how can i save performance

[Loren Holland]

i recently finished a red oak board bow for my twleve year old. it is 62" tip to tip, 60" ntn. I glued on an 8" riser (because i figured it would give me more working limb than the 10 I usually do, and his hand would be smaller anyways). it is 2 1/2" wide at the fades, with staight taper to 1/2" tips (way overbuilt for sure, but i have had several bloody noses and wanted to make sure that being this short and unbacked it stayed in one piece).  here is the problem...i was shooting for 40 lbs at 25 inches. I left it a bit heavy because i always seem to lose 2-3 lbs shooting one in and another couple on the sanding.  i was very pleased with myself, until we went out to shoot, and i realized he couldn't shoot the 40ish lbs i had succeeded in hitting. so i tillered down few passes at a time, exercised it, let him shoot it, until we got to a point that he could shoot without straining too much to affect accuracy.  I am sure you all can see what happened.  Now it shoots like a dog because it is just as if i had been overstressing it during tillering. Originally the set was at about 1.5", but now its 2.5 or embarrassingly more.   What can be done? heat temper, add a hickory backing, reflex.  I know they seem like overkill for a simple board bow, but i hate to waste it ( it was the straightest grain board i have ever seen).  If i take any width off, it will reduce limb mass, but wouldn't that eventually add even more set?  thanks for listening, i know ya'll have been doing this a lot longer than I, and can tell me how to fix a newbie mistake

[John Scifres]

Usually when you reduce a bow substantially, you are removing set wood and it actually helps in that regard.  I don't know why yours set more at a lighter weight with the same width.  I suspect it just got broken in after shooting it more.  Hard tellin'.

You have options for correcting the cast but the set is probably there to stay.  

I'd narrow the tips a lot.  You can probably shorten it too.  I make my osage kid's bows 48-50" and generally get 20# at 20" without any problems and 1-2" of set.

Red oak will definitely set more than other woods in general.  2.5" isn't bad.  Every red oak bow I have made has set 2-3".

It might just be easier to start over.  I'd not back it since i have not had good luck backing red oak, especially as a bandaid.

Heat tempering can work to correct set sometimes.  Toast the belly only and get it really hot without scorching.  It should change colors some but not burn.  Go slow and clamp it into reflex (no more than 2") until it cools.  See what happens.

Goood luck.

[Loren Holland]

thanks John, i made this extra wide, because i wanted 40 pounds and no backing.  TBB says you can trade width for length (within reason) to avoid set.  I was real careful tillering, never pulling over a few pounds over 40 ( you have to leave a few pounds to be erased when you shoot in and sand).  i think what happened was i introduced the set of a 40 pound bow, and then redueced to low 30s in wieght, but i alredy introduced the set.  I know that i can gain speed from reducing limb mass, particularly the tips (like you said).  I didn't know that when you take more off you are removing set wood, good to know.  i am just worried that  by reducing the width i will weaken it to reintroduce the same set or break.  i know you said you go shorter successfully, but the problem is my twelve yr old is pulling back 25 inches not 20.  i will try heating the belly like you said, i need to  make another trip to harbor freight anyways.  if that doesn't work i may try my hand at my first recurve.

that brings up another question, i have made couple of hickory backed bows ( glued with TB3) and thought of recurving them afterwards.  Can you? or does it have to be that way from the start, so you don't delam the backing?

[dutchwarbow]

make the next bow longer. You need a perfect tiller if you want little set on such a short-stiff handled bow.

2 1/2" wide at the fades isn't really wide for a pyramid bow, not even for a 67" version.

If you want to recurve your hickory-backed bows, you should either glue on siyahs, or delaminete your bow, recurve it, and glue it back together. Steam or heat will definately ruin your glue.

Nick

[Art B]

I think you should have re-established a new back profile to accomodate the lower weight instead of just removing wood from the belly. Lower weight bows would need less width but still enough limb thickness to maintain a good tension/compression ratio. I think you may have lost to much compression value which resulted in additional set.

You could go ahead and reduce the bow's width more suitable for the weight and then back it to bring the compression back up. Add in a little reflex as you do so for a little more performance. ART

[bubby]

go with the shorter bow with a bendy handle, and try a hickory, ah or a white oak board. i've had lots of luck with all of them, but if the bow get's to long, it could get unweldy for a 12 year old

[bubby]

that should read hickory, ash or white oak

[Loren Holland]

Nick- everytime i look at an eastern bow it makes me wish i knew a thing about how to glue on siyahs...what proportions and shape, length, how to insure you get the right string angle, do you need different glue

Art-I wish i had thought about tillering from the back, it makes perfect sense (its not like you have to worry about violating rings on a board bow).  Now about the compression ratio, i understand the idea of maybe changing the nuetral plane, but don't really know how to manipulate it

bubby- i am going to have to try a bend in the handle bow, i guess i am so afraid of handshock i keep putting off that design.  i also am going to have to try white oak, TBB listed it as having interlocking fibers like hickory but with lighter SG.

[Art B]

Loran, I wasn't talking about tillering from the back of the bow. I was referring to reshaping your pyramid design from the present 2 1/2" down to perhaps an 1 1/2" width, which in my opinion, would be more appropricate for the lesser weight. You need to have a certain amout of limb thickness to resist bending. Take a sheet of paper for example, being wide but thin, it has no compression value. Removing belly wood from a wide limbed bow to reduce draw weight has the same effect. ART

[John Scifres]

Tillering from the back will work on edge grain.  But will kill a plain sawn board quickly.

Short, bendy handled bows have almost no handshock, assuming you know to minimize mass in the last third or so of the limbs.  I would not make an osage bendy longer than 60" and 1" or maybe a touch wider.

I agree with Art on the width issues now that he explained it to my feeble mind.

Play

[Loren Holland]

Art-now i get what you were saying and that makes sense.  I need a better understanding of dimensions for different woods.  I was going off of 66" being an arbitrary start for 28" of pull. i took off 2" length for every 1" of pull, wanting a 25 inch draw.  I was unsure if this should be a tip to tip length or ntn lenth so i made it 62 inches ttt and shortened the handle to 8 inches to give me even more working limb. my reasoning was it would be easier to reach the target draw length, given my novice tillering. i went that wide because i thought that red oak was not a premium bow wood, and since i was wanting to finally make an unbacked bow ( i try to add a new feature, or tackle a new challenge every couple of bows), i thought you had to add enough width to overcome back ring violations because it was board.    i guess dropping from 40 to 30 pounds lessened the need for width.

without taking the art out of all wood bows (no offense the guys making glass bows, i just got my first kit from binghams and i'm gonna give it a try too) is there any chart of dimensions out there for given bow woods for variations in pull and draw length

[John Scifres]

If you are one for reading, I highly recommend Trad Bowyer's Bible V. I for a lot of the info you seek.

In general, for a rigid-handled, straight-limbed selfbow, I make whitewood bows 68-70" long and between 1.75" and 2" wide for half the limb tapering to 1/2" tips.  

Osage is 62-64" long and 1-1/4" to 1-1/2" wide, with 50# being the dividing line between widths.

These are relatively safe dimensions for average wood.

[George Tsoukalas]

Essentially, you confused the heck out of the bow. It didn't know what you wanted it to be. You kept shifting the neutral plane on it. I just finished a red oak board bow for a 14 year older. He's my Cumbaro's son.      It's about 1 3/8 in wide and bends in the handle. It's 35# and is quick set is around an inch. The bow is his height. No glued on handles. Forget them. They don't need them and they are more work for you. Most of my board bows have been way under 2 in for set but I never made many handle bows. Waste of time to me. More on my site. Jawge
 http://georgeandjoni.home.comcast.net/~georgeandjoni/

[David Holt]

Loren, I second what John said about the TBBV.  It has a great chapter on heat treating wood.  I've only made pyramid bows so far and my little brother wanted me to make him a bow so I decided to make a D bow using the instructions in Tim Bakers chapter on building your first Bow.  I finished the bow in a day.  It was well on its way to becoming 64" long 1 3/8 wide @fades 50# bow but it cracked a a swirl in the grain about 7 in from the tip.  I fixed that with epoxy and a wrap.  It's now 30# @ 26" and shoots faster than my heavier pyramid bows.  AND IT ONLY WEIGHS 16OZ!!  

[David Holt]

I mean 12oz.  I also backed it with brown paper...for S&Gs....

[Loren Holland]

I appreciate all ya'lls input.  I am reading volume 1 (got the set for Christmas) of TBB, and thats where i got the start point of 66. I am trying to learn from looking at build-a-longs, listening to ya'll, reading, etc.  I need to learn to post some pictures, my last bow was hickory backed oak that turned out well beyond my expectations.  68" tip to tip, 10" handle, 2" at fade to 1/2" tip, straight taper.  it ended up 45 pounds at 27 inches, no stack, no hand shock, shot well and seemed fast. (i don't have a chrono to tell for real, but after shooting my Bear 48, it didn't seem that much slower.)  After giving that one to a buddy, i wanted to keep getting better and had not successfully made anything unbacked. maybe i tried to combine too many features, i wanted unbacked, but relatively short ( and close to center shot, so my son could double up on using his wheelie bow arrows)  Thats how i ended up making this one.  Its not a bad bow, but i guess you can't have everyone give you a pleasant surprise.  Well, i am going to try and heat treat it.  I'll let you know how it turns out. In the mean time, i am learning from you guys, in particular i am rethinking layout dimensions for future bows. i can't say enough about how much i appreciate this site and all of the sharing of your knowledge. thanks