Fully-Functional LEGO Typewriter is More Than Meets the Eye

The typewriter you see in front of you is not the official LEGO Ideas set 21327 from 2021, which puts on a nice display with moving pieces that simulate typing but fails to produce any genuine text. Meanwhile, this design goes much beyond that, with real letters appearing on the surface intended to imitate paper.

Koenkun Bricks worked on this model for three months after the official set was released, driven by the solitary goal of creating something that could type. You’ll be impressed by the finished result, as all of the innovative mechanical solutions are achieved with conventional LEGO elements, gravity, rubber bands, and a bit of precision engineering.

First, each of the 26 keys must be pressed, which initiates the primary action. As you can see, each key is connected to a small mechanism that releases a small round tile with a letter from a gravity-fed magazine stacked above. The tile then glides down a short slope, guided by walls and an arch piece that rotates it around to the proper position. Once it’s aligned over the “paper” area (which is actually just a white plate held up by the carriage), the key’s release activates a rotating frame with a pusher that firmly presses the tile into place, made easier by the fact that some rubber bands provide just the right amount of tension and reset force.

The same procedure must be followed for each character, since the user must fill the magazines with letter tiles (which are actually little plates with the tiles adhered to them to make them stable), and the system will spew out one per keystroke. The carriage moves slightly after each press to handle spacing, due to a rubber band configuration coupled to the space bar via a side mechanism.

The only thing that isn’t completely automatic is moving to a new line, since after your row is complete, you must manually draw a string reel to lift the paper sheet up in a garage-door style fold consisting of arch parts and connectors. The carriage then simply moves back to its starting position, the sheet descends again, and fresh tiles are put into the magazines in preparation for the next line. There are no fancy bell sounds when you reach the end of a line, and no shift key for capitals, because this design is all about simplicity and getting the letters out.

There were a few issues that needed to be resolved early on, such as the pressing force being too weak at first, so the frame was reinforced and the rubber band placements were adjusted around to get better compression. The tiles occasionally got mixed up when they slid down the ramp, but that was addressed with stronger guidance and some slow-motion testing. Then there was the issue of having to put 26 different dispensers into a small space, which necessitated some careful planning and resulted in a few simplifications in some of the reload attempts that had proven to be somewhat dodgy.

In the end, the final demo typed out a whole reply letter to LEGO itself, and the characters actually landed on the plate in sequence to form some pretty readable words, despite the fact that it had a few little quirks, similar to some of the old vintage typewriters that would skip a beat or just tap out a light touch. Once the key is hit, the output remains stationary, providing a tactile record of each keystroke.