OT: Why Righty Tighty Lefty Loosey?

Like most all objects that spin and are held on by nuts or bolts they loosen in the direction that the object being spun would normally spin. It is unlikely that a nut or bolt will loosen if it has to spin faster than the object in the same direction that the object normally spins. Hense, the lug nuts on Chrysler vehicles had left hand threads on the wheels that were on the right hand/passenger side of the car. IF the cars used one nut on the center of the axel to hold the wheels on, all cars would still have left hand nuts on the right side of the car.

That particular site goes on about how the force is "small" and how that is because the Earth "rotates slowly". What I don't see there is an estimate of the magnitude. While I don't have the time or inclination to go back to my physics texts and work out the calculation there's something bothersome about the notion that "it takes hours before the tiny force could develop sufficient deviation".

Simple experiment--start the water in a sink swirling one direction--watch it as it drains, see if it keeps going that direction. Then try it the other way and see it it happens. If it reverses then that knocks the notion that it's due to preexisting rotation into a cocked hat.

Why would it not rotate? Because if the water in the vessel is not moving then it's not subject to the Coriolis force. There seems to be a major misconception about the nature of the Coriolis force inherent in that statement.

Mekon,

I was impressed by the toilets in Oz (I know, I know...it dosent take much). I don't understand why we cant adapt some of your construction stuff here in the US like the toilet design, having water drains in the middle of the bathrooms and laundry rooms, and slate roofs. Makes a lot of sense!

Skip

Skip Williams submitted this idea :

We also have switches on all of our power outlets too, which a few North Americans have found variously amusing/puzzling and impressive.

Oh and if any of you folk from up over do happen to be in Brisbane, give me a hoy and I'll try to lay on a tour or two.

Mekon

I was one of them. 17 and full of piss 'n vinegar with Daddy's car out in a snow storm. Hit a curb too fast and pfft goes the tire. Spent nearly all damned night tightening the lugs on that flat. Didn't have enough strength to shear the nuts off, but sure made it tough to finally get them started when someone suggested going the other way.

Bought daddy a new lug wrench the next day. The old one was...um..bent.

Back on topic, check out your right tilt tablesaw or RAS. Lefty tighty 'cause if it was righty tighty, the start up jolt might spin the arbor nut along with the blade off the arbor. It's not a problem on stopping since shutdown doesn't have the jolt. In my early RAS days, I'd turn blue in the face trying to get the arbor nut off - until I noticed the threads on the end of the arbor. That was when you did a lot of blade changing as HSS blades were about all that was available.

Mid-1970s, actually, IIRC -- my first car was a '68 Dodge Dart with left-hand thread lug nuts on the left side. My brother had a '72 Charger that I'm pretty sure was the same way. But my '85 D150 truck has right-hand threads all the way around.

Because the rotational force applied to the nuts by the rotation of the wheels as the car is driven is counterclockwise on the left wheels, and clockwise on the right wheels. Hence, the lugs had left-hand threads on the left side, right-hand threads on the right side.

It took Chrysler quite some time to realize what GM, Ford, and everyone else apparently knew all along: that the magnitude of this force is small enough that just making the lug nuts a little bit tighter is a far simpler solution to a nearly-nonexistent problem.

Well, it *was* documented in the owner's manual. Not the manufacturer's fault if the buyer doesn't read it...

Yep, the machines are left-handed.

Mekon,

You have switches on the power outlets because you pump 220 volts out of them and that would give quite a jolt...but i do remember trying unsuccessfully to get my laptop to power up for a while until i realized that the outlet switch was off.

We spent a month in Oz last November and had a great time...You have a wonderful country...we visited Sydney, Perth ,Adalaide, Augusta[sp], toured the Margaret and Borassa Valleys, drank a lot of wonderful wine! We will be back!! We have some good friends in Perth.

Skip

Yep...

I had a '51 Studebaker Commander and a '63 Plymouth Valiant so I had experience with the other side of the car's lug nuts! &^%$*^!!!

Skip

Tanus wrote in news:fhqfu9$khm$ snipped-for-privacy@aioe.org:

I wonder if that's the reason for the advice "If you can't get the nut to loosen, try tightening it and then try again." ;-)

Puckdropper

Got a left-tilt saw a few months ago. Seems absolutely unnatural to have a right-hand thread on a tablesaw. The tilt I got used to right away, but it'll be a lot of blade changings before I even start the wrench toward the proper side.

My British cars had knock-off hubs back in the day, and they were legitimately left and right thread.

Anyone know why the srew was designed as it exists today (in so many words).

Lots of responses, nary a single answer.

How hard is it to pull the wrench toward you to loosen the nut? Just like you always did.

Try ths:

Of course they did. You expected maybe Yiddish? Certainly not Greek.

Skip Williams expressed precisely :

Well if you do, don't miss out on Queensland again huh?

I took our German exchange student to the Barrier Reef we did 12 dives in three days, stunning stuff. That has to be worth a visit - at least one of your Presidents has been there. That is about 2 hours flying time of here, Fraser Island - A World Heritage location is about 3 hrs drive. Steve Irwin's zoo is an hour drive away as are some of the best beaches in the world.

And of course Brisbane itself, where you will have the services of a local guide!

Mekon

I went to the official source for such things, and asked Tevye.

The answer is, in his own words (with a slight Russian accent): Tradition!