This is a more elaborate version of thing https://www.thingiverse.com/thing:3382580, using the same technology as the other Zuse inspired parts.

A 3 to 8 decoder could be created with a collection of AND amd/or OR gates, but this would require several stages and clock-cycles. This design reduces it to one but for the price of having to move a chain of plates which due to tolerances becomes less reliable. The layout is unlikely to van been used in the real Z1 calculator, but it nicely shows how a decoder can operate.

In the realized decoder, each function has its own color; gray for the fixed structure, yellow for the inputs, black for the clock plate, green for the intermediate plates, blue for the output plates and red for the switching pins. The clips on the pins have the function of keeping the plates in place during movement.

• Die Rechenmaschienen von Konrad Zuse/Hrsg.: Raul Rojas. Mit Beitr. von F.L. Bauer, H.Dorsch, H. Petzold, R. Rojas, G.-A. Thurm und G. Widiger sowie zwei Patentschriften von Konrad Zuse ISBN-13:978-3-642-71945-5 Springer-Verlag Berlin Heidelberg 1998

• https://sdtb.de/museum-of-technology/exhibitions/1256/

• The Design Principles of Konrad Zuse's Mechanical Computers (https://arxiv.org/pdf/1603.02396)

• The Z1: Architecture and Algorithms of Konrad Zuse's First Computer (https://arxiv.org/pdf/1406.1886)

• Some more information on the reconstructed elements (https://electrickery.nl/mechanics/zuseGates/)