June 10, 2025
Description
When I first got the Navimow I was so disappointed I was planning on returning it. It couldn't navigate the grass at all. It would get stuck left and right. I turned to online and saw all the comments about how horrible the wheels were, but I wasn't willing to spend $100 for the "Offroad" wheels when I could waste hours and hours and build my own.
I felt the biggest issue with the mower was the low front bumper. The mower would sink into the grass a little bit and then be unable to "plow" through the grass. My main focus was width. I felt if the wheels were wider it could ride along the top of the grass better and the bumper wouldn't be an issue. I also wanted a more aggressive "spike" to help dig into the grass when needed.
While I was busy measuring making the first prototypes of this, I stumbled upon the iRim by Larsih. I took his measurements and built this from scratch in Fusion 360 (vs basing it on a canvas of the wheel). I also took his tread design as inspiration for the V1 Tread. I also took his axle ring as inspiration to make the support requirements a lot more reasonable.
When printing, I did not use any supports. The wheel assembly should be printed in a strong UV resistant material. I used PETG-CF. The tread should be printed in TPU, but I have it printed in PLA on mine right now and it has several concrete crossings. While it does not grip the concrete well, it has worked well in the grass / dirt areas.
You only need to print the single print tread or the modular tread. You don't need both!
Eventually I will upload the V1 design as middle rings for the modular design where users can pick and choose which treads they want to use.
Wheel Assembly ( PETG-CF / PETG / ABS / ASA / ETC)
Tread - Modular Design ( TPU )
If you go with the modular design (highly suggested), you really can mix and matching any of the versions, but you will need at least one top and bottom per wheel. The treads are rotated slightly, that's why there's a "middle 1/2". If you are mixing the different designs then the "Middle 1/2" doesn't matter as much.
Tread - Single Print Design (Original Style based of Larsih) ( TPU )
External Parts
Assembly
I have a lot of goals for this project. My first priority is to "cut up" Tread V1 and add the middle rings of it so they can be used in the modular design. I want to try out other tread designs (feel free to send them to me) to see if I can get even more traction!
The only downside I have found thus far is if you use one of the black crates as a "Garage" for the Navimow, it can barely fit now. If you lift the black crate up a little bit it works fine.
After hundreds of hours of mowing:
As promised… (albeit probably 8 months after I expected to do this) I have two more tread designs that I am currently testing. I am uploading to everyone just incase people want to try. They are all modular and can swap.
The Cube design is more in line with general off road vehicles. The paddle design should help it going in a single direction, going in the reverse direction it'll probably have reduced traction. So I can't say I'd run all of the “paddles” going the same direction.
As before, anyone with any tread designs please submit them and I'll create them as best I can!
License:
Creative Commons — Attribution — Noncommercial — Share Alike
Drew
