Primitive Archer
Main Discussion Area => Bows => Topic started by: Carl Galvin on April 06, 2018, 11:54:17 am
-
Hello Everyone,
I was wondering how you more experienced bowyers have learned to approach the tiller near the fades, in order to get near the most even tiller on both limbs in that area. It seems that, due to the weight burden on the fade area while drawing, this area is the most susceptible to hinging errors. I have taken to using the gizmo but have read that it doesnt help with the area near the fades. Any advice is much appreciated! Thanks!
-
The gizmo needs 3 or more inches either side of the area it's checking to work correctly. Therefore the fades really can't be checked with it, you just have to resort to doing it by eye. The fades really don't bend much if at all, It's right out of the fades that starts bending, and yes it can develop into a hinge if you're not careful. One thing I've done is measure the distanced from the string to a section of the limb with a tape measure when the bow is braced.
-
Thanks gfugal!
-
I just hinged one right outside the fades last week, I ended up with a 42# bow instead of a 50# bow. I took it too far on floor tiller. This is one reason I like to go to the tree while it is still far to heavy.
-
Watch my Gizmo video where I explain tillering some this area.
I just added a comment to the video when a guy asked if he should remove wood from the bows back to get the fades moving.
Here is my comment;
All the wood removal during the tillering process is on the belly of the bow. I make almost all my bows out of osage and have chased one continuous growth ring from one end of the stave to the other. If I removed wood from the back of the bow I would violate this one ring on the back and could cause a break and subsequent limb failure. If the fades are bending you will see the gap widen between the board and the back of the bow. My tool of choice for careful wood removal in the fade out area is an orbital sander. If you use a scraper always pull it from the limb to the handle, if you go handle to limb you will have a tendency to dish out a place at the end of the fade and make a weak spot. You can go either way with an orbital sander and not make a weak spot or get the washboard like grain steps you get with a scraper.
-
I tend to get the middle of the bow moving slightly first (at full draw weight) and then get the rest of the limbs coming round (of course the outers are moving to some extent top start with... (it would be daft to have rigid limbs with only the middle moving).
Del
-
Most of my tillers are elliptical. I want the wood to start moving there and increase going outward.
I start immediately...right from floor tiller to accomplish that purpose. I mark the area where I want the bending to start with a heavy pencil line. Later and if need-be I work the area just beyond the fades while the stave is strung.
The best way to avoid hinging is for me to use a scraper and work slowly. No hurry. This is my hobby. Go slowly.
Jawge
-
Thanks you all, I appreciate it. Great invention by the way, Mr. Krewson!! And great video!
-
I tend to get the middle of the bow moving slightly first (at full draw weight) and then get the rest of the limbs coming round.
Del
I do it mostly like this, but I guess I'm daft...... ;D. Honestly, it has upped my averages both finishing bows without breaking them, and hitting weight, but it takes some experience (just a "feel", really) about how the bow is going to act based on length, species, design, width, and crown, etc.
I am usually drying staves pretty quickly, so have them roughed out to an approximate thickness (say, an inch) all along the limbs with a thicker handle. It's been clamped essentially straight, and it's roughed out to width.
I do a little floor tiller check just to see how MUCH too stiff it really is, and refine the thickness using a caliper all the way down the limbs. I start shaping the handle dips at the same time.
Once the thickness is very consistent (allowing for knots) I shape in the front profile to "outside of the line" and go to the consistent reduction method from the TBB. The method is to rough up the belly surface with a rasp, then use a scraper to remove ALL the rasp marks. Then I check for high spots or mistakes and do it again.
Next, I get the stave on the tree. Each rasp/scrape pass helps perfect the slope of the fades and removes a pound or two of draw weight. I may do a couple passes in a row at first. I check the bend on the tree, only the intended draw weight. Nothing moves at first. But, since the limbs are consistently thick and fades are shaped, I KNOW that the area right at the bottom of the fadeouts WILL bend first. Has to.
The instant I see any bend in those first few inches, I stop and catch the other limb up withe the same rasp and scrape routine. With both bending I get just a couple or three inches of tip movement, and the rest of the limb will look stiff and straight. I mark those bending areas (sometimes duct tape it) and don't touch until later. Then, I keep doing the same thing on the rest of the limb. The bend gradually sort of moves down the limb from middle to tips. As each section starts to bend, I stop rasping there and mark it, etc.. usually by the time I can get a string on, the limbs are mostly bending right and I just need to tweak them as I reduce weight and increase draw length.
-
I tend to get the middle of the bow moving slightly first (at full draw weight) and then get the rest of the limbs coming round.
Del
I do it mostly like this, but I guess I'm daft...... ;D. Honestly, it has upped my averages both finishing bows without breaking them, and hitting weight, but it takes some experience (just a "feel", really) about how the bow is going to act based on length, species, design, width, and crown, etc.
I am usually drying staves pretty quickly, so have them roughed out to an approximate thickness (say, an inch) all along the limbs with a thicker handle. It's been clamped essentially straight, and it's roughed out to width.
I do a little floor tiller check just to see how MUCH too stiff it really is, and refine the thickness using a caliper all the way down the limbs. I start shaping the handle dips at the same time.
Once the thickness is very consistent (allowing for knots) I shape in the front profile to "outside of the line" and go to the consistent reduction method from the TBB. The method is to rough up the belly surface with a rasp, then use a scraper to remove ALL the rasp marks. Then I check for high spots or mistakes and do it again.
Next, I get the stave on the tree. Each rasp/scrape pass helps perfect the slope of the fades and removes a pound or two of draw weight. I may do a couple passes in a row at first. I check the bend on the tree, only the intended draw weight. Nothing moves at first. But, since the limbs are consistently thick and fades are shaped, I KNOW that the area right at the bottom of the fadeouts WILL bend first. Has to.
The instant I see any bend in those first few inches, I stop and catch the other limb up withe the same rasp and scrape routine. With both bending I get just a couple or three inches of tip movement, and the rest of the limb will look stiff and straight. I mark those bending areas (sometimes duct tape it) and don't touch until later. Then, I keep doing the same thing on the rest of the limb. The bend gradually sort of moves down the limb from middle to tips. As each section starts to bend, I stop rasping there and mark it, etc.. usually by the time I can get a string on, the limbs are mostly bending right and I just need to tweak them as I reduce weight and increase draw length.
This is fascinating. That's a much more methodical approach compared to my "hack wherever is my best guess, then check for errors" haha.
-
That's what I used to do! I am NOT a methodical person. I have serious clinical ADD for a 47 year old man.
BUT, I began using this method to help young kids, and other new guys on their first bows, online. So many want to, but even with websites and build-alongs like Sam's and George's, it's easy to get crossed up. A lot of them don't have any experience with tools to speak of, and a lot of them don't have adult male figures in their lives to help them learn.
A lot of guys would love guidelines and dimensions they can work toward, but that's not how wood bows work best, right? So I was looking for ways to keep these guys from getting frustrated, failing (which can be the end of the world for a 14 year old, if you have no access to trees or bought the only good board you ever found with your birthday money). And this is the result. I came up with a good list of regimented METHODS rather than dimensions, to help guys get a decent crack at it. Some kids look at an inch thick board and their cheap rasp, and just don't know how to make it all work. It's daunting.
Doing it this way shows you progress, but keeps you from running ahead of yourself. My other favorite I preach is how to thickness taper limbs the same way, by dividing a limb into 4ths and doing the whole limb once, then the second, third, and tip section twice, the third and tip three times, and the tip four times. Then divide it into three sections and do it again.
-
Springbuck, that sounds like a good logical sequence to keep you on track. And come up with a nice finished bow!
Hawkdancer
-
Lotsa good stuff here, fellas. :OK
-
I tend to get the middle of the bow moving slightly first (at full draw weight) and then get the rest of the limbs coming round.
Del
I do it mostly like this, but I guess I'm daft...... ;D. Honestly, it has upped my averages both finishing bows without breaking them, and hitting weight, but it takes some experience (just a "feel", really) about how the bow is going to act based on length, species, design, width, and crown, etc.
I am usually drying staves pretty quickly, so have them roughed out to an approximate thickness (say, an inch) all along the limbs with a thicker handle. It's been clamped essentially straight, and it's roughed out to width.
I do a little floor tiller check just to see how MUCH too stiff it really is, and refine the thickness using a caliper all the way down the limbs. I start shaping the handle dips at the same time.
Once the thickness is very consistent (allowing for knots) I shape in the front profile to "outside of the line" and go to the consistent reduction method from the TBB. The method is to rough up the belly surface with a rasp, then use a scraper to remove ALL the rasp marks. Then I check for high spots or mistakes and do it again.
Next, I get the stave on the tree. Each rasp/scrape pass helps perfect the slope of the fades and removes a pound or two of draw weight. I may do a couple passes in a row at first. I check the bend on the tree, only the intended draw weight. Nothing moves at first. But, since the limbs are consistently thick and fades are shaped, I KNOW that the area right at the bottom of the fadeouts WILL bend first. Has to.
The instant I see any bend in those first few inches, I stop and catch the other limb up withe the same rasp and scrape routine. With both bending I get just a couple or three inches of tip movement, and the rest of the limb will look stiff and straight. I mark those bending areas (sometimes duct tape it) and don't touch until later. Then, I keep doing the same thing on the rest of the limb. The bend gradually sort of moves down the limb from middle to tips. As each section starts to bend, I stop rasping there and mark it, etc.. usually by the time I can get a string on, the limbs are mostly bending right and I just need to tweak them as I reduce weight and increase draw length.
That pretty much describes how I normally do it. Once in a while I get a head of myself but I try not to. I never let the desired draw weight dictate what the bow will finish at. I would much rather have a good shooting 42# with no set than a poor shooting 50#. I do all my tillering right from the beginning at full draw weight. I find I am much less likely to run into surprises.
-
Great information here. Thanks to all of the more experienced bowyers for sharing their knowledge. As I've stated before the hardest part of building a good bow (for me anyway) is the tillering process. My eyes just need to get more educated.
-
Steve, some of us have that artist eye for tiller and some don't. I have never had a real accurate eye so I have found other ways to compensate. Going slow is the most important tool. Taking measurements and mainly just make sure your limbs are smoothly transitioning without dips.
-
Carl....I usually in my own shop do like Badger and Springbuck & like George as he mentioned getting it to bend more as it goes to the tip with eliptical tillers most times.Can do it just making a fat 3/8" tapered line along the edge too but getting it to the short string will take longer that way but with same result.Getting both limbs to bend evenly matched wise as soon as possible.I like to leave it very slightly higher in the center of the limb length wise or slightly crowned and then remove material chasing my draw weight.If need be you can draw a line right down the center of the limb length wise to affirm this.With most woods I like a flat belly on a AFB.Then remove material overall evenly slowly with a rasp rasping away pencil marks/scraping away file marks/and I like using 6" block of 2" by 4" with an appropriate grit on it for the density of the wood stroking it the whole length of limb.This completely eliminates any dips or waves.You can feel it with your finger tips also easily.Not a real critical thing at first with no extreme bending and with a wood like osage but with other not so tolerant woods it is important to stay away from stressing any portion of the working limb.The fades need to be the thickest and widest area of your working limb letting it slowly get thinner as it goes outward avoiding hinges this way.
That's why doing as many different types of woods helps with your patience and tillering skills.Then moving on to try more difficult designs.Key word as always is to do all of this slowly.If you feel pressed for time slow down!!!
-
Badger: "I never let the desired draw weight dictate what the bow will finish at." This is a really good point. Experience helps me look at this or that stave and say, "I can get a low 40's flatbow out of this" and I use the TBB width guidelines and go wider if I can on whitewoods, etc.
But, sometimes I'm wrong. Sometime you have to shorten the stave. Sometimes the wood just feels weaker than it should be, sometimes the knot is worse than you thought. If I'm taking any set noticeable set by brace height or a tad higher, I "manage my expectations" down a bit. If I'm taking none by 22" on the tree, I start to make a longer stiff tip, or narrow the limbs a bit depending on design.
-
you pose an interesting question about how to work the fades... I hope that more tillering gurus chime in on how they do this.
:OK
-
The fades are really an important area. When I talk about limb timing I am not talking about the timing of the two limbs. I am talking about how the limb unfolds. I feel the biggest cause of handshock is too much bend in and just outside the fades. If the fade and inner limb is bending too much the entire limb will slam home all at one time creating a shock wave. If the limb kind of unfold as you release the arrow with the inner limb hitting home first and the outer limb hitting home last you won't feel any shock.
At the same time we often need that wood to bend so we can make full draw without taking too much set. This is where proper design comes in, just make the bow wide enough where you can afford to tiller it properly.
-
I think this deserves a bump- all I have been doing to work the fades is sitting a 1x1x18" piece of wood inside the strap that holds my bow when tillering. The stick sits on the back of the bow grip/fade inner limb area. When I pull the string you can easily see the amount of movement in the fades. It's kind of amazing just how much it moves sometimes...
-
The old timers called it too round in the handle type tillering will produce hand shock.Which means exactly what Steve and Bob are talking about.
-
Springbuck this is the same approach I use. I feel this allows for The ease of stiff tips and you can transition in to the major work area without dealing with an incline both ways so the whole limb scrapes pull smoothly everytime. It just feels natural to me