For discussion: how this bow should be tillered

[Ishi]

Last year I have found sapling of tree of heaven. I didn't know its qualities, it is new wood for me so I made some testings. Sapling had almost 3" of reflex but very ugly positioned: in two spots on middle of the limbs. Also it was snaky. Because I didn't know its compression and tension abilities I was carefully. My question is: how this bow should be tillered? Here is just side profile pic. It has 1 3/8 " wide limbs to the half of length and tapering to the nocks, 68 ntn. I want to hear all, there are no stupid answers- we are all equal. Here you are friends, pic after loosing 1" of reflex during tillering...

[Wilfrid (✝)]

Ishi, it seem´s to me:

Nobody nows the trouble ,i´ve seen
http://www.youtube.com/watch?v=SVKKRzemX_w

sry, no idea

[Windmann]

Five or six years ago a close friend of mine had tested the tree of heaven. He had reaped the wood in the middle of the winter and dried it slowly. I don't know, but it had to be ten month later that he begun to fix the two staves. It was a short journey, because one of the wood was broken during the process of the tillering. Therefore the other one had got a backing from silk for safety. That works a pretty while, but not so much long. After all the bow had shot not as much as 300 Arrows, than we heard a ugly noise and that was the end of the short life of the last tree of heaven bow.
Unfortunately, I don't know if that is normal for that sort of wood. Both bows were in the shape of a full pyramid and I thougt it was all correct, what my friend had done. My advice is, be careful. It could be working, but ... you know.


However, I took a look on to your webside and I have seen all of the beautiful bow that you have done. I have a good feeling, you will fix it very well.

[acker]

Just flip / reflex the right tip like the one on the left side, so it´ll be easier to tiller and it will give you an equal looking tiller.

[Ishi]

Thank you Wilfrid for a link. :-)
Windman, this is experiment, how it should look like if we do everything how should be done.
Acker, in this moment on picture this stave lost 1" of reflex that was JUST IN THESE TWO SPOTS, not spread along the limb. If I would flip it how should tiller look like, where stiff and where bending? :-) This bow was big problem for me to deicide.

[Windmann]

I would handle it like ackers answer, with steam bending the right limb (black line). That will giving the stave a similiar look. For me the tree of heaven should have a smooth bending over the whole stick (red line). It could be working well. Than you should give the two spots, which ease off there tension of reflex, a little bit more wood. So you have an safety area during the first 100 Arrows.

[Ishi]

We spoke about this bow. As I sad it was very difficult for me to tiller it corectly, to have equal strain allover the limbs. Almost 3" of reflex in almost just two spots in the limbs....Also some snakyness. I was trying to follow all good manthras. In the middle of the bow there was a little reflex spot. So, what I have done: Because of its reflex, middle on the full draw should look stiff. Ok, done. Limbs to the reflex spots should bend normaly- done. But what now....reflex spots should look stiff on the full draw because of its reflex- one more than the other, it's reflex must be visible even on the full draw. What about limbs after that reflex spot?! If I make them bendible it will affect string angle very much...I deicided to keep them stiff but light. How then to achieve full draw lenght, I need more space? The only thing I could- sacrifice inner limbs and force them to bend more. When I finished this I recheck bow- still have 1 1/2 of reflex (lost one inch in the critical reflexed spots), so it is not overstrained. Badgers mass formula also confirm that its physical weight is almost correct (467 grams is formula and bow is 410 grams). I tried it on the target- very good, seems above average speed (hard and for me to believe). Because it is centershot (there must be some little torq but I do not feel it) the brace is low, just hair above 4" so arrow do not have to avoid handle a lot and gain some speed beacuse further travelling with string, to pick up some more speed that was lost with more bendible inner limb. One correction: bow is 55# at 30", my apologie, must be too much beer on weighing before. But when I looked it on the full draw- it is awfull. What to say....ugly but works very well. This was just an experiment how bows could be made even from worthless staves if you follow instructions from excellent master-bowyers from TTBB. Thank them.

[tomtux]

thats a wonderfull example of thinkfull tillering.
thanks a lot for sharing!

[Galighenna]

YESSSSSS this is absolutely how it had to be done! In Fulldraw you can still see the reflex and so bending and stress of the limbs should be very evenly distributed over the length.

Great work and a again a very beautiful bow!

I never before heard of "Tree of Heaven" so i googled it. In german it is called "Götterbaum"

[Ishi]

Thank you my friends I did my best, There is more space for some little corrections but now is too late, next bow from this wood will have knowledge from this one, and so on, multyplying...