Absolutely fantastic! Just curious, is that a hard drive mount on the upper part?
You are right. I forgot to mention that there are mounts for a 120 mm fan, a 2.5 inch disk (with cable minimum length 30 cm), 8x8 led matrix on WS2812 to display any events (I havenāt thought of any yet) and the router board itself on a removable panel. I will post the design soon and give a link here.
Updated on Nov 1. Please tell if you like the design.
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In terms of air circulation, it is much better than the original caseā¦ Could you provide 2 holes in the back (where the RJ45 ports are) for antenna pigtails? I have 10 antennas (6x WLan and 4x LTE). Could you also publish the files as DXF? I have the option of laser cutting. Only they need the templates as DXFā¦
Itās hard to make it with laser cutting since most components in this design have figures in all three axes.
Hm, ok. But could you provide 2 holes in the back (where the RJ45 ports are) for antenna pigtails? I have 10 antennas (6x WLan and 4x LTE).
Iāll release the step files soon, you may modify it to fit different manufacturing processes.
Go check the latest file selector.
Thank you for your work, @Stonty. Here is another idea you might be interested it. There is a problem with the stacked PCB design of the R4, which causes strong RF interference from the main board to the Wi-Fi module (check this thread). One solution would be to move the NIC away from the main board using two extension adapters like this one. I havenāt used these before, but Iām willing to check if they work.
Looking at the mezzanine add-on for the antennas in your design, there should be enough room to do so, possibly flipping the NIC upside down to keep the heatsinks ventilated. Beside the practical reasons, making the wireless part self-contained like that just seems cool to me.
I think my design could easily be adapted to your idea (just add a rectangular hole to pass the FPC cable through - this can be done with boolean operations in most software). To me, I guess the main problem with your idea is PCIe signal integrity - you may need to use a retimer or even a redriver in the extension module.
Flexible PCIe risers for PC work fine unless the length is crazy. Iāll keep your warning in mind, though.
I might add that in your design the main PCB is upside down when the mezzanine is used. That is not ideal for SFP modules and RJ-45 jacks, as the locking mechanisms end up facing down (SIM trays too). Connecting the wireless NIC with flex cables could change that too. Instead of both PCBs sitting in the middle of the air flow they could form the floor and ceiling of a wind tunnel, possibly reducing the overall height.
Actually, itās upside down on purpose. I first tried to put it upright, but I found that the heat sink put too much pressure on the NIC card and it bent (I used a zip tie to fix the heat sink).
To be honest, I think your idea is quite great. I also considered a similar idea when I was designing at the beginning, but finally gave up because of its complexity. In addition, regarding your mention of āFlexible PCIe risers for PC work fine unless the length is crazyā, in fact, although most PCIe devices have a high tolerance for PCIe signal integrity (I have even seen applications that transmit PCIe signals through USB D+/D-), I still recommend using best practices to avoid any problems. Especially from the past history, I donāt think that BPIās PCIe design redundancy may be sufficient.
Then it remains to be seen if the extenders work. If I end up exhausting all shielding options and the RF noise is still bad, that would be the only thing left to try.