The case uses the “T-slot” assembly technique, with #4-40 nylon screws and nuts. You saw one of these when joining the screen and speaker pieces.
Unlike that first slot, the remaining T-slots will be too deeply recessed to reach with fingers. Instead, you’ll need some masking tape to temporarily hold each nut in place.
Doesn’t matter if it’s the blue or tan type, but it does need to be masking tape. It has a relatively weak grip and doesn’t leave residue behind.
If using a Pi 3 or similar form-factor board, slide a nut into these two T-slots from the underside. The board with block them from slipping out the other side.
Cover each with a small piece of masking tape to keep them from falling out the front. The nuts should be captured in place now.
If using a Pi Zero, the sequence is a little different. Apply the tape first to the bottom face of the base piece, covering the two T-slots. Then, from above, slide a nut into each of the two slots. Really press them in to make sure they’re making good contact with the tape.
On the speaker/screen combo there’s four T-slots total, two above the speaker, two above the screen.
Procedure is the same: apply tape over the T-slots from behind, then press nuts into place from the front.
If the screen piece doesn’t have T-slots in these positions, it’s probably turned 180° from how it should be…go back to the “Cabinet Part 2” page and check the assembly instructions there.
And once more for the joystick support. Two pieces of tape from behind, two nuts from the front.
There should be 8 nuts and tape bits at this point.
Set one of the large side pieces flat on your work surface. Either one is fine…we’re using the right side here.
Hey! That wasn’t so hard. Wait for it…
Take the jumble of parts and try to (roughly) align the tabs on the speaker grille, screen and joystick supports with the corresponding holes in the side piece. They probably won’t stay in those holes for very long, but at least you’ll know where they belong.
Start to place other elements vaguely in position: Pi near the bottom, buttons near the front. Tabs into holes.
(The second photo shows the front black-buttoned piece slotted into place. While you can do this at this stage, it’s not necessary. Focus on the parts with T-slots. We’ll show how to insert all the non-T-slotted parts later.)
If you find your wires getting tangly again, it’s okay to disconnect and re-route them.
And so begins the interpretive dance called Sealing Up the Cupcade Case…
Pivot the screen support piece up slightly, fit the screen bezel into the slots on the speaker grille, and lower it all back into place.
Fit the joystick and button supports into their own slots as you’re working on this section. Use masking tape to hold these four pieces in alignment.
Notches along the top edge of the button support should align with tabs on the screen bezel. If not, your button piece was assembled upside-down. Remove the quick-connects, unscrew the buttons, turn the piece over and reassemble.
The trick now is to pick the whole thing up just enough to feed these two screws through their corresponding holes in the side.
The screws don’t need to be tight…in fact a little “give” is helpful at this stage. They just need to catch the nuts that are taped in place.
Some of the acrylic parts will fight a bit and not fit into their slots. Poke a small screwdriver through the hole and try to nudge these parts the right way.
If this is a dexterity challenge or you have smaller hands: rather than installing screws from below, remove the masking tape from the prior step and try fitting the side into place from above. Once the screws catch, you can turn it over and proceed through the same steps (just reversing right and left). Another approach is to scoot the whole assemblage just enouh off the edge of the table to reach the screw holes from below (one at a time).
A third screw installs from the side at the top of the speaker grille piece.
A fourth screw holds the Raspberry Pi base.
You can now remove the joystick-and-screen-aligning tape from a couple steps prior. Only this tape! Keep the other tape (holding nuts) in place for now.
Now to repeat these four fasteners on the opposite side.
Make sure all four nuts are still held in with tape. If any have fallen out, press them back into place.
Now set the other side piece on top, roughly in position. I can guarantee the tabs won’t all fit. That’s okay, we’ll align things one at a time…
Here I’m starting with the joystick area…but you might want to start with the base piece instead; it has the fewest interferences. It’s only because I’ve done this a few times and have the hang of it.
Get the tabs and holes aligned for nearby parts, then insert a screw. Do not crank it down…a loose fit is fine, just so it has a good hold on the screw.
Again, it’s okay if the piece with the black buttons isn’t in position yet. Focus on the T-slot pieces that require screws. We’ll get the rest later.
Work your way around the case, aligning the tabs closest to each hole and then inserting a screw, four in total.
You may need to nudge each piece into position using the tip of the screwdriver through the slots, or with a finger from behind (when it can fit).