CoCo SDC Cartridge Case

thingiverse

This is a straightforward layout for the CoCo SDC, which is an SD card-based disk controller for the TRS-80 Color Computer series of machines. Check out http://cocosdc.blogspot.com/ and http://www.cocopedia.com/wiki/index.php/CoCoSDC for information on this peripheral. Print Settings Printer: Monoprice Maker Architect Rafts: Yes Supports: Doesn't Matter Infill: Probably 10%. Anything will do; it's designed to be simple. Notes: Needed to resize the design to 1.065x to print at the right size on my printer. Make sure the supports inside the bottom of the cartridge are coming out with the correct spacing to hold the card in place. If not, adjust the size so they will fit properly. I printed it in PLA, but ABS might be worth trying as well. Post-Printing The cartridge prints at its maximum size that just fits into my CoCo 3's slot. My CoCo 3 is a bit more tolerant of large cards than my original CoCo, but this has been fine for me since the cartridge looks better if you sand it down a bit on the outside. So just sand it down to fit; it won't need much. The screw-holes were invented out of thin air. I went to the hardware store to find matching screws and discovered that something called a #2 x 1/2" wood screw is a nearly perfect fit. The case has five screw-holes, but it friction-fits well, so you probably don't really need them all. Use just one in the center post or use all five; whatever seems good to you. Be careful not to put too large of a screw through the center post since you don't want to apply outward force to the hole on the inside of the card. The center screw-hole is the only one that actually travels through a cutout on the board. The cartridge slot has some built-in supports. These work fine on my machine and prevent you from needing the complicated support system your slicer might come up with for you. Even just a few supports in there are probably overkill, so take a screwdriver or knife and carefully break them out when the part is done. How I Designed This I created this design using OpenSCAD, one of the cartridges and a game cartridge for reference, and initially a tape measure (because I lost my caliper); I replaced the caliper near the end of the project and used it for later measurements. It's designed with the following requirements in mind: - It should be simple to print because my printer settings still aren't perfect. - It should protect the card-edge as much as possible without complicating the design too much. - It should allow easy access to everything I might need; that is the card slot, the LED, and the switch on the front, as well as the on-board microswitches just in case I get a Dragon.