
Step 4: Decisions...
The toughest part of this build was deciding on painting, or staining, or using nothing at all.
I decided to paint, but I could've stained it all one colour, or used a different darker stain per layer. I could've used different wood types to denote the depths which in retrospect would've been really cool. Perhaps next time.
Painting is nice because it is cheap and really pops. You can change your mind about colours after the fact too...which I ended up doing as you can see. The first time I used a whole bunch of pigments, but I couldn't seem to hit the right gradient based on my tests prior even though I was writing down the combos.
The second time I used just two colours, a whole lot of cyan, and then I added black as I went through each layer, which simplified things ridiculously. In order to nail the colour gradient, I recommend using a gradient generator such as ColorHexa.com. I find the exact colour by downloading an app such as Color Picker that will tell you the RGB or Hex code of your base colour based on a photo, ie. cyan for me. The finished product is a bit less punchy but I think better balanced.
Step 5: Assembly, Final Thoughts
Before assembly I decided to sand all the edges with a rotary tool to remove the burned in look and any paint on the edges. Painting the edges would've also looked good, but in the end removing all the paint from the edges made any stray burrs easier to remove, and gave it that fresh CNC look.
I decided I wanted to screw the 4 bottom layers together from the back, so if the someone wants to change the colours in the future they could do so easily. The top layer will be eventually screwed on under a frame so there's no screws/holes showing. I would recommend drilling pilot holes for the screws to prevent cracking while the layers are clamped together, then throw the screws in. I used #9 3/4" countersunk screws.
I decided to leave the top layer unstained and unattached until the new owners decide on a top colour/stain to complement their walls, and then I'll sand the outer edges smooth once its all fully assembled.
I'm pretty happy with the results, and so are the new owners. Let me know what you think in the comments.