Description

Designed this case for an older GM328A transistor tester with a DC barrel jack socket. The PCB was marked as HW849A.

This case variant allows to access the MCU without disassembling case, yet covers the PCB.

FreeCAD source is available to use and modify.

Printing and Assembly

Printed with 20% infill using Spectrum PETG in 0.2mm layers.

Assembly requires detaching the screen and removing the brass mounting posts as they are no longer needed. The screen PCB is placed inside the screen shell and optionally secured using a few drops of hot glue in corners.

The main PCB is placed on the base part, then the cover is placed on top. The cover is designed for tight fit, but if some component is misaligned on the PCB, some sanding/cutting may be needed.

The cover is secured using four M3x10mm flat-head screws.

The knob was taken from The Ultimate Knob Collection by RasmusAdditive (file Knob-designv8.stl). Did a crop to 15mm, added negative volume cylinders of 5.8x12.5mm and 7.5x7mm for the encoder shaft using PrusaSlicer.