Rotating track flipper design

I see a few of these tracked robots that have a set of tracks that pivot 360 degrees around. I'm kinda stumped on how to build the flipping thing while still using COTS motors and tracks. Are all of these completely one offs, using some kind of custom-built sleeve that controls the pivot of the track, while the drive of the tracks is connected in the middle of the sleeve? How does this work? I've hopefully embedded a video that has an example of what I'm talking about. If you search youtube for "stair climbing robot" you'll run across a dozen or so different robots that use this design.

Well, my youtube didn’t get

Well, my youtube didn’t get embedded in. I’ll try it here:

I’ve done more searching,

I’ve done more searching, and I think my question has already been asked and answered here. For what it’s worth, here’s the answer:

Shaft within shaft

There are several ways to do that, but the front flipper frame which supports the front idler wheels needs to be connected to a hollow shaft which is connected to a slow but powerdul motor. The driven sprocket is connected to an internal shaft which is connected to a separate (propulsion) motor.


Thanks very much for the reply and info. I’ve looked for such shafts and had no luck. I’m guessing that all the articulated track robots I see have custom-built shafts. I’ve decided to just punt and settle for a strong-servo-driven connecting rod that will raise and lower the front/rear tracked platforms. It won’t give the 360 degree rotation like I’ve seen on some of the rovers, but it’ll keep me entertained for now.