I just broke a bow...

[akila]

Hy guys...it wass an honey locust bow (sap wood) and i just need it to do a little more tillering on him and it wass ready to go...but the things didnt happent that way at all.whenn brace it on the tillering stick at an all most full draw it just snap.The ring on the back give up on me.I dodnt know what to think now...maye i wass wrong at tillering and the middle limb wass bending to much, but i dont have a picture to show you so...I know that honey locust its not as good as black locust,and i also know that sap wood its not a verry good choise either,but i wass realy hoping to  make a bow from that stave.The tree wass cut in august,i wass spliting the log in half,and reduce the stave to bow dimension,and let the wood to dry untill a weeck a go... it wass drying for 2 mounth... you think that  this is why the wood give up?Im asking this becose i have the other stave from honey locust ,and i wood like to make a bow oute from her.And i also have some other wood that is reduce do bow dimension and they also have a mounth ,a mounth and half since they have been reduce to bow dimension and let to dry.You think its to earley to try to make some bows oute from those stave..?should i let themm more to dry??The wood its seams dry to me ...whenn i knok on the wood with my finger it make a nice sound like a bell...al most like an instrument.

[Justin Snyder]

My guess without seeing pictures of the broken bow is that it was stressed too much in the area that broke, maybe just bending too much. If you could post a picture of the broken bow it would help us try to figure out why it broke.  How long the bow was and what draw weight and draw length were would make a huge difference too.  If it was a short bow with a high weight and a long draw it would be stressed a lot more.  If it was not dry yet it should have just taken a lot of set, not broken.  Justin

[akila]

Here is some pictures with the broken bow.The bow wass 175 cm long and i wanted to make him 50# at 29"...but...this is the result.You think that 2 mounth its enugh for a stave to dry?? and to make a bow ou  of her?


I realy think that in the middle wass bending to much that limb ,,i wass trying to reduse the stress by remove wood from the other limb, and it seams ok to me at some point and i have strung the bow even more and thenn just snap.

[Justin Snyder]

175 cm is about 69 inches, that sounds plenty long for 50# at 29".  It looks like you got it figured out to me.  It was bending a little to much there and the back just let go.  One of the problems with tillering sticks is that you draw the bow and it holds it at draw too long while you step back to look.  Unstring the bow and look at the limb profile.  If the other limb goes back to straight, I would say it was plenty dry.  Justin

[D. Tiller]

Also, you might want to build yourself a tillering tree instead of a tillering Stick. The Tree allows you to slowly stress the limbs a little bit at a time before you draw it to alonger length and check the tiller again. Pre-stressing the limbs really helps in cutting down on bows that go "Bang!". 

[Beleg813]

Also, you might want to build yourself a tillering tree instead of a tillering Stick. The Tree allows you to slowly stress the limbs a little bit at a time before you draw it to alonger length and check the tiller again. Pre-stressing the limbs really helps in cutting down on bows that go "Bang!". 

Hey Akila after noticing D. Tiller's message above and I remember reading that you don't have much space a portable tillering tree might be something that would work for you.

http://www.primitivearcher.com/smf/index.php/topic,3423.0.html this is a link to my topic which contains a few more links--and a whole ton of helpful advice--I finished my tillering tree with very little problems now I just need a bow.

As far as why your bow broke--wow I"m so under-experienced I wouldn't know where to even start, so I'll let the more knowledgeable folks part with some of their wisdom. But, for some reason I just kept hearing "exercise the wood" a lot while during the tillering process--and patience would go a long way in the entire process, but particularly so when tillering.

I hope this helps

[D. Tiller]

Also, if you dont have a way of attaching it to a pole then make a base for it and pile on a couple 50 pound sand bags on the base and have it free standing. That way you can go anywhere with it!

[akila]

Hy and thks for all the help...i dont know how to start...it must be something that i do wrong here.Yestarday i put the bow on the stick with a long string and i strung the bow  2 inchies at a time...this take abute 5 minutes max. i wass seeing where the problem is, i try to fix that problem..i revmove wood from where i think that it should be removed,then i strung the bow even more ...again i removed the wood ..and it seams ok to me...thenn i strung the bow more..i think 17" or  so..it wass bening quite good at that distance and snap..the bow broke....so   do you think that i tiller the bow to quiqly??? something els that i want to say... in the first 5 minutes or so..when i have strung the bow just 12" or so ,the bow wass coming back  straight....then after i started to look to much on him on the tiller stick  the bow wass comming ot take set..aboute 2".so i realy dont know whatt to say...i will make a tiller tree first..i have a piece of wood 2 meters long and will make a tiller tree.But im thinking that maybe i do this all tillering stuf wrong.whatt do you mean whenn you say work the wood betwen tiller sesions?? its not like you can shoot the bow right???becose its not  finish..so i realy dont understand that...i dont understand how you tiller the bow and not take set at all or verry little,and how you can see the defects on the bow when you strung the bow inchi by inchi... .Here is where i do it wrong i think...i bend the bow to an long draw to quiqly i think and this is why its taking all that set...i have to learn to tiller the bow propely.

[GregB]

I think the bow was still too high in moisture content. Having cut it in August, and already making a bow now is to soon unless the bow had spent time in a hot box. We usually try to allow a year before we make a bow after cutting the tree.

I also agree with Justin, the tillering stick in my opinion should only be used to get the bow to brace height. After getting the bow to brace, you need to switch to a tillering tree which involves a weight scale, and pulley/rope with handle allowing you to watch the limbs flexing, know the draw length and weight at the same time. Never draw the bow past what you want the finished weight to be. Also when you're nearing full draw using the tillering tree, you shouldn't leave the the bow at full draw for more then a couple of seconds. Full draw maintained is a lot of stress on the bow.

Basically tillering using a tillering tree is many sessions of removing material and back and forth to the tillering tree...gradually working your way to full draw length. Each time after removing material, work the limbs multiple times on the tillering tree using short pulls to make sure the wood is accepting the changes you've just made by removing material off the belly. Failure to work the limbs each time can cause a hinge to sneak up on you.

[akila]

Hy ...i just realize after some more reading here on the forum that the bow had some naural reflex on him and i think that this is whatt trick me...i remove to much wood on that limb becose i thaught that its not bend enugh in that area ...and whenn i realize that it wass to late.And i also keep the bow to much time strung on a long draw on the tiller stick.I think for aboute 30 seconds or maybe more...its to much right... ?.I wass reading here on the forum that 2 mounth its enugh  for a stave that has been reduce to bow dimension to dry...the wood is making a realy nice sound like an instrument whenn i knok him with my finger...and im thinking that is dry enugh....but i also may be wrong... im not an expert on this things.I know that drying its not the same with curing the wood and all that stuff.Right now all the wood that i have its only 1 mounth or 1 mounth and half,2 mounth since they have been cut down ,split,and reduce to near bow dimensions.

[D. Tiller]

Also, when using the string dont shorten it at every bending. Keep it long and then keep extending the length of draw on the stick between tillerings. When it gets close to brace height then reduce the string length a bit more. Keep doing this untill you reach brace height and keep tillering untill you finaly reach your length of draw. Sound kinda like you where rushing the tillering process the way you were doing it there.

David T

[Badger]

Akilla, you may have made more than one mistake, which is just part of the learning process. You said the bow was taking 2" of set all of a sudden. You need to closely monitor the set at every new inch of draw length progress you make, every time you go one additional inch check for the bow taking set. If you see any set then you know you have to do something different. Either get more of the limb involved in bending, or lighten the draw weight. Instae of "noticing" 2" of set, you should have picked up on it when there wa 1/4" of set and made some desicions. Excessive set is also a possible sign of moisture or just underbuilding a bow, which is asking more from the wood than it has in it. Do you have any way to get the mass weight of the broken bow? Accurate to within 1 oz maybe if possible. Steve

[akila]

Akilla, you may have made more than one mistake, which is just part of the learning process. You said the bow was taking 2" of set all of a sudden. You need to closely monitor the set at every new inch of draw length progress you make, every time you go one additional inch check for the bow taking set. If you see any set then you know you have to do something different. Either get more of the limb involved in bending, or lighten the draw weight. Instae of "noticing" 2" of set, you should have picked up on it when there wa 1/4" of set and made some desicions. Excessive set is also a possible sign of moisture or just underbuilding a bow, which is asking more from the wood than it has in it. Do you have any way to get the mass weight of the broken bow? Accurate to within 1 oz maybe if possible. Steve

The bow wass not verry heavy .....i dont make bow to much thenn 65#.I like it to be to aboute 55#...and i usuly taper the bow from the start to aproximate this weight.I make  the bow equal in thicknes to abute midd limb and thenn i taper to the tips.So after i finish all the measure and i cut the bow to dimension usuly the bow only need a little tillering .becose i try to measure verry precise bouth limb.I all most my self a tiller tree....i have to buy tomorow a weel to put down for the string and im ready to go.I also have other Bow that i have to tiller it tomorow and its a tricky one.The stave its a little twist and the limbs are not straight,and the string its not exactly in the middle of the handle.I will make a new post maybe i will do this one right....with your help ofcourse.My name is Ciprian btw...sorry i forgot to mention that earlyer....

[Mark Smeltzer]

I do what Badger does, I unstring the bow often to check for set.  I want to know about the set long befor I discover 2"