Ambull01
Addicted to ArboristSite
Interesting. Why am I starting out slow with one of those? I've split wood before. That would be kind of cool for my wife, if I can get her to use it.
Tell me about Axes....
- Thread starter PLMCRZY
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Interesting. Why am I starting out slow with one of those? I've split wood before. That would be kind of cool for my wife, if I can get her to use it.
(Deep breath)
OK Marshy, let's forget bout the 3 ounce billiard ball completely.
Let's increase the velocity of the 6 ounce ball from 20 FPS to 40 FPS... which doubles its momentum, but quadruples its kinetic energy. So if the kinetic energy has quadrupled, why does the velocity of the struck ball only increase by the amount equal to the increase of momentum in the striking ball?? Why isn't the velocity of the struck ball quadrupled, or even tripled, or even increased a tiny bit over double??
The answer is because kinetic energy is not used to move the struck ball, momentum is. Kinetic energy does not have a "directional force" like momentum, or velocity, or acceleration... it's more akin to vibration, or magnitude. The result of greater kinetic energy is a higher frequency... the sound you hear when the balls collide is higher pitched and/or louder, but it doesn't affect the linear velocity of either.
Sometimes this higher frequency translates to greater shock (like tissue damage from a high velocity bullet), which can aid in splitting wood, especially relatively easy to split wood... but without at least some certain amount of momentum, shock is worthless (you need the penetration first). Like was stated by someone else in this thread... "I've never tried splitting wood with a tennis ball."
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OK Marshy, let's forget bout the 3 ounce billiard ball completely.
Let's increase the velocity of the 6 ounce ball from 20 FPS to 40 FPS... which doubles its momentum, but quadruples its kinetic energy. So if the kinetic energy has quadrupled, why does the velocity of the struck ball only increase by the amount equal to the increase of momentum in the striking ball?? Why isn't the velocity of the struck ball quadrupled, or even tripled, or even increased a tiny bit over double??
The answer is because kinetic energy is not used to move the struck ball, momentum is. Kinetic energy does not have a "directional force" like momentum, or velocity, or acceleration... it's more akin to vibration, or magnitude. The result of greater kinetic energy is a higher frequency... the sound you hear when the balls collide is higher pitched and/or louder, but it doesn't affect the linear velocity of either.
Sometimes this higher frequency translates to greater shock (like tissue damage from a high velocity bullet), which can aid in splitting wood, especially relatively easy to split wood... but without at least some certain amount of momentum, shock is worthless (you need the penetration first). Like was stated by someone else in this thread... "I've never tried splitting wood with a tennis ball."
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513yj
ArboristSite Operative
It might be faster yes. Just like the chevy and ford v-8 diesels might be faster off the line. But when one ponders the question of what engine configuration do semi trucks use for pulling the mountains out west the answer is inline 6 cylinder. Cain't none of the 8 cyl diesels hold the speed of a load up a hill like a Cummins.
PLMCRZY
Addicted to ArboristSite
I drive a truck. C15 550hp non acert i know what power is sonny boy
Cat made a 3408 which was a v8 big truck engine and it was a pulling mofo btw
513yj
ArboristSite Operative
The key word in this phrase is made, as in past tense. I'm also not saying you don't know what power is but I know staying power is best held by inline engines.
These are just my opinions of course.
PLMCRZY
Addicted to ArboristSite
Wasnt emission friendly...... Glad you like your dodge. Glad i wont be towing with the Ranger.
513yj
ArboristSite Operative
You probably can't tow with that Ranger anyhow since the front wheels will prolly be off the ground 30% of the time!
Ambull01
Addicted to ArboristSite
From axes to physics to diesel trucks lol. This site is about as ADD/ADHD as I am.
Idahonative
Addicted to ArboristSite
Don't let people (or spiders) try to fool you into thinking this thread is complicated. All you really need in your arsenal when it comes to splitting wood by hand is a sledge, a wedge, and a Fiskars X27. End of story.
Ambull01
Addicted to ArboristSite
Well I'm almost there if that's the case. Just ordered my X27, should be here this week. I have some nice sized rounds to test them on. I'll get the Council Tool 6# maul once my wife's memory fades about buying the Fiskars. Wedges are stuck in a stump in my yard. Some genius decided to pound them in until there was no hope in getting them out with a chisel. Promise, it wasn't me. Was there when I bought this house.
zogger
Tree Freak
Well, split what ya want, but I would suggest starting with smaller rounds, put inside a tire and up on a fat cookie splitting block. Get your swing and aim down first and be careful, easy to blow through a round and swing through and hit something interesting that you don't want to.
Most of the time, I stand feet apart, straight at the round, axe straight up and back overhead, swing down to my aim point with some gusto and drop my knees a scosh to add a bit more focus and speed as it gets there.
Ambull01
Addicted to ArboristSite
Yeah man, thought that would happen. Probably only good for small rounds. Guess you could noodle the bigger stuff then split it with the axe. I like to cut everything then go crazy with splitting though. Having to switch from chainsaw to splitting apparatus.
You're making it sound like the Fiskars will blow through rounds like a hot knife in butter. Hope that's the case. I've hit my shin with the side of a maul before. Didn't feel too great.
I naturally stand feet apart, feels more stable. You lift the axe straight up? I've always swung up it back over right shoulder then straight down.
PLMCRZY
Addicted to ArboristSite
Look at the fiskars review on YouTube. It blows thru alot of stuff honestly.
What-the-he!! does that have to do with what we were talkin' about??
He's talkin' about two separate masses, both in motion, powered by the same force, at the same time, and during the same time frame‼
At 3 minutes in, he says energy is the product of force times distance... that's true. But in the case of our billiard balls, the force is applied to only one ball, by the cue stick, and for only a short (very short) distance. As the cue ball glides across the table, there is no force applied to it (or, more correctly, work being done on it)... it is momentum that carries it across the table. The distance (or time) it glides across the table is not part of the equation... period‼
When the cue ball strikes the stationary ball, the force of momentum pushes on the stationary ball for very brief moment in time and/or distance (and the stationary ball pushes back with it's momentum of zero). Now, remember, force is not energy... energy expended (work) is the product of force and distance (which may, or may not be, measured by time), which is equal to the (in this case) kinetic energy (W=Fd=Ek). With the billiard balls, the principle of Conservation of Momentum applies, the momentum of one is transferred to the other, the stationary ball has zero momentum before the collision, but acquires the momentum of the moving ball after... and the moving ball acquires the zero momentum of the other.
So let's go back to the 3 ounce ball moving at 40 FPS striking the stationary 6 ounce ball. If the strike is square, the 6 ounce ball moves away from the collision at (almost) 20 FPS because the force acting (working) on it is the momentum... energy is not force, but momentum is. The kinetic energy that the 6 ounce ball acquires is the product of force (momentum) and distance (or time), the kinetic energy of the moving ball is not part of the equation... period‼ Which is exactly what was stated 3 minutes into your video. And the striking ball?? Well, the force acting (working) on it at the collision was the momentum of the stationary ball (zero momentum)... and the product of zero force and anything equals zero kinetic energy. Also exactly what was stated 3 minutes into your video.
Now I know I said that kinetic energy didn't really exist, but that's not entirely true... I was playing with words to make a point. Kinetic energy is a scalar quantity, not a vector like momentum... kinetic energy has no directional force (it ain't a force at all). And if energy, no matter its form, can not be created nor destroyed, and only half of the energy possessed by the 3 ounce ball was transferred to the 6 ounce ball... where did the other half go?? Well the other part of that physics law is that energy can be converted... the other half of that kinetic energy was converted into several forms, such as sound energy, heat energy at impact, vibration, and whatnot. There ain't any such thing as a truly "closed system" (on this planet anyway)... there will always be loss of energy through conversions, as well as some loss of momentum (or force). That's why I said, "(almost) 20 FPS."
So how does all of this apply to splitting wood??
Well, you can claim all the kinetic energy you want... but the force acting (working) to split the wood is momentum ('cause energy is not force)... there is also, or should be, at least some force from the user at impact.
I can shoot a small steel wedge (or steel core bullet) from a gun at several thousand feet per second, and it would carry an awesome amount of kinetic energy... but it won't split the log.
Enough said.
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Chris-PA
Where the Wild Things Are
I've stayed out of the billiard ball discussion as it is not a correct analogy and a distraction.
Your use of terms is all over the map - now we're on to force. OK then! Energy flows are the source of all work done and forces that are applied. There can be none of that without the flow of energy. Here ( http://www.physicsclassroom.com/Class/energy/u5l1d.cfm ) is a fairly good explanation of a similar system:
"A hammer is a tool that utilizes mechanical energy to do work. The mechanical energy of a hammer gives the hammer its ability to apply a force to a nail in order to cause it to be displaced. Because the hammer has mechanical energy (in the form of kinetic energy), it is able to do work on the nail. Mechanical energy is the ability to do work."
The potential energy (chemical energy) in your muscles is is transferred to the axe/maul as kinetic energy (mechanical energy). From the tool the mechanical energy (in the form of KE) is transferred to the block of wood at impact, where is does work. Work has the same units as energy, and in this case is essentially the change in kinetic energy of the moving tool. Work is force * distance, so that means that force times distance = the change in KE of the moving tool. Rearranging that you get F = KE/d, so if the tool stops in a short distance, and the KE was high, then you get a lot of force which hopefully breaks the fiber bonds and splits the wood.
But all of it depends on transferring KE to the tool, which goes back to my original statement you disagreed with.
It is all about transferring energy, and you have not yet explained how the energy gets from your muscles to the wood block where it can do work. In fact you have said that it cannot be transferred by the tool - and yet somehow forces are applied to the wood bock. The reality is that the transfer of energy and the relationship betwen energy and force is already defined, and you don't get to make up new rules.
Ambull01
Addicted to ArboristSite
Looks great. Did you see the video of that guy splitting a mass of rounds with a rope or something around it? Raced against the clock. I have to look for it again.
I would say two or three wedges, but I split 10 cords last month and only used the wedges on about 10 rounds, only needed two one time. Probably would have been easier to roll it back up and noodle it, but I had the maul in my hand. It was a 40" diameter bigleaf maple stump round. And I suspect you could substitute an ax for the Fiskars and be just fine. I have a 6 lb maul, a 3 1/2 lb double bit ax and two 2 1/2 lb axes, 3 steel wedges and can split anything I have ever encountered. I will probably get a Fiskars to try eventually, I am intrigued.
Yes, ergonomically, it expends less energy to thrust the maul straight up, then start it down. If you are using a maul or sledge on a wedge, if you get bounce and can translate the momentum into a big roundhouse, then it can make sense to let the hammering device get behind the vertical plane. Wish I could remember where I saw the study.
So much arguing...
