? to the bowyers here

[Mad Max]

Front of center Roy

X2 ben
This post is going nowhere, over and over and over

   

[monterey]

The people who built the Holmegarrds figured this out.  I have great respect for mathematics and engineering, but they did it from the gut.....unless maybe there were aliens involved   :eek:

[Nezwin]

Originally posted by bigbob2:
that is an illuminating little treatise there Nezwin!. Great information!      

You know me, Bob, why use one word when you can use ten?    :D    :D    :D    

 

Originally posted by LittleBen:
Fastest core will always be the lightest/stiffest material you can get.

X3 for that, but are the stiffness of the belly/back materials more of a factor than that of the core? Another benefit of a dense core, aside from stiffness (usually), is reduced set.

Reread the original question and it's covering performance AND smoothness, which are related but not always dependent on one another. You can have an inefficient but smooth shooting bow, for example.

[mikkekeswick]

The stiffness of the core has little to do with storing energy. The core doesn't feel tension or compression. Cores feel sheer. This is why the best core materials are diffuse porous (no earlywood to fail along) like maple, black walnut, bamboo (sort of!)and of course a great core needs to have great gluing properties and a low/medium density.
The core is simply a spacer to keep the back/belly surfaces the required distance apart for the desired draw weight.
Anybody ever looked at an H-girder and wondered why it is that shape?

So osage isn't a great core material because it is quite dense  :(  and heavily ring porous it's also not the best gluing wood out there...but of course modern epoxies mean we don't have to think about that last point much.
I wouldn't dream of using osage for a core lam it's properties are much better put to use as a belly lam on a wood bow.
I've used 0.030 thckness lams of it in glass bows under clear glass and it works in this respect but I definately would use it for the full core.
Heavy tips are often held to blame for handshock but it normally is more to do with a poor tiller or limbs out of timing.

[Roy from Pa]

This is getting funny. And you can apply all the mathematics and principles you desire. But I will still take Osage over any other wood out there. A 1/4 sawn Osage belly with action bamboo core lams, backed with natural bamboo, tillered to equal limb timing, has zero hand shock and just kicks ass...

Another sweet core material is Yew..

[fujimo]

having one of Roysters bows- i concur- it is a super sweet shooter.

you know whats funny- this post was moved over from Pow Wow- dont think the o.p. realizes that it was moved- he has never been back to this thread- he doesnt realize the mayhem he has caused- the virtual WW111- the wedge between friends, the irrecoverable chasm of despair, confusion and hatred conjured by virtue of the most innocuous of questions        .
 never pick a fight with an irishman- you will always lose!!

[Roy from Pa]

That's nothing Wayne.
My wife is Irish / Italian!
And she has the temper of both those nationality's combined into one body. That's why I walk the line, LOL...

[Bowjunkie]

Hmmm, she always seemed so sweet when I was there. Maybe it depends on who she's dealing with.

[daveycrockett]

quote:Originally posted by fujimo:
having one of Roysters bows- i concur- it is a super sweet shooter.

you know whats funny- this post was moved over from Pow Wow- dont think the o.p. realizes that it was moved- he has never been back to this thread- he doesnt realize the mayhem he has caused- the virtual WW111- the wedge between friends, the irrecoverable chasm of despair, confusion and hatred conjured by virtue of the most innocuous of questions    

[passion for knowledge]

320 @ 195

350 @ 188

Doesn't require a chart.

energy is equal to half the mass times velocity squared.

I could do that with pencil and paper, or a calculator - could likely do it in my head, given a few minutes.

Charts are so much more convenient. Someone's already done the work. No point re-inventing the wheel.

[passion for knowledge]

Monteray....

I made myself a Holmegaard last year, out of maple.

Cost me $20

#52 @ 28"

Sweet shooting bow.

Working on another one - adding recurve to the tips and going a bit thinner in the static outer limbs.

At the start of tillering with the long string.

[monterey]

I made one from an oak board.  Came in at 25#.  Gave it to one of the grandkids.  It has proven adequate for bunnies.

The eye opener for me was the very very little additional thickness that is needed to make the tips effective.

Would like to see the one you are working on!

[passion for knowledge]

Here's the bow I was referring to.

 http://tradgang.com/cgi-bin/ultimatebb.cgi?ubb=print_topic;f=125;t=002204

The steam bent oak thing didn't work out. I'm pretty sure it was a dry spot in the glue up that failed (some would disagree).

Love the Holmegaard.

I've built only 5 bows. Two broke.

The two that broke are the only two I've photographed the process of making them.

I'm not particularly superstitious, but ......

I'll post pics of the one I'm working on when I get to shoot it!

[monterey]

Very nice looking bow.

[Overspined]

It's basically been proven that arrow KE isn't a good measure at all at predicting penetration. It's a useless number.  

Osage is as fine a material as many others, but I'll say from experience that it can be design dependent whether or not you'll get handshock. I don't think it can be computed. Basically if a deep core bow is all Osage, I'd give it away. A thin limbed bow, or a mixed stack where there's more than just Osage would likely be fine. I think it's probably connected to the thickness of a very dense wood vs the thickness of the rest like the glass and other lams and such. It's a great strong self bow material though if you want to work with a pain in the butt wood. I'd take hickory or ash any day.

[fujimo]

thats dangerous talk around here mister    
any body dissing the "yella" betta be a tough fella      

[fujimo]

oops!