physics and Ashby

[Gunnyart]

Watching the videos Troy and Rocketman are cranking out it sure looks like they have stepped up their testing methodology and are producing some good data. My anecdotal evidence this year was impressive for what it's worth.

[enewman]

Agree. Sadly this first hurdle is one that if I had to hazard a guess, 80% of bowhunters don't ever get past. The two most common things I see/hear as advice... 1. just shoot a mechanical, and 2. just move your pins.

As I've read/watched more and more on this topic, I think less and less of Ashby. In a way his whole methodology is constructed around reinforcing his theories, I feels a lot like confirmation bias. It gets even less "worthwhile" when its pointed out he contradicts physics. For the bowhunting academics its a fun topic to discuss and sure beats watching reality TV.

It's funny, not long ago I was all into Ashby. But I found a guy with a physics background. He showed me lots of things wrong with Ashby. I fought with him tooth and nail.

But one day I started looking at what he was telling me. I went deep into looking at physics. Then I went back to the Ashby papers. I cannot believe how stupid I was. What is worst is the number of people that I taught Ashby to.

It truly bothers me how much I taught Ashby. Now, I don't hate Ashby he is a nice guy. But I do think it's worth my time and even being beaten up over it to show people what is going on.

Are my papers for everyone, no they are not. But I am always willing to help where I can.

[enewman]

Watching the videos Troy and Rocketman are cranking out it sure looks like they have stepped up their testing methodology and are producing some good data. My anecdotal evidence this year was impressive for what it's worth.

Yes, I'm glad they are too. I have noticed they are now talking more about energy and work.

I do disagree with some of there data they put out. I did an arrow deceleration test. they call there's speed erosion.

They are showing at the bow at a distance. that's it. then they want to show you how much better a heavy arrow does. That's ok data but lacking.

My test and it's on this sight I showed every ten yards to 50 yards. then I showed based on the lab radar the time in seconds it took for each arrow I tested. then I showed a trajectory tape.

They want you to believe heavy is the only way to go. it is absolutely not.

[Loneaggie]

Yes, I'm glad they are too. I have noticed they are now talking more about energy and work.

I do disagree with some of there data they put out. I did an arrow deceleration test. they call there's speed erosion.

They are showing at the bow at a distance. that's it. then they want to show you how much better a heavy arrow does. That's ok data but lacking.

My test and it's on this sight I showed every ten yards to 50 yards. then I showed based on the lab radar the time in seconds it took for each arrow I tested. then I showed a trajectory tape.

They want you to believe heavy is the only way to go. it is absolutely not.

Well they've yoked themselves to Ashby.... and are straight up fundraising for the foundation. So sadly any data they collect that directly contradicts Ashby.... I would be surprised if it came to light. Not saying its impossible, but I would be surprised.

[lovemylegacy]

Not to derail the thread, but, wouldn't it be paramount to teach people to tune their equipment? A fine tuned bow with a straight flying arrow is gonna hit the spot aimed at and penetrate with less effort and friction. Honestly, most people don't get physics, but could learn to tune their bow. Don't get me wrong, I appreciate your efforts and all the info you post and some I understand, some I don't, but me not knowing physics doesn't stop my arrow from killing. Your posts are intriguing though.

You mean a lighter faster arrow is harder to stop than a heavier slower arrow? Do tell?

[enewman]

Not to derail the thread, but, wouldn't it be paramount to teach people to tune their equipment? A fine tuned bow with a straight flying arrow is gonna hit the spot aimed at and penetrate with less effort and friction. Honestly, most people don't get physics, but could learn to tune their bow. Don't get me wrong, I appreciate your efforts and all the info you post and some I understand, some I don't, but me not knowing physics doesn't stop my arrow from killing. Your posts are intriguing though.

You mean a lighter faster arrow is harder to stop than a heavier slower arrow? Do tell?

Yes, I agree. Teaching tuning would prolly be better.

The lighter faster arrow would only be harder to stop when matching momentum.

Shooting from the same bow, the heavy arrow will be.

[RUNNING BEAR]

Ashby was given a very specific test to pass, so he catered everything he did in order to pass that specific test. That’s what I would do too, so not hating, just adding a bit of perspective. Also, he’s not wrong on a lot of things. Just no need to burn much brain power on this unless I’m hunting for bigger game.

[Buff]

Ashby is a mighty fine fellow. He helped me put together the arrow i used to kill an elephant.

My humble opinion is any compound bow will kill deer sized animals with any arrow you want to shoot.

Ashby research was the best that had ever been done for folks wanting to kill silly big critters with recurve bows .

When i was talking to him he pretty much seemed to be the smartest fellow i had ever talked to

but that is just me

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[enewman]

Ashby is a mighty fine fellow. He helped me put together the arrow i used to kill an elephant.

My humble opinion is any compound bow will kill deer sized animals with any arrow you want to shoot.

Ashby research was the best that had ever been done for folks wanting to kill silly big critters with recurve bows .

When i was talking to him he pretty much seemed to be the smartest fellow i had ever talked to

but that is just me

What one of the problems is the people backing the ashby foundation is *******izing his work. They are preaching that you need a 650gr arrow to kill whitetail deer.

Some of the worst teachings I have ever seen.

But my post is not about arrows. It’s about how ashby screwed the pooch when looking at physics.

[98ag]

Yes, I agree. Teaching tuning would prolly be better.

The lighter faster arrow would only be harder to stop when matching momentum.

Shooting from the same bow, the heavy arrow will be.

I’m confused, do you agree the heavy arrow is harder to stop? Isn’t that what Ashby says?

[98ag]

I think the important question to ask is: does more foc weight cause an arrow to fly straighter?

[diamond10x]

Did Joel Maxfield test these two arrows out of the same bow, multiple times getting an average, or did he just throw some random velocity numbers up there? One can easily plug in numbers to the equation to give the lighter arrow more KE/P. I'm not preaching light or heavy, just pointing out that I could plug in numbers and it would show Mr. Maxfield to be wrong.

[muddyfuzzy]

Ashby is a mighty fine fellow. He helped me put together the arrow i used to kill an elephant.

My humble opinion is any compound bow will kill deer sized animals with any arrow you want to shoot.

Ashby research was the best that had ever been done for folks wanting to kill silly big critters with recurve bows .

When i was talking to him he pretty much seemed to be the smartest fellow i had ever talked to

but that is just me

Can’t argue with results….


[emoji1662]

[enewman]

I’m confused, do you agree the heavy arrow is harder to stop? Isn’t that what Ashby says?

The test and what I’m talking about is physics.

Go back and read my paper. What I’m showing is that Ashby is wrong on what gives us penetration.

Dr ashby preaches that KE has absolutely nothing todo with penetration. Dr ashby states just that. In my paper the reference number one is his paper where he tells everyone in the world the KE has nothing todo with penetration.

Same paper and the statement about momentum is referenced in my paper, he states that two equal momentum arrows with unequal mass that the momentum built on mass will out perform. That goes againt physics. The test shows this. What I’m showing you and others is that ashby screwed the pooch.

Ashby spent to much time trying to prove that KE does nothing that he caused some testing to be skewed.

He talked about momentum but uses the definition of inertia.

There are so many flaws in the paper talking physics it’s horrible.

Now. I just used a equation based on Newton’s second law and work energy theorem. I just showed that ashby was wrong.

Does this mean a heavy arrow will not out penetrate a light arrow. No. That was not the test. Heavy arrows will out penetrate. Why.

Because as you increase weight the bow converts potential energy to KE better. Thus the heavy arrow will leave the bow with either the same KE (very efficient bow) or it will be a little higher ( not as an efficient bow). Due to inertia the heavy arrow will retain its velocity better. So at impact the heavy arrow will have more KE.

Now at impact. When an arrow is moving through the animal we have resistance. As hunters we can control the resistance some what. We do that by the broadhead.

Ke is a major player in penetration. Momentum is also very important. Ke is what gives us the capacity to penetrate momentum is what makes it harder to stop.

This is why light arrow people talk about shot placement. A 450 gr arrow with the correct broadhead will perform just as well as a 650gr. But you must stay off the bone. Is it a for sure bone break using a heavy arrow. No.

So why is there so much talk about all of this. It comes down to trajectory. Long distance shooting trajectory is a big thing. Misjudging yardage is a big thing. It all comes down to what is best for you.

Again the test was looking at ashby comment on two arrow with equal momentum. When doing this the heavy arrow will have less KE. Thus its capacity to do work is less.

[enewman]

Did Joel Maxfield test these two arrows out of the same bow, multiple times getting an average, or did he just throw some random velocity numbers up there? One can easily plug in numbers to the equation to give the lighter arrow more KE/P. I'm not preaching light or heavy, just pointing out that I could plug in numbers and it would show Mr. Maxfield to be wrong.

I can see you do not know joel maxfield. Look him up. When you do you may need to type in joel maxfield with Mathews.

Your question will be answers.

These test that I’m showing, are some I am working on. I am fixing tod a NEWTONIAN and NON-NEWTONIAN test.

Your question about same bow. No. You cannot test equal momentum doing this. Reason is thee is a big KE difference.

I have people tell me you cannot do a test like this, because I am changing bows. That normally comes from the ashby crowed. Funny thing is they seem to forget that ashby tested and compared to each other with a 40,54,70, and a 82 lb bows.

Funny is it was ok for ashby but not me. The difference is I’m showing different results and I using physics to support my test. Ashby did not.

Also a bow is just a machine. It’s purpose is to convert the energy you put in to drawing the bow into potential energy then convert it back to kinetic energy and transfer that energy to the arrow so the arrows has acceleration.

This is why I use a term I coined. K.E.D.D. kinetic energy delivery devise. That is all a bow is.

Ranch fairy calls it a kinetic energy spring. He is doing this I assume for the same reason I did. To show people when testing it doesn't matter what bow we use to reach what is needed to test.