Tillering question.....

[Stingray45]

I'm currently working on a poplar board bow. I know I know its not the best wood but I had some success in the past with poplar, I had a nice pyramid bow up to 45#@24" before it blew up at 25" on the tillering stick. There was a pin knot that showed on the back of the bow, which is where it cracked. So I got a better piece with straight grain and made it 68" ntn rather than the 66" the last one was. Right now I have the bow with good tiller, one limb is a bit stiffer than the other but not much. This morning I got it at 52#@25" and its pulling nice and smooth. My question is regarding the set it is beginning to take, right now the stiffer limb has taken on about 5/8" of set and the other limb has taken on 3/4" of set. I wanted to know what you all think about that and what I should/could possibly do about this? I'm shooting for about 60#'s or so @ 28", that way once I do final sanding and shoot it in I should end up somewhere around 55#@28". I have seen people say 1" to 1-1/2" for set, is that total? Or per limb? Should I try backing the bow with something? Or leave it the way it is? I was also thinking of flipping the tips once I got to 28" of draw and then adjusting the tiller accordingly when that was finished. Any advice is much appreciated it. I will try getting some pictures up on here after I get home from work. Thanks!

[colejack3]

Why didnt you just buy a good board the second time?

[Josh]

Personally if it survives and takes set i would just be happy with getting a successful bow from poplar.  I wouldn't worry about how much set it takes at all.    JMO.  Good luck on your bow!

[Stingray45]

I have other good boards. I guess it's the challenge of building it out of poplar. I like working with poplar in general. I have other things that I can and do work with, on this particular build I chose poplar.

[JackCrafty]

I've never used poplar for a bow but I've worked with poplar on a couple of woodworking projects.  I would put it in the same category as willow or cottonwood.  You need to be very careful to make sure you are not stressing the wood at all when tillering.

Do you have a copy of The Bowyer's Bible that covers "Bow Design and Performance"?  It covers many different types of wood and recommends certain dimensions for each.

You can make a bow out of any type of wood (including pine).  The secret is knowing how wide it needs to be to ensure a safe-working bow.  A perfectly rectangular cross section is also recommended.

[Stingray45]

That's what I'm working with now. I do have it, I havent read that section recently and didnt check it before I shaped the bow. The stats of the bow may help. I made it 69" ttt, 68" ntn, 8" handle, it's 2-1/2" at the fades and tapers down to 1/2" nocks in a pyramid style bow. I'm wondering if I should back it with 1/8" piece of straight grained maple or hickory that I have. I also have some really straight grained bloodwood but I've never heard of that being used for a backing before.

[JackCrafty]

I would probably back the bow with rawhide or cloth rather than a wood that is heavier than the poplar.  I'm not sure, but I think poplar is not strong in compression.

[Stingray45]

I was thinking about putting some rawhide on there if i can get my hands on some. I may look around and see what I can find.

[adb]

You're asking too much of the wrong wood. Also, <1" of set on any bow is outstanding.

[Stingray45]

I think the biggest part of it is the challenge in using it. I'll see what I can do. I believe on the advice of Jack I am going to shorten up the handle section from 8" to 6" so I can get more of the bow working on the limbs.

[sailordad]

stingray45
i like your attitude ,to make it out of polar becuase you wanted the challenge
just becuase some people think that your asking too much from the wrong wood doesnt mean that they are right and you shouldnt try
i say go for it and i wouldnt back it with another wood either
go for the raw hide that way when you get a good shooter from it,its from the poplar and not the backing
the proper demension for the wood choice,especially in this case,is gonna be important too
good luck and i cant wait to see the end results

                                                               peace,
                                                                      tim

[Stingray45]

Update on my poplar board bow..... it blew up tonight haha. However I will say not It wasnt because of the wood. I got it all tillered out to 28", I actually tillered it to 29" just for some leway. Came out to about 58#@28" took a couple shots and it was a real tack driver. So then i went to cut myself an arrow rest and did that. Than I decided I would throw it on the tiller stick rather than draw it just incase, worked it out but I think I still went to fast in pulling it to 28" and got a big split, right from the corner up the arrow rest up about 4" right up the middle of the upper limb. So the dimensions were good. I should have just glued a rest on the side of the bow insted. Now I know for next time. Bow didnt take on a lot of set either, 1-1/8" on one limb and 1-1/4" on the other.

[ken75]

sting i sure would like to see your bow , post us a pic if you can , nice to see people pushin the envelope

[half eye]

It seems to the old man that ya do have a viable bow in that poplar, and your learning as ya go......have ya started #3 yet? Personally I don't do the cut arrow shelf thing but up till then it sounds like ya had that bad dog whipped.......good for you on the ingenuity.
rich

[Stingray45]

I'm actually working on another bow right now but I'll probably be out at the lumber stacks looking for a strainght grained piece this weekend haha. It's one of those things now. I have alot of great boards at the house, hickory, walnut, hackberry and some real straight grained qrtrsawn sycamore but now I'm dead set on getting something out of poplar. I think I was good on the dimensions, I might even be inclined to go a little wider to see if I can take on less set but I wasnt upset with it at all, both sides were 1-1/4" or less. I think I'm going to have to start working on shooting off my hand or gluing a rest onto the side of the bow.

I would have posted some but I didnt taken any pictures before it blew up. If I get started on another this weekend I'll take some throughout the process and get them on here. I have another thing piece of maple I'm working with now. I'm trying to get it to bend the whole way through the handle and it's going well so far. I had originally started with a stiff handle and then changed my mind because its so thin I want more wood to be able to share the work. So Im just working down that handle so its even and doing its share. Ill hopefully get some pics of that tomorrow.