I'd like to build an exploratory robot that can fit within confined spaces1.
What traction mechanisms should I consider to propel a robot along the inside of a 4" pipe?
The pipe to be traversed will likely have fluid (assume water) within it to varying degrees from partially full to completely full. I'm initially planning on tethering the robot with coaxial cable.
So far, I have considered a 3 and 4 point wheeled approach, such as with a
X configuration of wheels. And I have considered treads instead of wheels. The robot will need to be able to navigate 90o turns on the way in, but can be hauled out via the coaxial cable if need be. Preferably, it will be able to back its way out for the majority of the distance it can cover.
The robot would not need to climb unassisted. The initial use will be in a pipe that drops several feet from the access point, and then slopes down approximately 5 feet over a 60 foot run. Retrieving the robot will be assisted by the coaxial cable or a tether line.
1 It's a rather boring application, actually. I want to see how badly the roots are creeping into the sewer line from my house.