Overview
Replacement part for the Makeblock mBot: Line Follower IR sensor protection against sunlight.
The mBot’s line follower module reads reflected infrared light off the floor to tell black lines from white ones, and that only works reliably if the sensor is shielded from ambient light. Makeblock ships the kit with a small plastic shroud around the IR emitter/receiver pair for exactly this reason, but it is a thin, fragile part: it is one of the first pieces to crack or snap off after a few sumo matches or line-following runs, especially once the robot starts getting used outdoors or under bright classroom lighting where stray light is more likely to confuse the sensor.
This model is a drop-in replacement for that shroud, matching the original mounting points so it bolts straight back onto the sensor board without any modification to the rest of the robot. I designed it after breaking the stock part on my own mBot during a robotics workshop, and printed a small batch so I would always have spares on hand. It is a tiny, quick print, well under the size where supports are needed, so it is a good part to keep printing in the background whenever you have a few unused minutes on the printer.
If you run mBot workshops or sumo competitions, printing a handful of these ahead of time is cheap insurance: it takes less filament than a single failed print, and it means a snapped sensor guard does not take a robot out of a match.
This is a good example of a category of prints I keep coming back to: not the flashy centerpiece of a robot, but the small, unglamorous part that keeps a much more expensive assembly working. Nobody notices a sensor shroud until it is missing, and by then the robot is already misbehaving.
OnShape
It also holds up better against dust and stray hands than the stock part did in my experience, since I sized the walls a bit thicker than the original OEM shroud rather than trying to shave off every gram.
A tiny, unglamorous part that quietly keeps a much more interesting robot working.
A cheap spare part that costs far less than a lost sumo match.
Project link: https://cad.onshape.com/documents/81690f84d3cc00785b341a90/w/2c9d2bd0c3efcc17cc8189a6/e/9f97a0437f2e46fbdf00103d
Download
The model is free to download and print, licensed under the Standard Digital File License.