Author Topic: Tiller shape vs front profile  (Read 19859 times)

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Offline Don W

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Re: Tiller shape vs front profile
« Reply #120 on: June 30, 2021, 10:18:04 am »
@ DonW
No one (AFIK) is insisting that everyone do the same.
A lot of us others spend a lot of time trying to not only help newbies advance their craft, but also advancing their own.
I'm always careful to point out that how I do things is NOT the only way, and I'm only too happy to learn from others.
I do however try to keep it simple and based on practical demonstrable theory and experiment.
Del

Sorry if I struck a nerve. I wasn't referring to you Del, and I agree you share a lot of information and you're youtube channel and post have helped myself and many other new bowyer wanna be's. I'd suggest you keep doing what you're doing other than going on the offensive. It's sometimes hard to judge written intent. Assume it's positive and you will help a lot more. It's hard to trust someone who doesn't trust themselves.

Remember, just because someone is new to bow design, doesn't mean they lack applicable knowledge. 
Don

Offline Don W

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Re: Tiller shape vs front profile
« Reply #121 on: June 30, 2021, 10:22:03 am »
  The work of Hickman et al covered a lot of this decades ago in Archery The Technical side.

 In fact when Torges and Baker started sniping at each other the comment was made  by Torges that Baker was lucky that the  copyright had expired or he could have been caught with plagiarizing.

There is no plagiarizing in work that's meant to be shared. If it's not meant to be shared then it must be a monetary thing. IMO it's ok to profit, but not ok to stifle progress to further profit.
Don

Offline mmattockx

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Re: Tiller shape vs front profile
« Reply #122 on: June 30, 2021, 11:19:51 am »
As a side note, I find it interesting that there are those who can function on such an advanced mathematical level and still be drawn to wooden bows opposed to glass.

IMO, wood holds a magic to it that you don't get with modern composites. It just speaks to some people. Besides, no one here is interested in absolute performance or they would be shooting a compound bow. The path to the highest performance bow has already been shown and we choose to not go that route.


Things get murky when some people tries to use higher math and physics to answer questions that are basically about skills, craftsmanship, or at most mechanics.

I can design a bow to any desired level of strain on the limbs, calculate how wide and thick the limbs need to be to not exceed that strain level at my target draw weight and whatever width/thickness taper is required to make it bend how I want. There is more than one set of skills and this is how I choose to exercise my particular skills and craftsmanship.


Mark

Offline PatM

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Re: Tiller shape vs front profile
« Reply #123 on: June 30, 2021, 11:22:27 am »
  The work of Hickman et al covered a lot of this decades ago in Archery The Technical side.

 In fact when Torges and Baker started sniping at each other the comment was made  by Torges that Baker was lucky that the  copyright had expired or he could have been caught with plagiarizing.

There is no plagiarizing in work that's meant to be shared. If it's not meant to be shared then it must be a monetary thing. IMO it's ok to profit, but not ok to stifle progress to further profit.

  The issue is more about re-sharing as if it's your own.  it's not always about money.  People like to keep credit for themselves if they did the grunt work.

Offline Don W

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Re: Tiller shape vs front profile
« Reply #124 on: June 30, 2021, 11:32:08 am »
  The work of Hickman et al covered a lot of this decades ago in Archery The Technical side.

 In fact when Torges and Baker started sniping at each other the comment was made  by Torges that Baker was lucky that the  copyright had expired or he could have been caught with plagiarizing.

There is no plagiarizing in work that's meant to be shared. If it's not meant to be shared then it must be a monetary thing. IMO it's ok to profit, but not ok to stifle progress to further profit.

  The issue is more about re-sharing as if it's your own.  it's not always about money.  People like to keep credit for themselves if they did the grunt work.

Agreed. Credit needs to be given where credit is due.
Don

Offline airkah

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Re: Tiller shape vs front profile
« Reply #125 on: June 30, 2021, 11:44:45 am »
... but I really think some old school commenters are really missing an opportunity to help further the craft...
I really think you are making assumptions about how some old school commentators practice their craft! ::)
Del (an old school commentator who does know the value of a cube root and can use a set of vernier calipers!)

I don't qualify as an old school poster but if I ever have to learn what those words mean in order to make a proper bow I think I would quit.

I could be wrong on this, but t seems like there are really two main approaches in this thread, bowyers that prefer to approach the craft from a science/math/engineering standpoint and those that approach from an art/intuition/spiritual viewpoint. I don't think either approach is better than the other, just different ways of attacking a problem.

Offline Don W

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Re: Tiller shape vs front profile
« Reply #126 on: June 30, 2021, 11:57:57 am »


I could be wrong on this, but t seems like there are really two main approaches in this thread, bowyers that prefer to approach the craft from a science/math/engineering standpoint and those that approach from an art/intuition/spiritual viewpoint. I don't think either approach is better than the other, just different ways of attacking a problem.

There is definitely overlap. Just like in hunting practices.
Don

Offline scp

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Re: Tiller shape vs front profile
« Reply #127 on: June 30, 2021, 01:21:07 pm »
Things get murky when some people tries to use higher math and physics to answer questions that are basically about skills, craftsmanship, or at most mechanics.

I can design a bow to any desired level of strain on the limbs, calculate how wide and thick the limbs need to be to not exceed that strain level at my target draw weight and whatever width/thickness taper is required to make it bend how I want. There is more than one set of skills and this is how I choose to exercise my particular skills and craftsmanship.

Mark

Feel free to let us know when you have a robot or a software that can turn a wooden stave into a world-class flight shooting bow. Good luck.

Do you have a simple flat bow design for Hickory boards that can shoot 170 FPS with 10 GPI arrows?

Offline RyanY

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Re: Tiller shape vs front profile
« Reply #128 on: June 30, 2021, 03:51:39 pm »

Feel free to let us know when you have a robot or a software that can turn a wooden stave into a world-class flight shooting bow. Good luck.

Do you have a simple flat bow design for Hickory boards that can shoot 170 FPS with 10 GPI arrows?

It’s this kind of antagonistic close minded bull crap that turns these threads sour. Clearly you’re on the distasteful side of your so-called observation of social interactions in this community.

Offline scp

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Re: Tiller shape vs front profile
« Reply #129 on: June 30, 2021, 06:49:51 pm »
I guess my musings were getting out of hand and becoming way too off-topic. To be fair to the original poster, it would be nice, as several people suggested, to have a nice example of good tillering "perfectly" matching the front profile.

It would be even better if that example is created using a modelling software for bow making. I sure can use a detailed description of the thickness tillering for a hickory board flat bow. But I am simply incapable of following the technical language used or mentioned by some people here. So I will stick to the ordinary language used by people like Tim or Badger.

What would be the best way to "match" the front profile with "perfect" no-set tillering? All I can think of so far are the so-called mantra and the mass principle applied to the tillering of each sections. My attempt to describe my meager understanding was a complete failure, mainly due to my unfortunate choice of common words that conflict with an established technical phrase.

I have seen a couple of promising starts, but they were not followed up, partly because of my distracting musings. I do believe we can have some useful principles with more explanatory power.

Offline willie

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Re: Tiller shape vs front profile
« Reply #130 on: June 30, 2021, 10:07:55 pm »


It would be even better if that example is created using a modelling software for bow making. I sure can use a detailed description of the thickness tillering for a hickory board flat bow. But I am simply incapable of following the technical language used or mentioned by some people here. So I will stick to the ordinary language used by people like Tim or Badger.

What would be the best way to "match" the front profile with "perfect" no-set tillering? All I can think of so far are the so-called mantra and the mass principle applied to the tillering of each sections.

here is a modeling project that could give you the shapes given the tapers, or vice versa.  It would not be necessary to input actual stiffness values obtained by testing, The default Moe is typical of many white woods.
you only need to provide the dimensions for your bow. Without specific test values, the resulting designs will be relative rather than actual. There is an output graph that shows stress, and the maximum stress is where one would first see set. 

the shoulders on the mollie where you suspect to much wood? You could get a pretty good idea of how to do it better.

https://www.virtualbow.org/

Offline scp

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Re: Tiller shape vs front profile
« Reply #131 on: June 30, 2021, 10:50:18 pm »
I have downloaded VirtualBow program, but never got around to make any bow using it. Has anyone made a hickory board flat bow using this program and achieved 170 FPS with a 10 GPI arrow? That's the maximum I expect from my intuitive tillering using just the graceful shape of bends. I expect dozens if not hundreds. Does anyone have the front profile and thickness tapering chart printout for such a bow?

Offline RyanY

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Re: Tiller shape vs front profile
« Reply #132 on: July 01, 2021, 12:03:30 am »
I have downloaded VirtualBow program, but never got around to make any bow using it. Has anyone made a hickory board flat bow using this program and achieved 170 FPS with a 10 GPI arrow? That's the maximum I expect from my intuitive tillering using just the graceful shape of bends. I expect dozens if not hundreds. Does anyone have the front profile and thickness tapering chart printout for such a bow?

Do you have any pictures of this bow? Or any bow for that matter?

Pretty sure this has been done by the people who developed some of these programs. At least one person as Steve (Badger) reported in this post from July 17, 2007.

As per my red Oak challenge. Our own Dave Woodbear sent in his bow, the only entry. I have a feeling he would have won if there would have been a hundred entries. he did a great job on this one. He sent the bow to me with instructions that it had not been drawn past 10" but should come out at 50# and 28" draw. Well, the bow hit 50# at about 24" so I halted any further testing until I got his permission to take it to 28". I did a force draw curve on it out to 28" and it read just shy of 60#. After excersizing on the tiller tree and shooting a couple dozen arrow through the bow she leveled out at 56#. The bow is 72" long and took less than 1/2 set. I used a 510 grain arrow for the testing, did several shots at 27" and then moved up to 28". A 3 shot series at 28" gave me a 179 fps, 180 fps and 181 fps, Bow came in at slightly over 18 oz, projected mass for this type of by via my own calculator would have been 20 oz. The unique traping method he used on the limbs effectively lowered the mass. At the fades the bow is about 1 1/2 wide on the belly side and 1" wide on the back side, very extreme trapping. Maybe Dave can tell us more about how he designed this bow. Steve

Are you asking this because you’re truly interested in if there’s a reliable method or for some other reason?

Offline RyanY

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Re: Tiller shape vs front profile
« Reply #133 on: July 01, 2021, 12:09:38 am »
Here’s the full thread about David Dewey’s (Woodbear) bow if anyone is interested.

https://www.tapatalk.com/groups/paleoplanet69529/woodbear-s-red-oak-entry-t13237.html

 Turns out you can design and build fast bows using science and maths as long as you actually know what you’re doing. The question here has an answer. It’s just that we’re missing the smart people to actually give us plebeians a dumbed down explanation. To say it doesn’t matter or that it can’t be done is just ignorant.

Forgot to include the link. This is what I’m talking about.  ::) :fp
« Last Edit: July 01, 2021, 12:46:28 am by RyanY »

Offline SLIMBOB

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Re: Tiller shape vs front profile
« Reply #134 on: July 01, 2021, 12:24:19 am »
Hey Willie. Thanks for the very nice comment yesterday. I think you may have found this fella some answers with this. And btw, in the event that I might possibly be one of the “old timers” refereed to earlier, I will have you know sir, that I’m in my prime. I enjoy the technical side of this as much as anyone. That was what I most admired about the things that Tim Baker brought to the conversation. His research answered many questions as to WHY, certain things we were doing worked, and others didn’t. I found the discussion fascinating. I still do. I am no master that has built a thousand bows. Maybe a hundred at this point. I’m a journeyman, at best. But I wouldn’t trade the moments I have accumulated over the years, building bows, for much else. I didn’t discover myself, or commune with the elders, nor anything else metaphysical. I was never searching for those things. But by doing, I learned, and I enjoy passing it on, like lots of others on here. I’m still doing and still learning, and helping others when I can. Wouldn’t trade away any of it nor change the way I’ve done it.
Liberty, In God We Trust, E Pluribus Unum.  Distinctly American Values.