Full Stream Ahead

When you start poking around in an older home, you are likely to find some odd things that make maintenance and repairs a huge headache. That was the case at YouTuber Stargate System’s parent’s home, where persistent blockages in the sewer pipe kept popping up. Professional crews were called in several times, but their fixes proved to be only temporary. As a last resort, they sent in a pipe inspection robot, but even this failed to pinpoint source of the problem.

Being an engineer, Stargate System recognized that the only way to fix this issue once and for all would be to get creative and start building. At some point in the life of the home, the sewer pipe was rerouted to a new collection pipe, which introduced a 120 degree bend that caused a blind spot for traditional inspection robots. Furthermore, right at the bend, a drain pipe fed directly into the sewer pipe, which someone apparently thought was a good idea 50 years ago. Stargate System believed debris from the drain pipe was causing the repeated issues, but would need to get a good look to confirm that suspicion.

With commercial systems failing to do the job, he set out to build a more agile, custom pipe inspection robot — and for a small fraction of the approximately $30,000 price tag of existing robots. To be sure, this was a difficult task. The robot would need to be able to fit inside of a 120 mm diameter pipe, travel long distances, and be capable of transmitting a video stream back to the operator.

To achieve these objectives, Stargate System 3D-printed a body for the robot and equipped it with a pair of powerful motors at the bottom, which kept the center of gravity low. These motors each drove an axle, which were connected to large gears. The gears drove tank treads, which were each threaded around an additional pair of wheels. This gave the robot a powerful and agile base for crawling through pipes.

Inside the case, a Raspberry Pi Zero was installed to run the control algorithms and process the images captured by a Raspberry Pi Camera. The camera was installed behind a Plexiglas sheet, as was a powerful LED that was used for illumination. For communication, a 65-foot Ethernet cable was wired into the robot. This cable also supplied power over a custom PoE solution that supplied both 5 volt and 48 volt rails, for the Raspberry Pi and motors, respectively. A voltage regulator brought the 48 volt rail down to 12 volts inside the robot. After installing the hardware, the seams between the 3D-printed parts were permanently sealed with acetone for waterproofing.

After writing some software to stream the camera data back to the operator and allow for manual control via keyboard inputs, this $150 robot was ready to be deployed. After traveling to the suspected problem area, debris from the drain pipe was indeed found. A custom tool, with a spinning chain at the end, was built to help clear out the hardened muck, which the robot helped to position correctly. After a bit of cleaning, the robot was again used to confirm that the pipe had been successfully cleared.

Since cleaning out the pipe, no further problems have been observed. Innovative thinking saved the day for the homeowners, and at a fraction of the cost of a commercial system (or regular visits from professional crews). Hardware hacking for the win!