Which Way to Turn?

So you can tell the difference between water and electricity.

Electrons are negative, so the operation has to be reversed. Duh.

The reason taps are closed in the clockwise direction is because a right handed person can apply more force in that direction. Perhaps volume controls turn on clockwise because clockwise is psychologically associated with increase. Clocks turn in that direction (the direction a sundial's shadow turns in the northern hemisphere.)

I like your hypothesis about clocks.

"We tend to draw graphs with the X axis increasing to the right"

But for polar coordinates, the convention is for angles to increase counter clockwise

There's always a rebel!

I'll take a wild guess.

When you look forward and then estimate an angle upward you deem that as a positive angle. Negative angles would be downward in pitch. Up - Down...

Looking forward is akin to looking along the X axis in a direction of increasing X, thus making positive angles go counterclockwise.

I am thinking that we naturally relate looking forward as moving to a positive direction (increasing or moving into the future)) and behind us as a negative direction (that where we have already been or moving back into the past). It's how we ambulate as a general rule. So, when you go forward it is as if you are increasing along the X axis.

The same thing with going up in altitude or climbing is an increase and analogous to increasing Y.

If that guess holds true, then the natural sense of direction is forward into increasing X and upward as increasing Y. Zero degrees is dead ahead and +90° is straight up, tilting your head in the natural direction, which is back.

Just guessing, but it would be interesting to hear other thoughts on this.

Probably because valves (as in plumbing) employ a screw thread for actuation, and a right hand screw has traditionally been preferred. Thus, rotating a valve stem in a clockwise direction closes the valve seat or gate.

Note that at, least in the US, fire hydrants normally work in the opposite sense, rotating the stem clockwise opens the hydrant. This has "screwed up" many a rookie fire fighter.

Now, potentiometers can be wired to operate in either sense, so, where the convention of clockwise to increase came from, I don't know.

I didn't know that was how hydrants worked (in the US), but it makes sense now.

I think you are right about the right hand thread seating the valve.

The CCW thread and the weird pentagonal nuts on fire hydrants are probably attempts to foil kids who want to open one up to cool off on a hot day!

Actually, an interesting thought!

I saw it as opening the valve on a hydrant was the most important trait and if you put a spanner on the nut, turning it clockwise to open it (as looking down on the nut), makes sense because most people's right arm is the strong arm and pulling a spanner towards you (clockwise), puts the strong arm at the end of the wrench where the leverage is greatest.

In the United States almost all fire hydrants open in the counterclockwise direction and close in the clockwise direction. One of the most popular fire hydrants, the Mueller Super Centurion, is only available in RH threads. This has been verified with our water supplier, who supplies water for the majority of this state.

http://md-calvertcounty.civicplus.com/documentcenter/view/5107

http://www.mh-valve.com/upl/downloads/catalog/products/operations-maintenance-manual-style-129-reliant-fire-hydrant-3fd60382.pdf

http://www.codepublishing.com/wa/Auburn/html/auburn13/auburn1316.html

During my tenure as a volunteer firefighter, I have only encountered one CCW opening hydrant and that was an old one used in a unique situation. It was replaced within a year. It was used as a connection to an underground 20,000 fire fighting water storage tank. I have contacted others personnel in different states and they all use the CW hydrants.

I have found that the thing that "screws up" many a rookie fire fighter, also many experienced ones, is not knowing which way to open a valve or other things. Hose fittings, pump fittings, nozzle fittings, you name it, they first try one direction and then the opposite (if they can figure out what the opposite way is!) When training I always use the "Lefty loosey, righty tightey" concept".

TNX

Nothing like coming up with elaborate theories to explain something that isn't true!

You provide a good example of the first two laws of mechano-technics:

Lefty -loosey and , rightee, tightee. This law is true for all the above-mentioned electronic controls that work with a knob, as well as all the mechanical/plumbing valves.

"This law is true", except in those cases where it isn't.

My cold faucets "open" clock-wise while my hot faucets "open" counter clock-wise.

All my electronic dials go to 11 - regardless of what direction I turn them!

"All my electronic dials go to 11" Now there's a man with a fine collection of Marshall amplifiers and possibly a Tesla car. Note that if the numbers are on the front plate the numbers increase clockwise, but if they are on the knob itself they increase anticlockwise.

Which model of Marshals have 11 as the max?

Every one I remember seeing (in the US) had 10 as the max, but they were mostly 1970 vintage stuff.

I believe the Marshalls started with the 10 maximum, but went up to 11, and then to 20.

TNX

Look up "This is Spinal Tap⁽¹⁾" to get the original source for amps 'going to eleven.'

Notes:

1. Normally written with an umlaut over the n⁽²⁾, but that's hard to do with a keyboard.
2. Don't bother asking how that's supposed to affect the pronounciation, everyone just says it like the umlaut is mere 'rocker dots' decoration.
   

Here's something you don't see every day.

Shades of "Spinal Tap"!

Why do we push-pull the throttle of fixed wing aircraft and twist the throttle of rotary wing aircraft?

I'm not a helio pilot, but I understand the controls.

The throttle is not adjusted as much as the collective, or so I was taught by an instructor in a simulator.

Most of the work is done with the collective and my experience with using it was that I could more finely control the position of the collective than I could the throttle.

I think it was a UH-60 sim that I flew and the throttle only turned 90°, which wasn't a lot of fine control there, whereas the collective moved almost 18" up/down.

I do have real fixed wing experience and flown a number of the sims for military jets. The throttle is much easier to manipulate as push pull and it's the only way to change aircraft speed, besides diving and climbing.

Also, the fast jets have what is called HOTAS (Hands On Throttle & Stick) and the grips are loaded with buttons and knobs on the throttles. Having a twist throttle would sharply limit what you could do as far as grip switches and knobs.

Most of the aircraft functions can be controlled without taking your hands off the throttle and stick. The same goes for rotary aircraft.

Just being obstreperous.

Yes, I understand. In the position it's in you can't twist the throttle more than 90° without letting go either.

And when flying fixed wing aircraft, one usually has a free hand to adjust trim settings. OK, when not adjusting collective or throttle your left hand is free too.

Obviously, it went over my head. ;-)

Spigots and such close clockwise because of right hand threads being the default.

Controls on electronics, such as volume, increase by turning clockwise, probably because we read from left to right and generally view above the nob for demarcation.

Referring to the control as 'volume' leads to increasing clockwise as a point on the nob passes values increasing as if counting from left to right.

To be consistent, if the control were referred to as 'resistance' it would make sense to reverse the operation, suck that clockwise turning lowered output.

For the mechanical engineers out there, I'm thinking that the packing nut may have something to do with it. Can continued usage of a water valve loosen the packing nut? If the valve operates clockwise, maybe the packing nut will loosen with use.

When I was in college, I had a 1964 Chrysler New Yorker. I remember taking off the wheels and my dad told me that the drivers side lug nuts were backward (make sure I turned them the right way and that I kept the right side lug nuts on that side).

Since packing nuts have been known to come loose, maybe ...

Well, for every counterclockwise twist of the faucet, there's a corresponding clockwise twist.

But, it's easier to loosen a nut, so.............................................

NASCAR's worst, they always make left turn. Lyn must know something bout it.

I had experience back in the 50's of an exposure control for a photo contact printer.

It had a potentiometer with a vertical sliding bar.

You would think that an upward motion would increase the brightness of the exposure lamp.

But not in this case. The logic was that the slider was arranged to 'increase' the brightness (highlights) of the finished print that in fact needed 'less' exposure light.

For non-photographers and those not aware of the contact print process; a light is shone through a negative on to a light sensitive paper. More exposure means darker images. less exposure means lighter images.

The machine operator had to 'best guess' (assisted by a light meter) the amount of light needed to produce the range of greys to produce a viewable print. He had to 'learn' the slider went up to reduce the light in order to produce a whiter picture.

...and then there is the "AMBiHELICAL HEXNUT"...

No matter which way you turn it, you're screwed.

I think that AH gave a logical answer (based on the human's anatomy). Probably, there is, also, a kind of "psychological reason" for all these. The "clockwise movement" obviously is easier for the majority of the human beings (right-handed people). This movement should be "connected" with the safety issues and urgent situations. The more "safe and urgent" situation is to stop the flow of the water (not to waste it, not to be flooded e.t.c.). So, it's much more natural (at least for right-handed people) to proceed in a clockwise movement for such a situation. (A similar situation is the key-turning: a clockwise movement locks the door which leads to a more "safe" situation.)

Concerning the electronic devices, I think that such a "safety and urgent" issue is not valid. If you want to stop the device (e.g. an urgent situation) you just use the "on-off switch" and not the "volume knob". So, the volume knob is "free" from this kind of "safety issues". It could be turned clockwise or anticlockwise in order to increase the voltage/current. Probably, as AH said, it was more natural to be turned clockwise as this movement depicts that "something is increased" (as the clockwise movement of the clock's pointer depicts an increment of time).

A similar situation is the key-turning: a clockwise movement locks the door which leads to a more "safe" situation
Not so. If a door is locked by a clockwise movement on one side it will be locked by an anticlockwise movement on the other side

Yes, you are right... Bad example...

Water. Not always true.

Had a laundry valves where the hot and cold valves were mounted opposed 180 degrees. Up was on and down was off.

Replaced it with one that had the valves mounted at an angle. The left one is down for on and up for off and the right one is up for on and down for off. Annoying.

Keys for car doors. One manufacturer uses "toward the front of the car" for unlock, others uses counter-clockwise for unlock,

Just found out that some or all, who knows, place sin Europe use UP for off for power switches.

Shower mixing valve uses CW for "more hot".

Lug nuts on some vehicles changes the orientation depending on the side of the car.

The upper position of a switch for the power door locks is unlock on many cars.

What standards?

Some shower mixing valves use CW for "more hot" and many others use CCW for the same. Moen uses the CCW for more hot(ter).

Power door lock switches are that way to duplicate the way the older manual "pop-up" lock handles/posts were operated.

Also- Double handle (one for hot and one for cold) kitchen and bath faucet sets operate in opposite directions. Hot- CW to shut off, CCW to open. Cold- CCW to shut off, CW to open.

Good Luck, Old Salt