Thinkpad 4-Pin hexagon to USB-C adpater

About this:

This is a Power adapter for ThinkPads that have the Hexagonal Power Plug on the back.
According to https://www.thinkwiki.org/wiki/Power_Connector the following models are known to use this connector:

• ThinkPad 355, 355CS, 355C
• ThinkPad 360, 360P, 360PE, 360CS, 360C, 360CSE, 360CE
• ThinkPad 370C
• ThinkPad 555BJ
• ThinkPad 700, 700C
• ThinkPad 720, 720C
• ThinkPad 750, 750P, 750CS, 750C
• ThinkPad 755CD, 755CX, 755CV, 755CDV, 755C, 755CS, 755CSE, 755CE
• ThinkPad 760ED, 760XL, 760L, 760C, 760CD, 760EL, 760ELD, 760E, 760XD
• ThinkPad 765L, 765D
• ThinkPad Power Series 800, 850
• ThinkPad 820, 851, 860

According to https://thinkwiki.de/Netzteil (German) there's also Japan-Specific ThinkPads that use the same Connector Shape with a different Pinout and different Voltage.

Additional parts and tools required:

• 3x M2*6 Self Tapping Screws
• 1x A USB-PD trigger board that looks like this: https://amzn.eu/d/8ZMENQG 
  • about 30mm long, 20mm wide, 4,7mm high
• 2-4x Hirose DF1B-2022SC##
  • Tested with DF1B-2022SC, but the last two letters only specify packaging and plating and probably don't matter for this application.
• Some wire between 20 and 22AWG.
• A crimping tool. I used one meant for Dupont connectors and it worked just fine.
• A Soldering Iron.
• Wire Strippers, cutters etc.
• A Screwdriver for the 3 screws.

Assembly:

1. Print it in this Orientation with decently thin layers.
   I used the 0.12mm Fine preset on my X1C. Only plug_h1 and plug_h2 need to be this fine. The other two parts can also be printed with thicker layers.
   
2. Crimp the Wires to the Connectors. You only need two, but four make for a slightly better grip when plugged in.
3. Pull the wires through their respective channels like this:
   
   The wire should go through without any snags. The connector is held in by friction, so don't try to pull it in by yanking on the cable. Press it in by pushing the whole connector-half onto a flat surface.
4. The two connector-halves should fit together without any friction. 
   For some peace of mind you can add some Kapton-tape between them where the exposed sockets are. I didn't.
5. Thread the wires through the holes in the main box and push the connector-halves in until the screw holes align.
   
6. Hold the connector-halves together while screwing in two of the M2 screws.
7. Put the USB-C PD board onto of the cables, making sure they're in their channels.
8. Solder the cables to the correct terminals. If you have the same PCB as me, you might need to cross them.
   
9. Set the Voltage using the DIP-Switches on the board.
10. Plug it into a USB PD power supply and use a Multimeter to measure if the Voltage and the Polarity is correct.
11. Put on the lid and screw it on with the remaining M2 screw. It should fit without any force. If it doesn't, make sure you don't pinch any wires.
12. You're done. Measure the Voltage and Polarity again just to make sure.

Usage:

Plug it into the back of your compatible Laptop. The Rectangular part of the connector is supposed to go into the Socket as well. It might need a tiny bit more force when plugging it in than the hexagonal part does. 
Remember: Old Plastic is brittle, and your Laptop is made from old Plastic.

Known issues/TODOs:

• The lid isn't secured at the front and sometimes flexes when plugging in a USB-C cable.
  • Workaround: Stick the USB-PD board down with double-sided tape.
• The connector-halfs like to spread apart when putting in the screws.

Files: