Since posting my LEGO Mindstorms Telegraph machine and Printer, I’ve received several requests to make a video showing how to set it up and calibrate it. All of this information is documented in the original blog post, but hopefully it will be a little more clear for some people in video format.
printer
Telegraph Machine and Printer
One project that had been on my to do list for a long time was to build a working printer using a single LEGO Mindstorms EV3 kit (31313). In addition to having basic printing capabilities, I also wanted an easy way to tell it what to print on the fly, without having to manually change the program. For that I added a touch sensor, essentially turning it into a telegraph machine, so that you can tap out a sequence of letters using Morse Code which it will then print.
I put together building instructions for it, which you can find along with the program file and more detailed information about how it works, down below.
The printer is designed as a plotter, using a gel pen mounted on a carriage to deposit ink on the paper. It can accommodate standard sheets of letter paper cut in half. I posted a video a couple of months ago explaining how the printer works in detail, which you can watch here.
I hope to explore different ways of sending information to the EV3 unit to print, but the first step was to program it to print text on demand. The advantage of using Morse Code is that it is an extremely simple and effective way of communicating textual information, that requires only a single touch sensor to implement. In this video you can see the telegraph machine in action.
LEGO Mosaic Printer
Over the last couple of months I’ve been working on an ambitious project – to build a LEGO Mindstorms EV3 machine that can scan an image and then print out a LEGO mosaic of it. Here’s a video of the final model printing out the LEGO logo.
It is built entirely using LEGO parts. It first uses the EV3 colour sensor to scan the source image and save the data on the Mindstorms unit. It can then print multiple copies from the saved image data. The 1×1 plates used for ‘printing’ the mosaic are supplied using a gravity feed system and the printing head is simply a 1×1 round plate that can pick up and place the 1×1 plates.
I created a series of videos documenting my progress as I built it, so if you are interested in seeing how this project evolved be sure to check them out here. I also explain and demonstrate in more detail how many of the components of it work in these videos.
I had originally hoped to be able to scan any type of image and have the program pixelate it based on the colours of the plates in the supply. Unfortunately the EV3 colour sensor is no where near precise enough to be able to do this. I resigned myself to require pre-pixelated images to be scanned.
Perhaps in the future I will expand this project into the realm of 3D LEGO printing. Stay tuned!