Request for those who are starting a new bow.

[Badger]

  I don't think so because the heavier arrow and longer draw will always have more KE. maybe ratio of KE to draw weight? The formula we have been using is supposed to equalize stored energy ratios.

[willie]

Steve,

"formula" is a confusing choice of words in this discussion. It can refer to an estimate, or to the equation that defines a physical law of motion.

woodbears method is a way to estimate results.  Your method is similar, but it uses powerstroke rather than total draw length, gives a slightly different result, but is still an estimate?

"ke=1/2 mvv"   when written out, is casually called a formula, but the relationship described between energy, mass and velocity is really a physical law.  Only one correct value for any particular weight arrow at a given speed.

Not sure if I should go on, as it may be sidetracking this discussion, but I think it is an important distinction to make if we are to understand the mechanics of the bow.

[sleek]

No formula can be perfect here, cause it represents perfect world scenarios. If every bowyer who uses the formula built perfect bows, id wager the formula is spot on. How ever, there is a variable that the formula can not account for, and thays the human error variable. You cannot accurately predict how well a lerson tillers a bow to get desired results the formula predicts should exist.

But it will tell you how good you did.

[Badger]

No formula can be perfect here, cause it represents perfect world scenarios. If every bowyer who uses the formula built perfect bows, id wager the formula is spot on. How ever, there is a variable that the formula can not account for, and thays the human error variable. You cannot accurately predict how well a lerson tillers a bow to get desired results the formula predicts should exist.

But it will tell you how good you did.

   I know what you are saying Willie, they are using a formula to arrive at an estimate. That is why I prefer not to use any method other than 10 grains per pound at 28" draw.

[Badger]

Myself with wood bows I'd rather not use any heat at all on these bows.Just a thing I have about heat weakening wood sometimes.Not always of course and type of wood heat treated considered too.Just flipping the tips some and working with naturally slightly reflexed bows.Seems to me most times those hold up the best.

   I use heat to set up my profile but don't do any actual heat treating. I am not really sure if the amount of heat I apply while straitening out the bow has a heat treat effect or not.

[BowEd]

No Steve intermittingly like that I don't think so myself.A spot or two 1" one on each limb I would think not.A good heat treatment is a torturous cell changing experience most times depending on how stressful the profile made is.That goes for alterations too I guess if they are extreme.
Some woods like hickory don't seem to be affected by heat as much as others I would say though.Guess what I'm saying is it might be more weakening to some woods more than others.Especially on the working parts of limbs more so than the static of course.
No matter.
Glad your getting results in from your proposed test especially from other talented bow makers on here.

[PatM]

Here's an interesting quote from Mason's book.

" Lieut. Allen, U. S. Army, has described the excessive pains which the Copper River Indians bestow upon the fashioning and caring for their bows. There are no first rate, tough, elastic woods near them. Birch and willow and such soft species are the only stock in trade. And yet, by dint of heating or toasting, boiling, greasing, and rubbing down they convert these poor materials into excellent arms."

 There is also a quote regarding Red Cedar that could have been written by someone on here.

[willie]

  I don't think so because the heavier arrow and longer draw will always have more KE. maybe ratio of KE to draw weight? The formula we have been using is supposed to equalize stored energy ratios.

or perhaps KE to Stored Energy?

I am still not sure that comparing a bow at 24, to a bow retillered to a different weight as it is drawn to 28 and retested at 24 tells us much. The way Leon did it seems more apples to apples, but maybe I don't understand the purpose of the experiment well.  In the opening post you described the operation of the experiment, but when I go back and re read I am not sure what the purpose is, could you clarify?

[BowEd]

Here's an interesting quote from Mason's book.

" Lieut. Allen, U. S. Army, has described the excessive pains which the Copper River Indians bestow upon the fashioning and caring for their bows. There are no first rate, tough, elastic woods near them. Birch and willow and such soft species are the only stock in trade. And yet, by dint of heating or toasting, boiling, greasing, and rubbing down they convert these poor materials into excellent arms."

 There is also a quote regarding Red Cedar that could have been written by someone on here.

I did say if not now but earlier some woods do like heat very well and perform unaffected and better than their natural state.Hickory from my experience.

[willie]

Here's an interesting quote from Mason's book.

" Lieut. Allen, U. S. Army, has described the excessive pains which the Copper River Indians bestow upon the fashioning and caring for their bows. There are no first rate, tough, elastic woods near them. Birch and willow and such soft species are the only stock in trade. And yet, by dint of heating or toasting, boiling, greasing, and rubbing down they convert these poor materials into excellent arms."

 There is also a quote regarding Red Cedar that could have been written by someone on here.

found the account of the copper river bow ok.  Can you point to your red cedar reading better? tribe? place? page? 

[PatM]

Here's an interesting quote from Mason's book.

" Lieut. Allen, U. S. Army, has described the excessive pains which the Copper River Indians bestow upon the fashioning and caring for their bows. There are no first rate, tough, elastic woods near them. Birch and willow and such soft species are the only stock in trade. And yet, by dint of heating or toasting, boiling, greasing, and rubbing down they convert these poor materials into excellent arms."

 There is also a quote regarding Red Cedar that could have been written by someone on here.

found the account of the copper river bow ok.  Can you point to your red cedar reading better? tribe? place? page?

 
    Part 4 of 7 Bows and arrows of various tribes etc.
"The constructive industry of the men was confined principally to the making of arms, bows, arrows, shields, and spears. These were all objects in which they took great pride. The favorite material for bows was bois d'arc (Maclura aurantiaca). When these could not be obtained hickory or coffee bean (Gymnocladus Canadensis) was used. The name ti-rak-is, bow, seem to indicate that bows were once made of bone, the ribs of the buffalo or other large animal, skillfully fitted and wrapped throughout with sinew. Forty years ago bows of this kind, and also of elk horn were occasionally found in use. Choice bows were some times made of red cedar, and if carefully used answered well, but were extremely liable to be shattered by any rough handling. The making of a good bow was a task involving long and painstaking labor. It was wrought into shape only a little at a time, being repeatedly oiled meanwhile, and constantly handled to keep the wood pliable. When finished the bow was sometimes wrapped with sinew and its strength thereby greatly increased. The string was of sinew from the back of the buffalo. As soon as the sinew was taken from the animal the par ticles of flesh adhering were scraped off and the minute fibres carefully separated. The best of these were selected and twisted into a string of uniform size and elasticity. One end of this string was fastened securely in place upon the bow, and the other furnished with a loop so adjusted that in an instant, as occasion required, the bow might be strung or unstrung.

[leonwood]

Leonwood, were you using some sort of shooting machine?  I'm trying to figure out what's the best way to shoot right at 24" draw.  It seems it would be hard to get consistent results trying to eye a mark on the arrow. 
I don't want to build a shooting machine.  I would rather spend that time building another bow 

No I just shot the arrows myself. I did put some tape on the shortest arrow and a black line on the others to know where tomdraw it to. This worked pretty good because I shot ten arrows at each  drawweight/length and the speeds where consistent within 5 fps with only one or two extremer ones which I ignored

[sleek]

Tie a steing between the handle and bow string that has 24 inches of slack, measured from the back of the handle. When you hit 24 inches of draw, the string gets tight and you let loose. Easy day.

[Badger]

  Willie as long as the arrow weight is proportionate it shouldn't make any difference if you retiller it. The level of performance is not supposed to change unless it takes set.

[Bayou Ben]

Thanks Sleek for that tip.  Your explanation brings up a question that I've been meaning to ask.  How are we all measuring draw length for this test? 
I know this seems like an elementary question, but I was surprised to find out how many bowyers do their own thing when it comes to draw length.  Not that any one way is right or wrong, as long as you are consistent in measuring the shooter and projecting that to the bow you build. 
I go by AMO draw length.  Deepest part of the handle plus 1.75".