Another longbow build-along...

[red]

Nice to be learning as we are going. I think I'll stick with the first pattern, just because it inspires more confidence (rightly so or not). In keeping with learning, what are the differences in the arrows one would choose for the different patterns?

[smj]

Archers paradox. Here is some info on it -
www.texasarchery.org/Documents/ArchersParadox/Archersparadox.htm

With either pattern, the stiffness of the arrow is where they will differ. Even the first pattern won't be perfectly to the center of the bow, hence, the arrow needs to flex some to clear the grip at shooting. The second pattern, the arrow will have to flex more to get around the greater width of the grip. Hence, shafts between the two will differ by stiffness. If you get the arrow to stiff, you will see the arrow shoot left as it seems to bounce off of the grip which deflects it a bit (assuming right handed shots!). If you get a way stiff shaft for a given bow, arrow flight is really bad indeed - as it is with to soft a shaft, too! What I find is that you want the shaft that is most stiff, but still shoots without deflection. Of course, form and release also enter in to this equation. I tend to shoot my arrows just a tad stiff for the bow, and then help it out by having a smooth release. They bounce a bit left but I still get good arrow flight, until I get a bit tired and my release drops a bit below my standard! Time to stop shooting at that point!

I have some wood arrows that my pal Kevin gave me. He has a whole basement of them - it is amazing! I tried to shoot these out of my glass longbow and I could never get them to shoot at all for me. Just really bad flight. On the last bow I made, the second pattern selection - they shoot perfect at his wifes draw length! I mean perfect!!! Anyway, I think we might need to shop around a bit once the bow is done. I'll find some that shoot well for me and pass the info on to you, at least give some suggestions as to which shaft to try.

[red]

Makes sense once you explain it. Thanks.

[smj]

So, first we will rough cut the belly board. We can set the chosen pattern on the board and mark the width needed. Next we will cut it and trim it to proper width, length, taper on the limbs, and rough the glue surfaces with a band-saw blade. While we at this step, we need to check that the pattern is still straight. To do this, a 1 inch section of round stock (flattened a bit so it won't roll around) is set on the limb tips. A string with weights on either end is laid over it and compared to the original centerline that was marked on the pattern back when it was originally made. If the pattern shows bend in it - time for a new pattern! We are in luck, no bend, still nice and straight! (This is why it is a good idea to finish the pattern once it is cut out and sanded down - this helps slow the effects of changes in humidity) In the pic, you can see the centerline down the pattern, and the thread over top. Note that the pic is at an angle, hence, you can see both. When directly over top, they align perfectly.



This is a fat board! We will have to chop it down some to make a bow out of it. I will cut it down to about 0.400 inches at the grip for thickness. Any thicker and I have trouble getting it to bend the way I want it to bend in my jig.

This pattern allows for a 69 inch bow tip to tip, nocks get set in a half inch from the tip leaving a 68 inch nock to nock length. This length can move around a bit as we cut out the bow. The bow will be 1.5 inches wide max, tapering out to the tips as seen in the pattern above - which will be used to mark up the bamboo we cut out.

[red]

Ah, the Master at work in his shop. Looks great so far. After shooting compounds so long, 68 inches sounds huge. I'll have to start looking around for some Merry Men to join me.

[smj]

Green tights, buddy. You need to find you a green pointy hat, too.

As for calling me a master - do take note that should be a lowercase "m" rather than an uppercase "M" !!!

When I finish preping the belly wood, I will post a couple pics and an account of how I got there. Why I went there, and so on.

Then we will prep the bamboo.

Glueup.

Grip.

Cleanup & pre-tiller & nocks.

Tiller.

Final sanding.

A little shooting.

Apply finish.

Done.

[red]

Good thing I look great in green tights. Always been interested in the tiller part...I hear folks asking," is it tillered for 3 under or spit finger". What are they referring to?

[BT]

Follow up to that question of reds....what would you tiller for a bow that could be shot either 3 under or split finger?.

[smj]

Positive tiller measured at the base of each dip, a ballpark value, is around 3/16 inch. This reflects the difference in stiffness from the upper limb to the lower limb. Hence, the distance noted on the upper limb when measured should be 3/16 inch longer, or deeper, then that taken on the lower limb. The lower limb is typically more stiff than the upper. This is for one finger over, two under. If you intend to shoot three under, then the tiller gap will extend a bit... Maybe 1/4 inch.

Tiller also results with limbs of equal strength when one limb is longer than the other, for example a bow with an upper limb 1.5 inches longer... Different moment on the limb. Another place to measure this is to come in 12 inches from each nock and measure from bow to string. You should see around 1/16 of an inch difference upper limb to lower limb.

I have read about different stress in the limbs being the reason. That would be easy to tie back to the finger placement on the string when shooting... A lot of bows are being made with equal tiller right now, both limbs the same length. I prefer a longer top limb, I like what this does to the balance of the bow.

Also note that with a wood bow, a less homogeneous material, this tiller measurement does not carry so much meaning. What the bow looks like a full draw is what matters most. The more layers the more homgeneous the materail of the limb becomes, the more the tiller measurement has worth. An old branch from some tree - measuring the "tiller" might have zero meaning.

More on this later - I have to get going right now!

[red]

Wow...glad I am just the shooter and not the builder....far too complicated for my unfrozen cave man lawyer brain.

Anyway, I tried both and split finger felt more comfy for me.