As with the power card, I suggest only cutting one of these cards initially, from some of your thickest 3 mm acrylic. Use that card to test fit your circuit boards and test fit in the card slots before cutting the other nine.
Step 1. Remove 30 RCA Ports
For 3 out of 4 Raspberry Pis, you’ll need to remove the RCA video port to use this card design. (Removing this port allows us to pack the Pis together more tightly.) I recommend desoldering the port using a soldering iron. I tried using a heat gun with a custom-made shield to keep the rest of the card from getting too hot and it was ineffective, because the melting point of the solder they use on these is rather high.
Step 2. Laser Cut and Glue Acrylic Parts
The process of cutting and assembling the parts for this card is essentially the same as the process for the power cards. Please refer to that step if you have any questions about the general procedure for assembling these cards.
As is noted in the Inkscape .svg file, many of the stacked parts in two of the layers are the same. Therefore, you can save yourself a lot of effort during assembly if you simply cut half as many of those parts out of 6mm acrylic.
Step 3. Assemble the Finished Card
Like with the power card, you’ll end up with a top and a tray.
Place the Raspberry Pis into the card. Note, I left one space at the end of the card for a Raspberry Pi that hasn’t had the RCA video port removed. This will save you the effort of removing the RCA port from a total 10 of them. Of course, they’ll still fit in the card if you remove the port from all of them.
And here’s a nice shot of the parts from 6 of these cards curing, after a 2-hour gluing session. Always remember to work with adequate ventilation, especially when you have a lot of parts to glue.
|3. Power Cards||4. Raspberry Pi Cards||5. Router Card|