Skid Steer Robot Chassis Takes A Beating

[Engineering After Hours] wanted a highly maneuverable robot chassis with a tight turning radius. Skid steering seemed to be the perfect solution, but the available commercial options didn’t take his fancy. Thus, a custom build was the answer – with impressive results.

The build packs two large RC motors, one for each side, with each driving two wheels through a belt drive. This reduces the electronics required to the bare minimum for skid steering. It’s all assembled within a plasma-cut metal chassis which is more than tough enough to take some hard knocks.

One of the primary goals on the build was to eliminate the risk of vibrations and shock damaging the motors and gearboxes. Many off-the-shelf designs couple the wheels directly to gearbox output shafts, potentially damaging the expensive components over time. In this design, a separate bearing assembly is used to take the load from the wheels instead.

It’s a great example of how an engineering-first approach can build a sturdy ‘bot with a minimum of fuss. Outfitted with some fat off-road tyres the performance is impressive, with the ‘bot having no trouble tearing it up in mud, snow, and water.

We’ve seen other great builds from [Engineering After Hours] before, like the active aero RC build. Video after the break.

Continue reading “Skid Steer Robot Chassis Takes A Beating”

Skid Steer Mows Airport Grass Autonomously

Sure, mowing the lawn is a hassle. No one really wants to spend their time and money growing a crop that doesn’t produce food, but we do it anyway. If you’re taking care of a quarter acre in the suburbs it’s not that much of a time sink, but if you’re taking care of as much grass as [Roby], you’d probably build something similar to his autonomous skid-steer mower, too.

This thing isn’t a normal push mower outfitted with some random electronics, either. This is a serious mower that is essentially a tractor with blades attached to it. Since it’s a skid steer, it turns by means of two handles that control the speed of the left or right drive wheels. Fabricating up some servo linkages to attach them to specialized servos takes care of the steering portion, and the brain is ArduPilot hooked up to a host of radios, GPS, and a compass to allow it to drive all around the runways at the airport without interfering with any aircraft.

This is a serious build and goes into a lot of detail about how servos and linkages should behave, how all the software works, and the issues of actually mounting everything to the mower. The entire project is open source too, so even if you don’t have a whole airport runway to mow you might be able to find something in there to help with your little patch of grass.

Thanks to [Vincent] for the tip!

Continue reading “Skid Steer Mows Airport Grass Autonomously”