Hammer flipping experiment?

[Neil WyattModerator @neilwyatt]

This little piece was written as a space filler in MEW 294.

Anyone fancy giving it a go? No spoilers please, I want your own theories:

Here’s an interesting little experiment to try in your workshop (or outside in the garden) as an alternative to going stir crazy (come to think of it, if the neighbours spot you, they may think you have already gone stir crazy). Please be careful throwing heavy tools around…

Take a hefty claw hammer, the sort with a decent wooden shaft. Hold it in your good hand, the face pointing down and the claws upwards. Flip it gently upwards in a single end over end spin and catch the handle.

Which way is the head pointing now? Repeat it, which way is the head pointing. Repeat this a few times and see if you can spot a pattern.

Now hold it with the head horizontal and the face pointing to your left.

Again, flip it gently upwards and catch the handle. Which way is the head pointing now? Repeat the action a few times.

I’m particularly interested in your personal theories about what is happening rather than the results of any internet searches.

Neil

[Neil WyattModerator @neilwyatt]

[Ady1Participant @ady1]

spooky science

[JasonBModerator @jasonb]

Don't try it in your flip-flops!

[Pete RimmerParticipant @peterimmer30576]

I flipped my claw hammer 10 times. Dropped it twice but each time I didn't drop it I caught it with the hammer face down.

[Nick Clarke 3Participant @nickclarke3]

Actually my foot, but you get the idea!

Edited By Nick Clarke 3 on 06/07/2020 19:25:14

[JasonBModerator @jasonb]

Always the same way up with mine

[BufferParticipant @buffer]

Freaky!

[BufferParticipant @buffer]

 

 

Edited By Buffer on 06/07/2020 20:02:40

[Neil WyattModerator @neilwyatt]

Well so far I've learnt what a clumsy lot you are. Should never be allowed near rotating machinery, let alone 'ammers!

Neil

P.S. very good Jason

[duncan webster 1Participant @duncanwebster1]

I don't actually own a claw hammer, too much like woodwork for me. However I've tried it with my collection of ball pein and straight pein hammers and they stay the same way up, ie face down

[David NobleParticipant @davidnoble71990]

 

 

 

 

 

Edited By David Noble on 06/07/2020 22:15:55

[David NobleParticipant @davidnoble71990]

Very strange, I've just been reading about this

I'm having trouble copying and pasting though. Try Googling "Russian astronaut wing nut"

David

(edit) Sorry Neil, just spotted the no internet searching bit 

 

 

 

Edited By David Noble on 06/07/2020 21:02:25

[Nick Clarke 3Participant @nickclarke3]

Posted by duncan webster on 06/07/2020 20:24:41:

I don't actually own a claw hammer, too much like woodwork for me. However I've tried it with my collection of ball pein and straight pein hammers and they stay the same way up, ie face down

In my case it should be spelt pain!

[DiogenesIIParticipant @diogenesii]

..has this come about from your researches into the Grateful Dead, Neil? ..there's a certain relevance..

[steamdaveParticipant @steamdave]

Or for some Real fun with a hammer, try this:

Dave
The Emerald Isle

[SillyOldDufferModerator @sillyoldduffer]

Posted by Neil Wyatt on 06/07/2020 18:26:33:…

Take a hefty claw hammer, the sort with a decent wooden shaft. Hold it in your good hand, the face pointing down and the claws upwards. Flip it gently upwards in a single end over end spin and catch the handle.

Which way is the head pointing now? Repeat it, which way is the head pointing. Repeat this a few times and see if you can spot a pattern.

Now hold it with the head horizontal and the face pointing to your left.

Again, flip it gently upwards and catch the handle. Which way is the head pointing now? Repeat the action a few times.

I’m particularly interested in your personal theories about what is happening rather than the results of any internet searches.

Neil

Results

1. Flipping the hammer with the face down and the claw up (vertical) results in the hammer rotating 360° back to the same position, face down.

2. Flipping the hammer sideways (face and claw horizontal) results in the head and claw swapping sides, ie the head rotates horizontally by 180° during the 360° turn.

The horizontal turn is too fast to follow, but I think its only 180° not 540°.

Duffer's Hypothesis

Head down the hammer is balanced along the axis of the handle. All the forces acting on the hammer are in the same plane, so the hammer does a single turn at right angles to it. The axis is the hammer's centre of gravity,

Head horizontal, the hammer isn't balanced along the handle. The head is heavier than the claw. When the hammer is tossed, two forces are applied because the centre of gravity is off centre in one plane. As the hammer rotates backwards it also turns sideways.

Confirmation.

Of concern is the hammer appears to rotate more or less exactly 180°. If the centre of gravity hypothesis is correct, I would expect the hammer to turn at some angle proportional to the imbalance. Testing with other types of unbalanced hammer (ball pein and cross-pein types) shows they also apparently rotate by 180°. And testing with a balanced mallet (same head shape and weight both sides) shows it too spins by 180° Claw hammers are a red-herring.

Conclusion,

Duffer's First Hypothesis is either wrong or much too simple.

Second Hypothesis. The unbalancing force is due to the earth's rotation.

This may have legs. Tossing the balanced mallet facing south, it appears to reliably turn anti-clockwise by 180° and facing north, it appears to reliably turn clockwise. Facing East and West, the mallet still turns, but it appears less reliable, maybe spinning only a bit over 90° Not confirmed – the turns are hard to follow by eye. Wish I had a high-speed camera.

Dave

[GeorgineerParticipant @georgineer]

… – the turns are hard to follow by eye. Wish I had a high-speed camera.

Dave

When somebody tried to teach me juggling, I was given silk handkerchiefs to start with because they slow the gravity down. Would it help if you started with a rubber hammer, or one made of marshmallow?

George B.

[Howard LewisParticipant @howardlewis46836]

My brain can't handle this, it does my head in, causing too much pein. It has me clawing at the walls!

Howard

[pgk pgkParticipant @pgkpgk17461]

Posted by Georgineer on 07/07/2020 12:29:51:

When somebody tried to teach me juggling, I was given silk handkerchiefs to start with because they slow the gravity down. Would it help if you started with a rubber hammer, or one made of marshmallow?

George B.

You're going to upset Mr Newton by tryng to slow gravity. Anyhoo…David Noble's search link shows this happens in zero grav on the ISS. Parachute hammers are not the answer. Nor apparently that the ISS is going quite fast in a circle – as indeed are we…

pgk

[BazParticipant @baz89810]

To me this just proves that we need to get out more😃

[Ady1Participant @ady1]

It's not a hammer it's a Coventry spanner!

[Neil WyattModerator @neilwyatt]

If your hammer stays face down, have you tried the sideways bit?

Try it with a tennis racket.

Neil

[Harry WilkesParticipant @harrywilkes58467]

Posted by Ady1 on 07/07/2020 16:20:25:

It's not a hammer it's a Coventry spanner!

Could well be but an 'ommer' is defiantly a Black country sponner

H

[SillyOldDufferModerator @sillyoldduffer]

New hypothesis:

The 180° turn is due to the increased couple provided by the horizontal head with a twist imparted the oval shaped the handle. When the hammer is flipped, the head isn't perfectly horizontal so one side of the head accelerates up while the other is pulled down by gravity. There isn't enough time or energy for the head to spin more than once so when the hammer is caught by a hand, it's oval handle stops the turn at a near exact 180°.

Partly physics, partly human inaccuracy and the shape of the handle.

To test this I need a hammer with a perfectly round handle, and a flipping machine to keep the head horizontal during launch.

Dave

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