GM328 Tilting Case

thingiverse

This case is essentially a complete set of replacement parts for the most commonly used acrylic housing sold for DIY GM328 component testers. Although it includes all necessary replacement parts for the original acrylic components, with the exception of the small battery partition piece, it requires the 8 M3 screws, nuts, and 4 nylon standoffs that came with the case to be completely included. This set lacks the little partition piece because I designed a more user-friendly battery compartment into it. Among the parts in this kit are three different left outer panels and two different right outer panels. You'll only need one left and one right side piece. If you use my battery compartment, select a left and right piece that says "w_battery" in the filename. There are two left sides with the "w_battery" label, one with holes for sheathed banana jacks for connecting probe leads, and one without. 90% of what I use this tool for is easier handled by way of alligator clips rather than the onboard ZIF socket. I connect my banana jacks to terminals 1 and 3 from the back side of the board. Starting the device with a component connected to terminals 1 and 3 will put it into batch mode, allowing it to remain powered up and locked into the initial test. If you have 50 capacitors, resistors, diodes, etc. to test, this feature is great. Using terminals 1 & 2, or 2 & 3 will cause the device to run a single test and power off. I made this case because I've done the GM328 kit twice. I built mine two years ago and another for a friend just a month ago. When I built mine, I drilled holes for my banana jacks in the front center panel. To access those connections, the device must be laying flat on the bench, which is not a good viewing angle. When I built one for a friend, I designed a tilting stand using a 3D printer and posted it here a few weeks ago. Unfortunately, I couldn't use the stand on mine because the probe leads would bottom out on the bench. I wanted to make replacement pieces for the ones I drilled and for the left side with my holes already in it. I also wanted an easier way to change the battery than disassembling the whole case each time. Since I'd already modeled the back for the tilting stand, followed by the left, right, and front center portions of the acrylic case, I decided to eliminate the acrylic parts entirely. The measurements are fairly true to the original case design, and the pieces are individually interchangeable with the original case pieces. Use this kit entirely or use only what you need from it. If you're already using my tilting stand with the replacement case back, there's no need to reprint that part to use other parts from this kit. UPDATE 03052020: Added labels for screw terminal holes on face. Silk screen labels are no longer visible without the acrylic face, and I can never seem to remember which terminals are inputs or outputs. If you use this device as a basic function generator or for measuring pulse width modulation, you really need that information.