Designing the ultimate wooden bow......

[the Ferret]

Stan an excellent design for ash is 4" handle 2" fades, 1 3/4" wide at fades to mid limb tapering to 1/2" tips 68" ntn flat belly (actually this is a good design for nearly any white wood.)Ash makes a pretty bow, the feathering on the belly and dips is awesome and it takes a stain well. I know you shoot in the mid 40's @ 28" and that is very doable in that design.

[Shaun]

I wish this thread would finish up with a statistical consensus so I can build one. With only 2 completed I can't add much for opinions, but I'm ready to try making the universal bow that is being discribed here.

[RB]

Just so that I am on the right learning track here....is it safe to say that the composite specs that Mickey compiled from your posts...more 'performance' built rather than the classic 'overbuilt' (for durability & performance)? I am asking this after seeing many specifying their width to 1/3 of limb rather than to mid-limb (or just past). Or have many of you learned an ideal compromise between durably-overbuilt, and durably-high performance?

Is 'full width to one-third' a feature that best be used on only osage rather than whitewood bows? Just trying to learn about this :-)

[Glasspoint]

Lots to take in here    !

FWIW, here's mine

50# elm, 66" NTN, from a 3" dia. max slightly snakey sapling. Center 1/3- 1 1/2" mol wide tapering to 1/4" nocks, semi rigid handle with a hand placement indicator and a wiggle at the arrow pass to help with paradox.

Flat belly, rawhide and sinew wrap-on nocks, air backing, no handle wrap, finished with parafin or Watco oil and furniture wax. Give it an inch or so of set and string'er up with one of Calvin's flemish strings.

Critiques?.......Please?

[the Ferret]

RB the full to 1/3 is new to me too but from what John was sayingon page 2 I believe, makes some sense to have extra wood working where you need it most to prevent cast robbing follow, from fade to 1st 3rd of the limb and then less out on the end where you need it least in the last 2/3's. Sort of a straight taper from the fade with a litle support in the 1st 1/3 of the limb. I think your description could be very accurate being more "performance' built than "over built".  Every design is a compromise in some areas over the ideal design, and the ideal design depends on what you are trying to accomplish. If you want rock solid reliability at the expense of some performance you overbuilt, if you want performance above all you build to the edge and give up some reliability. I hope John et al come back on and chime in.

Shaun I think it was back on page 4 that i ran the statistical numbers on the ideal bow for this group, and although a few have added their numbers since then, they were in line with the others enough not to alter the "average". Here it is:

Osage, 64" ntn, rigid 4" handle, 1 1/2" fades, full width for 1/3 of the working limb length then tapering to the tip, even length limbs, slightly rounded belly, unbacked, with a leather glued up rest and some kind of bone overlays on the tips. It would have a more or less straight profile, be sealed with true-oil,have a leather handle covering and a flemish string. String material was interestingly split evenly between dacron and a ff type material.

Glasspoint nothing wrong with your design that I see other than 1 1/2" wide might be a little skinny for elm with a semi rigid handle. If it was a D bow, bend thru the handle I think the 1 1/2" would be good with a slight 1/4" narrowing at the handle for your arrow pass. The flat belly would be a good idea on such a high crown sapling.

[John Scifres]

Someone PMed me the following question.   I'm posting it here because I think it belongs:

 

Could you or someone you know well make some translations to hickory? I don't have any osage and would like make a good hickory one. I didn't want to ask on the thread 'cause it seems that you pro's should be doing all the talking on there. I don't understand the latitude a builder has for fade lengths and one third or midlimb on the tapers.
 

Hickory is fairly variable in its density so you must judge it (usually subjectively) first. Heavy wood just feels heavier than lighter wood. Let the wood speak to you  If you want to play it safe, make it at least 1.75" wide for half the limb, tapering to 1/2" nocks. Make it 70" total length. Make your handle 4" and your fades 2".

The concept behind the latitude a bowyer has is that each piece and type of wood is different. A bowyer must judge it if he wants to live close to the margin between a bow being as efficient as possible and a bow being broken. If you are new, just follow the overbuilt design above. As you learn more about woods, you can start pushing the envelope.

As for the variability in carrying full width to different parts of the limb, that is aimed at putting the most wood where it does the most good. Again, the balance thing. If you put more wood where the bow limb is doing the most work, set is minimized and efficiency is maximized.

The bow I specified in the thread is overbuilt by maybe 10% for average osage but I was told to make it be the bow I am going to shoot for 5 years. I don't want it to break. There are much more efficient, yet less safe, design that I would use if I were designing a bow for speed.

John

[John Scifres]

RB,

Overall length of bow makes a difference too.  For a 68" or less bow, carrying the length to 1/3 for osage is not a marginal design, it is somewhat overbuilt.  

Thinking in terms of pushing the envelope, a very fast design is the Holmegard.  Look at this article   Holmegard article  which kinda shows you some of the ideas in the extreme.  While this one is overbuilt some, this design can really push the envelope, especially on lighter woods.

Glasspoint, I made an elm 2" wide and it still took more set than I like.  I'd go wider.

[the Ferret]

Here's a good rule of thumb for working with woods you are not familiar with. Start with an overbuilt design as in the board bow instructions on John's website. 68" ntn 1 3/4" wide at fade carried to mid limb tapering to 1/2" tips 4" rigid handle and 2" fades. If you build a bow of this design and it takes little set but is doggy and slow with poor cast you'll know it is overbuilt and the wood can take more. Build the next one a little shorter and a little narrower. Say 66" ntn and 1 5/8" wide. Again look at set, and cast. If it can take more, go shorter and narrower 64" and 1 1/2" wide.

We know from experience that whitewoods generally require a minimum of 68" and 1 3/4 wide for efficiencey (the exception being some of the hickories)

Because of the density and strength in both tension and compression an osage bow built to those dimensions would take little set but would be doggy and have poor cast so we go smaller looking for the optimum combo which it seems most of the bowyers have agreed on as being 64" and 1 3/8" wide.

Length of handle and fades are often personal design choices but the longer the handle and fade the less working limb you have and vice versa the extremes being a 10" non working section in a 5" handle and 2 1/2" fades vs a complete working section in a D bow or bend thru the handle bow. The more wood you have working the less wood you need which is why a d bow could be 60" long or less where a bow with a stiff handle section might need 68" or more.

We generally figure 2 X draw length for working wood  PLUS a little safety margin of say 10%. SO in a D bow if you have a 28" draw that would be 2x28=56 +5" for safety = 61". In a rigid handled bow with an 8" non bending section that would be 2X28=56 + 5" for safety + 8" of non bending wood = 69" for a 28" draw. Because of osage's toughness you could fudge these numbers a bit to the low side and because whitewood isn't as tough you'd want to fudge these numbers a bit to the high side.

[StephenR]

I have a Hickory bow started that is 66" long and 2" at the fade,2" at mid limb and then tapers to 1/2" tips.I was told the handle is too long.What is normal 4" handle and 2" for each fade,8" overall???

Stephen

[the Ferret]

Stephen that would be very average. You almost need 4" for a handle to fit your hand in there (Scifres and Hackbow both said they use a 3 1/2" handle but everyone else said 4") so the only option is fade length. Most opt for either 1 1/2" or 2" fades for 7-8" of non bending wood overall.

I don't know who told you your handle was too long, but I would disagree with them. I think it's just about right in a rigid handled design.

[John Scifres]

The part of my hand that grips the bow is about 3.25".  The fleshy part is maybe 3/4" over that but it doesn't do any real work holding the bow.  I'd call my hands average size.  You know what they say about guys with big hands, don't you?

[John Scifres]

They wear big gloves.

[Hackbow]

Hey....I wear big gloves!

Seriously my hand is 4.25" across at that point, but I prefer to grip the bow with just the first two (sometimes three) fingers wrapped around the handle along with the base of the thumb. That's how I manage to use a smaller, rigid handle area. That, in addition to my shorter fades, effectively increases the length of the working limbs. I do usually achieve the higher end of average set (1-1/2 to 2"), but that seems to add a measure of shootability to an otherwise short bow. I just don't like really long bows, so I'm looking for the ways that will keep them under 62" and be pleasurable to shoot.

[the Ferret]

Good point John and Darren about the fleshy part of the hand not doing any work (ok I ran down and measured across my hand, just under 3 1/2"). I too use the "Mims grip" (a thumb and 2 finger med high grip with a pinky or two extended)and could probably get away with a 3 1/2" handle area but you know those "suitcase grip purists" would never get their hands in there ha ha

Wow now look I'm going to have to build another bow completely out of my comfort zone...3 1/2" rigid handle, 1 1/2" fades, full width for 1/3 of the working limb.

Ok have a question on that gentlemen. Are you counting the working limb from end of handle to tip, end of handle to nock slot, end of fade to tip, end of fade to nock slot? Not that it's going to make a whole lot of difference, but just for definition sake.

[Hackbow]

Mickey....I try to get the limb moving somewhere IN the fade. I like the thought of having the movement end in a transitional area vs. an abrupt point. Theoretically, that makes it seem like a softer landing for the limb. That, combined with the set I get and a heavy arrow gives me an very smooth shooting bow for the length.

I try to leave the last 1-1/2" or so a *little* stiff making the limb tips just a hair thicker than the previous part of the limb, while still tapering the width down. It's similar to introducing another fade, but not nearly as drastic as a Holmegaard or Meare Heathe, or whichever one has the double fade and long, stiff limb tips. This does take a tiny bit away from the working limb and is one of the contributing factors to the set, but I believe that's where I gain a little performance back. Most of these results are still conjecture as I haven't built that many bows, but I like the ones that I've done like this.

Oh, and I don't make many exact measurements, so most of this is guessing. After floor tillering, I just faithfully go back and forth between tree and scale as I pull the excess off. I think I started using this basic design because I cut too deep with a draw knife once and just made adjustments as I went. I certainly didn't plan it to come out that way.  

[tom sawyer]

I call working limb, from fade to tip.  But I only get things working to within an inch of the fade.  Although you guys are giving me other ideas.

[tom sawyer]

Darren you have a Catch-22 with a short bow.  You need to make the tips a little stiffer to help with string angle and prevent stacking, but you're already dealing with a minimal amount of working limb.  Thats where a static tip design helps.

[Hackbow]

Lennie, I've got the perfect stave set aside for the sole purpose of making a performance static. I'll be VERY careful with that one and the measurments.

[RB]

Few more questions:
1. The majority state that they prefer a rigid handle, which is about an 8" non-working portion, and this preference is coupled with a length that is on average, 64" which is 'fudging' quite a bit (~ 5 ") below the ~69" guidelines [@28"] that are published in many references. So here are two parameters that coupled together are reducing the amount of working bow by about a foot.

When this is considered with the prevalent concept that a bendy handle or semi-bendy handle provides *more* working wood...., what has (recently?) been learned about osage design that permits this seeming contradiction of maximizing the amount of working bow? Yet it sure sounds convincing that this design has been optimized by the one-two punch of a (a) powerhouse 1/3rd working portion and (b) the arrow flipping, light weight pyramidal 2/3rds outer limb and narrow tips.

2.Is the preference for rigid handles related only to reducing felt handshock? What else? Because to a novice (me! :-)it seems that the surrender of a foot of length just to lower handshock is 'pinching' the limits in a way that seems less elegant than simply letting the bow bend more along it's length and using a cushioned handle. Help me out with this. Maybe the answer to this is in the first question :-)

3.. Back to the One-third working limb: How is this design tillered? Is the 1/3 portion tillered elliptical and the remaing 2/3's tillerd just like a Pyramid design - circular (except the tips)? If so, why doesn't the outer 2/3rds take more set, since it's bending more and has much less width? I haven't studied this bow anywhere; could someone post some pictures of one at full draw?

4.. I noticed that most of you guys whipped out the 1/3rd working limb pretty fast as if it's a pretty common design, yet Mickey and Lennie find it interesting...or *new* to them (which made me feel better...). How new is it? And who gets the credit for first using it? I think Scifres noted that these composite specs made it a Torges bow, but is this 'one-third limb' a Torges attribute?

I'm asking way too many novice questions...; sorry. Just tackle what you feel like. As you can tell, it's still muddy to me...but mighty interesting!  :-)

[the Ferret]

Roy, you are like a sponge for knowledge...I love that. Not sure I can answer them all but I'll tackle what I feel I can.

(1) Most guys prefer hunting with a shorter, thinner bow, a by product of our culture where 56" bows are now called longbows.

they also prefer a rigid handled bow for 2 reasons IMO (a) smoother shooting (b) it's more like the glass bows they were shooting before going to self bows

osage is so tough in tension and compression that it will let you get away with that 5" fudge factor you were speaking of whereas a red oak like your first bow would either take horrible set or just fail completely. It's not ususual to hear of a guy building a rigid handled osage bow for a 28" draw only 60" long ntn but that is really pushing the envelope (but proves it can be done).

The one third wider limb would be tillered a standard elliptical tiller, as there would be too much wood to bend thru the handle. I too would expect any follow to be in the outer 2/3 of the limb, which would be the purpose of leaving extra wood in the 1st 1/3 of the limb. A little follow in the first 1/3 translates to a lot of follow in the tips if it is not controlled. The extra width length would be that controlling factor.

The 1/3 wider working limb design is definitly a new one on me and I have studied bow design for years. It is not described by Torges, at least not in HOB where he describes a slight convex line going straight from 1 5/8" fade circle to 5/8" tip circle. I have many reference books and can find no link to this design anywhere.

We are all novices at this and I get to learn everyday. It's still exciting to me.

Roy if you would, please email me [email protected] I have a question for you