Primitive Archer
Main Discussion Area => Bows => Topic started by: Minuteman on April 24, 2007, 10:56:20 pm
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:o :o Here we go again folks! Everybody run! Parker's tryin to tiller a bow again. ;D Nah it ain't like that. I'm gonna ask for all of the experienced bowyers on this site to give me their advice as I go. Here are the particulars on the bow blank;
69 1/2" tip to tip, 6" handle section , right now the upper limb is almost 2" longer than the lower. Not too sure about that much difference between the two.
The limb tips sit 1 1/2" in front of the handle and there is about 1/4"of deflex( just barely noticeable) in the middle third, roughly.
Back is sanded and edges are rounded and smooth.
First pic is long strung on the tree with the 5 pounds of scale hanging from the string
Second one isstill on th long string pulled to near where a 4" brace would put it and around 40#.
I need help.
To me it looks like its not bending enough in the inner portion of the reflexed part.Mid limb?
I ain't touching it til I get some feedback.
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I would leave the fade outs, and start getting the whole limb bending more. Justin
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I agree with Justin. Leave the inner 1/3 alone for a while and get the outside bending. Your limb progression looks good so far. It is just bending a bit much inside...or, not enough outside. ;D.
Gosh, the trials and tribulations of a hickory backed black cherry bow :( AND the bowyer's name is Parker. Sheesh!!! ;D That's 2 strikes ain't it! ;D Pat
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Yeah, if my name was Parker, I'd run for the hills. The good news is, I have had a student in my shop this week named Parker who's turning out a nice self bow. There is hope.
By the way, these guys know what they're talking about. Leave the inner 18" alone for now. Good luck--the whole team is pulling for you.
J. D. Duff
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You can do it Parker! ;D
DanaM
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I agree with all above.Stay away from the fades.I like to work them out close to last anyway. :)
Pappy
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It's no use, I believe us Parkers were cursed long ago when one of our ancestors offended the wrong person back in whatever country it was that they kicked us out of when we came here (maybe Merlin hired our 14-times-great-grandpappy to build a hick-backed cherry bow for King Arthur :) )
We don't have much luck, but damn, we're good looking ;D
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Hillbilly, If you are going to break bows, you might as well look good doing it. :-* Justin
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Do ya'll think 2" difference in the limbs is too much? Should I shorten the upper limb ?
Whats the normal difference in limb length for a non symmetrical bow?
Chris
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Worked on the outer thirds this mornin'. Upper limb will be on right from now on to avoid confusion.
Got them both bending a little more, to about 6 1/2" of brace height if it were braced, ~40 # roughly. The upper limb started to develop a lil hinge about 8 or 10 inches from the tip but I think I got it stopped soon enough. I removed wood from the whole lower limb and some from either side of the hingey area.
Whattya think...
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Looks good man. The upper limb is bending farther. I would keep working the areas that you have been. Only scrape each limb about 10 times, then exercise it. Justin
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Chris, borrowed your picture, hope you don’t mind.
In my experience, with glue-ups similar to yours, the area between the red arrows will be stiff at first, with the area where the blue arrow is, week (like you found out). The transition between the two areas tends to be the hard section on a refex/deflex for me (with glue-ups like this). Get the area mid to lower mid limb moving well before you get it on a short string and you shouldn’t end up with any big surprises.
After you get a short string on it, and it doesn’t show week outer limbs, I start to work the entire limb.
I have the most luck floor tillering a bow like that, in front of a mirror, until the mid limb comes around and doesn’t show a stiff area. Then I go to a short string.
Don’t know if any of this helps, it looks as if you got it figured out. Just figured I’d throw my 2 cents in.
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Don't mind at all,Matt. In fact thank you . :) I'm beginning to understand why forlks say RD bows are a pain to tiller. It was just like you said the part I had reflexed(where the clamp was) didn't wanna bend and the part where the reflex softened some wanted to bend quicker. I'm thinking thats why Torges trapped his limbs through that section. At least I think thats what he said in the video if my memory serves me.
The inner part of the limb near the fades hasn't been touched yet . Its still full thickness nearly 3/4". I'm wondering how the deflex has affected the woods response to tension. Seems to want to bend readily. Neat stuff, to me its all new. ;D
I'll get on it again tomorrow in the mornin if my migraine is done by then. :'(
Chris
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The way I see deflex is like a big lever. If you set a lever almost strait up, under a big rock its hard to pull down (no leverage). If you set the lever under the big rock at waist level, you gain better leverage. Deflex is like setting the lever lower. If that makes sense.
You might be right about why Torges says to trapp the mid limb. It also gives you a better neutral plane in that area of the limb. So it seems to serve 2 purposes.
Another thing that might help, once you get the bow on a short string, get the limbs absolutely as even as you can. Its tougher to see the quicker bending areas at brace height, but its a huge help in avoiding a hing.
I think you'll get a good bow out of this one, just take your time.
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You want to leave the outer limbs alone for now including the outer red arrow. Work the inner limbs, where Matt has put a red arrow
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Is this bow hickory backed cedar?
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Ray, It is hickory backed black cherry. Pat
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I think to be safe I'll start scraping on the inner most non-deflexed part.Inner mid limb.Then see what it tells me.
The deflex has plenty of movement in it still and the way the tips acted on the last bow and how quickly the upper limb developed that hinge I'm thinking the cherry is kinda running on the edge of giving up just about all the time.
I've got the reflexed part bending some and it feels like it'll hinge pretty easy if I try to get too much more bend in it too soon.
I dunno, I'm gonna err on the side of caution if at all possible. I sure do want this pece of wood to become a bow somethin' fierce!
Thanks for the help so far folks, more pics to come!
Chris
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Your long string is too long. You want it just as long as the bow, no longer. Adn even then, a long string makes the outer tips look stiffer than they really are. So you really want to work that mid-limb. As soon as you get a reasonably smooth bend to the equivalent of brace height, I would string it briefly and see what it really looks like.
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First pic is about 3 1/2" or 4" brace height.
Second one is drawn to 13" and 28#.
Right limb (upper) stiff in the inner third?
They both seem a little stiff on the inside to me.
Whattya all think?
I dunno what it is but taking a picture of it and seeing it on the computer sure seems to make it easier to spot problems.
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Look at the lines at the tips. The right limb is bending farther than the left. You need to get them bending the same distance. I would remove the wood from the area between the marks on the inner limb. (excluding fades) Justin
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So NOW that I got 'em bending mostly even I should worry about how far each limb is bending?
Justin if I take wood off both limbs won't they just keep bending the same distance ?How will removing wod from the areas you suggested change the distance the limb travels? I need to make that connection.
I saw the stiff spots you arrowed for me, so I guess I ain't as bad off as I'd thought! ;D
More Pics tomorrow.
Chris
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I would remove it only from the left limb until they are close. Or remove 5 scrapes from the right limb and 10 from the left. Did I ever mention EXERCISE THE LIMBS A LOT. Justin
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Well I did like ya said, :o Took some from the right and 2x some from the left. And exercised it a bunch 30 or more times after every wood removal. Heres what I've come to'
Its at 24"( from 4 1/2" brace height) and ~38-39 # Shootin for 50 or at least high 40's.
Left limb looks pretty good as far as I can see. the right one just got away from me somehow. I couldn't get the left limb to come around enough tomatch the right. Right limbwas 2" longer than te left so I cut off the nock ( about 5/8" ) and recutthe nocks hoping that would stiffen it up some and keep it from bending so far. Didn't seem to help a thing.
Is there a chance of getting 45# outta this thing? What do ya normally gain in the last few inches of draw, 2#/"
If I could get 8 more pounds in the last 4 " I'd be happy, that and even it up a bit.
This tillerin stuff is rough.
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How far apart are the lines on the tillering tree? Is that weight and the picture before or after you piked the bow 5/8". Do you specifically want the bow to have one limb longer than the other. I am quite sure you can get 6# in 4 inches. But the tiller needs fixed. Justin
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The lines are 1 1/2" apart. The weight/drawlength info and pic are after I shortened the upper limb.So what now.? Remove some on the left limb, mid limb area... try to get it looking more like the right one ,Right?
Does making the limb bend more in the middle make the limb tip travel more or less? Is it a matter of draw weight / limb or does where the limb bends affect how far the tip travels?
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At least its still in one piece, maybe I shouldn't say that probably cursed ya now. ;)
DanaM
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Chris,
take this with a grain of salt. I would take quite a bit off the inner limbs (relatively speaking). Then I would go ahead and take it to a 6" brace. Maybe draw it to 18" on the tree and see where your at. Weight goes fast with a reflex deflex. Thats why I like to floor tiller them, and then go right to a short string with a low brace. String em heavy.
Get the limbs bending smooth, then worry more about the way they bend with each other.
the limb on the left needs to move a little more near the handle. But first get a smooth bend in each limb so they look close.
You can see the transition area that I was telling you about. It can be a pain.
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43# @ 25"with a lil < 6" brace.Took some meat off the inner third of the left limb. Seemed to help even things up.
If I can get 5 more #s after final tiller and sanding I'll be one happy camper. ;D ;D I know the right limb is stiff right outside the fades but if I fix it it'll make ,... :o hey wait I want a little positive tiller right? The limbs are even ( measured from the belly to the string either side of the handle) so If I get just a leeeeeetle more bend in the right limb, inner third that'll weaken the limb a lil and give me a little positive tiller right?
EDIT;
Well looking at the pic again it didn't even it up quite as much as I'd thought.It did geta little more bend in the left limb mid section and the tips are closer to the same. Damn, these digital cameras don't lie!
I think we can pull it off guys. What would you do to it? I mean other than not let the limbs get uneven in the first place.
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Hold off just a little on the positive tiller there Chris. If one limb is longer than the other, the positive tiller isn't necessary. If your at 43#@25" your in pretty good shape. Take care of the stiff area. Then work the left limb to get it bending the same distance. Justin
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Lookin good Chris. Time to slow down even more. Careful now eh.
DanaM
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Chris
Inner limbs are not bending enough, especially just out from the fades. You can tell from the thickness that they are quite a bit thicker. You really should go a bit slower with your tillering.
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Well if ya gotta get scolded and told to slow down, ya might as well take it from someone that knows what they're talking about.
Thanks ,Marc. ;D
I'm just happy its still in one piece. I'm in" super slow , 3 or 4 scrapes, then exercise the bow" mode now. I didn't think I was going too fast but I guess ya don't know the proper speed til ya go slow enough to do it right.
I still have 69 1/4" of length if my weight comes in a little low. I'll get some dinner and scratch on it( and my head) a little this evening.
I appreciate all the help and advice ya'll have been giving me.
I'll post some more pics this evening.
Chris :)
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You want to leave the outer limbs alone for now including the outer red arrow. Work the inner limbs, where Matt has put a red arrow
Guess I should 've heeded Marc's advice . I can't seem to get the upper limb to bend in the fade at all.
Theres one thing that I haven't been able to figure out throughout this whole process, and I know I'm missing it and I still can;t figure it out. What makes the distance a limb tip travels different from one limb to the other? I mean on this bow the upper limb (Right) is longer than the lower limb and it was stiff in the fade area and the first third of the limb. Now even with the inner part of the limb being stiffer and therefore stronger than the other one it still traveled farther. I shortened the upper limb once more by about another 1/2" er so. Its around 68 1/4" long now.
Ok, I'll refine my question to save my poor typing : Does removing wood from a limb, anywhere on the limb, always make the tip move more? Can the portion of the limb that is bending cause the tip to move more or less .
If all the bend is in the middle third of one limb and its whip tillered on the other one which one will travel further or does it matter?
I went ahead and removed the scale from the tree so I wouldn't get hung up on draw weight , I know I've shot past where I wanna be. This has gone from looking reasonable to being a fiasco and I did it to myself
Well got more wood in the drying box after I'm done tearin this one up.
I'll try and get some pics up tomorrow of where I am with it. At least I can practice on it and get the tiller as right as I can even if it comes in at 20# . :'(
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The limb is only as strong as its weakest point. If you have a weak area, the limb will pull back farther, regardless of where the weak area is. When Marc said to slow down, he didn't mean you cant tiller a bow in a day. If you feel rushed to finish a bow, you will mess it up. If you start to feel that way, stop and breathe. Set the bow aside and take a breather. Sometimes I will put a bow on the tree and exercise it, take it off and walk away. I might come back later and do it again and again without ever removing any wood. When I do remove wood, I am in a nice relaxed state. If I am unsure, I will put it away again. Sometimes you can tiller a bow in a day, but most times it will take me 4 days. Justin
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Hey Chris. You should listen to Justin :o. If there is anyone that knows how to successfully build a wood bow, its him! ;D
Actually that is excellent advice. If your brain ain't into it or you're agrivated, best to put it down and walk away. Believe me! ;D Pat
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Yeah, thanks guys,. Pat ,I'm gonna hit 'im up for tillerin' skills at Pappy's place come saturday mornin'! You're gonna be there too right. I'll bring this bow along and another blank if I can get one glued up in time.
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Yeah, His skills ought to be at their apex come Saturday morning. ;) Pat
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I was kinda planning on introducing myself Friday evening and then looking him up come Saturday around lunch time er so. I dunno the way things are going I may not have anything ready for the trip. My hikree pile is rapidly becoming second rate stuff.
Maybe I can buy some backing at Pappy's
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I just went and dug through the pile of hickory at the hardwood store. I bought a 2"X7"X10' piece of hickory that is premium for backings. I am going to cut it all into backings. I will bring you a couple. Justin
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Justin, I bought a similar piece a few years back. I cut it into 2 pieces...one 6' the other 4'. The 6' piece I cut into backing strips and a few belly pieces and the 4' section I will eventually cut into backing strips. I cut mine to 3/16" thick. By the time you remove the saw marks it should be about 1/8" or a bit less. Pat
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I'm going to cheat Pat. I'm cutting it all into 3/16" pieces, then Ill take it over to my cabinet maker friends house and using his high dollar plainer to smooth them out and get them even thickness. Justin
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Well, I guess that will work. ::) Some of us don't have rich friends with lots of fancy tools. :'(
Do look out for swirls or irregular grain. The planer will tear them out sometimes. Pat
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I tried using it on bow laminations, but it chewed them up. This board has almost no grain run out and no knots in 8 feet. I will cut it 6' and cross grain. Then it should be no grain run out and do knots. :o The plainer should like that. As for rich friends. They are more like poor dumb working class guys, like me. Justin