timber density calculator for arrow making

[Stephen Georgiou]

For those of you who have access to microsoft excell on you computers here is a calculator I have been working on that makes it easier to select the right timber density when making arrows for a certain bow.
I have been making arrows from Oregon and needed wooden arrows heavy enough in spine and mass to shoot from a 70lb bow. Now I can enter the mass ( weight in grains ) of my arrow billets and have a very good idea of how much the finished shaft will weigh.
I have some instructions in the excel sheet so have a go and let me know how useful it is.
Regards Stephen G.

[Stickbow Hunter]

That is well done mate and I'm sure it would be very handy for anyone making their own shafts. You need one for working out the spine now.

Jeff

[Stephen Georgiou]

Ok I'll get to work on that. Although is appears that spine is harder to work out because of the density of timber is between 1400 - 1500 kg/m3 with the ratio of hard and soft components of the wood being the governing factor. ( read this somewhere ) Making a Spine Table of a particular species might be possible and then the density can be a rough guide to spine. I have tested some of my sample pieces and found that some of the lighter arrows have a heavier spine than heavier pieces of the same dimensions. This is most likely due to different moisture content of the billets. The heart wood is more moist that the sap wood. ( I think ) all will be revealed once I get hold of a timber moisture probe. Once I have some reliable data I'll stick it in this post.

[Stickbow Hunter]

Yes mate it would be extremely difficult to do - near impossible. I have also found that the spine doesn't vary as per the density of the wood - lighter shafts can have a heavier spine than heavier pieces of the same dimensions. Some wood species can be extremely dense yet do not have the stiffness (spine) of lighter woods etc. Anyway I'm sure it could consume quite a few hours of your spare time if you let it.

Jeff

[Stephen Georgiou]

Jeff I am finding out that there is a fair bit in traditional archery gear that has some parallels to gear in modern compound archery. In both cases the quality of the equipment is very important. Byron Ferguson said in one of his books that you can go into the yard and cut a bow out of a tree but the arrows need to be of the highest quality and consistency. This is why I am interested in finding out more about arrows and the timber they are made from.
For me the simple act of making an arrow is so satisfying. From this working with wood I believe that some day soon I might be tempted to make my own bow.

[Stickbow Hunter]

For me the simple act of making an arrow is so satisfying. From this working with wood I believe that some day soon I might be tempted to make my own bow.

Be tempted mate, making your own gear is fun and gives a great sense of achievment.

Jeff

[ichiban]

awsome work, definatly gonna try it

[pdccr]

I will be looking forward to the finished results, sounds like it looks good.

[Stephen Georgiou]

the program is ready for use Toby. download it from the first post and see how you like it
regards SG