Propeller bow

[Selfbowman]

Should have taken a pic of this stave roughed out. Some straightening required. I don’t mind the snake but that with a pretty good propeller kinda sucks. There is better Osage out there. I’ve had this stave for about 8 years. I guess if I’m going to make a bow out of it I might as well get it done.

[Selfbowman]

Getting closer..

[Bob Barnes]

Looking good Arvin.  One of the guys in our local group has always told me that "prop twist makes a faster bow".  I have seen threads arguing the point for years... and I don't know.  He said it was what Jim Hamm taught him.  Looking forward to seeing it.   

[bentstick54]

I don’t know about that Bob, but could that be because of needing extra heat to straighten the out?
I’ve had more experience with crooked and twisted staves because that’s the majority of what I’ve had to work with. But other than the extra time involved I can’t say there any slower than bows I’ve made out of straight staves.
I will be curious to get Arvins thoughts after he turns out the finished bow. If anybody can get the optimal performance out of 1 I believe Arvin can.

[Selfbowman]

I disagree with Jim GOD bless his soul. If the wiggles and humps can cause any shock it slows the bow down. Not saying it won’t shoot pretty good just not as fast but they are interesting to look at and a challenge to build. Well the internet has come to a crawl on PA again! Maybe to many adds to load fast.

[sleek]

Any limb twist in a bow causes a torsional load to be applied when drawn. That laod takes up some of the energy you put into the bow but adds nothing to the draw length, so its parasitic. Releasing the string the bow twists back to its normal profile but none of that energy release goes into the arrow. It wont make an arrow faster and it reduces the efficiency of the bow.

[Bob Barnes]

Any limb twist in a bow causes a torsional load to be applied when drawn. That laod takes up some of the energy you put into the bow but adds nothing to the draw length, so its parasitic. Releasing the string the bow twists back to its normal profile but none of that energy release goes into the arrow. It wont make an arrow faster and it reduces the efficiency of the bow.

I think that's true, but I think his thoughts were that energy was created when it snapped back to its original shape.  My friend doesn't even try to remove the prop twist with heat... he likes it.   Wiggles are more mass and not good for efficiency for sure.

[superdav95]

Looks like a decent cook for corrections Arvin.  I’m sure you’ll straighten it out in no time. 

[RyanY]

Can't beat a clean straight stave. But good and beautiful bows can be made from sub par wood. Some of the most beautiful bows in my memory came from pieces of wood that look like they'd be horrible to work with.

[Eric Krewson]

For me it has always been wood density what determines how a bow performs and osage density varies a lot. We all have had that one tree that made bows that were head and shoulder above any other wood we have used.

This is a billet bow was was made from very twisted but hard as rock osage with tiny early wood rings. It took at least a dozen heat correction sessions to tame it but it was a super performer as bow. I put two billets of this wood back for to make my personal bow out of but old age got the best of me and my bow making journey fell by the wayside.

The bow was just getting it's skins in the picture. Another strange thing about this bow, I made it as a 65# bow for the buyer, the billets had been in my shop for years, I have a pinless moisture meter that is spot on all the time, the wood was bone dry.

The owner called me about 6 months after he got the bow and said the bow felt more like 70# than 65#, I checked it and he was right, I dropped the poundage to 62# for him. The owner stopped at a public archery range on his way home from work, and put 100 arrows 4 or 5 times a week through the bow so it was well broken in.

Through the years the owners health declined and he had me drop the poundage several times, first to 57# then to 52# and finally to 47#. The bow never developed ANY string follow and continued to be a performer. I am still scratching my head about this spectacular wood. In 26 years of bow making I had one other bow gain poundage after it was finished and shot in, I suspect it is from relieving stress from the wood with a heat gun and having the stress come on its own later.

I have straightened the heck out of some hickory staves with heat only to come back to them later and find that they went back to their pre straightened crooked condition several days later. I have one hickory stave that I have straightened at least 6 times and it always goes back.

 

[Selfbowman]

Eric I agree all Osage is not equal! Dense Osage is better bow wood. Having less early wood will make Osage more dense . I to had a bow that took no set and broke flight records. It blew doing a stretch test to see how much the wood would stretch in the draw process. Clamping metal strap material to the back of the bow letting one end move as drawn. The strap moved about the  thickness of the limb. Assuming the bow took no set I feel compression and tension must have been close to the same. Now I think that the distance that happened in stretch should be divided half in compression and half in tension because there was no set. I only say that because I’ve been told that Osage is pretty even in compression and tension. Eric you have built bows longer than me and probably more so I respect your opinion. But any time we have to remove crooks and bends and we can’t get it all out I think it affects the performance. Both in shock and speed. Can they be beautiful bows of course. Now some of you guys are probably better bowyers than me and can tiller a bow with character Better leaving the mass exactly even in both limbs. Leaving virtually no shock . My hat is off to guys that can achieve that! I can’t see limb twist being a advantage to power stroke in a limb. Jim admitted to having extra mass on the outer limbs not helping in speed after building the slowest bow in the world. I think that was done at mojam. Long before my time. Maybe a bit off subject but hopefully interesting!

[superdav95]

Eric I agree all Osage is not equal! Dense Osage is better bow wood. Having less early wood will make Osage more dense . I to had a bow that took no set and broke flight records. It blew doing a stretch test to see how much the wood would stretch in the draw process. Clamping metal strap material to the back of the bow letting one end move as drawn. The strap moved about the  thickness of the limb. Assuming the bow took no set I feel compression and tension must have been close to the same. Now I think that the distance that happened in stretch should be divided half in compression and half in tension because there was no set. I only say that because I’ve been told that Osage is pretty even in compression and tension. Eric you have built bows longer than me and probably more so I respect your opinion. But any time we have to remove crooks and bends and we can’t get it all out I think it affects the performance. Both in shock and speed. Can they be beautiful bows of course. Now some of you guys are probably better bowyers than me and can tiller a bow with character Better leaving the mass exactly even in both limbs. Leaving virtually no shock . My hat is off to guys that can achieve that! I can’t see limb twist being a advantage to power stroke in a limb. Jim admitted to having extra mass on the outer limbs not helping in speed after building the slowest bow in the world. I think that was done at mojam. Long before my time. Maybe a bit off subject but hopefully interesting!

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