Primitive Archer
Main Discussion Area => Bows => Topic started by: Ink on September 09, 2013, 07:02:42 pm
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Got an issue on a bow here. The right limb is staying stiff at a couple of pins. However I need it to look like the left limb. The problem is that everytime we try to take off wood on the stiff area that limb starts to bend way more than the other. Got about 4 more inches to go on the tillering tree, and plenty of draw weight to play with. Any good suggestions on how to go about getting these two limbs bending better?
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just dont scrape as much, take 10 scrapes then check it, scrape 10 more, then check it.
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Take some rough sand paper on a sanding block and do 10 strokes(down and back) across the limb. Do that until done.
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Make the right match the left and nevermind the pins, they will bend.
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Make the right match the left and nevermind the pins, they will bend.
+2 on that one.
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Sounds like a plan, off to the tillering tree
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Take it off the tree, put and arrow on the string 1/2" above center, pull the bow 20" or so and look at tiller in the mirror or take pics, then judge it.
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To me your inner two thirds of the right limb needs some reduction.Your in the ball park but you ai'nt sat down yet.Minor bit of adjustmentyou got there.Go slow at this time like what was said.
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Is the right limb longer?
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Make the right match the left and nevermind the pins, they will bend.
+1
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I would stay completely off the right fade. It looks to be bending there more than the left. Start taking wood off that limb 8 inches or so past the fade. I think that's why it's bending more without shaping up like the left.
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The limbs are identical lengths
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I would stay completely off the right fade. It looks to be bending there more than the left. Start taking wood off that limb 8 inches or so past the fade. I think that's why it's bending more without shaping up like the left.
I think you just hit the nail on the head there slimbob. So what I'm gathering from everyone is stay away from the right fade and go slow working on that stiff area. I'll post a pic after me and my friend get it adjusted. Thanks everyone
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That's what I'm seeing. Is the unbraced profile straight? If it's a bit deflexed there at the fade it would only appear to be bending more there, but isn't.
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The right limb definitely needs some scrapes from midlimb outward.
You'll want to make sure that at brace, both limb tips are equal distance from the lines drawn on the wall. It's hard to say without seeing a brace picture, but it looks as though it's sitting cockeyed on the tiller tree (looks like the right fade is closer to the lines on the wall than the left fade). You may have to shim up one side of the handle while tillering. I use sandpaper, folded up into as many layers as it takes. Those lines on the wall don't mean squat if the bow isn't lined up proper to begin with :) As you get the tiller better on the right limb, you will have to do even scrapes the entire length of the left limb to keep it coming around with the right. Once you get them both bending nicely, determine which limb is stronger, and use that as your bottom limb.
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Golden rule - never pull it further than you need to see a mistake!!!!
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Quit scraping that right limb, and heat treat the left one. It will force the right one to bend more. Then slowly ( as noted on your bow above the tree ) remove maybe 15 scrapes at a time taking pics often. You will get it.
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I wouldn't recommend heat treating just one limb. I don't think that is the way to correct this problem. You need to remove wood from the right limb until it matches the left.
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I wouldn't recommend heat treating just one limb. I don't think that is the way to correct this problem. You need to remove wood from the right limb until it matches the left.
No question about it. Heat treating one limb WILL come back and bite you a 1000 shots later.
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Your bow is a good example of uneven tiller. It will have a shorter life, it will have increased handshock due to the uneven tiller, and it will not balance well in your hand.
Fixing it is not hard. You only have to make both limbs bend the same. You have to match the limbs to the weaker one now. You should try and keep your tiller even throughout the process, and stop pulling the limbs further until you do. What will happen now is... you'll lose draw weight by having to even your tiller.
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The heat treat road is not the road I'd take.My saddle[where handle sits] on my tillering tree is slanted too.Could fix it but just put a spacer of some kind to even things up.The ending procedure of your bow was explained to a tee by Camaroo.But even still the way this bow sits there you can see the right limb is stiffer.Just balance it and be done with it.Use a tillering gizmo if you got to.
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Thanks for all the input everyone... this is actually a bow that Ink is helping me make and since the first picture was posted I've taken some the the advice above and worked on the right limb. I've taken another picture with the "progress", and now that I'm looking at it on a computer, it seems to me that I need to just keep slowly working that right limb. Here it is below: (link: http://imgur.com/LrGrVI1 if the pic embed doesn't work)
(http://imgur.com/LrGrVI1)
Another thing that has developed is that when unbraced, the left limb reflexes a bit from the plane of the back of the handle while the lower limb is in the same place. It makes it look as it the limbs have taken uneven set and I believe it is a part of the problem with the tiller. Any ideas as to how this can happen?
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I'm not sure if I understand exactly which limb is doing what, but one limb will definitely take on more set if it is doing the majority of the work. From the pic you just posted, you can clearly see that the left limb is bending much more than the right. This should have been dealt with before even attempting to draw the bow as far as it is in that picture.
As Mike stated above - Never draw a bow back farther than what is required to see a problem. Also never pull harder than your intended final draw weight.
These are two mantras that should be burned into any bowyer's mind.
Keep scraping that right limb to get it bending. You are going to lose draw weight, but at this point just consider it a lesson for your next one :) Learning how to evenly tiller a bow is much more important than making weight!
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Thats the longest 8hr bow build i have ever seen!! You been hangin with Jason way too much. Lol >:D
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adb gave you some well heeded advice above. Your tiller at this stage should be much closer than you have it. It's fixable. In the future, I would recommend getting a string on it at low brace, 2-3 inches. Straighten out the tiller. Pull it a few inches, check and straighten out the tiller. Pull it a few inches farther, check and fix the tiller. You may only be at 7-8 inches or so at this point, but your tiller will be very close. Go to full brace when you can, pull it a few inches, check and fix the tiller. Continue to repeat in small measures until she's done. In addition to avoiding the tiller problems you have now at full draw (way late in the game) you will also eliminate the concern of losing a lot of poundage and coming in under weight as you correct the problems. Something your fighting now.
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Lots of good advice has been offered. The only thing I would add is that, in the future, employ the little four inch block or tillering gizmo along the belly and do more looking and checking and less pulling and scraping. It's easy to get in a hurry and mess up a good thing. I am guilty of getting in the habit of mindless scraping and rasping. Lately, I tiller by only scraping where I have marked when I see a problem area on a limb. In reducing weight on a bow that is pulling evenly already - I try to match the number of scrapes, strokes with the rasp, or passes down the belt sander for each limb. Good luck with your bow.