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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

#61

Post by Amygaz »

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.

Considering that this is a rather a rounded triangle, I doubt it has anything to do with tightness, and more with convenience, esthetic. A symmetrical displacement is also slightly less constraining in term of keeping the overall circumference/periphery (i.e. less deformation).

A better design would have been to flatten the wheel into an more oblong or even an egg shape, like snowmobiles or tanks have. However, it requires more mechanical displacement and adjustements.

Re: Darpa Literally Reinvented the Wheel for Army Combat Vehicles

#63

Post by st26 »

strken wrote: post #24
allthenews wrote: post #21

So they took a simple wheel and added a couple hundred parts, increasing cost, maintnence complexity, failure potential, and weight. Is it worth it?

That's the point of RnD, though, right? Try a hundred things, extensively test ten of them, end up with one or two that actually work.

And, if you're lucky, also end up with ten neat brand new ideas that are spawned by the RnD that lead to entirely new things.

All the tech that went into this wheel, might coincidentally open other doors, that lead to still other doors...

Re: Darpa Literally Reinvented the Wheel for Army Combat Vehicles

#64

Post by Amygaz »

gpm wrote: post #43
qaq wrote: post #35

Earlier quoted context omitted.

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

Given how much money the US spends on its military I'd expect them to be prepared to fight just about anywhere. Certainly in "foresty mountanous terrain" since that isn't particularly rare. Exists inside of the US. Exists on both borders of the US. Etc. Producing a military optimized for "blowing up unsophisticated enemies in desserts" seems like a very shorted sighted way to spend the military budget. (None of the a…

DARPA should fund the development of 74-Z speeder bikes, and nothing else!

Re: Darpa Literally Reinvented the Wheel for Army Combat Vehicles

#65

Post by sooper »

make3 wrote: post #53

That video at the end about the army throwing Humvees without properly setting up the chutes was pretty incredible

From what I read, not so much "without properly setting up", more sabotage: https://www.armytimes.com/news/your-army/2017/07/05/soldier-...

Re: Darpa Literally Reinvented the Wheel for Army Combat Vehicles

#66

Post by TheSpiceIsLife »

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?

Here's a video from Mattracks (2014) where the geometry changes like you've suggested: https://www.youtube.com/watch?v=6zTxMwYM1tI#t=20s - that should start at 20 seconds in.

It doesn't look like their whole wheel rotates though.

Re: Darpa Literally Reinvented the Wheel for Army Combat Vehicles

#67

Post by blackrock »

Swizec wrote: post #20
banku_brougham wrote: post #17

Earlier quoted context omitted.

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.

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…

It sounds like you need an Imperial Walker instead.

https://vignette.wikia.nocookie.net/starwars/images/8/88/Var...

We can sell you some lightly used units from our last imperial war. They have excellent maintenance records. And comes with a 5 year, or 50,000 mile warranty, whichever comes first.

Re: Darpa Literally Reinvented the Wheel for Army Combat Vehicles

#68

Post by jandrewrogers »

gpm wrote: post #43
qaq wrote: post #35

Earlier quoted context omitted.

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

Given how much money the US spends on its military I'd expect them to be prepared to fight just about anywhere. Certainly in "foresty mountanous terrain" since that isn't particularly rare. Exists inside of the US. Exists on both borders of the US. Etc. Producing a military optimized for "blowing up unsophisticated enemies in desserts" seems like a very shorted sighted way to spend the military budget. (None of the a…

The US military has divisions that specialize in "foresty mountainous terrain". There are parts of the world (and US) that are effectively inaccessible to any mechanized units and the US military has large combat units that are setup to operate effectively in those environments. Terrain that is prohibitive to mechanized units is traditionally the domain of "light infantry" divisions (e.g. 10th Mountain Division), distinct from mechanized infantry divisions.

The US military has dedicated units and training facilities for virtually every environment on Earth.

Re: Darpa Literally Reinvented the Wheel for Army Combat Vehicles

#69

Post by gnarbarian »

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?

If it wasn't symmetrical it would be far more difficult to balance properly for when it's rotating in "wheel mode"

Re: Darpa Literally Reinvented the Wheel for Army Combat Vehicles

#70

Post by JshWright »

Amygaz wrote: post #61
edaemon wrote: post #51

Earlier quoted context omitted.

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.

Considering that this is a rather a rounded triangle, I doubt it has anything to do with tightness, and more with convenience, esthetic. A symmetrical displacement is also slightly less constraining in term of keeping the overall circumference/periphery (i.e. less deformation). A better design would have been to flatten the wheel into an more oblong or even an egg shape, like snowmobiles or tanks have. However, it re…

"Better" is meaningless in isolation. The design you propose is better in some aspects, but likely not in the areas the designers of this wheel are optimizing for (simplicity, reliability, etc)
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