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# mirror lever

push one end of lever in one direction, other end moves in mirror image direction
 (+2) [vote for, against]

I was reading about the first manned electric helicopter (link). For minimum additional weight and maximum simplicity, the controls were connected directly to the rotor axis. This meant the flyer had to move the controls counter-intuitively: push left to go right, pull back to go forward, etc.

I was trying to think what mechanism would be needed to make the controls intuitive: push left to go left, etc.

I came up with several alternatives (see illustrations). Obviously some more suitable for helicopter controls than others.

In the illustrations I have only shown the straight up/down configuration because I am too lazy to show the angled configurations.

I have also not explained how they work. It is left to the reader's imagination to figure if (and how) each of them would work.

I realize that some (or perhaps all) of these mechanisms are known, however I am not a mechanical engineer and have not seen them so they're new to me at least.

Are there other ways of achieving a 'mirror lever'?

 — xaviergisz, Feb 17 2012

first untethered, manned electric helicopter flight http://www.gizmag.c...opter-flight/19716/
... a big set of handlebars (incorporating the collective control) that literally tilt the main weight of the aircraft underneath the rotors - as his steering assembly. But this increased [the flyer's] risk factor by a significant margin - because it meant the controls would be reversed compared to a normal helicopter. [xaviergisz, Feb 17 2012]

Illustration 6 http://imgur.com/a/BHQZ1
[xaviergisz, Feb 17 2012]

Illustration 5 http://imgur.com/a/1MmiG
[xaviergisz, Feb 17 2012]

Illustration 4 http://imgur.com/a/Gapu8
[xaviergisz, Feb 17 2012]

Illustration 3 http://imgur.com/a/Wzvbn
[xaviergisz, Feb 17 2012]

Illustration 2 http://imgur.com/a/PgJzD
[xaviergisz, Feb 17 2012]

Illustration 1 http://imgur.com/a/uo7X2
[xaviergisz, Feb 17 2012]

Mirror lever 7 http://imgur.com/a/8gN1a
[xaviergisz, Feb 17 2012]

how about a sea-saw kind of lever ?
 — VJW, Feb 17 2012

illustration 3 is the closest I have to a see-saw lever. Perhaps there is a more efficient way of doing it?
 — xaviergisz, Feb 17 2012

Bun for the cool illustrations.
 — ytk, Feb 17 2012

I like the way #5 functions.
 — 2 fries shy of a happy meal, Feb 17 2012

//counter-intuitively// au contraire: I'm surprised that aircraft rudder pedals aren't the opposite of the way they are since that would provide physical bracing for the pilot and intuitive directional control.
 — FlyingToaster, Feb 17 2012

I also disagree on the control scheme being counter-intuitive. Try reversing the directional controls in a video game. It's very awkward for a few minutes, but then becomes perfectly natural. The brain adapts amazingly well to such things.
 — Aq_Bi, Feb 18 2012

 //I'm surprised that aircraft rudder pedals aren't the opposite of the way they are//

 When I got a set of flight sim rudder pedals a few years ago, not being aware of the actual way rudder pedals operate I configured them the way that seemed intuitive to me—i.e. backwards. It wasn't until some months later that it occurred to me to check how they were supposed to work. But ever since then, the correct way has seemed counterintuitive to me.

If you have any motorcycle riding experience, it helps to think of it the same way: pressing on the right handlebar causes the bike to go right. Oddly, even though this principle is called "countersteering", it's always seemed perfectly logical to me that it works that way.
 — ytk, Feb 18 2012

Motorcycles (and high-speed bicycles) work that way because the turning axis of the front wheel is 'raked', or angled backward. When the wheel pivots, the wheelbase is marginally reduced on one side, causing the bike to tip in that direction. Similar notion, but different principles.
 — Alterother, Feb 18 2012

[Alterother] I don't think that's the main effect. Countersteering works, and is needed, even if the headset or triple tree is exactly vertical. The steering axis angle contributes to the need to apply countersteering torque to the handlebars throughout the turn (as it makes the handlebars rotate in the direction of the lean, and that must be partly counteracted by the rider), but it's not very important in causing the lean in the first place.
 — spidermother, Feb 18 2012

Au contraire; an experienced rider can maneuver a motorcycle with balance alone, albeit to a limited degree. But that's not what this post is about, so I'll shut up now.
 — Alterother, Feb 18 2012

 Hands-free balance steering still involves countersteering; the handlebars are just turned indirectly, via road and gyroscope effects. (See the Wikipedia 'countersteering' article).

The real question is, how do you incorporate motorbikes into a lever?
 — spidermother, Feb 18 2012

 It's called countersteering because you do. To make a turn on a bike, you actually start to turn very slightly the other way. This throws the bike out of balance, allowing you to lean correctly not to fall as you start turning. It has nothing to do with which way you push on the bars during a turn.

The countersteer is almost imperceptible, and you don't notice when you do it because it's learned instinctively when learning to balance the bike. If you look at tracks in dirt or from wet tires on a sharp turn, however, you will see a slight loop of the front wheel in the opposite direction at the start.
 — MechE, Feb 19 2012

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