In 2023, after tinkering with typewriters for a while, I finally bought a Teletype machine. They work via a current loop. The sender interrupts the loop in a morse code like system called Baudot Code ( this is also where the work baudrate comes from ). The receiver uses an electromagent to decode those interruptions back into their respective character.
The Lorenz lizensed Teletype Model 15 machine I now owned used the german ADoS, so called Walzenstecker, connection for this loop. Two contacts for the sender, two contacts for the receiver
Finding this out took me long enough but since they are not in use since the 1960s I had to find a way to connect my machine to the needed current loop
My LO15 Telex Machine
I quickly decided to design and print my own socket
As information about this old connector are very sparse I had to take some measuremts along with reference photographs.
Reference Photos
There where some conditions I wanted my desing to fullfill
-
Security
The socket should be held securely in the socket
-
Part availability
The socket should use only hardware that can easily be ordered
-
Printabilty
The socket should be 3D printble. Preferably without support structures
-
Mountability
The socket should be mountable in various orientations
-
Flushness
The connctor should be flush against the socket
After some design itterations I finally came up with an easily printable 2 part design
I first thought about using pogo pins for the electrical connection but decided against it because of cost as ease of implementation in 3D printed case. Instead I am using the metal part that is used to hold two tubes together. You might know it from a parasol. I do not know if they have a special name but I found them as Snap Springs. I am also using battery spring contacts for the bottom center contact. I would have prefered copper contacts but for what it is these work suprisingly well
The snap springs are preloaded against the plastic and held in place with M3 screws which also work as the main terminals
The end result
While using steel contacts is not the best in any situation the desing does work realiably and even has a satisfying click as the connector is inserted.