S1 Plus Gearbox Disassembly and Cleaning
Overview
Disassembling and cleaning the S1 Plus gearbox is an important maintenance step when certain issues occur. This process is typically needed in the following situations:
- Runout switch not actuating properly – The filament runout switch, located inside the gearbox, may stop triggering correctly due to dust, debris, or mechanical wear.
- This can look like the S1 Plus not detecting when a side is empty after the filament has run out and been fully pulled through the S1 by the printer, causing a failed reload.
- It can also appear as strange loading behavior or the S1 Plus randomly showing a red light (empty) when filament is still present.
- Gearbox Gears Grinding – If the S1 Plus has been grinding through filament, the drive gears can collect plastic debris. This buildup reduces grip, increases wear, and can lead to feeding or reloading failures.
Cleaning the gearbox ensures the runout switch functions correctly and the drive gears maintain proper contact with the filament. Performing this maintenance after a filament jam or any incident of abnormal feeding will help prevent future failures and extend the lifespan of the gearbox assembly.
Gearbox Disassembly
1. Remove the gearbox using this guide.
2. Carefully pull the runout switch wires out of the wire channel.
3. Separate the top and bottom of the gearbox.
4. Remove the idler lever and shaft.
5. Remove the drive gears.
6. Push back the runout switch snap lock and Push the switch out by inserting a small tool into the hole on the outer cover.
7. Remove the runout switch actuator ball. If needed, push filament into the gearbox inlet to pop this out.
Gearbox Cleaning
1. Blow out all passages using compressed air.
2. Brush out the drive gear using a fine bristle brush.
