January 2, 2018
Recently the price of crypto currencies has exploded. Through December 2017 we saw a massive value spike across the board on almost all major currencies, based mostly on the movements of BTC.
Whilst I’m not a huge fan of BTC currently (price surge and the networks scalability means that the cost per transaction is around 20USD), I do dabble in Ethereum (ETH).
I used to have all my ETH stored in online wallets with my exchange, however recently I had a urge to begin mining currencies which spurred me to setup an offline wallet that I can manage myself.
One of the the outcomes of setting this wallet up was that I was given a public wallet address that I can use to reference my distributed currency on the blockchain.
As you can see above, one of the neat things you can do with your wallet address is view it as a QR code. This simple thing gave me the interesting idea to 3D print a QR code version of my ETH wallet address that I could keep in my wallet.
3D Modeling a QR Code
In order to create the 3D model, I referred to this Instructables tutorial about how to do it in Blender.
I generated the SVG of my QR Code by using QRCode Monkey, however, there are a number of services online that will help you to do it. Remember to pick the quality and density of the QR code based on the limitations of your printer.
Once you have the SVG, load it into Blender using the import menu.
The layer will load into Blender with an awkward square background shape. You can remove this OR do what I did and simply hide the layer, as we will likely use this later on as a base plate for the QR code.
Next you want to select all the layers in the workspace. The easiest way to do this is to hold CTRL and Click & Drag around the pieces.
Convert all the layers to a mesh by going to the Object menu (bottom left) and select Convert To then click Mesh from Curve/Meta/Surf/Text.
Merge all the layers into one object by going to the Object menu (bottom left) and select Join. You can alternatively press CTRL+J
Next, extrude the single layer upwards by going into Edit Mode, and enable Select faces. Then do as you did before and select all the meshes in the workspace.
Finally press the E key and drag upward to extrude.
3D Printing the QR Code
In order to 3D print the QR code, I needed a stable platform for the blocks to be etched onto. I decided to add a bottom layer to the code so that I wouldn’t have to do any insane hotgluing later on.
The final results looked as follows in CURA. I had to scale the size down as Blender likes to export at a 1 meter scale.
You can also find the Blender and STL files for my QR code here for reference:
The plan was to quickly change the filament out half way into the print, just before or during the extrusion of the QR blocks. I had a lot of worries around what effects the hot printing tip would have on the base if left too long, however in the end I was able to swap out the reel in time so that no large amount of damage was caused.
The Final result worked out fantastic, however I did notice that the red was difficult for most of the QR apps I used to scan. I first thought that maybe in my stupidity I hadn’t realised that QR can only be Black and White, however I later rules this out, as all QR apps seem to convert the image input to Black and White before reading anyway.
BONUS: 3D Printed QR Cube
I also tried out how a cube would work if printed in a similar fashion (however I can’t do the filament swap here).
I simply duplicated the base pattern for each side of a cube.
When loaded into CURA, the inside was hollowed out so that the print was cut down to sub 2 hours.
The final result for this experiment worked as expected, It doesn’t scan exceptionally well due to the single colour; however the shape is very clear and defined and it’s a neat little desk toy.
In the future it would be interesting producing little keychains, and if I ever get a dual extruder for multi-colour prints I could produce some nice little bricks!