Author Topic: tillering issues  (Read 216 times)

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Offline Calios

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tillering issues
« on: June 05, 2025, 09:41:47 pm »
Hello, i've been working on this bow for a while now, previously aiming for a 30lb, 67inches bow from hazel but i've encoutered some issues during tillering and found a crack mid lower limb on one side, probably due to an overheating from heat-treatment. I've saved it though, but by greatly reducing the profile, finding myself with a 55inches bow, barely touching 20lbs at 25. Because of the odd way the wood responded, i've reached final tillering stages with something i'm not completely sure to be ok. I would be glad to regain some pounds of power, was originally thinking about reflexing tips as to balance string follow too or a second heat-treatment, but I've never really tried on such a short bow, so i'm unsure. Do you have any tips?

photos:1- strung bow (upper limb is always the right one)
           2- drawn to 17 inches
           3- drawn to 25
thanks for the help
« Last Edit: June 05, 2025, 10:42:52 pm by Calios »

Offline sleek

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Re: tillering issues
« Reply #1 on: June 05, 2025, 10:08:58 pm »
You know, as uneven as those limbs are from each other, you did a good job getting them to bend smoothly. That's actually impressive with how much they are bending, cause thats A LOT!

I dont know how far you are trying to draw the bow, is it to full draw there? If so, apply heat treat to the limb thats bending more than the other. If you still have draw length to gain, just scrape the weaker limb.
Tread softly and carry a bent stick.

Dont seek your happiness through the approval of others

Offline Calios

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Re: tillering issues
« Reply #2 on: June 05, 2025, 10:54:21 pm »
Yes, this is how far i am actually daring to pull to really. i've kind of got the thought that the upper limb on the right (just corrected, not the left one) is bending more but evenly... so i do not have any idea on how to proceed and control weight loss. Moreover i've read that a general rule of thumb would be to make the upper limb having a slight positive tiller, but i doubt this could be considered 'slight'. At the momente the upper limb tends to take more set than the lower one, but by stretching both on the opposite way back by hand they regain a straighter look. Lots of odd aspects that never occured to me before, even with hazel.

Offline sleek

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Re: tillering issues
« Reply #3 on: June 05, 2025, 11:05:37 pm »
On this bow, for various reasons, I wouldn't worry about the set. Just get the limbs bending evenly. Now, if you want to try a method I use a lot, take your weaker limb and heat treat it while its clamped to a board. Apply heat to the belly and cook it till its so hot you can't touch it without discomfort, and it should turn a light brown. This is about an hour long process. When you let it cool, it will be stronger than the other limb and bring the total weight of the bow up. You might be able to still hit your draw weight if you treat both limbs this way and retiller it back down.
Tread softly and carry a bent stick.

Dont seek your happiness through the approval of others

Offline Badger

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Re: tillering issues
« Reply #4 on: Today at 01:28:04 am »
   I don't think it is as bad as it looks. The limbs come out of the handle in different directions and that affects the part of the tiller that influences everything else. I think 25" is too long to draw that bow and I would imagine it already has more set than is desirable. I would just start another one.

Offline Muskyman

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Re: tillering issues
« Reply #5 on: Today at 09:44:29 am »
If you heat it don’t draw it for a day or two. It’s liable to explode on you if it’s to dry.

Offline Calios

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Re: tillering issues
« Reply #6 on: Today at 10:20:04 am »
Ok then, i'll go for a heat treatment of the upper limb first, and then i'll figure out whether to repeat the process on the lower one as well. What about a reflex instead? I have been watching some of Del videos, and he mentions that a way to balance set is to counter with a reflex virtually realining tips with the handle. I am not sure if this would be a proper case to try this out, i would prefer not to overstress it. I might reduce max drawenght to 23/24 if the heat treatment sufficently increases weight

Offline sleek

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Re: tillering issues
« Reply #7 on: Today at 11:22:29 am »
Ok then, i'll go for a heat treatment of the upper limb first, and then i'll figure out whether to repeat the process on the lower one as well. What about a reflex instead? I have been watching some of Del videos, and he mentions that a way to balance set is to counter with a reflex virtually realining tips with the handle. I am not sure if this would be a proper case to try this out, i would prefer not to overstress it. I might reduce max drawenght to 23/24 if the heat treatment sufficently increases weight

Please dont! Do not reflex that poor bow haha! Reflex makes the limbs have to bend even further to get to draw from unbraced profile. What did that poor bow ever do to you anyway? Lol

Nah, heat it flare, or a little deflex if anything. You can reflex the tips to regain your string angle and early draw weight if need be. But no, reflex is the opposite of what you need to do here.
Tread softly and carry a bent stick.

Dont seek your happiness through the approval of others

Offline Calios

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Re: tillering issues
« Reply #8 on: Today at 05:22:35 pm »
of course, the idea was to slightly reflex just the tips, not the whole limb. I mean, i have a backset form, but as i can understand it's not a good solution to give it a backset

Offline jameswoodmot

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Re: tillering issues
« Reply #9 on: Today at 08:18:21 pm »
If it was mine I would reflex the tips just a bit to help with string angle. 

I have a little 55” bow I’m working on at the moment that is tillered to 27” but it’s at about 18lb and got a good bit of deflex and flipped tips. The tips end up about 1 1/2” behind the handle. And it really stacks past 26.

An unbraced photo of your bow would be good