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Darpa Literally Reinvented the Wheel for Army Combat Vehicles

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Re: Darpa Literally Reinvented the Wheel for Army Combat Vehicles

#51

Post by edaemon »

namirez wrote: post #49
stefco_ wrote: post #46

Earlier quoted context omitted.

Note that the whole assembly rotates when in wheel mode. Making it radially symmetric (i.e. a triangle) in track mode means that it can switch modes with at most a 120 degree rotation rather than having to rotate through up to 360 degrees to get the flat bottom into position.

I didn't say anything about the design of it, which is by the way, very cool. I don't understand the point of the triangle. The same mechanism could be used to change the geometry of the wheel only at the bottom.

I would guess that it has to do with the tread tension. A rounded top with a flat bottom may leave the tread too loose. The triangle keeps it taught.

Re: Darpa Literally Reinvented the Wheel for Army Combat Vehicles

#52

Post by protomyth »

orbital-decay wrote: post #22
protomyth wrote: post #15

That would actually be pretty useful on some farm vehicles. No need to pick a wheeled or tracked tractor, you can have both.

...for twice the price.

I assume if they get the tech to the level farmers would be buying it, it would not be twice the prices.

Re: Darpa Literally Reinvented the Wheel for Army Combat Vehicles

#54

Post by Johnny555 »

oh_sigh wrote: post #27
allannienhuis wrote: post #23

Isn't the advantage of using tracks supposed to be the increased surface area for traction and weight bearing? This seems to only slightly increase the surface area. It doesn't seem that this would have enough traction advantage to make the complexity worth it.

The contact patch goes from ~ 1 sqft/tire to ~3-4 sqft/tire. That's pretty significant.

Seems like they could get most of the benefit at much less cost and complexity by going with side-by-side "dualies"

If one of the tires goes flat, then there's built-in redundancy from the other ones and it could be replaced in the field if needed, but no one's going to be able to overhaul this track mechanism without a shop.

Re: Darpa Literally Reinvented the Wheel for Army Combat Vehicles

#55

Post by macintux »

banku_brougham wrote: post #17
AndrewKemendo wrote: post #5

That thing looks like a maintenance nightmare.

And how often do humvees get stuck anyway? I like the product, but it’s obviously wasteful. During the Iraq insurgency what was wanted was armor plating. Literally just 1/4” slabs of steel. This is of a piece with the F-35.

Heck, just last year one was stranded in Montana for days.

https://www.jqpublicblog.com/air-force-lacks-resources-retri...

Re: Darpa Literally Reinvented the Wheel for Army Combat Vehicles

#56

Post by bluedino »

mc32 wrote: post #31

Other than military applications. Looks like this could have potential for snow-bound vehicles. Ski areas and backcountry in the winter.

Mattracks sell conversions for street driven vehicles that bolt on where normal wheels go

http://www.mattracks.co/

Re: Darpa Literally Reinvented the Wheel for Army Combat Vehicles

#57

Post by hsienmaneja »

edaemon wrote: post #51
namirez wrote: post #49

Earlier quoted context omitted.

I didn't say anything about the design of it, which is by the way, very cool. I don't understand the point of the triangle. The same mechanism could be used to change the geometry of the wheel only at the bottom.

I would guess that it has to do with the tread tension. A rounded top with a flat bottom may leave the tread too loose. The triangle keeps it taught.

Note: taut (pulled tightly) and taught (past tense of teach) are homophones

Re: Darpa Literally Reinvented the Wheel for Army Combat Vehicles

#58

Post by intrasight »

PhasmaFelis wrote: post #13
stefan_ wrote: post #7

Earlier quoted context omitted.

What is the benefit on this suburban parking hell landscape? That's where they had their demo, after all.

The benefit of filming in the parking lot of the engineering building is that you don't have to drag your prototype and a film crew out to the nearest swamp.

The "nearest swamp" is pretty near with all the rain we've been having here. Hopefully we'll see a side-by-side comparison in the mud soon.

Re: Darpa Literally Reinvented the Wheel for Army Combat Vehicles

#59

Post by forapurpose »

qaq wrote: post #35
Swizec wrote: post #20

Earlier quoted context omitted.

Humvees get stuck a lot! The US donated (I’m sure with wink wink strings attached) to us, Slovenia, some years ago and it was quickly found that they are too large and cumbersome for our foresty mountanous terrain. They’d get stuck all the time on tiny roads or between trees. I think these days they’re used for paraded to show we have them but day to day the military keeps using their trusti Puchs from who knows when…

US is not fighting in areas where getting stuck between trees is a big issue.

> US is not fighting in areas where getting stuck between trees is a big issue.

They need equipment for future wars, which are very difficult to predict. Also, the military's main purpose is to deter enemies by having capability. Enemies would be thrilled if the US military couldn't operate in wooded areas.

Re: Darpa Literally Reinvented the Wheel for Army Combat Vehicles

#60

Post by gukov »

namirez wrote: post #44

I don't understand the benefit of turning the whole wheel into a triangular track; would it not be sufficient to make only the bottom third flat?

I'm guessing the triangular track mode is the default mode. If the track gets damaged the whole thing can be switched to the wheel mode and continue working that way.
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