[James Bruton]’s unusual Möbius Tank has gotten a little more unusual with the ability to bend itself, which allows it to perform turns even though it is a single-track vehicle.
The Möbius Tank was a wild idea that started as a “what if” question: what if a tank tread was a Möbius strip? We saw how [James] showed it could be done, and he demonstrated smart design and assembly techniques in the process.
He’s since modified the design to a single-track, and added a flex point in the center of the body. Two linear actuators work together to make the vehicle bend, and therefore give it the ability to steer and turn. A normal tread would be unable to bend in this way, but the twist in the Möbius tread accommodates this pivot point perfectly well.
It works, but it’s not exactly an ideal vehicle. With the tread doing a 90-degree twist on the bottom, there isn’t a lot of ground clearance. In addition, since the long vehicle has only a single tread, it is much taller than it is wide. Neither does it any real favors when it comes to stability over uneven terrain, but it’s sure neat to try.
Even if it’s not practical, Möbius Tank is wild to look at. Check it out in the video, embedded just under the page break.
sorry, with two twists, that track is not a Möbius strip
The second twist isn’t really a twist, it turns 90 degrees one direction, then back the other direction whereas the mobius strip bends a full 180 degrees
You’re right, I hadn’t noticed that.
whups! I sit corrected. I stared at that for way too long to have gotten it that wrong. thank you for the correction
Looking at the photos, I can see the bottom tread is lifted up a bit before the twist. Why not lift it up even higher, and bring the top tread down, so they’re even at the twist. Then they can use the same bearing point at the twist, one on each side. That would improve both the ground clearance and height issues.
The video answers all your questions…the bottom is kept where it is so the side of the tread can ride on the ground and they must pass through center to rotate both directions.
I don’t like the idea of lifting the bottom section so much. It reduces the surface area by about 40% and the goal of using tracks is to increase surface area.
Also, all the track segments are quite short, and there are a lot of them. There would be around 30 segments on the floor if the bottom was straight. That would mean that if there is an 2 degree angle between each of the segments, then there is already a 60 degree arc of tracks touching the ground.
And two degrees is not much. If the tracks are made slightly arcwise, I guess somewhere between 5 and 10 degrees could be designed into the tracks segments quite easily. It’s not the track itself that is the problem, but the stiff frame that is normally inside the tracks.
I largely agree, but I’m struggling to imagine a mechanism to gracefully bend the track.
At it’s simplest, you’d want to mechanically constrain all sections to the same bend radius… From a traction perspective it’s probably better to have an almost snakelike approach where a bend angle starts at the lead block and “rides down” the vehicle with that pair of track blocks.
Bendy tracks have been done before – I think it was usually pushing or pulling the mid point of the tracks idler wheel in or out relative to the fixed sprocket at the front and back. But no doubt many other weird mechanical ideas have been tried in the early more experimental days of tracked vehicle.
Yes the WWII Bren Gun Carrier warped the track by pushing the bogies laterally, allowing gentle turns. Further movement of the steering then engaged the track braking.
The last version of the Australian built Bren carrier had a better track warping arrangement by pushing the front idler left to right, taking the stress off the bogie suspension. Same system was also used for the experimental 1 ton tracked truck GS.
I think they were the only wartime vehicles to use that steering system.
Like most of his builds its funny and interesting but hardly practical
Until like lots of weirder ideas it is…
I can’t see a real reason why this one would take off either, but in all the varied forms of human endeavour it might. Perhaps for space constraint reasons – can’t pack it straight, but can pack it folded and no assembly required is essential or maybe just for motor reduction and tighter turning radii for the ground pressure – can’t pack all the extra motor to drive the separate tracks and the fold in the middle steering in your power budget or something.
Wouldn’t be the first time some bonkers idea finds a place it actually does something better than the usual and conventional option.
I’m missing something. Ok the Mobius bit is different, but it’s not adding anything to the function of the bendy tank. Both top and bottom runs could be 90 degree forward and backward twists, of for that matter, they could both be 180 degree “Mobius” twists.
If it has one or two mobius bend, it would need both sides of the track being same. If it has same-side-return bends, the track can be same as normal tank or excavator, with guide and drive spines on the back. I want to build this as a tracked motorcycle but would probably not put the effort in it.