PetSafe Simply Clean (v2) gear box upgrade

thingiverse

This is a complete drivetrain for the [PetSafe Simply Clean](https://smile.amazon.com/PetSafe-Simply-Self-Cleaning-Automatic-Clumping/dp/B07GYX7RLD/) (the "new" one). The gears are provided in both straight and 15° helical cut. It is apparent the geartrain requires a complete redesign. Although this train is somewhat stronger, it has the limitations of smaller gears. Caveat: my tests were on a 0.6mm nozzle with some weaknesses in the teeth. A new gearbox design with planetary gearing will be most functional. # Helical gears Helical gears have greater contact area and spread the load across teeth better, thus are less prone to damage under stress, quieter, and more efficient. As I purchased mine in September 2020 and it made it barely to mid-November on its (poor-quality) metal gear, and then destroyed an ABS gear by January and a PLA or PETG gear weekly (I've had PETG gears last for mere hours), I re-engineered the drive train. Do note the machine is actually pretty phenomenal, it's well-designed, and it's a *huge* upgrade from the prior version; there are some bugs to work out in the drive train. I also anticipate making a new version of the drive train case itself, and then modifying that to accept a 6W motor so I can run at slightly-higher RPM (I'd like to turn the bowl 50% faster). These helical gears are printed such that the drive gear will slip upwards toward the motor, and the intermediate gear will slip downwards. The orientation of the gears holds them together as such and, besides, the intermediate and bowl gears are screwed in place. All three gears must be helical for this to work. Changing the intermediate gear is a bit difficult, requiring the removal of the switch. # Straight gears If you just want to swap the drive gear, use the straight gear. If you're going to pull the switch off, I recommend switching to helical gears. The intermediate and bowl gears both take little strain and will probably never need replacement, but you need all helical gears if any one gear is a helical gear (turning an axle with a different gear attached doesn't count, which is how this thing drives the bowl). # FreeCAD File The FreeCAD document is included, for those interested in investigating and adjusting this. You will need FCGears. ## Build considerations The bottom ring on the drive gear is removed because it's unnecessary (it's an artifact of the way the metal gear is produced) and because the bottom part of the D hole is often smaller for some reason (Elephant's Foot). Just flip the gear over. If you want that thick spot that badly, use the one with the base in the FreeCAD file and print it upside down, and hope your bridging works; otherwise just friction fit the part. Blobs and other defects are not helpful at these tolerances. A work-around is to make the bowl gear axle shaft just slightly larger (try half a mm or so). This will prevent an imprecise gear from locking up, but it will also stress the teeth and cause the gears to break (or, if they slip, to grind away). This is the one time you may want to make use of your 0.2mm nozzle and shy away from the Delta with the 1.2mm Supervolcano.