GM328 Tilting Case

This case is more or less a set of replacement parts for the most common acrylic case sold for housing the DIY GM328 component tester. While it includes replacement parts for all the acrylic parts of the original case, with exception to the small battery partition piece, it requires the 8 M3 screws, nuts, and 4 nylon standoffs that came with the case to be absolutely complete.

This set lacks the little partition piece because I modeled in to it a more user friendly battery compartment.

Among the parts in this kit, there are three different left outer panels, and 2 different right outer panels. You'll only need 1 left and 1 right side piece. If you use my battery compartment, select a left and right piece that say "w_battery" in the filename. There are two left sides "w_battery", 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 terminals designated 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 a 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.

Why did I make this case that is so close to the original acrylic case? I've done this GM328 kit twice. I built mine 2 years ago, and another for a friend just a month or so ago. When I built mine, I drilled the 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 had a 3D printer and designed a tilting stand for these. Unfortunately, I couldn't use the stand on mine because the probe leads would bottom out on the bench.

I wanted to make a replacement piece for the one I drilled, and a replacement piece 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 I posted here a few weeks ago, followed by the left, right, and front center portions of the acrylic case, I decided to eliminate the acrylic parts entirely, and modeled the entire case.

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, the part is identical to what's included in this kit, so there's no need to reprint that 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. I'm dead set against using the voltage input on this device, but I labeled the terminals for those who may decide to use that feature.

Category: Electronics