Primitive Archer
Main Discussion Area => Bows => Topic started by: Willibow on June 10, 2015, 02:48:14 pm
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I've been working on this hickory bow to hopefully take antelope hunting in a couple months. I've been long-string tillering so far and am not really sure how to proceed. I'm hoping some of you more skilled bowyers out here can take a look and offer any criticisms, advice, etc.
The images below show the bow at about 14 inches of string movement at 48 pounds. I'm aiming for 50-55 pounds at 28# when all is said and done. Currently it's 68" tip to tip, 67" nock to nock. This piece comes from a board, and is scraped down to one continuous ring for the back. Pyramidal design going from 2" at the fades down to a hair under half-inch at the tips. Small osage tip inlays are currently in place. Man is that stuff tough to file through! I thought my fingers would fall off before the nocks were done. I need a more aggressive rat-tail file for hard inlays like this!
I always have the hardest time with the early stages of tiller like this. I just recently broke a rawhide backed black walnut bow, and I'm in no hurry to re-live that sorrow :-)
I appreciate any help you can give.
(http://www.paleotube.com/m/photos/get_image/file/ad4270f2cd7479b245c8d63c865e199d.jpg)
And without the grid.
(http://www.paleotube.com/m/photos/get_image/file/e32a7a351088f1c0a20cf22e69b0ed5d.jpg)
Thanks again!
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Brace it up about 2" high and take a few more pics at the same draw weight you have it at now. Your well beyond long string tillering.
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Chain saw files work great for cutting in nocks. ;)
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I agree on 2" brace. It will show you more than long string pulls. Looks like you need more bend in mid and outer limbs for pyramid tiller. It is already bending well right out of the fades. Too much bend there will cause a lot of set though.
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So tonight I tried to string the bow at a low 2-3" brace with a new string I made up for it last night.
I always make Flemish twists from BCY B55 and have never had a problem before, but tonight it looks like the string is stretching like crazy :-(
It's 14 strand, and looks to be made at least as well as the other half dozen or so strings I've made in the past. What's happening is when I string the bow, it initially is at the desired brace height, but as soon as I take tension off of my bow stringer the tips slowly begin to return until the string is tight against the bottom of the handle. After 30 seconds or so the movement is complete.
The only thing I can think of is that the string is stretching. Where else could this movement come from? One difference from my older strings is I'm using pure beeswax on this one, which I melt in using friction along the string with a piece of suede leather.
Has anyone else ever seen this magnitude of stretch with new B55 strings? This stuff is supposedly lower stretch than B50. How should i proceed? I'm worried about having to over stress the bow and pull it way hard in order to string it at an insane brace height so that it will settle to two or three inches at brace.
Thanks again.
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Low brace height puts more strain on the string at brace height.
I'd also suggest taking the level out of the picture when viewing the arc. It's a real distraction.
Looks like you need to thin the limbs along the full length because too much of the bend is at the fades.
Jim Davis
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Can you post a picture of it unbraced as well.
I'd recommend reducing the depth of your handle a 1/4 inch or so and blending the fades in a shallower radius.
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Are you using looped ends, or are you tying a bowyers knot on one end. I have had bowyers knots slip when low bracing
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Thats the reason I use FF or linen as a tillering string. Low bracing is a pain in the butt with stretchy strings. I would suggest thickening the string a bit, just for use as a tillering string and maybe some extra wraps on the bowyers knot.
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Thanks for the replies. The string is a Flemish twist, no bowyers knot.
I'll take new pictures unbraced tonight after work and I'll also take the string into work and try to get it to 200 or 300 lbs of tension for ten minutes or so to properly stretch it. After doing some research, it looks like this is the way a lot of people are pre-stretching their Dacron strings.
Thanks!
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To get stretch out of your string put it under tension then get a piece of leather fold in half, string in the middle and rub it up and down until the string gets warm.
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I use natural beeswax exclusively on my strings. I use b50 to tiller with out to about 22 to 24 Inches. Now I make FF string to do the final tiller. I make a flemish style string and add a few pieces of the b50 to the loop section. (thanks missilemaster).
When I stretch my tiller string I use a rachet strap between two trees. My tiller string is 16 strands of b50 after stretching I've gained 6 to 8 inches at least. Patrick
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Good recommendations, I'll have to try these tricks to stretch the string out, or maybe just move to a FF material to save the time.
So I've stretched the string enough to get it braced at about 1.5" above the handle (2.5" above the belly of the bow). Pictures are posted below of the tiller at 15", pulling 50 lbs.
I'm afraid I've already induced about a half inch of set since there used to be about an inch of natural reflex in the bow. Pictures posted for that as well.
Thanks in advance for helping to share the wisdom. This community rocks!
Unbraced with no grid:
(http://www.paleotube.com/m/photos/get_image/file/bb56e824e03732b7c27e4ceba9fe5c19.jpg)
Unbraced with grid:
(http://www.paleotube.com/m/photos/get_image/file/6f0db6a8bc81f45741dd1135057f67f8.jpg)
Pulled to 50 lb at 15", no grid:
(http://www.paleotube.com/m/photos/get_image/file/06ff6e79ea0f63f635801cb0a2aea765.jpg)
Pulled, no grid:
(http://www.paleotube.com/m/photos/get_image/file/bdd9e61a1841284f383857320ffd7463.jpg)
Sorry the right limb tip got cut off in the photos. I need to rig up some way of holding the bow at draw that is more stable than my arm for photos!
Thanks again!
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You probably should avoid holding the bow at draw for more than a few seconds at a time. Get a tripod for your camera instead. ;)
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everything looks pretty even, Id get her braced higher
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Thanks, I'll get her braced at 4 or 5" tonight and do some more work. Just wanted to make sure I wasn't pushing forward with any serious flaws or hinges in the making my untrained eyes might have missed. ;D
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It doesn't look too bad, maybe a little stiff on the outer third of the left limb. But get it braced a little bit more. Then post more pics and we will take a look! Patrick
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The right limb is stiff out of the fades then bends a shade too much mid limb with the outer/tip being stiff again. Left limb is good. BEFORE bracing it higher sort out this problem! These are the sort of things you need to not miss ;)
Never increase brace height until it looks perfect otherwise you will just overstrain the weak spots.
Also I would find somewhere where you can trace the (side)profile of the stave with a pen. This is so you can hold the bow up to the 'original' profile to see exactly where it is taking set. If one area on a limb takes set then you know 100% that spot is weak and the rest of the limb needs weakening. You should be aiming for no set inner limbs, a little midlimb and the rest out to the tips.
Also once you get to 20 inches of draw then you should be drawing the bow by hand and taking photos of it in hand as the forces will be different to your tillering tree.
Good luck and keep osting pictures
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The right limb is stiff out of the fades then bends a shade too much mid limb with the outer/tip being stiff again. Left limb is good. BEFORE bracing it higher sort out this problem! These are the sort of things you need to not miss ;)
Never increase brace height until it looks perfect otherwise you will just overstrain the weak spots.
Also I would find somewhere where you can trace the (side)profile of the stave with a pen. This is so you can hold the bow up to the 'original' profile to see exactly where it is taking set. If one area on a limb takes set then you know 100% that spot is weak and the rest of the limb needs weakening. You should be aiming for no set inner limbs, a little midlimb and the rest out to the tips.
Also once you get to 20 inches of draw then you should be drawing the bow by hand and taking photos of it in hand as the forces will be different to your tillering tree.
Good luck and keep osting pictures
Very good information mikekeswick, I wish someone would have told me that when I started making bows! Patrick
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Okay, time for some more pictures as the bow build progresses. Having a lot of fun and really taking my time using cabinet scrapers.
I've got the bow braced at about 5.5" above the belly at this point, puling 52 lbs at 20"
See images below of braced and drawn profiles:
(http://www.paleotube.com/m/photos/get_image/file/7bcc8774fc186c7cea952ce78c60dfaf.jpg)
(http://www.paleotube.com/m/photos/get_image/file/68ec90d46c94d1ca5dbd5045d74f6090.jpg)
And drawn:
(http://www.paleotube.com/m/photos/get_image/file/aee4a28496e17eeba9590ff426d9cc71.jpg)
(http://www.paleotube.com/m/photos/get_image/file/60fe88ad882dd52c0a5666801834abd6.jpg)
Tiller is looking a lot better to my eye, though I'm not really sure how long to make the stiff tips. I feel like they are too long at the moment and the bow ought to be bending more closer towards the tips. Is there a good rule of thumb for this to ensure you don't make a whip-ended bow while still allowing work to be done as far out as possible on the limb? Something simple like leaving 6" or 12" unbending would be great for newer bowyers like me.
Set is at about an inch on each limb immediately after unstringing, measured from a flat table up with the back down on the table. Most of the set seems to have occurred about mid-to 2/3 down each limb, where I found some hinges using my tillering gizmo earlier on. I am not sure how much the limbs will relax, but will check again tomorrow after work.
I'm getting excited as I get closer to the end, so it's a good thing the work week is starting up again to keep me from getting back to it too fast!
Thanks again.
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Looking good :)
Right limb looks a tad stiffer than the left?
It's almost impossible to get the very tips bending as there is virtually no leverage, but the outer 1/3 can certainly bend.
Sometimes looking along the limb as you are flexing it or when it's drawn helps you see the bend.
The difference between arc of a circle and elliptical is pretty small especially when as you can't bend the very last few inches.
I know what you mean about ending up whip tillered. I ended up with chrysals near the tips on one bow 'cos I tried too hard for that elliptical tiller... that's one reason why I tend to go for arc of a circle... it's more clearly defined.
Sorry I'm rambling now ::)
Del
BTW. My personal view is that it's better to allow the bow to rock on the tiller on a curved support rather than a square support. Try to mimic how it behaves in the hand. So pull it from the nocking point not the centre of the string.
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Thanks Del, I appreciate the input.
So you build up a half-circle and balance the bow on that while pulling on the tillering tree? It was suggested that I pull it by hand from here on out, but I'm not sure I'm comfortable with that yet. I'm not familiar enough to know what about 20 inches of draw at about 50 pounds would feel like, nor am I set up to take pictures while doing that yet.
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Thanks Del, I appreciate the input.
So you build up a half-circle and balance the bow on that while pulling on the tillering tree?
Yup, that's it...
It's a bit of an eye opener, because it will be severely tilted when you first start to pull it, but will even up as you draw.
If you actually look at a bow as you put an arrow on the string and start to draw you will see it tilts.
Del
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You have a heck of a bow going. I like it.
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Got a couple more inches towards full draw tonight. Currently drawing 54 lbs at 22". I decided to shift up a bit and shoot for 55 lbs at 28" when she's all said and done. A great pile of scraper shavings is building up around my feet and the aroma of hickory fills the garage. Good times any time I'm making shavings ;D ;D
I put an effort in this night to get the outer third of each limg bending more without letting the last 6" or so of the limbs bend. To my eye, the right limb still needs more bend in the outer third, please comment on this. I also narrowed the tips a bit from a hair under 1/2" to about 3/8" wide.
Pictures follow:
Braced:
(http://www.paleotube.com/m/photos/get_image/file/52d2a5a3d449ff8ea24f49c8d9c75fa7.jpg)
And with grid:
(http://www.paleotube.com/m/photos/get_image/file/0e8dc007cb8155e8752430fcfc059a03.jpg)
21.75" or so draw:
(http://www.paleotube.com/m/photos/get_image/file/721272c95f202e0fa1ecb9566f677689.jpg)
Drawn with grid:
(http://www.paleotube.com/m/photos/get_image/file/3d6edd72b1c64f457fe9cf7d32f22cdf.jpg)
Now, I've noticed the set has increased a bit. I would really like to see 1.5" max on each limb, but I think that's slipping away from me as I progress. I'll refer to the limbs in the following pictures as they are typically seen when the bow is on the tillering tree in the past pictures. Any advice on how to proceed with attention paid to minimizing set would be appreciated. I've read badgers notes on zero-set tillering, but he says in his post to be familiar with side tillering as a prerequesite. Unfortunately, side tillering is something I'm completely unfamiliar with and hadn't heard of until that post.
First, overall unstrung profile. Right limb here is the same right limb as is normally shown, despite the fact that it is upside down. I placed the bow upside down because I had the sneaking suspicion that the flat base of the handle was not planed level.
(http://www.paleotube.com/m/photos/get_image/file/ea8418fc33fb46995894d2a4f9817b51.jpg)
Next, the left limb is at about 1.25" set immediately after unstringing. This one has had more set throughout the build, and I feel like it may be from where the bow was bending a bit too much out of the fades in the beginning of the process. I'd appreciate thoughts on where you all think the increased set is coming from on this limb. Note: There is a small hump in the limb about 2/3 of the way down it's length that may be contributing. This is a little easier to see in the above unstrung picture.
(http://www.paleotube.com/m/photos/get_image/file/bde088ef870e38f541499ef41dbd3713.jpg)
Right limb is at a little less than 3/4" set immediately after unstringing:
(http://www.paleotube.com/m/photos/get_image/file/861540fbf8946e3298e9366ad8e2861f.jpg)
Next, side profile looking down the right limb with 3/4" set:
(http://www.paleotube.com/m/photos/get_image/file/94628df6b2015cfcc017b66269f727e4.jpg)
Left side profile, limb with 1.25" set:
(http://www.paleotube.com/m/photos/get_image/file/d3cb5dced95162ece98c78a0ec58e6c4.jpg)
Finally, the back profile of the bow for reference. Dimensions are about 2" at the fades (I wanted to increase my chances of a working bow as much as possible as I intend to take this on a hunt in early August) and tapering to about 3/8" at the tips. 67" ntn. I may try piking this bow to shorten it up a little. If I do pike it, what would be a recommendation to start with? 68" tip to tip is the current dimension and I feel like I could probably get a little more manageable length out of it if I try.
(http://www.paleotube.com/m/photos/get_image/file/ef806d1ed06e14adf0626c7ea54d4736.jpg)
Thanks so much again for any advice, random thoughts, ramblings, compliments, scoldings, or anything else that might help along the journey!
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Wow, that last post is a lot to digest. I've got another question to add to that pile:
I'm considering adding an arrow-pass cutout. Is that something I should have done earlier in the game? If so, would I be okay narrowing the handle, and how narrow would be a good starting point to bring the bow closer to center-shot. As it stands, the handle isn't much more narrow than the 2" fades. If memory serves me, the handle is about 1.75" wide in the center of the bow and 1.5" at the most narrow points offset two inches from the center. There doesn't appear to be any working or bending of the stave under the glued-on riser. Riser is 1" thick.
I'd really like to either narrow the handle considerably or add an arrow pass to bring the arrows much closer to center. Thoughts?
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Grip and arrow pass IMO are finishing jobs... you do 'em last to make 'em fit the hand and the bow.
It's looking good, the bit of set seems spread pretty evenly along the limb which is good. If you can see an area that isn't taking set, then it can maybe work a tad harder, and any area that has set can be left alone.
My workshop could do with one of those magic grids ;)
Del
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I'm approaching the end of tillering for this bow and I would appreciate another close look from all of your keen eyes 8).
Currently pulling 55 lb at 25". Will be tillering out to 55 lb at 28", so I've got there inches of pull to make any necessary adjustments.
I really appreciate any further comments, ideas, criticisms, etc.
I'm currently planning on figuring the handle when I get to 26" and to finish tillering with the figured handle completed. It will lower the bow down closer to the shelf of the tillering tree and I'm worried that if I figure the handle after tillering is complete, I'll effectively lose some good amount of poundage as the point of measurement for draw length will have moved forward a half inch to 3/4 of an inch or so, depending on how the handle comes out. Plus, this will leave a little wiggle room for adjusting balance, etc.
Also, I'm currently thinking of making the left limb the bottom limb. It is effectively about 1/4" shorter than the right limb since I put in a nock for a stringer closer to the outer edge of that limb. I remember reading that the bottom limb should be shorter and a bit stiffer. I would really like to hear some thoughts on how I should proceed with this.
Thanks in advance. You guys have taught me a huge amount in a very short amount of time!
(http://www.paleotube.com/m/photos/get_image/file/e4c791b9e79974c219a039cdeb9d4567.jpg)
(http://www.paleotube.com/m/photos/get_image/file/ffa48e4d67bbee35f57810431ae6472f.jpg)
(http://www.paleotube.com/m/photos/get_image/file/dffa026f9e64191bf18c42545c088049.jpg)
(http://www.paleotube.com/m/photos/get_image/file/9cf850ddcda2ec613fa5bf9ba58eed0b.jpg)
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You're there :) :-
Just breaking wind carelessly in the vicinity of the bow will get you back those last 3" >:D
Ok a slight exaggeration ::).
I reckon on 26" being as near as dammit to 28" but rounding off edges, narrowing tips (as much as you dare) removing tool marks etc will get you there. There's only room for the slightest of tillering adjustments now... I'd shoot a few arrows through it at short draw and allow plenty of lookin' at it time and the odd bit of fiddling and fettling.
Drawing it in the hand and seeing how it looks is more important than what it's like on the tiller now.
If you want me to be picky, I'd say the outer 1/2 -1/3 of the right limb could bend a tad more? Dunno, could be an optical illusion caused by background noise and Wily Goat ;D )... but just rounding the belly a tad would probably do that...
But you need to see it in the hand.
Also start tuning up the arrow pass and grip to suit the string line...
Del
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Good advice from Del, middle 1/3 of right limb maybe a touch, but looking really good. I would shoot it a bit and recheck. Nice job. :)
Pappy
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Good advice from Del, middle 1/3 of right limb maybe a touch, but looking really good. I would shoot it a bit and recheck. Nice job. :)
Pappy
I'm with del and pappy. The outer third of the right limb could us a few scrapes. But put it in your hand and draw it in a mirror and watch the bend. If you can try drawing it while someone is video taping you. The flip the bow over, bottom to top, and do it again. Then you can watch the video several times. This helped me a lot with a character bow I built. Good luck and keep posting pics. Patrick
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I'm the last one to give tillering advice. I constantly run my gizmo up the limbs and really have to study the pictures I take. I'm with the others, though; looking good.
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I'm with the rest.
The picture below shows that the right limb is still a tad stiffer mid-limb, but at this stage I don't really care much about such details anymore, as long as it shoots true and feels good in the hand.
Next time, heat treating the belly (making it stronger) in an earlier stage could maybe help you get a little bit less set (mind you, nothing to be worried about right here), especially with hickory being very tension-strong wood.
joachim
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Cool picture Joachim, I've never seen one with the ovals in there. I guess that means I built it to an elliptical tiller? I just ran my tillering gizmo up until the last couple inches of draw in order to tiller. That, and incorporate the advice here :-)
Funny how those ellipses show the stiffness on the right. My uneducated eye says the right side is bending more than the left. Got lots more learning to do :-)
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That looks great, very nice and as you said nothing to worry about on that one. Nice job. :)
Pappy
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Yo, I'm not trying to be contrary... (honest ::))
This is just to illustrate how the fitting of curves is a matter of some interpretation...
The previous ellipses show a bit of a gap just out of the fade on the right limb...
I'd give it a more circular interpretation, (I've deliberately gone a tad more circular than I should)... mind I don't claim to be "right" in the slightest.
You can see I've centred my curve a little further out along the fade too.
I've seen some newbies just force a curve over the whole bow and think it's fine without actually studying it... on the "It fits where it touches"
principal ::).
(I'm not saying Joachim's ellipses are like that)
Del
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Still looks good to me. Perhaps I ant that picky, :-\ it's a self bow. ;) :)
Pappy
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Haha Del, I was also making another fit of a more circular tiller AND an elliptical tiller. My point is mostly that fitting two identical ellipses (or circles, which is an ellips with two identical radii, actually) helps you to see differences between limbs with a detailed precision you couldn't see otherwise.
But it's not because you can fit a circle to a limb curve that you have a circular tiller. To see that I add a circle with the top of the circle at the fade, and then I remodel it to whatever fits one limb, and clone it to the other limb. I also kept one circular, and one circular but moved the top of the circle towards the limbs (cheating a bit; you see a tiny gap at the fades). That way you immediately see the difference (circular-elliptical), and you can also see if your profile matches expected tiller shape (arc of circle per limb for a pyramid,etc).
This said, I wouldn't mess with the tiller anymore.
As said before, the differences you still have are irrelevant in the hand. Actually, my placement of circles/ellipses assumes the arrow rest/nocking point is in the middle of the handle. It probably isn't, so you may need tweak the tiller according to where you want to place the arrow.
JOachim
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I've got the bow pulling 58 lbs at 28", though at that weight I can only draw it about 27"! I'm used to shooting my wife's 35 pounder and need to work up some muscles!
Please let me know what you think of tiller at this stage. There's still some meat left to adjust without going under my target weight of 55 lbs.
Thanks again!
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Looks spot on to me...
I'd be careful of that alien brain sucker device poised ominously above your head :o
Del
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Thanks Del! I'll have to tell my alien friends to quit photobombing my tiller check videos ;D
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Wow.
I was finally able to take this bow out back for the first full-draw test shoot.
Holy smokes! This thing moves arrows like no other bow I've built. Granted, that's only five or six and only one was comparable in draw weight, but it was inefficient as all get out.
Where I'm going with this is to say thanks for all the advice. I see the positive outcome of this bow very much as a group effort ;D
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Thats great bud! I hope you will be shooting it for a long time! Patrick
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Glad it all came out like you wanted , nice job. :)
Pappy
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Well done! Shooting a bow you really own is a great feeling.