Trad Gang
Main Boards => The Bowyer's Bench => Topic started by: Bryan Adolphe on August 26, 2023, 11:04:18 AM
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So this set of t/d limbs I come in 3/4 of a pound over expected, but my limb balance is off a bit, my lower limb is slightly strong when drawn to 28” What is the best way to move that lower limb without losing draw weight? Limbs are 1/8 pos. Thanks guys. B
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if you are an 1/8" strong. (shorter tiller measurement) on that bottom limb i wouldn't worry too much about it unless you are getting a buzz. quite often guys do that on purpose, and claim they are tillering for 3 under.... How does it shoot? any buzz or had shock?
there really isn't a way to adjust that without loosing a bit of draw weight. but an 1/8'' isn't much... might loose a couple pounds at most sanding glass or trapping the belly.
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Thanks Kirk I have not shaped the riser yet. I just had it up on the tree bending it and at 28 “ my lower limb tip doesn’t catch up to my upper limb tip by about a 1/2” . So I thought I would fix that before shaping the rest of my riser, but I really didn’t want to lose any weight. I’ll go ahead and finish shaping the riser and shoot it. 👍👍
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i thought you said it was only an 1/8" positive tiller measurement????? How do you get 1/2" difference?
There is another way to adjust it if you absolutely cannot loose draw weight. You can add an overlay on your limb butts and slightly increase the preload on the weak limb by sanding it on an angle. To figure out how much you need, and ....if it will work......try adding a 1/16"-3/32" thick shim to the end of your riser pad. That will tell you the story... Kirk
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Hey Kirk, it’s an 1/8 positive when I measure at brace from the end of the wedge fades to the string, but when the Bow is on the tree and I draw to 28” it shows on the graph on the wall that the lower limb tip is behind the upper limb tip by a half an inch at full draw so in my head, the limbs aren’t equally balanced during the draw cycle ? which means they wouldn’t return to Brace at the same time is that true? My tree is set up so that I draw 1 inch high from centre if I draw from centre both limbs draw equally, but if I pull from where I would normally draw approximately 1 inch high, the lower limb is behind the upper limb. Hope this makes sense. Maybe I’m over thinking this, but I want to figure this out the right way. :goldtooth: I appreciate your input :thumbsup:
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I always go negative tiller 1/8" to 3/16"
If you are pushing from center of bow and pulling above that, top limb stronger.
Split finger--You can go even tiller with the center of your middle finger/RED to the deep part of the grip being the same distance from the centerline/broken line of the riser.
(https://i.imgur.com/h2GvzWZ.jpg)
People tell me my bows hit where they are aiming.
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Hey Kirk, it’s an 1/8 positive when I measure at brace from the end of the wedge fades to the string, but when the Bow is on the tree and I draw to 28” it shows on the graph on the wall that the lower limb tip is behind the upper limb tip by a half an inch at full draw so in my head, the limbs aren’t equally balanced during the draw cycle ? which means they wouldn’t return to Brace at the same time is that true? My tree is set up so that I draw 1 inch high from centre if I draw from centre both limbs draw equally, but if I pull from where I would normally draw approximately 1 inch high, the lower limb is behind the upper limb. Hope this makes sense. Maybe I’m over thinking this, but I want to figure this out the right way. :goldtooth: I appreciate your input :thumbsup:
limb timing and balancing is something that is done by getting your limbs bending the same top and bottom. string the bow and trace the back of the limbs on a piece of butcher paper. then flip the bow 180 degrees and compare the top and bottom. balance the limbs on the tiller tree with a single hook at dead center. you can also build a fingers hook 2.5" in width . put it on the tiller tree and check "where" the limbs are bending bot top and bottom limb.
What you are describing measuring the tips at full draw with an off center pulling point and adjusting it equally is not going to give you the results you want... it's what happens when you drop the string that matters.....bring them in to close to even tiller, then do your fine tuning as you shoot the bow to get the buzz out of it.... Kirk
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OK :banghead: for some reason I had in my head that because I shoot split finger and draw the bow off-center that I needed to balance those limbs which was really throwing me off , thank you guys for making me understand ,I very much appreciate it. I couldnt figure all this out without your help. 🙏🏻 :thumbsup: B
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Great topic to be up, Im working on a bow and im at the point where im measuring for any positive or negative tiller. The grip is dead center on the bow and the shelf is 1 1/4" from center. I was measuring a dead even tiller at brace measuring out to several equidistant points on the limbs. I shoot three under, am i clear to move on or should i be looking to induce some aspect of positive or negative tiller? thanks
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Great topic to be up, Im working on a bow and im at the point where im measuring for any positive or negative tiller. The grip is dead center on the bow and the shelf is 1 1/4" from center. I was measuring a dead even tiller at brace measuring out to several equidistant points on the limbs. I shoot three under, am i clear to move on or should i be looking to induce some aspect of positive or negative tiller? thanks
well I’m not one to be giving anyone advice quite yet. I’m still getting a feel for it all myself, so hopefully someone else chimes in for you, but if you’re sitting at even Tiller right now, I think a good bet would be to shoot it see how it feels / sounds . :archer2:
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Great topic to be up, Im working on a bow and im at the point where im measuring for any positive or negative tiller. The grip is dead center on the bow and the shelf is 1 1/4" from center. I was measuring a dead even tiller at brace measuring out to several equidistant points on the limbs. I shoot three under, am i clear to move on or should i be looking to induce some aspect of positive or negative tiller? thanks
just follow the past advice from Kirk and Mad Max and I’d say you’re good
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Great topic to be up, Im working on a bow and im at the point where im measuring for any positive or negative tiller. The grip is dead center on the bow and the shelf is 1 1/4" from center. I was measuring a dead even tiller at brace measuring out to several equidistant points on the limbs. I shoot three under, am i clear to move on or should i be looking to induce some aspect of positive or negative tiller? thanks
I have a couple questions for you…. Why on earth are you pushing your shelf height up to 1.25” above center? Is this a recurve or long bow?
I cut most of my shelves out at about 7/8” above center , and have some long bows that I go down to 3/4” . The closer you have that shelf to center, the less the cant of the bow effects windage. Shooting right off your knuckles you can cant that bow 90 degrees in either direction and still be on target if your arrows are tuned properly….. I’m just curious why so high? Kirk
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My shelf's are 1" and some 3/4"
Tiller is a topic with mixed answers.
Tiller/limb balance I believe is like kirk said, after you release the string, a high speed video may help but I don't think it's needed.
If it shoots good and hits where you want it, call it done. :thumbsup:
Let others shoot it also
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Kirk there are a few posts on here discussing arrow shelf placement and a lot of folks use somewhere between 1" and 1.25", I also am using a set of plans and when I measured the plans, which are to size, it seemed like the shelf was 1.25" above the bow center. I also filed a radius on the shelf back to belly which thinking now probably puts the shelf closer to 1 inch above center after working the handle section down. It's a deflex/reflex longbow.
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I was just curious.... there are a lot of guys that like a lower shelf that use an elevated weather rest so they can shoot vanes instead of feathers in the rain. A lot of target archers use an elevated rest and use a fixed crawl, or are string walkers. This allows the fingers to be placed closer to the bows center and eliminate the tiller adjustment needs.
I've known a lot of bowyers that tinkered with different length limbs, and trying to tiller a bow to an off center hand placement. A lot of the old school bowyers went down that rabbit hole ... Bottom line is it creates excessive hand shock doing that... period... the more hand shock you have, the more wasted energy is staying in the limbs instead of being transferred to the arrow shaft... food for thought... Kirk
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Keep feeding brother! I'll take any information and use it for progress whether it helps my process or let's me see why I would or wouldn't choose to do something. I understand what you're saying with shelf placement and will begin to play around in the 3/4 to one inch.
Get this, in some original binghams plans one of their longbow models called for shelf 2 inches above center, read that anecdotally so don't quote me.
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Kirk I am so far down that rabbit hole I am going to need a backhoe ot get out. I think the next one will be 3/4" .
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Get this, in some original binghams plans one of their longbow models called for shelf 2 inches above center, read that anecdotally so don't quote me.
I think Bingams Recurve and Long bow were based on 50's bows.
Damon Howitt bows have a higher shelf also, they were trying to stay in the current archery Tournaments.
They were making all kinds of arrow rest back then above the cut in shelf.
This is a old spitfire bow from Groves archery.
It was broke in half, so I glued it back together using the arrow rest bolt HOLE to pull it together.
Only 25#@28"
(https://i.imgur.com/UGgsTOJ.jpg)
(https://i.imgur.com/MIY68SW.jpg)
(https://i.imgur.com/XzttTqg.jpg)
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That’s what is so fun about building these things is that their is so much philosophy and so many rabbit holes to explore. :biglaugh: When you come up with something you think is original….. it’s most likely been done before.
When it’s all said and done, you have your finished bow, and compare it to the last one you built, you may or may not see or feel the difference and need to test it to see if there were any gains…. When other people shoot your bows, some will love it, some won’t, but very few could actually tell the difference between them.
When you finally get what you feel is the perfect combination, and a customer says, “I would like my bow tillered for 3 under”…. What do you do?
I have the perfect solution myself, but am curious what other bowyers do when this request is made. Kirk
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Kirk I do not sell them. So the only person I have got to keep happy is me.
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Get this, in some original binghams plans one of their longbow models called for shelf 2 inches above center, read that anecdotally so don't quote me.
Certainly true of the ASL designs. Using the typical ASL/"Hill" design it's near impossible to place the shelf any less than two inches above center.
Some of these older style bows have the bottom limb piked by an inch or more. That would place the shelf closer to center but I wonder what it would do to limb timing even if tillerd to zero pos and neg? And that may not have been the bowyer's intent. Maybe just an extreme response to a major mismatch in lams?
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Not all ASL or Hill style bows are created equally. I noticed a few of the builders that specialize in them finally came around to using power lams to push the working portion out further on the limbs which takes a lot of the kick out of that design…..I’m not sure where they locate their shelves on that design. I don’t go there myself…
but I can see using a higher shelf height on a bow when heeling down on a straight grip and putting more pressure on the lower limb. Makes sense… Kirk
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Yeah, I've been using power lams on mine lately. Picks up the performance by about 7 or 8 percent and prevents set.
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Yeah, I've been using power lams on mine lately. Picks up the performance by about 7 or 8 percent and prevents set.
I don’t build ASL bows per say, but I have one form that has a lot of reflex that comes out looking exactly like an ASL when strung. I use an 18” riser tip to tip of fades and a 30” double ended power lam for 62”-66” bow lengths with 8” tip wedges. I drop down to 6” tip wedges on the 62” length.
The sad part is… these things have no hand shock at all, and are 25% more efficient that your typical ASL , and HH crowd won’t even look at em after the string comes off. And when they shot the bows they said , there wasn’t any thump to them and they shot the arrows too fast…. :dunno: :dunno: :dunno:
I never could sell those things for some reason… that HH group is a tuff crowd to cater too.
Btw…. That shelf is 3/4”-1” above center on that design. Kirk
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Kirk. How fast taper did you use on that bow?
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Kirk. How fast taper did you use on that bow?
I used a pair of .002 tapers with a total of .004. the power lams were .125'' thick with a 10" flat spot in the center and tapered to the tips in 10" each direction. So the taper rate for the power lam was .0125 to the fades. Bow center to fade tips on each end was 15". here is the form i use.
Dont pay no attention to that osage stave laying on top of it... i've been working on that off and on since i built that form in 2011. :biglaugh: One of these days / years i need to finish that thing.
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