Primitive Archer
Main Discussion Area => Bows => Topic started by: toomanyknots on December 04, 2012, 07:04:59 pm
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I have always made my handle directly in the center of the bow, and tiller the bow to have a stiffer bottom limb to balance the bow, so that the bow will shoot straight. But lately I am getting tired tillering the bow with a stiff bottom limb, and than a year later, my bottom limb is weak from being stressed more than the top. I was wondering what all you guys on here, who obviously have much more experience and expertise than me, do regarding handle and arrow pass placement. I've never really understood this in general that well, as well as never really wrapped my head around the fact why the bottom limb is more stressed at all? :o
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I must admit I'm a bit ambivalent about the whole lower limb stiff thing. It's not so critical on ELBs.
With the arrow pass 1" above centre my bows end up with a shorter lower limb. (grip approx 4", so ball of the thumb is supporting the bow about centre)
I tend to just make sure I tiller the bow supported (loosely, not clamped) and drawn as it will be in the hand and just get it looking even, (with maybe the lower limb a tad stiffer if there is any asymmetry).
Pulling it like that on the tiller, it starts off canted over towards the upper limb (because the draw is bound to be above the hand position) and it pulls back straighter as it is drawn.
You can see what I mean in the video in this blog entry, it starts with the bow tilted down on the right (top limb).
http://bowyersdiary.blogspot.co.uk/2012/11/it-lives.html
I've only had one bow really shift on me (Ash primitive), but I make sure I give my bows plenty of exercise these days.
My last ELB ended up getting turned round, as supporting it dead centre and pulling it 1" above centre looked very different to how it looked with it turned round (effectively a 2" difference in where the string is pulled made a visible difference to the tiller).
Have a look at the pics here on my blog.
http://bowyersdiary.blogspot.co.uk/2012/11/caramel-and-cream.html
I invited comments in that entry, but got none!
Del
(Sorry this post is so long :-[, but it's a good topic)
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Yep, 2 inches shorter for me.
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i'm like pinecone, find the center and 2" both ways, Bub
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I think this is one of those issues where experience doesn't matter. A guy might make 1000 bows and never care about the small difference in arrow speed or hand shock or whatever in his bows that could be improved if he wanted to experiment with the stresses and geometry. It seems to me that, at the end of the day, it doesn't matter.
Having said that, I make my upper limb longer, proportionally so depending on the length of the bow.
To me, its about how far the limbs tip move relative to each other, from brace to full draw, and so it makes "sense" to me to pull the string from a point as close as possible to the center point between the tips.
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I've done it both ways alot. I like the way an asymmetrical bow balances in your hand but equal limbs are sometimes a bit easier to tiller... When I make my bottom limb shorter its usually by an inch and a half.
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I almost always make my bottom limb at least an inch shorter than my top, and tiller the top to bend more. It feels to me like an assymetrical bow is more balanced
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I generally make the bottom limb shorter so the bow balances better in the hand when being carried.
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I always made my bottom shorter but lately im putting my handle on center and im liking it
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I swing both ways so I'm bisymetrical :laugh:
It just depends on the wood and the design of the bow...each has its own advantages,and one is not better than the other IMHO. A few times I've had to lay them out 3" assymetrical so I could get the most length out of a stave because of knot placements..and if I had centered my handle I would've lost almost 6-8" of length...ya just gotta read the wood and the design your making and apply the best method,which could be either way.
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I swing both ways so I'm bi :laugh:
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sorry I think I misquoted you
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I do both ways depending on the bow. Most the time shorter on the lower limb but some of the shorter bend through the handle bows I'll go dead center.
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Paul, that was beautiful what you just did. That probably made me laugh more than anything I've ever read on here, ;D. Thanks everybody for the input, it is all very much appreciated!
EDIT: One thing I've always wondered, is if the drawing technique has, or should have, any influence or effect on where the arrow pass should be placed, or symmetrical verses asymmetrical?
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sorry I think I misquoted you
:laugh: :laugh: :laugh: I see someone took the bait :laugh:
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If your bottom limbs alone are weakening its not a result of where you handle is being placed.
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In billets to bows, Glen St Charles describes his method of making the lower limb shorter. This is on yew long bows. With the center of the bow in the center of the handle he tillers the bow with even bend in both limbs, once he has it tillered symmetrically to full draw, he cuts 1 1/2" off the lower limb and viola, perfect tiller on asymmetrical bow.
Glad you started this thread Toomanyknots. I have been trying to wrap my head around the whys of a shorter lower limb. I think it boils down to balance in the hand, like Gordon mentioned. Good balance in the hand equates to better "point-ability" of a hunting weapon. Makes it quick-on-the-draw.
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I shoot three under, I have always felt the lower limb takes more abuse...so it is always a bit stiffer than the top limb. As CMB mention St. Charles BILLETS TO BOWS which was one of my first books, and followed his example.
VMB
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i've alway made both limbs the same which make the arrow pass about 1 1/4" above center, i've never had any balence issues. i think that really just depends on the wood and your shooting style
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I do about like Killer Duck,I lay them out[most of the time] even from the center of the stave,then after tillering I will shoot it and then decide where the arrow pass goes,I move up and down a small amount till I fine the sweet spot for me. Never had a problem with balance in my hand,I hold on to it when I shoot anyway. :)
I truly don't think it makes any different. I think the bottom limb gets more stress when stringing it more than shooting it. I usually go 1/4 to 3/8 pos.[stiff] on the bottom limb,I don't quite understand why making them even would help keep the bottom from getting weaker over time if you are having that problem. :)
Pappy
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Not that I could tell from experience, but I try to make the bow so that the point where my (slightly open) hand presses onto the wood is in the centre of the bow. This is usually way above the center of the grip. It's more where my index finger touches the thumbs palm. The lower part of the grip is just where my other fingers find space. So the arrow will pass just about 1/2" over that center, shot off the nuckles.
Lately I try to just shorten the handle, since it doesn't even have to accomodate my entire hand. Actually I think 2" would be entirely sufficient. That way, the lower limb doesn't get that much shorter.
And one thing: I find it just plain ugly if the arrow is placed way into the upper half of the bow, especially on shorties. Just a matter of taste, but important to me.
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Never on stiff handle bows
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I do about like Killer Duck,I lay them out[most of the time] even from the center of the stave,then after tillering I will shoot it and then decide where the arrow pass goes,I move up and down a small amount till I fine the sweet spot for me. Never had a problem with balance in my hand,I hold on to it when I shoot anyway. :)
I truly don't think it makes any different. I think the bottom limb gets more stress when stringing it more than shooting it. I usually go 1/4 to 3/8 pos.[stiff] on the bottom limb,I don't quite understand why making them even would help keep the bottom from getting weaker over time if you are having that problem. :)
Pappy
I do about the same thing usually just to make sure the bow is balanced before I do the handle and arrow pass, but for the most part I lay the bow out symmetrically, and place the arrow pass about 1/2" or so above center. This ends up making the ideal arrow pass close to the center of the handle alot of the time. Which is probably not ideal, ;D. This is one of the reasons I like cord wrap handles. It makes things more simple for me, as I can basically nock the arrow pass where ever the sweet spot is as you call it. But it's weird with me. If I draw a typical recurve draw, with a anchor point around the bottom of the chin or so, it seems like it stresses the bottom limb a bit more. On bows that I draw like this, I seem to need a stiffer bottom limb than usual. Where as on a bow that I draw across the chest, it seems to stress the limbs more evenly, and can get away without having either limb overly stiffer then each other. This is what it seems like to me anyway. That is a good point about stringing. But for the most part, if I don't use a stringer, than I string my bows in front of a big mirror to make sure I am stressing the upper limb more for this reason. Most of the time, what I will do when tillering a bow, is check with a fist melee on each limb and balance each limb until the fist melee is almost perfectly even, with maybe one side being no more than an 1/8" of an inch lower, and alot of time I try to get them closer than that. Than I will determine by drawing and shooting in the bow, which actual limb is stiffer, and make that my bottom limb. So I guess I lay my bow out symmetrically, and tiller darn near symmetrically too, :o. I have been thinking of trying a more positive tiller, but aesthetically I just don't like it. My OCD just won't let me for some reason, haha. I have heard that on a bow with a shorter bottom limb, positive tiller is not always necessary in order to have a balanced bow? Is that true? I have a question for everyone. If you were going to lay out a 60" bow with a 4" non-working handle, and make the bottom limb shorter, how exactly would you personally do it?
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I lay out the bow so the handle is slightly below center. Better balance, tiller 3/16 positive. For 3 under shooter I tiller even but still keep same lay out. When I lay out bow on stave the first thing I do is find center line then decide which is bottom limb.
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No, I don't make the bottom limb shorter. I do what Pappy does. Jawge
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Almost never. I think as Blackhawk said above, that if it gives you a longer workable bow blank, makes sense. As a general practice, I don't see a big benefit. I do what Pappy does.
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Never on stiff handle bows
+1
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I've made the top limb longer on some and don't see a diff really.Most of my arrow passes end up 1and3/4" above center of bow.Grip is mostly centered on bow.1/8" to 3/16" positive tiller.
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I use to build some bows with stiffer bottom limbs and some with shorter bottom limbs. Now I mainly build stiff handleD,equal limb bows tillering the same for a good 15 years. I have never had anyone return a bow that needed retillering. And I've shot some of my bows 10,000's of thousands of shots. So I can't see building anything other than EQUALLIMB BOW'S,WITH THE LIMBS TILLERED THE SAME.
I LIKE THE EVEN LOOK WHEN TILLERS FINISHED.
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I have made a few that way,just simpler the way I do it at least for me.The ones I did ,I just found the center of the stave and measure from center ,say for a 64 n-n
31 inches from the center to the tip of bottom limb and then 33 to tip of the top,then lay out the handle from the center line,that will give a 1 inch shorter bottom limb,if want it more than an inch just adjust the measurements. You will need to decide top and bottom limb at that point,with and even limb I usually get it to low brace and see how it feel or if it favors one side or the other and then decide on top and bottom,if nether suites me I will adjust to make it suite me with heat. :) If you are using good seasoned wood/moisture is right/tiller is good/and is treated right when braceing it you shouldn't have much trouble with the tiller changing at least I don't. :)
Pappy
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I do both ways depending on the bow. Most the time shorter on the lower limb but some of the shorter bend through the handle bows I'll go dead center.
I'm with Keenan
simson
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1-1/4 to 1-1/2 for me. Something about balance in the hand, arrow passing at center of bow...Well it was good enough for Glenn ST.Charles and Dean Torges!!! Anyway, I like how the bow handles in my hand and they shoot well.
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This is interesting. From a letter written by Aldo Leopold in 1934.
"I have tried to build into this bow the main recent improvements in bow-design, but since some of them are not visible, they will bear mention. The square cross section and waisted handle are, of course, visible innovations, but probably less important than the new location of the geographic center. In former days this was put close under the arrow plate, but in this bow it lies as near the center of the handle as is possible without overworking the lower limb. In a 3 1/2" handle I have found this spot to be 1 1/2" below the arrow plate. Some authorities make it 1 3/4", but I know from observation that these too-modern bows never appear at two successive annual tournaments, or if they do, they are "on crutches" and ready for premature pensioning to some idle peg on the bow-rack."
It is interesting to me that he is talking about 1/4" difference in placing the geographic center resulting in an ideal bow or an early retirement bow.
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Good post Carson. That's interesting, I'll be pondering those words all day today. Hmmm
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I say there are too many factors at work to readily sort them out and draw a conclusion.
First, if the arrow passes at center, the bow is not supported at center. (No two objects can occupy the same place at the same time.)
Conversely, if the bow is supported at center, the arrow cannot pass at the center. (Same logic as above.)
Second, a shorter limb of strength equal to that of a longer one will return to rest faster--less mass, shorter distance. A shorter stronger limb returns even faster. Either arrangement guarantees that the top and bottom limbs will return at different rates. Not an aid to accuracy.
Third, when we string a long bow using the push-pull method (I do and always will) we pull at the handle and push part way out the upper limb. This makes the lower limb do most of the bending. I have begun pulling at the fade of the upper limb to see if this prevents the lower limb from taking an unequal set. (Check back in a year or so on this :).
Jim Davis
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I have begun pulling at the fade of the upper limb to see if this prevents the lower limb from taking an unequal set.
This is what I do more or less if I don't use a stringer, and yes, it does help the limbs work more evenly. Try doing it in front of a mirror. I do it in front of a big mirror every time, just to make sure it is bending evenly. It does help there is a big old mirror in the room with my bows though, ;D.
Second, a shorter limb of strength equal to that of a longer one will return to rest faster--less mass, shorter distance. A shorter stronger limb returns even faster.
EDIT: Here's that thread I was talking about, ;), https://www.primitivearcher.com/smf/index.php?topic=21882.0
I once noticed, when looking at videos of me shooting some of the bows I have made, that in slow motion the bottom limb always came home first. Sometimes even when the upper limb has only moved a little bit. I posted a thread about it, as it was kinda confusing? Never really figured out why at the time. Makes sense now, ;D.
EDIT: Here's that thread I was talking about: https://www.primitivearcher.com/smf/index.php?topic=21882.0
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I would never have thought that stringing the bow would cause the lower limb to take set. Obviously, the limbs are not stressed evenly during push pull stringing, but the lower limb is still nowhere near the strain it is at during full draw, right?
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I would never have thought that stringing the bow would cause the lower limb to take set. Obviously, the limbs are not stressed evenly during push pull stringing, but the lower limb is still nowhere near the strain it is at during full draw, right?
CMB, you may be right. I always assumed that last part to be true. Just can't think of another condition that stresses the limbs unevenly--so I'm trying this.
Jim
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i for one usually make my bottom limb shorter. there are occasions where i leave the bow symmetrical, but i prefer to leave the bottom limb shorter.
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I have begun pulling at the fade of the upper limb to see if this prevents the lower limb from taking an unequal set.
This is what I do more or less if I don't use a stringer, and yes, it does help the limbs work more evenly. Try doing it in front of a mirror. I do it in front of a big mirror every time, just to make sure it is bending evenly. It does help there is a big old mirror in the room with my bows though, ;D.
Second, a shorter limb of strength equal to that of a longer one will return to rest faster--less mass, shorter distance. A shorter stronger limb returns even faster.
EDIT: Here's that thread I was talking about, ;), https://www.primitivearcher.com/smf/index.php?topic=21882.0
I once noticed, when looking at videos of me shooting some of the bows I have made, that in slow motion the bottom limb always came home first. Sometimes even when the upper limb has only moved a little bit. I posted a thread about it, as it was kinda confusing? Never really figured out why at the time. Makes sense now, ;D.
EDIT: Here's that thread I was talking about: https://www.primitivearcher.com/smf/index.php?topic=21882.0
I have noticed this as well. And in some cases I will recurve the upper limb just slightly more than the bottom.