Post by: Honest Jon on January 03, 2025, 05:51:41 PM
Jon
Post by: WhistlingBadger on January 03, 2025, 08:41:18 PM
Post by: Mo_coon-catcher on January 03, 2025, 09:45:23 PM
Kyle
Post by: Pat B on January 03, 2025, 10:26:14 PM
Post by: willi on January 04, 2025, 07:34:29 PM
Quote
what do you use as the fulcrum point in the handle section of the bow.
not anything that has so much contact that the bow cannot be free to tip side to side and not anything so pointy that the bow is hard to keep from tipping erratically
a soft leather or cork pad about an inch wide? (placement as per mo-coons advice)
I also have a small loop of string a couple of inches long that I can hitch to the tillering string that serves as a place to hook my pullrope. the hitched loop can slide on the tiller string with effort, but does not move without effort.
Post by: Mo_coon-catcher on January 05, 2025, 09:47:34 AM
Kyle
Post by: Pat B on January 05, 2025, 10:57:44 AM
Post by: WhistlingBadger on January 05, 2025, 12:30:46 PM
His picture shows well how I attach the bow to the tree. I use a loop of rope and a caribiner to clip to the scale.
Kyle
Interesting setup, Kyle. It's almost the opposite of mine, which supports the bow with a wooden stand underneath and has the scale on the pull rope. I might like your way better. You have me thinking...
Post by: Mo_coon-catcher on January 05, 2025, 01:53:35 PM
Kyle
Post by: Kirkll on January 05, 2025, 10:04:01 PM
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but i use the rounded piece for shaped risers.
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When i built my tiller tree it was years ago when i was doing a lot of prototype work and running DFC charts on the different designs. So i kind of went off the deep end here and built a section below the bow mount with a track and put a light in it... if you look real close you can see the holes in the black plastic that are spaced exactly 1 inch apart. There is another hole in the string hook block that the light shines through as you crank the bow down . that hook is shaped like fingers would hold the string.
here is the whole set up.
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I mounted a boat wench on a wood pedestal and use a pulley at the bottom. I can use this with tje bracket hook, or just clip it to the string with a carbiner.
Post by: Bowjunkie on January 08, 2025, 05:27:44 PM
That precise spot can be found with a few measurements taken from the edge of the bow cradle/handle/shelf location to locate the nock on the string(I set my arrow 1/8" above perpendicular to the shelf), then from there measure the thickness of the arrow nock, half the width of your middle finger, or whatever your deal is. Take your time and make sure this is all as accurate as possible. Then at that spot, your actual string fulcrum, draw a vertical plumb line on the wall under the tree to articulate perfect fulcrum travel straight down the wall.
If a bow's limbs are balanced relative to your hold on the string, the hook will follow the line down the wall exactly. If one limb is acting stronger than the other, relative to your hold, the hook will drift toward the stronger limb. It's easy to see just a tiny imbalance. Weaken it until the hook follows the line. When the hook follows the line to full draw, you're done. Balanced bow. You'll love how it shoots.
If you want to find exactly where the bow hand fulcrum is or attempt to move it one way or the other, you can set the bow up to pivot at the handle. I have this capability, and like to play with it, but honestly it's not necessary. The above method works great and makes for a fine shooting bow every time.
I've never tillered a bow by drawing from the center of the handle or center of the bow because it never made sense to me to tiller the bow while drawing the string from one spot, only to shoot it while drawing it from somewhere else.
Post by: Stagmitis on January 08, 2025, 08:12:28 PM
Post by: Bowjunkie on January 09, 2025, 03:12:05 AM
If you understand that, and the line/balance method, hopefully you can see how it wouldn't matter if you supported that flat grip with a 2-3/4" flat cradle or a full 4" flat cradle to hold it. You're going to get the same feedback from the bow and tillering tree, and get the same final result in limb balance.
Make sure your handle area(not necessarily bow tips) is level in the tree cradle, your string fulcrum location accurately represents the center of your pressure on the string, and the line on the wall that represents its perpendicular movement down and away from the handle is plumb. Good to go.
Post by: WhistlingBadger on January 09, 2025, 09:10:42 AM
Post by: Mo_coon-catcher on January 09, 2025, 09:21:09 AM
Kyle
Post by: Stagmitis on January 10, 2025, 08:48:18 AM
Moon-catcher, slo mo videos are a great tool to witness what the eye cant:)
Post by: Mo_coon-catcher on January 10, 2025, 11:04:22 AM
Kyle
Post by: Roy from Pa on January 13, 2025, 07:27:14 AM
Post by: willi on January 14, 2025, 01:30:05 AM
..... Then at that spot, your actual string fulcrum, draw a vertical plumb line on the wall under the tree to articulate perfect fulcrum travel straight down the wall.
should the pulley at the floor be aligned with this drawn line?
Post by: Roy from Pa on January 14, 2025, 08:42:29 AM
Post by: Roy from Pa on January 14, 2025, 08:48:50 AM
Post by: Roy from Pa on January 14, 2025, 08:50:28 AM
Post by: willi on January 14, 2025, 01:14:29 PM
Yes.
thanks Roy, so unless your pulley and line is easily movable, "find the string fulcrum and draw a line" could be better stated as "adjust the seating of the bow handle such that the string fulcrum is directly above the line and pully" ?
Post by: Roy from Pa on January 14, 2025, 02:36:59 PM
Post by: willi on January 14, 2025, 02:46:58 PM
Yes, my lower pulley is adjustable. I just slide it left or right then lock it down.
is it neccesary that the bow sits perpendicular to the line?
Post by: Roy from Pa on January 14, 2025, 05:24:41 PM
Post by: Bowjunkie on January 15, 2025, 03:08:13 AM
Yes, that would work just as well.
I have a lower pulley set up like Roy's, except mine has four pullies on it, so I can draw the bow as a split finger shooter or 3 under shooter, whether the top limb is facing right or left, all without moving a pulley. Being able to flip the bow around helps to verify that you have your tree setup properly as well as verify what the bow is doing, what you're seeing, and deal with some natural selfbow stave irregularities. With multiple pullies, I can change string position in 2 seconds.
Post by: Stagmitis on January 15, 2025, 11:36:16 AM
https://www.amazon.com/gp/product/B09JS83DDT/ref=ox_sc_act_title_3?smid=AR88GRBHPCMHU&th=1
Bowjunkie and Roy- This is how I plan to set my tree up. Comments?
Post by: Stagmitis on January 15, 2025, 11:49:15 AM
Post by: Roy from Pa on January 15, 2025, 03:16:55 PM
I ground a thin 2 inch flat spot on the lower pulley shaft so I could slide the pulley where I wanted it, then lock it down with the set screw..
Post by: Bowjunkie on January 15, 2025, 03:31:53 PM
Post by: Stagmitis on January 15, 2025, 05:06:51 PM
Post by: Stagmitis on January 15, 2025, 05:07:35 PM
Post by: Stagmitis on January 15, 2025, 05:08:56 PM
Post by: Stagmitis on January 15, 2025, 05:11:05 PM
Post by: Honest Jon on January 15, 2025, 05:40:17 PM
Honest Jon
Post by: Roy from Pa on January 16, 2025, 01:05:49 PM
Ya need me to come down and shoot it in for ya?:)
Post by: Stagmitis on January 16, 2025, 01:29:33 PM
Post by: onetone on January 16, 2025, 04:13:52 PM
Post by: Stagmitis on January 18, 2025, 08:01:19 AM
Post by: Roy from Pa on January 18, 2025, 08:56:11 AM
Post by: onetone on January 18, 2025, 11:07:53 AM
Post by: Stagmitis on January 18, 2025, 12:47:14 PM
Post by: Kidder on January 18, 2025, 05:59:20 PM
However, I’m a big believer in finishing tillering (the last couple inches) by drawing in hand and photographing it. There are aspects that you can’t see necessarily but you can feel and I find that helpful.
Post by: Bowjunkie on January 19, 2025, 06:48:56 AM
BUT, I've found those inserts almost entirely unnecessary. When I balance bows as described earlier, they balance perfectly during and up to full draw, and shoot an arrow dead straight away from the nock point location on the string that I originally intended, from the very first arrow.
When the bow is done on the tree, it's dynamically balanced, it feels finely balanced in the hand each and every time, no additional adjustment/tuning/corrections needed. The pictures I've taken at full draw revealed that balance. All I have to concern myself with after the bow is done is arrow spine. Work moves straightforward toward that first arrow launched, no backtracking, no guesswork, bows are inherently tuned. Nothing to fix, no discrepancies to try to overcome by moving nock point location, etc. This is the main benefit to tillering with focus on dynamic balance... it's the quickest & easiest, consistently reliable way to a balanced bow that I've found.
Post by: Stagmitis on January 21, 2025, 05:25:30 PM
Post by: Kirkll on January 22, 2025, 10:23:52 AM
Bowjunkie Ive seen you post the nock height that you tiller at before...... 1/8" above 90Deg and nock above? This has always puzzled me since my knock point is higher :bigsmyl:
Your exact arrow knock location will vary from one archer to the next depending on where the pressure is applied to the grip, and your finger placement on the string. Balancing the limbs has a huge effect on hand shock and overall performance of the bow, but string knock location and arrow flight is dependent on set up.
With that being said…. There is a huge difference between tillering a self bow, and tillering a composite backed bow.
Post by: Bowjunkie on January 24, 2025, 07:02:59 AM
Ultimately the arrow may be a wee bit less than 1/8 above perpendicular when everything is considered... arrow taper, arrow diameter vs arrow nock thickness, etc, but I'm fine with that.
Kirk, I balance limb strength in glass bows the same way I do with wooden bows. Due to the materials used, there's a difference between selfbows and glass bows in construction methods when it comes to 'tillering' the limbs for even flex or the curve wanted, but the physics is the same, and my practice in achieving dynamic balance is the same. I balance glass bows the same way as selfbows, boo backed, sinew backed, all of em. All nock points are set at the same place, then I balance the limbs as closely as I can relative to the archer. I mostly make bows for myself, but when I've made them for others, I collect as much pertinent info about their shooting idioms as possible and design and build the bow accordingly, and they've remarked on the shooting characteristics that come with such balance and appreciated not having to make adjustments to nock point height. There should be no need for that if we collaborated well and I do my part.
Post by: Kirkll on January 25, 2025, 02:27:55 PM
Stag, just to be clear, when I say that, I mean the back end of the arrow is raised 1/8" above perpendicular, and that would be measuring from the shelf to the bottom of the arrow nock(not the nocking point on the string). Assuming the arrow nock is 1/4" thick, which mine are, the bottom edge of the actual nocking point on the string is then 3/8" above perpendicular to the shelf.
Ultimately the arrow may be a wee bit less than 1/8 above perpendicular when everything is considered... arrow taper, arrow diameter vs arrow nock thickness, etc, but I'm fine with that.
Kirk, I balance limb strength in glass bows the same way I do with wooden bows. Due to the materials used, there's a difference between selfbows and glass bows in construction methods when it comes to 'tillering' the limbs for even flex or the curve wanted, but the physics is the same, and my practice in achieving dynamic balance is the same. I balance glass bows the same way as selfbows, boo backed, sinew backed, all of em. All nock points are set at the same place, then I balance the limbs as closely as I can relative to the archer. I mostly make bows for myself, but when I've made them for others, I collect as much pertinent info about their shooting idioms as possible and design and build the bow accordingly, and they've remarked on the shooting characteristics that come with such balance and appreciated not having to make adjustments to nock point height. There should be no need for that if we collaborated well and I do my part.
You are absolutely right about limb balance and the "tiller" being the same with self bows and glass bows. Only the tillering process is dramatically different. Most of your bow tiller adjustments in a composite bow is determined by your taper rates and wedge configurations in the limbs, and controlled by consistency in mill work and laying them up the same without anything shifting in the core. If everything is accurate, and your limb width profiles are the same, it's just a matter of sanding glass to balance things out, and maybe a little limb trapping.......
But.... i'd be willing to bet that 90% of the bowyers out there don't actually "tiller" a composite bow at all... they sand the glass to an even "Tiller Measurement" or 1/8" positive for 3 under, and just call it good.... There is a difference between adjusting the limbs to a set tiller measurement, and actually tillering the bow and balancing the limbs.
Now if something shifts slightly during lay up, things can get a bit more interesting trying to get things balanced and have the limbs bending the same. Kirk
Post by: Roy from Pa on January 26, 2025, 06:53:18 AM
Exactly, Kirk...
Post by: Bowjunkie on January 26, 2025, 07:46:15 AM
Post by: Kirkll on January 26, 2025, 11:00:50 AM
I agree that's what many do, set the brace height according to conventional 'wisdom', like 1/4" positive for split finger is a common practice... with many selfbow makers too unfortunately. It makes it quicker and easier for the bowyer... but doesn't result in the best bow.
I’m curious where you came up with 1/4” positive tiller measurements is common practice for a split finger shooting application? You called that “conventional wisdom” ? Or was that tongue in cheek?
Btw…. There is a big difference between a seasoned bowyer, and someone that has just built a lot of bows. The season self bowyers that learn to manipulate natural materials and get longevity from their creations are what I would consider the masters in this trade. They understand how these things work a lot better than most glass bowyers do….. But…. It’s just too much heart break for me to indulge that much time and energy into myself. My hat is off to you masters out there.
Kirk
Post by: Bowjunkie on January 26, 2025, 12:46:44 PM
Post by: Kirkll on January 26, 2025, 02:04:27 PM
But ......there are a lot of bowyers that truely want to build a better product out there. But how many of them that are willing to take the time and effort to actually do it are few and far between. It takes experience to get there. The knowledge i've accumulated has taken many years building a lot of different limb designs and documenting test results, materials used, and detailed lay up data in my log book. If i can share a few tips here and there to get the new bowyers off on the right track, i'm all in... Kirk
Post by: Honest Jon on January 28, 2025, 01:17:34 PM
Post by: Kirkll on January 28, 2025, 08:14:59 PM
Post by: Honest Jon on January 28, 2025, 09:02:42 PM
Post by: Kirkll on January 29, 2025, 12:53:23 PM
That baby’s wrapped in oil tan leather.
:thumbsup: :thumbsup: :thumbsup: :thumbsup:
Post by: Stagmitis on January 30, 2025, 09:43:05 AM
Post by: Roy from Pa on January 31, 2025, 05:48:47 AM
Post by: Stagmitis on January 31, 2025, 01:28:05 PM
Post by: Bowjunkie on January 31, 2025, 02:59:54 PM
Post by: Stagmitis on February 01, 2025, 12:51:30 PM
Post by: Kirkll on February 01, 2025, 01:23:16 PM
https://www.amazon.com/Pullies-Loading-Material-Handling-Project/dp/B09XDLWH2S/ref=sr_1_9?crid=W0EN5VGW0RZ6&dib=eyJ2IjoiMSJ9.Iny1n07ZrBEykCvTqwGFMmsp5qftMSeupZJoyJfXNh8Px1bDQ8N8ITCGvr6bkAd3cdwboSzNG5PV9dHFCBIt8I6wSvWpUepGshMaooXlOGjGOHpTBQy7vBFONPYPNybaulz1vTmrSs0Nz0itb8enntEsuB7_Smfqk3IZajqO9mtAYsEVRwHmakLJn8RKA2WumdFJdygQq1tuh-_pY0ZAxm5ZdUwSMjmKciu2un6HPjw.2R_86FLaOZerRhH1sKxuk9SxBx5NZ-aZj8L5GWz64Lo&dib_tag=se&keywords=pulleys&qid=1738434088&sprefix=pulleys%2Caps%2C177&sr=8-9&th=1
https://www.amazon.com/SHINICO-Stainless-Bearing-Equipment-Clothesline/dp/B092TC62BW/ref=sr_1_8?crid=W0EN5VGW0RZ6&dib=eyJ2IjoiMSJ9.Iny1n07ZrBEykCvTqwGFMmsp5qftMSeupZJoyJfXNh8Px1bDQ8N8ITCGvr6bkAd3cdwboSzNG5PV9dHFCBIt8I6wSvWpUepGshMaooXlOGjGOHpTBQy7vBFONPYPNybaulz1vTmrSs0Nz0itb8enntEsuB7_Smfqk3IZajqO9mtAYsEVRwHmakLJn8RKA2WumdFJdygQq1tuh-_pY0ZAxm5ZdUwSMjmKciu2un6HPjw.2R_86FLaOZerRhH1sKxuk9SxBx5NZ-aZj8L5GWz64Lo&dib_tag=se&keywords=pulleys&qid=1738434088&sprefix=pulleys%2Caps%2C177&sr=8-8&th=1
Post by: Stagmitis on February 01, 2025, 02:03:37 PM
Post by: Roy from Pa on February 01, 2025, 04:47:51 PM
Post by: Kirkll on February 01, 2025, 10:20:41 PM
But.... i suppose that doesn't apply to guys that are heeling down on their flat shaped bow grips and gripping the the bow hard enough to choke a chicken with a bent arm so it doesn't rattle their teeth loose shooting it.
But you are right... You self bowyers are the masters...
Post by: Roy from Pa on February 02, 2025, 07:10:26 AM
Post by: Stagmitis on April 04, 2025, 01:09:16 PM
Question ? Regardless of the fulcrum point established by the fingers at full draw at the moment of release and when the string stops released isn’t a “vee” formed in the string and all pressure shifts straight through the nock?
Post by: Roy from Pa on April 05, 2025, 12:00:09 PM
When tillering for equal limb timing, the tiller is just whatever it is when limbs are balanced.
Post by: dbeaver on April 05, 2025, 04:23:49 PM
Post by: Kirkll on April 05, 2025, 04:36:14 PM
My very first glueup i mixed up a lam stack from one set of plans with the curves of another set and was never able to get a string on it. I just started messing around with it this year after years of it sitting and staring at me had to narrow the limbs quite a bit to get it down to 60 pounds and in doing so i developed a half inch of negative tiller. These limbs are scary narrow from 1 inch at the fades to 3/8ths nocks and tracking perfectly down the center of the limbs. That all said i decided to shoot it quite a bit before moving forward and its really extreme but this 1/2" negative tiller has reliably cast the flattest arrow trajectory on a range of different weight and spined arrows. This is just anecdotal and wasnt on purpose but it has gotten me thinking.
Those ones that come in real heavy and are trimmed down skinny as a whip will always be fast. As far as tiller goes….
1/2” difference in tiller measurement says nothing of the limbs actually being tillered. Have you mapped the limbs to see if they are bending in the same spots?
Post by: dbeaver on April 05, 2025, 05:19:11 PM
Post by: Kirkll on April 05, 2025, 07:29:09 PM
Most guys building recurves build them much wider than they need to be, thinking it’s needed for stability. Kirk
Post by: Stagmitis on April 07, 2025, 12:05:51 PM
Post by: Roy from Pa on April 07, 2025, 02:01:51 PM
Post by: Jon Lipovac on April 08, 2025, 11:22:37 AM
Post by: Stagmitis on April 08, 2025, 01:23:48 PM
What I’m struggling to understand is this. At the moment of release all pressure shifts from wherever the pressure is initially exerted in the string to the “nock”.
So what is the significance of straight line travel at the fulcrum point?
Post by: dbeaver on April 08, 2025, 01:42:59 PM
I tried to convince myself the string does more than go flat to new string angle at the nock as your fingers release but this slow mo vid points to what stag is saying
Post by: Kirkll on April 08, 2025, 02:46:04 PM
Quote
So what is the significance of straight line travel at the fulcrum point?
I honestly don't believe there is any significance. The limbs timing, tiller, and balance as that string comes comes forward back to brace height, and what happens to those limbs after Elvis has left the building is more significant.
Post by: Jon Lipovac on April 08, 2025, 03:44:31 PM
Maybe you can tiller some from the arrow nock and some from the finger fulcrum and see which methed produces the best and most consistant results.
I personally have always tillered to brace measurements and on occasian mapped a set of limbs, but never as Bowjunkie has described. This is the way I was told to do it when I learned a few years ago.
Trying this way of tillering on the next one.
Post by: Roy from Pa on April 10, 2025, 06:21:24 AM
That indicates the limbs are bending in sync.
Quiet smooth shooting bow.
Post by: Stagmitis on April 10, 2025, 08:14:08 AM
I think it would be easier with equal limbed bows compared to mine that are 1.5 shorter lower limb. Typically they are 1/4" positive when first strung. Thats a ton of work to get the limb to go in the opposite direction :)
Post by: dbeaver on April 10, 2025, 08:30:44 AM
This is also provided you don't have a grip on the bow that will affect which limb gets more bend. I saw a photo in one of G.Fred Asbell books where the grip position was changed between two photos of the same bow and in one of the photos the lower limb bends about a 1/3rd more from hand placement.
Post by: Roy from Pa on April 10, 2025, 11:19:05 AM
Quote
This is also provided you don't have a grip on the bow that will affect which limb gets more bend. I saw a photo in one of G.Fred Asbell books where the grip position was changed between two photos of the same bow and in one of the photos the lower limb bends about a 1/3rd more from hand placement.
Modify message
That is possible on any bow, changing from a high to low grip changes the torque applied to either top or lower limb.