Powermac G3 Sleeper PC Conversion Kit

Edit: All parts are at 0.1x scale in mm due to fusion 360's exports being funky. Files will be updated soon.

This is a conversion kit with enough parts to turn a Powermac G3 into a sleeper gaming/workstation PC. There's a few things to note hardware wise before starting this conversion:

• Case: Some modification is required, but should be reversible. The top bracket that holds the cd and floppy drive reader and power supply needs to have its rivets drilled out, but could be riveted back in later. I took out just the front section and left the back for the PSU to rest on, but in retrospect I should have taken the whole thing out. Additionally, all of the motherboard standoffs must be drilled half of the way down, minus the top left. This allows the top left standoff to be reused, and the rest should be reversible with spacers. I don't like destruction of old hardware, but this was the best compromise I could come up to stop the standoffs from shorting or interfering with the back of a motherboard. Other conversions have you remove them entirely which I'm not a fan of.

• Motherboard: It is designed to accommodate micro-ATX motherboards with the top PCIe slot(for gpu) spaced one slot down from the top. This is to ensure that the motherboard IO lines up with the rest of the case. I used the MSI Mortar b650m. Full ATX motherboards probably fit too but won't be fully held in with all the holes and will still be limited to the case's 4 PCI slots anyway.

• Cooler: I used the ID-Cooling IS67XT, but it was too tall and needed to be modified by bending the heat pipes so it would be flatter. ID Cooling makes other really good and affordable low profile coolers, so I would recommend them as a brand. Needless to say, the cooler must be shorter than the IS67XT, which is 67mm tall. You could use an AIO bottom mounted on the case if you want to drill out the bottom. I prefer air cooling and only needed to cool a ryzen 5 760p anyway so aio wasn't the route I took.

• PSU: There are power supply requirements. The PSU must have the AC power plug to ATX spec, but most modern PSUs don't do this. Power supplies that work include the Thermaltake Smart, but I got a old Silverstone ST85F-GS that works with spacers or modification. I just use the Silverstone unit and washers but its a bit expensive, and the Thermaltake Smart isn't the best PSU out there, so I'll do some looking for better units for this conversion.

• GPU: More problems here. The Height of the GPU(that being how tall it is from the motherboard to where the power plug is) is an important factor. If you don't want to duct the exhaust out the old intake for better thermal performance then it doesn't really matter. That said, the Powermac G3 comes with an intake around where the GPU goes, and included in the files(exhaustductforbracket) is an insert for the metal intake that adds extra ducting for a slim 120mm fan(would recommend Arctic's fans) to provide exhaust. I also made a bracket to further duct the fan(ductforbracketexhaust) for 12cm tall gpus. The other included exhaust duct(newguidedduct) is for gpus as tall as the AMD RX6800 refrence(couldnt find height online and dont feel like taking out a gpu rn).

• 3D Printing material: Don't use PLA, while it doesn't melt it'll get soft and deform and smell a bit. I used transparent white/clear PETG cause it matches the offwhite seethrough aesthetic of the case, and has been fine for months for me.

Aquire parts

1.  See above for pc parts.

2.  Other parts include 6x6x6 push button switches

3. wire

4. jumper leads

5. dual usb3 to motherboard cable(https://a.co/d/h7rYa3X)

6.  a sleeved cable extension set(easier cable routing)

7. a 140mm fan for intake

8. a 120mm slim or dual 92mm slim fans for gpu exhaust(see above)

9. heatserts for motherboard

10. screws for heatserts

Assembly instructions:

1. Gut the powermac case hardware, and outer plastic

2. Drill out rivets holding in the optical drive and power supply shelf to remove it

3. With the exception of the top left motherboard standoff, drill standoffs half way down. I used a drill bit slightly wider than a standoff to do this. 

4. Clean all metal shavings

5. Print motherboard tray and insert heatserts. Check motherboard fit.

6. For the power button tray, hot glue in the switches and six solder wires to the three buttons(should be a positive and ground wire per button). The tray should screw/snap into place once the old pcb is removed.

7. Other instructions pending