Developing SMS socket to connect to paddle cards

WHIPPING UP A FEMALE SMS SOCKET FOR THE BOX

I think I have a good plan for a female socket to plug into an SMS paddle card. I built some SMS signal paddle PCBs that I could adapt.

Using some 1/8" or 3/16" stock, I could cut some pieces and drill holes so they create a channel for the incoming SMS paddle card. Another larger plate sits on top of those side channels and creates the socket. Soldering some spring contacts on the pads of my PCB will allow good contact when the male paddle card is inserted. I could also add a block to stop the paddle card from inserting too deeply. 

I soldered some RF shield fingers as springy contacts - it wasn't a perfect job but they are all there with no shorts. Next I cut up some brass I had as the spacers and a plastic spreader as the top.

Very quick and dirty, but sufficient to test out the concepts and spacing. The brass spacers were .09" high and the tests I did shows that I need the space to be almost1/8" otherwise the contacts have to bend too much. However, by loosening the nuts slightly I could insert another SMS paddle card into this makeshift socket and verify connectivity for all thirteen pads. 

I have one additional spacing detail - I need grooves on the sides that are 2.2" apart. The SMS signal box in the 1130 into which the socket attaches has top and bottom rails separated by just over 2.2", thus the socket is held in place while in the system. 

Based on these tests, I will design a socket structure to connect with my SMS paddle card. It can be 3D printed fairly easily. 

I believe I can design a simple 3D printed part that can be attached with screws and nuts to form a socket, something cleaner than some scrap parts cobbled together. I will work on that but this temporary socket gives me an emulator box that can be long term loaned to the System Source Museum for use whenever the 1053 typewriter is out of service.