Pictured above is the earliest photo I took as I was test fitting the pieces. The general build order is:
- Get the metal plate cut
- Handwire the keyboard and test it
- Meanwhile, print all the printed bits
- Insert the inserts into the printed parts
- Fit the screen and assemble the screen housing
- Fit the battery, charging circut and USB hub into the tub
- Fit the Kippah and pi together into the right smaller tub
- Wire everything together
- Bolt all the bits to the plate
- Attach the screen
- Attach the cover over the electronics
There's a lot there to do, but nothing particuarly difficult. Reach out with questions. Here's one KEY point before I dive into more photos...
Check that business! Different batteries/charging boards have different JST pinouts.
Make sure you check your combination and adjust the plug as needed.
Okay... with that done.....
You can see the plate alone in the photo above. You can choose any material, but I went with stainless steel as it's cheap and strong. To have the switches properly latch into place you'll need to have a thickness around 1.2mm. Too much thicker and the switches won't seat correctly and the plate is the only thing holding them in place.
I use SendCutSend here in the US, and I've heard good things about LaserBoost in Europe. The file is ready to go under /case/plate_v01.dxf. Scale is in MM if your service asks you to verify.
There is a whole page on the details of this. Check the navigation below. Key thing is to do this before you start bolting anything else to the case to make things as easy as possible.
All the STL files you'll need are in the /case subdir. You'll need one of everything. Tubs are the
bottom pieces and bezels are the top. The screen has it's own files screen_tray_* with a bottom
and top piece.
The USB retainer can be used if you like to shim a small area between the metal plate and the external USB ports. It's not required and can be a bit of tight fit, depending on your printer.
All the screws mate into threaded brass inserts. I set my soldering iron to 250c, which is just above the melting point of my filament, and use an old tip which fits inside the insert. This allows me to heat the insert and use the iron to push them in. I usually end up needing a set of tweezers to hold the insert in while I remove the iron.
Most of the inserts are for securing case pieces, and these use M2.5 inserts and screws. There are some for the lipo charger and kippah, thes should be M2.
Use the longest inserts you can. All the blind holes (no exit) for the structure/case need inserts. Some screws go from the top through the plate and into the inserts (screen area and around the keys of the keyboard. The remaining ones are screwed in from the bottom through the tub pieces, the metal plate and up into the bezel pieces to sandwich everything together.
This is the only photo I took that shows the screen sitting in the top of the tray. It friction fits in
and should hold snug. Make sure you remove the protective coating before you insert it and screw the tray
together. I used kapton tape to tidy up the cable extension PCB and secure it to the back of the screen.
The version of the screen tray back pictured here is missing a cutout for the extender PCB which I added
later to make the whole thing fit easier.
The extension cable will need to be mated to the PCB and routed inside the screen tray and out the bottom. Here's the best photo I have which shows the routing:
The battery and USB hub are friction fit, as is the switch for the charging board. The board itself screws into M2 inserts. In the photo above I still have the normal mini-USB plug on the cable for the hub, but I cut this and extended it so it can reach the port on the Pi.
The output of the charger needs to be wired up to the pi, you can either fit a mini-usb plug to it or just solder onto the pads under the board as in the photo above.
Refer to the photo above. The Kippah is secured with two screws and the Pi just plugs in to it and is not secured in any other way.
Check the assembly photo above to see my final wiring. This has the USB hub cable extended, the power routed to the Pi and the keyboard controller plugged into the internal port of the USB hub. There is a good amount of room, so you should not have to be toooo fussy.
Some of the 3d printed tub pieces are secured to the plate with screws from the top. The remainder are screwed through the bottom tub pieces and the plate into the bezel pieces. Hopefully from the placement of stand-offs, plate holes and pieces this will be clearer. Feel free to ask any questions along the way.
Once all the body pieces are secured, the last big task is to secure the hinge to the screen tray and then screw through the big tub below the screen into hinge. I used solid brass 2.4mm diameter rod as a hinge pin. I suggest using two pins, one for each side, but you could go stright through with one long piece if you like.
Once you've got the screen tray attached to the hinge, you can secure the assembly to the unit with screws through the tub underneath. Use the longest screws/inserts you can here as this takes a bit of force.
Depending on your printer tolerances, etc the screen may or may not hold position when open. You can adjust this a bit
with printer settings, or print the Friction_wedge_v3.stl and insert these from the sides to add more friction. This
is one of the trickier bits and there is not substitute for experimentation here.
There is thin cover that secures directly to some standoffs in the screen tub piece. Secure it with short screws to keep everything tidy and protected. Then, you are done!
Install any OS you like, but Raspian is well supported by Adafruit with the Kippah driver, so I'd suggest sticking with that unless you are daring.
Thanks for reading this guide and maybe trying to build one of these. Reach out if you do, I'd love to see what you built and learn from your experiences.