# Bowmaking curiosity



## Hoot (Aug 1, 2015)

For those who have built a bow, have you ever noticed this?

On the tillering rig (or whatever they are called), it looks fine.  When installing an actual bow string, the tillering is way off.

That's what my first project is doing.  It looks great on the tillering rig.  But when I install an actual bow string, it is almost "hinging" at one point on one limb.  I realize that the string angles are different between the two setups, and that is probably the cause.  The tips are bent about as far back in each scenario.  But the problem is, if I have it looking good on the tillering rig, and it looks bad in actual use, then I don't really see the purpose of a tillering rig.

I hope this makes sense.  What am I missing here?


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## Philbow (Aug 1, 2015)

I think that you are probably using a long string on the tiller tree which put less initial stress on the limbs then when you string the bow the added stress causes the "hinge, weak spot" to appear at a longer draw length.

Using the long string is only 1/2 the tillering needed. after you have finished with the long string, using a string for the correct brace height, start all over on the tiller tree correcting the limb bending.

I use a long string then a tight string, it is tight on the bow but does not bend the limbs, and finally the bow string on the tiller tree. 


Or it is possible that if you are using the step thru bracing method you might be bending one limb, usually the bottom limb, more than the other limb producing what looks like a weak spot. If that is the case then just working the bow usually evens the limbs.


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## Hoot (Aug 4, 2015)

Tuning a bow is absolutely maddening.  I get the limb bends looking good on the tiller tree, and it looks horrible when I install a bow string.  I got that part corrected this morning, though.

I am getting pretty bad limb twist on the tiller tree and with a bow string installed.  I am about to the point where I need to research using heat to correct the limb twist.  Shaving the wood down isn't helping at all.

But, what I'm gonna do first is just do a full draw test, and if it doesn't blow up, shoot it and see how it performs.  It would really, really stink to get it tuned really well, then have it blow up.

No matter what, I imagine my first bow might become campfire kindling.  Especially if it blows up when I draw it.  Shame, because it's a really beautiful red oak longbow, and I already made and installed phenolic tips.

Fortunately, I have enough wood to build 3 more.  This is a huge learning curve for me.  Not in woodworking (that's the easy part), but in making a proper bow.


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## Hoot (Aug 4, 2015)

Update to my post above.  Well, it will make some real nice campfire kindling.  Went to full draw, and I heard a very slight cracking sound.  Didn't "blow up", though.  Hit what I was aiming at.  Noticed some pronounced "hinging" out toward one tip.  Felt the front face, and yep - there was a little splintering, right about where the "hinging" was.  I know that installing backing on it might prevent a catastrophic failure (and protect the tensile face from handling damage), but that wouldn't prevent minor splintering like I got.

Scratch one bow.  Glad I didn't do more work on it.  Maybe I will try again.

Maybe.


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## Todd Cook (Aug 4, 2015)

First, sorry to hear about the blow up. It's part of making wooden bows however, and the very best still have them break sometimes. If you want to learn to make bows, just move on to the next piece. 

Second, the long string on a tillering board is important to get the limbs started bending properly. But you want to go to a short string( about a 4" brace height) as soon as possible. That long string will lie to you about what the limbs are doing. 

The key is to get the limbs bending even from the beginning. I know, I know, easier said than done. But if you put the long string on it and get the tips moving about 6 inches or so, don't pull any farther until it  bends even. This sounds obvious but it took me forever to figure that out. You want to get the tiller even early; that way you're just reducing weight after that. If you start with a hinge, or too much movement near the middle, if you don't catch it fast you'll have a 20 pound bow before you know it.

Make a tillering gizmo. It's a 6 inch block with a hole through it for a pencil. If used properly you won't get a hinge. Make sure the wood is dry enough. Osage and locust can take a little moisture; hickory must be DRY!

What wood are you using? Can you post pics? I'm certainly no expert but I'd be glad to help.


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## SELFBOW (Aug 4, 2015)

Todd Cook said:


> You want to get the tiller even early; that way you're just reducing weight after that. If you start with a hinge, or too much movement near the middle, if you don't catch it fast you'll have a 20 pound bow before you know it.



Aint nothing wrong w a 20# bow. I got one that shoots pretty good @25# right now


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## Hoot (Aug 4, 2015)

Todd Cook said:


> First, sorry to hear about the blow up. It's part of making wooden bows however, and the very best still have them break sometimes. If you want to learn to make bows, just move on to the next piece.
> 
> Second, the long string on a tillering board is important to get the limbs started bending properly. But you want to go to a short string( about a 4" brace height) as soon as possible. That long string will lie to you about what the limbs are doing.
> 
> ...



That was the initial problem.  With a long string on the tillering tree, the limbs were bending nicely and evenly.  Where I messed up was not using a short string on the tillering tree.  And I didn't deal with the limb twists early enough.

But those were secondary problems.  The main problem (as I see it) was the splintering I got on the front face.  I wanted to see if it would break, before I went through even more trouble of tuning it correctly.  On a board bow, I'm not sure how to get around that splintering.  I had a nice, flat, even and smooth front surface.  But that doesn't necessarily follow the grain, and therein lies the problem, as I see it.

It was a red oak bow, cut from a 2" thick plank.  It had seasoned in my basement for 10-15 years, so even though the moisture content was probably fairly high from the humidity, the wood was definitely not "green".  I don't have pictures uploaded yet, and besides, the splintering wouldn't show up in a picture anyway.  It was very subtle, but I did hear it when I drew back to shoot, and I can definitely feel it.  Plus, there is a permanent "hinge" where the splintering is, even after removing the bow string.  This bow is toast.

When (if) I make another one, I need to find out how to prevent that splintering, before I start cutting out the blank.  Should I bandsaw along the grain, instead of along a straight line?  Or split the board with a froe, and use the split edge for the front face, and bandsaw the back face?


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## Todd Cook (Aug 4, 2015)

A board bow works good, but it's very different from a stave. You need to orient the grain like this. This way there's nowhere for the split to start. You make the flat edge shown the back of the bow, and taper the belly side. Truthfully with a board bow, a pyramid design where the limbs go from 1.75 inches to maybe half inch tips works good, with very little thickness tapering. The 2nd picture will break just about every time, because the growth rings will lift and separate. Please forgive my artwork.


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## Todd Cook (Aug 4, 2015)

SELFBOW said:


> Aint nothing wrong w a 20# bow. I got one that shoots pretty good @25# right now



Good point. I've started several 50 pounders that ended up 30.


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## Hoot (Aug 4, 2015)

Todd Cook said:


> A board bow works good, but it's very different from a stave. You need to orient the grain like this. This way there's nowhere for the split to start. You make the flat edge shown the back of the bow, and taper the belly side. Truthfully with a board bow, a pyramid design where the limbs go from 1.75 inches to maybe half inch tips works good, with very little thickness tapering. The 2nd picture will break just about every time, because the growth rings will lift and separate. Please forgive my artwork.




Thanks for the drawings.  That helps a lot.  Yep, I think that was my problem.  I will study the grain on my plank and try to cut the next blank out so it is aligned more like the top drawing (if I can).  Live and learn.

I'm new to the naming technology, and was calling the "back" the "front", and the "belly" the "back".


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## Hoot (Aug 5, 2015)

Studied the grain on my plank today, and I won't be able to make 1 or 3 more bows out of it (there is enough wood for such).  It is warped in the wrong direction.  If I cut out more blanks, the bows would be warped sideways.  That warp was why I cut it out the way I originally did - to try to use that warp to my advantage, even though I knew the grain pattern wasn't in the best direction.  Turns out it was in the worst direction.  Lesson learned.  I'm just glad I didn't buy the plank for this - I have had it for 10-15 years.


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## NCHillbilly (Aug 5, 2015)

Red oak is a very marginal bow wood anyway. If you're specifically wanting to make a board bow, I would look for some rift sawn hickory or ash, or if you use red oak, back it with a 1/8" piece of hickory. Even better, go cut you a good straight hickory, ash, hophornbeam, or elm sapling with no limbs for about 6', and use that.

I always try to get on the short string as soon as possible. As soon as the limbs are bending fairly evenly and it's weak enough to string, I slap one on it at a low brace height. As you found out, using the long string for too long on the tree will often hinge those tips. 

Limb twist is usually caused either from the grain of the wood, or from removing wood unevenly from the belly, leaving one edge thicker than the other.


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## Hoot (Aug 5, 2015)

^^  Yeah, I wouldn't have bought red oak, but I had some, with no use for it, and I was hankering to build a bow.  When I get some wood for my next one, I will get something better.

I never liked oak for woodworking.  It is a pain to work, because of the grain, splintering, burning from router bits, and the fact that the grain needs to be filled for many finishes.  Cherry has always been an utter charm to work, for me.  Absolutely beautiful, and because it is very hard, actually easier to work (IMO).  But I bet it would make a horrible bow wood.  Too brittle.

A few months ago, I cut down a problematic Ash in my backyard.  I thought of making a bow or paddle out of it, but decided against it, at the time, and cut it up into logs.  Now I am wishing I hadn't done that, and kept a long piece of it to make a bow.


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## NCHillbilly (Aug 5, 2015)

Hoot said:


> ^^  Yeah, I wouldn't have bought red oak, but I had some, with no use for it, and I was hankering to build a bow.  When I get some wood for my next one, I will get something better.
> 
> I never liked oak for woodworking.  It is a pain to work, because of the grain, splintering, burning from router bits, and the fact that the grain needs to be filled for many finishes.  Cherry has always been an utter charm to work, for me.  Absolutely beautiful, and because it is very hard, actually easier to work (IMO).  But I bet it would make a horrible bow wood.  Too brittle.
> 
> A few months ago, I cut down a problematic Ash in my backyard.  I thought of making a bow or paddle out of it, but decided against it, at the time, and cut it up into logs.  Now I am wishing I hadn't done that, and kept a long piece of it to make a bow.



Cherry backed with a very thin strip of hickory can make a good bow. Oh, and ash is an excellent wood for beginning bowmaking. It's not the best, but makes a good bow. I have a couplle ash bows I made probably 15 years ago that I still shoot occasionally.


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## Hoot (Aug 5, 2015)

NCHillbilly said:


> Cherry backed with a very thin strip of hickory can make a good bow. Oh, and ash is an excellent wood for beginning bowmaking. It's not the best, but makes a good bow. I have a couplle ash bows I made probably 15 years ago that I still shoot occasionally.



Man, I wish I had a big plank of cherry.  Thinking about it, I see the dynamics, if a hickory backing is there - the hickory taking most of the tensile forces, and putting the cherry in compression.  I can see how that would work.  And it would make the most beautiful bow ever (at least when viewed from behind - wait...I am talking about bows, not women.   )

On that thought, maybe my notion about cherry not being used in bows came from the reason I heard it is not used in gun stocks (being too brittle).  I have, for a very long time, wanted to build a gun stock out of cherry.  Maybe I should try that for a .22, and if that works, then start working my way up the recoil tree.  Maybe I could get rich, if that worked.


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## Todd Cook (Aug 5, 2015)

Cherry is fairly strong in compression, brittle in tension. I've never tried it but backed with about 1/16th of hickory would probably work good.

Where in Ga are you? Our Traditional Bowhunters of Georgia banquet is this coming Sat. night in Barnesville. I've got a hickory stave you can have. If you're going I'll bring one.


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## Hoot (Aug 5, 2015)

Todd Cook said:


> Cherry is fairly strong in compression, brittle in tension. I've never tried it but backed with about 1/16th of hickory would probably work good.
> 
> Where in Ga are you? Our Traditional Bowhunters of Georgia banquet is this coming Sat. night in Barnesville. I've got a hickory stave you can have. If you're going I'll bring one.



Thanks for the offer, but I won't be going.


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## NCHillbilly (Aug 7, 2015)

Hoot said:


> Man, I wish I had a big plank of cherry.  Thinking about it, I see the dynamics, if a hickory backing is there - the hickory taking most of the tensile forces, and putting the cherry in compression.  I can see how that would work.  And it would make the most beautiful bow ever (at least when viewed from behind - wait...I am talking about bows, not women.   )
> 
> On that thought, maybe my notion about cherry not being used in bows came from the reason I heard it is not used in gun stocks (being too brittle).  I have, for a very long time, wanted to build a gun stock out of cherry.  Maybe I should try that for a .22, and if that works, then start working my way up the recoil tree.  Maybe I could get rich, if that worked.



I have a couple of friends who build some amazing flintlock rifles, and both of them occasionally use cherry for stock wood. Sure makes a fine looking rifle. And yes, cherry is weak in tension, but good in compression , and has low hysteresis.


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## The mtn man (Aug 10, 2015)

How would mulberry work? I watch an instructional video for backing a bow with skin, the guy had a mulberry self bow, it looked pretty nice, just curious how it would hold up, I have lots of mulberry trees, no problem getting one sawed either.


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## Todd Cook (Aug 10, 2015)

cklem said:


> How would mulberry work? I watch an instructional video for backing a bow with skin, the guy had a mulberry self bow, it looked pretty nice, just curious how it would hold up, I have lots of mulberry trees, no problem getting one sawed either.



Mulberry makes a good bow. It's in the osage family, although not as strong( still plenty strong). It's pretty wood. If you cut one, you want to split the logs into staves instead of sawing it. With mulberry you drawknife off the bark and sapwood and make the bow from the heartwood.


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