Help with avoiding set

[jameswoodmot]

There must be endless discussion of this but I can't find anything particularly useful after an hour of searching, any links to previous posts would be great.
Im happy with my tillering in general, the relationship between limb width, thickness and bend is fine. I can make bow with no set, but I can’t get any kinda weight out of a piece of wood and not have it banana.
I am mostly using Ash and Wych Elm, both of which I can make a fine 45lb bow from.

I've been trying for an 80lb ELB but I just cant get them to weight, I have seen plenty of bows in these timbers well over the weight I am looking for.

I keep coming across people talking about "treating the wood right" and "being kind" to it but I’m not sure how.

I've kept the section relatively wide and flat as I can on the belly, kept the length long. Tillered to the gentlest long string tiller, heat threated them and then started tillering, never pulling back further than I need to see the bend, exercising as im going and they just banana. Nice even set the whole way along the bow, no stiff or weak spots, the wood just can’t handle what I am asking of it.
Yet I know the species of wood can do what I want because I’ve seen it, Im just not sure where I’m going wrong.
My wood is good, my tiller im happy with, the dimentions match what I have seen before, so there is something im missing.

And I suspect whatever Im doing wrong here is also having a negative impact on the lighter bows I’m making.

Any pointers at all would be great, all I can do for now is just keep making the bows lighter in draw weight which isn’t what I’m currently after.

Cheers

[sleek]

This is my favorite subject of bow making. I will give you an absolute solid rule of thumb I have learned. Every inch of set indicates a bow that was underbuilt by 25%. So increase the bows working area by 25% for 1 inch of set and you will find yourself with a much better bow. Some woods however just dont wanna work, and thats across all species of wood.

[willie]

going from 45 to 80 will require almost twice the width

how wide and long are the bows you shoot for 80,  with those species?

[jameswoodmot]

This is my favorite subject of bow making. I will give you an absolute solid rule if thumb I have learned. Every inch of set indicates a bow that was underbuilt by 25%. So increase the bows working area by 25% for 1 inch of set and you will find yourself with a much better bow. Some woods however just dont wanna work, and thats across all species of wood.

Talk about efficiency and arrow speed seems a bit controversial here from what I’ve seen, but it’s what I am most interested in achieving. It certainly seems the most complex aspect of bow
making.


I have another piece of elm that I’m going to aim for a heavy flat bow, just wide and long and see what I can get out of it.
The problem with overbuilding an ELB is it becomes a flat bow pretty quickly.
I’ve got the feeling I’m missing something in the tillering process, more than the design or materials. I’m seeing people make bows with the similar materials and dimensions as me and getting nearly double the draw weight.pretty sure it’s my skill that’s falling short, I just don’t know where

[jameswoodmot]

going from 45 to 80 will require almost twice the width

how wide and long are the bows you shoot for 80,  with those species?

The most recent was Ash, 77” long and about 1 1/2 - 1 5/8” wide (can’t remember exactly and it’s fire wood now so can’t find out)
Wych elm was similar volume but a little shorter and wider.

[Badger]

 Elbs have their own challenges because your dimensions are pretty well-locked in. From what you are describing it sounds like you are doing better than most but I do understand how we can get hung up on a little bit of set and it does reduce cast significantly. I don't think I have ever had zero set but I can usually limit it to about 1". Ash is very inconsistent about density, I have seen some at about a 60 sg all the way up to about 80. One technique I use is as follows. I like to keep the center section pretty stiff but only if I can get away with it. If I am at 24" and start to pick up set I will go back to the center to gain my additional inches always carefully monitoring the set. Toward the end, it becomes a puzzle: Where can I remove more wood to get my last couple of inches?  The pattern I follow when making an elb is as follows. Based on the draw weight I will select a width and length. From there I just go ahead and carve out a longbow knowing it will be a bit stiff by floor tillering. Then I put it on a long string and check the weight and tiller. Contrary to popular belief a long string will give you a fairly accurate weight reading regardless of how long the string hangs down. If I am making a 100# bow I start right off with 100# pulls and then just start removing wood until I hit the draw length I am looking for.   

[jameswoodmot]

Elbs have their own challenges because your dimensions are pretty well-locked in. From what you are describing it sounds like you are doing better than most but I do understand how we can get hung up on a little bit of set and it does reduce cast significantly. I don't think I have ever had zero set but I can usually limit it to about 1". Ash is very inconsistent about density, I have seen some at about a 60 sg all the way up to about 80. One technique I use is as follows. I like to keep the center section pretty stiff but only if I can get away with it. If I am at 24" and start to pick up set I will go back to the center to gain my additional inches always carefully monitoring the set. Toward the end, it becomes a puzzle: Where can I remove more wood to get my last couple of inches?  The pattern I follow when making an elb is as follows. Based on the draw weight I will select a width and length. From there I just go ahead and carve out a longbow knowing it will be a bit stiff by floor tillering. Then I put it on a long string and check the weight and tiller. Contrary to popular belief a long string will give you a fairly accurate weight reading regardless of how long the string hangs down. If I am making a 100# bow I start right off with 100# pulls and then just start removing wood until I hit the draw length I am looking for.   

Thanks Badger, in my searching last night I found your detailed description of no-set tillering which was really insightful.

Both of them I started pulling to 80lb, keeping the long sting for quite a lot longer than I would normally, minimal set before I braced them. Quite an elliptical tiller to start but as I progressed I had to make it more and more compass as the mid limbs were getting over strained.
I find it quite difficult to judge how the tiller will change between long and short strings but that will come with time I guess.


As far as exercising goes, lets say you had a bow that was perfectly tillered but had never been bent before. If you were to string it and draw it you could get it to full draw length with a perfect curve but i imagine if you surprise a piece of wood with that much bend in one go its going to either break or take massive set.
How much would you want to exercise a piece of wood to get it to full draw as a bare minimum, excluding the bending and exercising needed to check the tiller.
The tillering process on the Ash elb was really quick for me which I was pleased with, it was a very uniform piece of wood and I started at a good point but I have a suspicion that it lead to less exercise and more set.

[Del the cat]

Some very good discussion here.
At the limit, you can only get a certain amount out any bit of wood. Anyone will struggle to get a good heavy weight ELB from Ash or Elm without leaving the belly fairly wide and flattish (maybe slightly trapped back) and heat treating.
(people often round the belly of ELBs far too much
The most common mistake is making the bow too short for the required draw weight/draw length.
I always say make the bow 2" longer than you think you need, you can always shorten it.
Maybe start at 80", you should be able to make it with very little set. That will give you the confidence to trim it shorter and re-tiller by degrees.
Don't get hung up by a little set. If a bow has taken no set, it isn't working hard enough! Most bows that claim to have no set, probably started with an inch of reflex!
Del
Here's the playlist for videos of my ELM Warbow
https://www.youtube.com/watch?v=5PYVl88Hnu8&list=PLBz2tD9476KQ2STSgrH89kndJ40B6RKC8

[jameswoodmot]

Some very good discussion here.
At the limit, you can only get a certain amount out any bit of wood. Anyone will struggle to get a good heavy weight ELB from Ash or Elm without leaving the belly fairly wide and flattish (maybe slightly trapped back) and heat treating.
(people often round the belly of ELBs far too much
The most common mistake is making the bow too short for the required draw weight/draw length.
I always say make the bow 2" longer than you think you need, you can always shorten it.
Maybe start at 80", you should be able to make it with very little set. That will give you the confidence to trim it shorter and re-tiller by degrees.
Don't get hung up by a little set. If a bow has taken no set, it isn't working hard enough! Most bows that claim to have no set, probably started with an inch of reflex!
Del
Here's the playlist for videos of my ELM Warbow
https://www.youtube.com/watch?v=5PYVl88Hnu8&list=PLBz2tD9476KQ2STSgrH89kndJ40B6RKC8

Cheers for the input, Del.

I shot the bow a few times before getting rid and it was slow and had a lot of hand shock, I put this down to the limbs already being too long, arrow was about 600 grain and I wouldn’t want to put anything heavier through it as it was already slow. The tips were probably about 13mm square and a pretty straight taper from the middle, they were taking set so I didn’t want to thin them to lighten them anymore. I had been hoping to get it to weight at 77” then start shorten it  to make it shoot sweeter. I feel like an 80lb 80” bow is going to be a bit long and probably not have much cast over a 72” 70lb bow, I’m I wrong in my assumption?
I’ve never shot a nice ELB before, yet I know they exist. They have all been slow and hand shocky like the one I made and yet I know that that’s just a bad bow.
I’ve got a lemonwood/purpleheart/ ash laminate gluing up (thanks for the advice on cascamite earlier in the year). Laminate ELBs leave me a bit cold but hopefully I’ll get a shooter out of it and get my confidence back.

How wide would you have the stave for an ash bow at the handle? I didn’t trap mine but also didn’t round the belly until near the tips, I gave the edges a good rounding along its length but left at least 2/3 of the width of the belly flat. Am I better off leaving it completely flat and just taking the sharp edges off?

[Del the cat]

Ah! Your doing that thing of changing from one question to another!
1st question was how do you avoid set, but when I say make it long, you are worried about it being slow!
I think you have to solve one problem at a time.
There are plenty of inter related factors, and it's a matter of balancing and optimising them.
The fastest bow will probably have a bit of set and may have a short life. The bow with no set may well be overbuilt and sluggish.
The 100# Elm warbow I built shot over 300 yards, but that was with a light flight arrow which rather jarred my elbow ( I have some tennis elbow)... So I named the bow "Dennis Elmbow" 
40mm is probably a sensible maximum width, but with a rather rectangular section, the corners (even when rounded ) will be uncomfortable in the hand, and that's (IMO) what is often mistaken for hand shock.
So, sorry, but no simple easy answers I'd suggest Lemonwood backed with Ash (edge grained like this ||||||||||||||| ) might be a better combination.
Your assumption about length is right, but of course it also depends on draw length.
I have experimented with short ELBs for flight purposed... one got name "Ill Bastardo" as it kicked like a mule, was short draw and left some hideous bruises on my mate JT's bicep... it was fast but short lived... it did have some set.
If you cant find Yew stave , maybe you can find Yew heartwood to back with Ash or Boo, which will make a good fast bow.
Good luck
Del

[RyanY]

Your dimensions seem reasonable. How much set are you getting exactly? I’d also like to see your tiller on these bows. What’s the moisture content of the wood?

[jameswoodmot]

Ah! Your doing that thing of changing from one question to another!
1st question was how do you avoid set, but when I say make it long, you are worried about it being slow!
I think you have to solve one problem at a time.
There are plenty of inter related factors, and it's a matter of balancing and optimising them.
The fastest bow will probably have a bit of set and may have a short life. The bow with no set may well be overbuilt and sluggish.
The 100# Elm warbow I built shot over 300 yards, but that was with a light flight arrow which rather jarred my elbow ( I have some tennis elbow)... So I named the bow "Dennis Elmbow" 
40mm is probably a sensible maximum width, but with a rather rectangular section, the corners (even when rounded ) will be uncomfortable in the hand, and that's (IMO) what is often mistaken for hand shock.
So, sorry, but no simple easy answers I'd suggest Lemonwood backed with Ash (edge grained like this ||||||||||||||| ) might be a better combination.
Your assumption about length is right, but of course it also depends on draw length.
I have experimented with short ELBs for flight purposed... one got name "Ill Bastardo" as it kicked like a mule, was short draw and left some hideous bruises on my mate JT's bicep... it was fast but short lived... it did have some set.
If you cant find Yew stave , maybe you can find Yew heartwood to back with Ash or Boo, which will make a good fast bow.
Good luck
Del

I thought it was obvious by now I want you to tell me exactly how to make a perfect bow first time  so I don’t have to put the leg work in myself!
I guess my desire to avoid set is actually a desire to make a fast bow, or at least a reasonable performer. Or actually maybe just a white wood ELB that is nice to shoot. Or maybe all the above, I’m trying to get past my dislike of them and currently I’m just reenforcing it!
The first problem that I have come across when making them a the heavy set which I have seen other people manage to avoid, seeing ash and elm bows of average length reaching over 100lbs and I’m struggling to get over 65, I’m pretty sure my material is good, it ain’t the tools so that just leaves me!

I’ve got enough lemonwood for a second longbow and I got some Ipe, waiting on ordering some bamboo.
My interest in making things has always been achieving the best an average piece of material can give, not going straight for the best materials. Professionally I am a toolmaker and I find far more gratification in getting an average quality tool steel to perform to its limits, and out perform many supposedly better steels, that to take a very heigh quality piece of steel and only achieve 75% of its potential and say “that’s good enough”.
If I can get a piece of elm over 80lb and to shoot over 150fps, I will be far happier than achieving 170 with a piece of yew or exotics.
Not sure how much sense I’m making but I hope you get the gist of what I’m aiming for.

[jameswoodmot]

Your dimensions seem reasonable. How much set are you getting exactly? I’d also like to see your tiller on these bows. What’s the moisture content of the wood?

Unfortunately I don’t have any photos of either tillered. Set is probably about 2-2.5”, a bit more with string follow.
Moisture content I don’t know, I’m not sure how to get it any lower. It’s actually easier in winter here as i can leave a stave on the radiator and keep weighing it, in the summer the humidity in the house is closer to outside. I’m thinking it might be time for a hotbox or dehumidifier

[willie]

Nice even set the whole way along the bow,

when tillering, how close to full draw do you detect the set beginning to occur?

[jameswoodmot]

Nice even set the whole way along the bow,

when tillering, how close to full draw do you detect the set beginning to occur?

Fairly early on, not long after bracing, so I start dropping the target weight but it’s difficult to guess how much and quickly to lower the weight.