Shell Cuts (for LiPo)
There are a handful of cuts you will need to make for fitting the AGBM-11 or AGBM-12 boards in a shell. This process may be different depending on the shell you purchase, but I've found most of the back halves of shells across various aftermarket sources are similar.
Also be warned that cutting into the shell may leave marks or whitened parts of the shell that can show through in transparent shells. Attempt this at your own risk. Also be prepared to do a bit of trial-and-error in doing these cuts, they're a bit hard to show diagram...atically?
(Remember: using an AA build does not require any shell cuts, gets you longer battery life with NiMH rechargeables, and won't be in danger of exploding!)
- Hand drill set
- File set
- A junk GBA shell to practice on
- Optional: Displex and microfiber cloth for polishing clear/translucent shells
The JST port for the battery sticks out through where one of the AA battery springs were, and the JST port is taller than the plastic allows so you need to shave it off a bit. Also, the USB port has to stick out in a specific location and that requires the circuit board to jut out into an area where there is shell interference. You'll need to shave off a few sections.
This is another view of the shell from the top-down. The boxed area is the same area as the top-right-hand-corner box in the above image. I sometimes use a hand drill to get rid of this section of plastic, just very carefully drill straight down. When cutting the USB-C hole in the next step, you'll need to file this down further, so don't worry about how it looks just yet.
For yet another view for clarity, this is the part of the shell the PCB interferes with.
Cutting this hole into the shell is tricky and requires a lot of guess-and-check. What I generally do is:
- Put the bare PCB in the shell and make sure it's centered with the mounting holes in the proper places
- Mark roughly where the ends of the USB-C port will be on the shell (bias it away from the edges of the port so you have room to file) - see pictures below for reference
- Drill three holes with a hand drill and a drill bit with a smaller diameter than the thickness of the USB-C port - two on the edge of where the port will be and one in the middle
- Carefully cut away the plastic between the holes, and smooth out the hole with a file
- Now that the starter hole is cut, solder in the USB-C port in the board to make it easier to figure out where exactly to file
- Slowly file away the edges of the hole until the port fits in - checking the fitment is a bit tricky, because you have to angle the board as you put it in the shell to slide the port into the hole
It's a lot of slow, procedural cutting. Be careful, as you don't want scratches in the plastic! The right side of the port requires a decent bit of plastic to be removed so don't be surprised if it takes a long time. It usually takes me at least an hour to get a good-looking hole cut (so I don't do it a lot).
You also want to make sure the USB-C port is sitting in the shell gently, and not flexing the rest of the circuit board when it will be screwed in. The bottom of the hole should be lined up approximately with the bottom of the curved section of the shell. The plastic on the top of the hole will stick out farther from the GBA than the plastic on the bottom. In this picture, the view is straight down from above, and the red shaded area shows the cut plastic.
And yet one more view of the hole - notice how much cut plastic there is exposed on the left side compared to the right side:
There's a divider in the battery bay in some shells (OEM ones in particular) that are used to keep the AAs in place. Many aftermarket shells don't have this ridge. If you have it, you'll need to cut it out.
Also, you'll need to take the connecting spring contacts out. Don't pull them out by force, you will risk bending or breaking the shell. Push on the metal piece with a small screwdriver from inside the shell. It's held in with some metal tabs, so just push those in and it should slide out a lot easier.
Special thanks to users Riggles and White from the r/Gameboy discord server for this helpful information! This applies to shells that are "mirror clear" - completely translucent or transparent. If you want to clean up any errant scratches on the shell, or clean up around the hole, you can put some Displex on the shell and rub it in with a microfiber cloth.
Also, if you're very dedicated, you can make frosted clear shells into fully clear ones using displex and a cloth, but it will take a long time and a lot of effort. I have used a rotary tool with a cloth polishing head on a low speed, but BE CAREFUL, because if the tool heats up the plastic too much during polishing, you will get microcracking or even shell deformities that cannot be fixed. So whatever you do, just make sure you do not heat the plastic up, and take your time!! No worse feeling than getting one hour into polishing only to polish too hard in one area.
While I can't convey to you what that feels like, I can show you what it looks like:
