Chopping wood - torque question

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Discussion Overview

The discussion revolves around the mechanics of using an axe and hammer to split wood, specifically focusing on the concept of torque and the effects of lever arm length on the force felt by the user. Participants explore the physics involved in this process, including shock absorption and the role of the center of mass.

Discussion Character

  • Exploratory
  • Technical explanation
  • Conceptual clarification
  • Debate/contested

Main Points Raised

  • One participant describes their method of using a hammer on an axe to split wood and questions the relationship between lever arm length and the force felt in their hands.
  • Another participant suggests that holding the axe further from the impact point may dissipate shock along the handle, reducing the force felt in the hands.
  • A later reply acknowledges the shock absorption theory and reflects on the importance of the center of mass in relation to torque.
  • Some participants inquire about the type of axe being used and suggest alternative techniques for splitting wood, indicating that different tools may affect the experience of force and effort.

Areas of Agreement / Disagreement

Participants express varying views on the reasons for the differences in force felt based on hand positioning, with some supporting the shock dissipation theory while others consider additional factors like torque and center of mass. No consensus is reached on the primary explanation.

Contextual Notes

Participants mention various factors that could influence the experience, such as the type of axe used and the technique employed, but these factors remain unresolved in the discussion.

Who May Find This Useful

This discussion may be of interest to individuals exploring the physics of tools and mechanics, particularly in relation to woodworking and the application of force in practical tasks.

kusiobache
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So, I was just chopping the wood, and the way I do it is this : I get the axe wedged in the wood (duh), but instead of going all the way through like that, I get out a hammer and use it on the axe (which applies a downward force), and thus the wood is split. (I may draw a picture if this is hard to understand)

Now my question is this, it is torque because the hammer applies a downward force, which is perpindicular to the level arm (the axes handle). Thus, it is torque.

Torque is \tau=r x F right?

Now, sometimes when i hit the axe w/ the hammer I hold the axe very close to where the hammer strikes (short lever arm), and other times I keep it far away (long lever arm).

Now, by the torque equation I should feel more force when my hands are further away (and I believe this is true because it is much harder to hold onto the axe).

However, my hands hurt more if I keep my hands closer to the area of impact. That is, my hands hurt more when there is a SHORT lever arm. I'm wondering why this is? If the force increases w/ the length of the level arm wouldn't my hands hurt more then?

I'm probably just forgetting a factor, but I'm not sure. If I had to guess, I would say that it is because when the lever arm is longer I can't quite hold onto the axe. If I let go earlier I the time over which the force is felt would be less and thus I would feel less force with the longer lever arm. Basically, just human error. I'm just wondering if my guess is correct?

EDIT: and I know that there are a ton of different reasons that this could possibly happen, I was just wondering if my guess is feasible? And maybe what other reasons there could be for it.
 
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I think the reason why your hand doesn't hurt as much when you are holding the axe far from the point of impact is because the shock of the hit gets dissipated along the length of the handle. However, when your hand is close, your hand absorbs most of the shock before it reaches the other end of the handle.
 
jokkon said:
I think the reason why your hand doesn't hurt as much when you are holding the axe far from the point of impact is because the shock of the hit gets dissipated along the length of the handle. However, when your hand is close, your hand absorbs most of the shock before it reaches the other end of the handle.

Yeah I had thought of that, but dismissed it initially. Now that I think about it again though, that's probably it.

I realized my problem. The torque is at the area of impact, and it gets bigger the further that point is from the CM. I forgot about the CM. I'm assuming my hand positioning affects the torque because I need to apply an upward force to keep the axe from being knocked out but that shouldn't make too much of a difference.

SO yeah, you're probably right about it just being the force dissipating. I feel quite dumb for dismissing that before :\
 
Are you using a felling ax for chopping wood? Like that of a Michigan or a Californian head? Or are you using a maul? You shouldn't have a problem splitting wood with a maul in one chop, but a felling ax would have that problem.

Also, have you tried, instead of hitting the back of your ax with a hammer, lifting the piece up with the head and cheek still inside the wood and dropping it back down? It saves a lot of effort while chopping wood if you get a knotty piece.
 
MotoH said:
Are you using a felling ax for chopping wood? Like that of a Michigan or a Californian head? Or are you using a maul? You shouldn't have a problem splitting wood with a maul in one chop, but a felling ax would have that problem.

Also, have you tried, instead of hitting the back of your ax with a hammer, lifting the piece up with the head and cheek still inside the wood and dropping it back down? It saves a lot of effort while chopping wood if you get a knotty piece.

Oh no, I'm not having any problem chopping the wood, I was just wondering about the physics behind it =)

and yeah, that's exactly what I do for the knotty pieces. It's pretty useful
 

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