Neato Botvac Main Brush Motor Gear

thingiverse

The brush gear on my Neato D7 Connected Botvac stripped itself out and I had to replace it. Looking around online I never dreamed it would be so expensive for a tiny bit of plastic. Most places want $40 USD and I finally found a used motor assembly including the gear, motor, belt, housing, and sensor for $15 with $5 shipping. Given the cost, I'd rather not have to continue to buy these gears especially if this is a common occurrence (the original lasted ~9 months). According to the product page, this assembly should fit a Botvac 65, 70e, 75, D75, 80, D80, 85, and D85 and the comments suggest that it fits a D3, D5, and D7. I had never worked with OpenSCAD before and decided before installing the replacement part to take all the measurements and try to model up a spare just in case the new gear stripped itself as well. Close to everything is set via variables just in case this part doesn't quite work out of the box on your printer. I found and used two libraries in making this part. The first is called Polygear by dpellegr and can be found on Github. The second is called Regular Convex Polygon Library - OpenSCAD by VincentD and can be found here on Thingiverse. I had to increase the center shaft hole diameter a few times before the gear would slip nicely onto the shaft but you might have to go back down? I measured the shaft on my part at 7mm but the gear wouldn't fit until I increased the hole to 8mm to give an idea. The belt seems to fit perfectly around the teeth and connecting the motor to 12v gets it spinning quite vigorously. The hexagon also fits quite nicely into the replacement brushes I've got. That being said, I haven't tested the part in a real cleaning cycle yet as I haven't gotten the motivation to take the robot apart again after just getting it back together. Please let me (and others) know in the comments if you needed to tweak any of the parameters to make it work with your machine. The top of the hexagon was filled in with some iterations of my print. Clearing the support material from them was difficult and while attempting to do this with a drill I accidentally discovered the top of the center shaft was only ~1-2 mm from the end of the part. I removed the top so that the center would no longer need to be cleared and the part still feels strong enough to work. You still need support material around the outside to hold up the belt guard but it's not too difficult to clear off.