Product Description
This is a metal replacement gear for Lasonic TRC-920 and TRC-931 switches. If your switch knob just spins or isn't able to change selection modes, then it's possible the plastic gear inside the switch has split or crumbled. In order to replace this gear, you should be sufficiently capable of removing, desoldering the switch assembly and replacing the gear. We cannot help you with this and you assume any risk associated with this "fix." This gear will allow you to "upgrade" this gear from plastic to metal.
The hole in the model is exactly the same size as the shaft, so it should slide on with moderate resistance, but some minor adjustment may be necessary for a good fit. If too tight, you will need to either file down the hole or reduce the size of the shaft until the replacement gear is able to slide onto it. Although the models are drawn accurately, the 3D printing process does have some tolerance variations which varies depending upon the type of material chosen, so please understand this. We have also included a 1.5mm hole in the gear so you can set it in place with a set-screw. To do this, you will need an M2 setscrew, an M2 tap, and a 1.6mm drill bit to ream out the hole. If you choose not to use a setscrew, you can glue the gear onto the shaft, but please understand this may make it difficult or impossible to remove the gear in the future.
This gear was successfully printed and tested in PA12 nylon material and it was a tight fit that required some minor adjustment in the interior hole sizing. We expect that this will be the same with metal.