Enclosure for 10/25GB Thunderbolt Network Dock

This is an enclosure to fit together a Thunderbolt dock with PD charging, a Mellanox ConnectX-4 Lx 10/25GB NIC, and assorted other components into a reasonably sized box with quiet and effective cooling.

Parts you'll need:

• TH3P4G3V3 (or similar) Thunderbolt GPU dock
  • Requires the two small screws that are supposed to hold on its included bracket, but not the bracket itself.
  • The rubber feet should be removed from the bottom.
  • I got the 85W charging version but from photos I believe the 60W should work interchangeably.
• Mellanox ConnectX 4-Lx card
  • Mellanox, HPE, and Lenovo branded cards should fit, Dell cards have a different bracket and port layout and would need a tweaked model.
  • Some other cards may fit, or could fit with simple modifications to the model.
  • The bracket isn't required but the screws (two M3x6mm button head) that attach the bracket are.
• Supermicro RSC-R1U-E16R PCIe riser, no bracket or hardware needed.
• PicoPSU
  • I'm using a 90W model, which seems to be plenty for my laptop which came with a 45W USB-C charger, but if you want to use the full 85W charging capacity you will likely want a 120W model.
  • Requires a 4/8 pin CPU power connector for the dock to work.
• Power brick with the appropriate power/voltage/connector for the PicoPSU
• Sunon GB0555PD fan or equivalent.
  • Commonly found used under Dell part numbers 0W857R or W857R
• Optional for quiet operation: A fan controller with temperature sensor. I got one of the small import models that uses a single button, three LEDs, and a confusing flow chart to program.
• #4x1/4" or 5/16" (M2.9x6mm or 8mm) flat head sheet metal screws for the enclosure, QTY 13.
  • I used Plastite screws but regular sheet metal screws should work.
• A Thunderbolt 3/4 / USB4 cable
• Some sort of 10/25G transceiver or cable.

Print Instructions:

• Enclosure: Prints with the ports down on the bed, supports required only for the two screw recesses under the ports
• Lid: Prints large side down, no supports
• Fan retainer: Prints flat side down, no supports

I used PETG-GF because I wanted to try it out, but any PETG and probably PLA would be fine, just make sure it'll print 200mm tall thin features without too much warping. Very few parts should have infill, adjust perimeter count and width until most of the walls are solid, then adjust the infill however you like for the rest.

Assembly Instructions:

1. Remove screws and feet from dock
2. Remove screws and bracket from NIC and PCIe riser (if it came with any)
   1. This would also be a good time to re-paste the heatsink on the NIC, that thermal compound is probably quite old.
3. Install the PicoPSU in the power jacks of the dock, don't forget the 4/8 pin CPU power connector (the 4 pin fits in one side of the 8 pin on the dock.)
4. Install the riser into the dock.
5. Install the NIC into the riser.
6. Holding everything roughly in place so the NIC doesn't tilt and break the riser slide the assembly into the enclosure, there's a small ridge which should slide under the NIC to support the PCB on the side opposite the riser.
   1. Expect to flex the side of the enclosure a bit to get the screw mounts to slide past the heatsink.
   2. The SFP ports may require some careful pressure to get the spring tabs through their openings.
7. Screw in the two dock screws in the front.
8. Screw in the two NIC screws in the holes for the bracket. Try not to strip them, but as long as one is in solidly and the other is more or less holding itself in place it should be fine. Worst case, find slightly longer screws.
9. Install the power jack into its port on the front of the dock.
10. Now might be a good time to power it up and test it out before sealing up the enclosure.
11. Fit the fan onto the lid, fit the fan retainer over it, screw in both screws.
12. Poke the fan blades with something thin to make sure they spin freely and aren't bound up on something.
13. Wire the fan and optional controller to the PicoPSU. There are plenty of methods here, just make sure the wires reach and whatever connectors fit in the space to the side of the PCIe riser.
    1. I cut most of the wires off the SATA/Molex pigtail and soldered the fan controller directly onto the 5V and Ground wires, then soldered a 4 pin connector to the fan and double-stick-taped the controller to a spot on the riser in a way that nothing would short out (my photos are from a previous wiring setup.)
14. Some how get the lid on with no wires pinched, particularly on top of the riser, but also around the heatsink.
15. Screw in the 9 screws on the top, I suggest starting by the power jack and working backwards.
16. Screw in the 2 screws under the back of the enclosure, into the lid.
17. Plug it in, try it out, make sure the fan spins, do a speed test or two.

The .fcstd file was made with FreeCAD version 1.0. If you want to change the port layout I suggest not modifying the original sketches, because too many other features depend on those, instead start at the end of the enclosure part and add or cut out material. You should be able to move the bosses that the NIC screws into and the heatsink location without breaking anything, adjust the dimensions in the sketch dock→nic_top.