Gordon vs Bearpaw

[Bvas]

You fellers are either purty dang smart, or some of the best BSers ever.    I'm keeping up with this logic for the most part.  But then there's that part of me that says "Screw it, put a string on the dang thing and lets fling some arrow!!"

[Flem]

Thats what happens when you eat PB&J while sniffing glue

[Bvas]

Mike, I'm betten these guys chewed the erasers off their pencils and ate that white glue in grade school and carried peanut butter and

jelly sandwiches in their lunch boxes:)

I never had a lunch box.....carried my sandwich in my pocket

[Forwardhandle]

My head hurts  Flem how does that apply when say you put .030 on the back & .040 on the belly ?

[Flem]

 So assuming the core is homogenous and will not be a variable. if you increase the resistance to bending on the compression side, it would move the neutral plane toward the back of the bow, in contrast to a 40/40 or 40/30 scenario.
I want to be clear, I'm not saying that any of this would or would not be discernible, but it still exists as a physical reality. Does it matter? Maybe. Have to ask a Physicist for that answer. It's hard to ignore what you have come to know, unless it could be unknown because those erasers you ate somehow found their way into your brain.

[Crooked Stic]

samich musta been in your hip pocket and it B flat 

[Roy from Pa]

Clem, AH NEVER MIND....

I thunk the glue dun did ya in...

[Shredd]

First I would like to correct one of my previous statements...

     I said,  "Tension almost always trumps compression when dealing with bow limbs therefore I would think that the neutral zone is naturally more toward the tension side of the limb...  I would also think that the closer that you can get the neutral zone to the tension side the better the performance that you should get out of a limb"...

   I had it backwards... It should say,  I would also think that the closer that you can get the neutral zone to the compression side the better the performance that you should get out of a limb"...

  Flem...  I think that you have got it backwards...  Contrary to your statement...  The more that you strengthen one side you move the neutral plane to that side...  So if you increase the resistance to bending on the compression side, it would move the neutral plane toward the belly of the bow...


  Here are some videos to prove my point...  If you notice where the beam is more reinforced the neutral plane is closer to that side...



Go about 5:30 minutes into the video where the 'T' beam is and you will see where the neutral plane is closer to the stronger side...

[Roy from Pa]

If I gotta worry about all this stuff, I'll quit making bows first...

[Flem]

I don't think that's an completely accurate representation of the forces at play in a bow. Those examples incorporate 2 axes, we are dealing with one. Also you have to look at the total mass represented in those examples, not just the distance from each surface to the neutral plane. In that "T" cross section there is more mass on the compression side of the neutral plane. So because the compression side has been strengthen with more material, there is less total material in tension. We want more material in tension because it's more elastic, less friction.

[Shredd]

Your quote...  "So assuming the core is homogenous and will not be a variable. if you increase the resistance to bending on the compression side, it would move the neutral plane toward the back of the bow"...

   In the illustration they did exactly what you said... They increased the resistance on the compression side... Though it is a bit extreme it allows you to see where the neutral plane has moved... You are saying the complete opposite in your statement... And I fail see how this basic law of physics does not apply to a bow limb...

 All I have left to say is that I have to respectfully disagree with you on the movement of the neutral plane due to the reinforcing or strengthening of the tension or compression side of a beam or bow limb...

  For you guys in the peanut gallery...    I applaud you for your tasteless humor...    If you are having trouble comprehending something I think you need to come up with better jokes...  I mean seriously we are talking about the inner workings of a bow limb...  The low tech humor did not seem to apply... I think you need to step up your game a little... Because it begins to sound like BS...  And I think BS is not needed when two men are trying to have a serious discussion... If you can't step up your game save your humor for where it might apply better...  I am just a straight up guy telling it like it is...   

[Mad Max]

My guess is a 45 bow with either glass will need a chrono to see the difference.

x2

[Flem]

Thats why I said it's not an accurate representation of the forces at play in a bow. You are comparing a symmetrical cross section(1st example), which is what we work with on bows, to a non symmetrical one. Additional forces acting are on the cross section.

[Shredd]

Find a reputable source, other than your own opinion, anywhere on line that says that the neutral plane moves away from the more heavily reinforced side of of a beam, bow limb, ect... And I will be all ears...    You make it sound like the laws of physics change when it comes to bow limbs...

  Until then I am done with this discussion...  Good Luck...

[Flem]

So in the example you presented, they are working on baseline equations. So we need to pay attention to what is being said in addition to what is being illustrated. It's clearly stated at 5:18 "movement is negative, so tension at top and compression at bottom. Then when they shift to the non-symmetrical cross section, they clearly state, "same span and loading", so tension is still at the top and compression at the bottom.
Even still, I don't think that's the best example of what we are building.

[Shredd]

Lets keep it simple... Just find a source that supports your theory...  No more opinions....

[Flem]

The one you presented did just that Shredd. I could make the same request, since my assertion has been validated by the example you presented. Are you not willing to acknowledge that this statement is incorrect?

 " In the illustration they did exactly what you said... They increased the resistance on the compression side... Though it is a bit extreme it allows you to see where the neutral plane has moved... You are saying the complete opposite in your statement... And I fail see how this basic law of physics does not apply to a bow limb..."

[Roy from Pa]

All this neutral plane bow limb crap doesn't mean diddly dip without bringing into play tension wood, compression wood, and reaction wood characteristics.

What side of the tree did the limb materials derive from, the downhill side which is affected by gravity and is compressed already.

The uphill side which is already under tension from being stretched over from gravity.

Or the reaction sections of the wood which is chasing its tail between the compressed and tension actions on it.

Then ya got those wind shakes inside the wood.

For thousands of years, Caveman and Indians made bows from all natural wood.....

Then modern man decides to glue glass onto the wood and all hell broke loose.

I have no clue where the neutral plane is in my bows or if there even is such a thing in my bows.

All I know is my wood/boo bows are faster, quieter, and more accurate than those stupid glass bows:)

Go have a beer and relax.

[Crooked Stic]

I dont know about the faster part but the rest is 

[Shredd]

  First let me say that I am cool with the whole discussion other than the lame jokes... 

   Well said Roy...  Thanks for joining the discussion and sharing your opinion and some valuable info instead of talking about sniffing glue and such...   Nothing wrong with some tech talk... We are all in this for different reasons and have different approaches and we are not always gonna agree... But on this topic I agree to disagree and choose not to take it any further...  I am glad I was involved in this discussion...  I learned a very valuable point through my exploration on the topic... Which will better my understanding how the limbs work...  Sorry if it was painful for some of yah all to listen in on the topic...  But the jokes seem disrespectful when I am trying to talk some serious tech...  If you all prefer I will will take my tech talk to private messaging next time... Just let me know...  Or you all could just not tune into the thread...

   Sounds like you need the beer...   

  I prefer wine...   

   PS  I love this craft and a very passionate about it and my gig is about improving performance...