Trad Gang
Main Boards => The Bowyer's Bench => Topic started by: razorback on February 24, 2009, 08:34:00 PM
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Well here is the first bow from the unidentified board that I have. The right limb is not bending as far as the left limb by about 1/2 inch at the tip but is bending a little more in the first 1/3rd of the limb. What do you think and where do you suggest I scrape to bring them even. i want to go to about a 4" brace and continue tillering but want it even first.
(http://i648.photobucket.com/albums/uu207/aussiearcher/DSCF0535.jpg)
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Go about 5 more notches with the long string before you go to low brace.
Bending looks fine. Let the stronger limb be the lower limb.
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Looks pretty good to be so far. I take my tips to about 8" of travel before I low brace it at 4".
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Ok I have been working slowly on this bow trying to get it right. Below are three pictures, the first is low brace, the second pulled to 15" and the third is pulled to 20". It is pulling 45# @ 21" and I am shooting for 50# @ 28". My draw is closer to 29" so what would this give me and how should I tiller that. Should I take it to 29" on the tiller stick and see what the poundage is.
1st. Low Brace:
(http://i648.photobucket.com/albums/uu207/aussiearcher/DSCF0541.jpg)
2nd. Low brace pulled to 15":
(http://i648.photobucket.com/albums/uu207/aussiearcher/DSCF0542.jpg)
3rd. Low brace pulled to 20"
(http://i648.photobucket.com/albums/uu207/aussiearcher/DSCF0545.jpg)
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I think it's looking great so far. The right limb is a little stronger than the left, so use it for your lower limb.
As for the drawweight, 45@21 so far is good. You have plenty of room to make your weight of 50@29.
What you have to do now is keep everything even as you remove weight. From now on, draw the bow to 50#. Never exceed 50# on the scale. It might be 50# at 23" right now. As long as it's still bending evenly, remove more wood and draw it to 50# again. This time it might be 50# at 25". Everytime you remove wood, exercise the limbs about 50 times.
Keep going slow like this until you get to 50# at 27". Once you get here, as long as the bow is still bending evenly, start rounding off your limbs and getting everything real smooth so you won't loose much more finishing it off.
Come back when you get that far.
One thing to always remember is to exercise after wood removal and don't draw the bow anymore than it takes to reveal a flaw in your tillering. As soon as you see something that you don't like, fix it ASAP.
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Thanks No-sage. At what point should I go to regular brace and start shooting it in. I have seen various ideas on this point.
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What I like to do is get the bow about 5 lbs heavy at my finished drawlength. Once I get it here, I like to give it some long stringing times at a regular brace height. I like to let it sit strung for an hour, then go 2 hours, then keep going up to 4 hours. This will usually work a bit of weight off it.
Then I shoot it in. I don't want to have to remove weight anymore once I start shooting it in. That's why I will have everything smooth already. I don't typically loose more than a pound during final sanding. What I'm really looking for is any tiller change. I'm ok with 5# too much or 5# too little, I'm not ok with a tiller that is off.
Once the tiller is good and remains stable, it's done for me, even if it's a bit heavy or light.
I like to shoot it in at least 500 times, little by little, keeping an eye on everything.
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what they're saying is good. looks to me like youve got a bit of a stiff spot at the inner to middle third of the right limb. i would take a few scrapes there, and excercise it well. this should even out your limbs too.
i would get it to your final brace as soon as you fix that. work it down to the draw weight your at now, then continue with the tillering. your very very close with your tiller so after getting it to final brace, and to 20 inches or so, i would shoot it in with at least 100 arrows (at 20"). then re check your tiller. if it hasnt changed, and your not picking up any strange set, continue to 25 inches and do the same.
at 25 inches, i like to let it sweat overnight and recheck everything.
this is just the way i like to do it, and its been working for me. if youve got a better way, then by all means go for it. just trying to help :)
Phil
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Ok. I have been trying to reduce weight and keep it even. In doing so I seem to have developed a slight hinge in the left limb near the tip. I think this has come from trying to leave the tip stiff and not removing wood from there. What do you guys think is the best solution for this. it also seems like this limbs bends more at the fade than the other limb. I like the bend of the other limb.
The limbs have been switched from the earlier photo's. Left is now right and vice versa.
Four inch brace
(http://i648.photobucket.com/albums/uu207/aussiearcher/DSCF0548.jpg)
21" draw
(http://i648.photobucket.com/albums/uu207/aussiearcher/DSCF0549.jpg)
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Your left limb needs to bend more now. Take it slow and easy. You can always take more off. It's real hard to put it back.
When you are trying to reduce weight take long swipes, the full working length of the limb with your scraper. If your belly is rounded a few swipes down the center of the crown will reduce weight the quickest. Take a few swipes, exercise the limbs and check tiller and weight again.
I also brace new bows for a while like No-sage. When I string my bow for a 3D shoot or to sit on stand, I want to know it will be the same at the end of that time period as when I started...or at least close.
You are coming along nicely. Take your time and keep up the good work.
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Watch that left limb. It's almost hinging 2/3 of the way down. Jawge
http://georgeandjoni.home.comcast.net/~georgeandjoni/
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The left hinge is the problem. I really like the look of the right. The left starts bending at teh fade more than the right and has that almost hinge towards the end. Any suggestions on how to fix both of these and get it looking more like the right. Left is still a little stronger so I have some towork with before I go to just weight reduction.
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Mark the areas that are bending too much and stay away from them while you remove more wood. The only way to repair a hinge is to remove the wood around it until the limb bends evenly...then remove the wood from the other limb until they are both even.
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Man, you are calling it a hinge but that's not a hinge. It's a bit stiff in the inner 2/3rd's of the left limb. Give that 10 scrapes at a time and bend it 30 times until they are even.
If you are taking weight off, go slow, 10 full length scrapes and then lots of exercise at a draw length that hits your target weight. Do that until you are at your target draw weight at your target draw length. You are doing great and will have a fine bow when you are done.
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I agree, it's not a hinge, it's normal progress.
Take a deep breath and read your signature line 3 times. ;)
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NO-Sage. LOL
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No not a hinge but almost. If it were my bow I would leave the last 8 inches alone and get additional draw length by working the inner 1/3 from the fades out. Jawge
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Thanks Jawge. I made the handle 4 1/2" so I have a little to work with there. I did some more work on the middle of the limb and seem to have it looking good now.
Last time I put it on the string the limb I was not wworking on seemed to loose about 1/2" of bend while the one I was working on gained 1/2", thus evening them up. Bend was very even. Is this normal for a limb to loose some bend even when not being worked. Will weakening the strong limb reduce some tension on the weaker limb?
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It's normal.
Everytime you waeken one limb the other gets stronger relative to the first limb. They both work together.
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Ok. I have this to 50# @27" with the string at a 6" brace. Limb on the left is the upper limb. They are bending fairly even with the lower being a little bit stronger. When shooting it has a lot of hand shock. From these photo's do you think it is too much mass in the tips, poor limb timing or something else, possibly both. What would be the solutions for these causes. I don't have specific arrows, or dampeners in the string yet.
Unbraced;
(http://i648.photobucket.com/albums/uu207/aussiearcher/DSCF0572.jpg)
braced;
(http://i648.photobucket.com/albums/uu207/aussiearcher/DSCF0573.jpg)
Drawn to 27";
(http://i648.photobucket.com/albums/uu207/aussiearcher/DSCF0574.jpg)
Limb Profile;
(http://i648.photobucket.com/albums/uu207/aussiearcher/DSCF0578.jpg)
Tip Width;
(http://i648.photobucket.com/albums/uu207/aussiearcher/DSCF0569.jpg)
Tip thickness;
(http://i648.photobucket.com/albums/uu207/aussiearcher/DSCF0577.jpg)
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You could narrow the tips a bit more. You didn't cut the string grooves across the back did you? If so, cut them off and re-cut only on the sides and belly. If you add overlays, you can cut across the back.
The braced and full draw look quite good. You have a little set but that is an acceptable amount.
By pulling your bow to full draw on the tree you should be able to see if the tips recover together.
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Thanks Pat.
No I didn't cut the string groves across the back, there is about 3/16-1/4" of back between the grooves.
When you say that the "tips recover together", what do you mean by that. I am using a tiller stick and thus have less vision of the bow bending. Am working on putting a tree together.
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You want both limb tips to go back to their starting point(at brace) at the same time and same rate of speed when you let down on them. This is limb timing. If one recovers before the other does or at a different rate, you will feel it as hand shock.
Get your tiller tree done. Your bow building will improve.
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Pat. I have the tiller tree done and checking the return of the limbs, the upper seems to return quicker and first. I hae put some wool in the string and reduced the tips some more but the hand shock is still there. How do I balance the limbs timing. Do I remove more from the slower/lower limb, which is also a little stronger than the upper limb. Or should I just finish this one call it good enough for a first bow and start another one.
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You might be able to remove a little physical weight without loosing too much draw weight by scraping the edges of that limb. This might be something you will have to play with so take a few scrapes off, exercise the limb and then see. If, after removing wood from the edges, you notice any extra set, stop.
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When you say edges are you referring to the sides or the outside portion of the belly, leaving the center untouched. And should I remove it from the whole limb or the tip area.
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That right limb looks stiff about 10" from the fades causing the end of the limb to bend much more. Does anyone else see this? Or am I wrong?
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Big Country I do see that.
Razor, Yes the sides. Side tillering is an option that not many folks use. Steve Gardner(Badger) wrote a chapter in the TBBIV about bow mass and that is how he removes some mass with little effect to draw weight.
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I think your left limb is a bit stiffer than the right. I'd giveit about 10 scrapes full length. I also see a couple tweaks in the right limb. Correct those and then check again.
(http://residents.bowhunting.net/sticknstring/ranger1.jpg)
Your tips are pretty big. I like to have them about 1/2" wide (side-to-side) for the last 6" of the limb. You could probably thin (back-to-belly) them a bit too.
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I have been working that stiff spot on the right limb pretty hard, (compared to the rest of the bow) and she just doesn't want to bend. I will keep working it slowly now and try to get it to give some more.
Pat, will also do some reduction of the sides for mass reduction.
Thanks guys, I appreciate the input.
Razor
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Work(exercise) the stiff part well after each wood removal and go slow with removing the wood. It can all of a sudden give and that can cause a hinge.
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Pat, when exercising I hold the bow and short draw it about fifty times rotating it so each limb does some work as top and bottom and also using both left and right hands. Is this a good way to do it or is it better to put it on the tree and use the rope. I am concerned that that section will all of a sudden give and I will end up with too weak a bow fixing it, therefore I am moving slow with it.
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I think you are better using the tree for exercising. You have better control over the distances you pull.
That stiff area might just have to be a stiff area in your finished bow. How does the bow shoot now? any less hand shock?
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Timing is improving and hand shock is diminishing. I am not so much worried about the stiff spot as the final feel when shootiing. Like you say wood is wood and we have to take what it gives us. Overall I am very happy with how it is turning out. Will have it sanded and finished in a couple of days and then will go back to that osage stave with all the cracks in it. Should have lots of questions for you on that one too. :bigsmyl:
Razor
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Bring it on!!! d;^)
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Well worked on it some more, got it looking good and improved timing. Did a bunch of sanding and got it nice and smooth. Spent some time shooting it in tonight and between sessions looked the bow over and found a splinter about 2" from the fade on the back of the lower limb. it is not a run out and I am going to superglue and wrap it with silk. Hopefully it will be ok as it was feeling good. Will post pictures later.
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Lookin' pretty good. Generally, you need more bending closer to the handle if you are aiming for more draw length. Otherwise, let the bow tell you as you draw it. If it is stacking up on you work that area close to the handles with a scraper. Jawge