Primitive Archer

Quote from: willie on February 23, 2026, 05:00:02 pm

Quote from: superdav95 on February 22, 2026, 05:14:24 pm

Like any sturdy backing added to an existing bow it moves the neutral plane further towards the belly.  The neutral plane is generally in the middle of the bow limb but this can be manipulated with laminate backings or sinew or linen even on the back.

Thanks for replying. There is indeed quite a bit to consider when working with materiels of different stiffnesses. 
I like to think that a laminate of two materiels of different stiffnesses, when bent, the neutral plane will move towards the stiffer side. It shouldnt matter whether the stiffer materiel is on the "back" or the "belly" or rather, which way the laminate is bent.

I may be thinking of neutral plane little different perhaps… in my mind the neutral plane would move the other way.  Towards the weaker side.  As an example take a bamboo backed hickory bow.  The boo strip will most definitely overpower the hickory if not made very this and appropriate tapers.  On early boo backed bow builds it took some experimenting to get this right.  I even had to trap the boo backing to even this issue out.  In my mind the neutral plane had moved too far towards the belly (weaker side) causing stress compressing fractures.  The sinew is great in that it is much less harsh to mitigate this issue.  It’s a more gradual softer transition than a hard backing like bamboo for example.  I hope this illustrates my point on this. 

Quote

I’ve built self bows in the past and backed with heavy layers of sinew and glue only to find it was slower then before

Did this a bow have a long working length bend and have sinew applied thruout?   Yes it was and it was in my early days of sinew backing and still learning.  Placing the sinew in the right spots like bending portions of limbs makes a difference in the cast of the bow.   I learned with each bow that I sinew.  And still learning. 

Sinew is wonderfull stuff that can stretch much more than other bow building materiels, but because it is not all that stiff, it needs to be stretched alot further to store the same energy as wood. Which is to say the most energy storing part of the sinew is furtherest away from the middle of the laminate.  If only there was a way to place the sinew even further away from the center of the bow limb.   Agreed!   It is great stuff and it turns a regular bow into something alive feel to it.  Almost magical.   

Quote from: superdav95 on February 22, 2026, 05:14:24 pm

Like any sturdy backing added to an existing bow it moves the neutral plane further towards the belly.  The neutral plane is generally in the middle of the bow limb but this can be manipulated with laminate backings or sinew or linen even on the back.

Thanks for replying. There is indeed quite a bit to consider when working with materiels of different stiffnesses. 
I like to think that a laminate of two materiels of different stiffnesses, when bent, the neutral plane will move towards the stiffer side. It shouldnt matter whether the stiffer materiel is on the "back" or the "belly" or rather, which way the laminate is bent.

I may be thinking of neutral plane little different perhaps… in my mind the neutral plane would move the other way.  Towards the weaker side.  As an example take a bamboo backed hickory bow.  The boo strip will most definitely overpower the hickory if not made very this and appropriate tapers.  On early boo backed bow builds it took some experimenting to get this right.  I even had to trap the boo backing to even this issue out.  In my mind the neutral plane had moved too far towards the belly (weaker side) causing stress compressing fractures.  The sinew is great in that it is much less harsh to mitigate this issue.  It’s a more gradual softer transition than a hard backing like bamboo for example.  I hope this illustrates my point on this. 

Quote

I’ve built self bows in the past and backed with heavy layers of sinew and glue only to find it was slower then before

Did this a bow have a long working length bend and have sinew applied thruout?   Yes it was and it was in my early days of sinew backing and still learning.  Placing the sinew in the right spots like bending portions of limbs makes a difference in the cast of the bow.   I learned with each bow that I sinew.  And still learning. 

Sinew is wonderfull stuff that can stretch much more than other bow building materiels, but because it is not all that stiff, it needs to be stretched alot further to store the same energy as wood. Which is to say the most energy storing part of the sinew is furtherest away from the middle of the laminate.  If only there was a way to place the sinew even further away from the center of the bow limb.   Agreed!   It is great stuff and it turns a regular bow into something alive feel to it.  Almost magical.   

I had a few requests for higher poundage bows over the years but nothing over 65#, that is why I started putting double nock grooves on the top limb an a wider one the bottom limb, so I could  could use a simple cord bow stringer to string those bows when they were first strung up at probably 75#+ pounds. At first I left the overlay chunky and filed it down to one groove as I finished the bow. Later I started incorporating the second groove in the finished bow as a way for the owners to easily and safely string their bow with a two loop piece of parachute cord.

A chunky stringing groove that has almost been filed away and one on my later bows;