Author Topic: A different type of "Molly"  (Read 11990 times)

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Offline RyanY

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Re: A different type of "Molly"
« Reply #30 on: December 25, 2012, 03:56:27 pm »
With a straight taper for the levers that's probably a good taper for those lams. If the taper were from wider at mid limb to narrower at the tips then the taper should be more even or actually even increase toward the tips. One reason why I'm not a fan of the Molly design is that there's no easy way to efficiently tiller the transition to stiff tips and then the problem if making sure they aren't excessively deep.

Offline PatM

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Re: A different type of "Molly"
« Reply #31 on: December 25, 2012, 05:26:31 pm »
A lever is upposed to be stiff so reducing until the lever flexes slightly is a sign that too much is taken off.
 It is likely that a slightly flexing or a slightly oversized lever will shoot about the same but that doesn't mean that the optimum is still not between those two extremes.
 I've never had trouble with the transition from working limb to levers. It's no different from a handle dip through the fades except on a smaller scale.

Offline RyanY

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Re: A different type of "Molly"
« Reply #32 on: December 25, 2012, 05:48:23 pm »
PatM, a lever with less mass will shoot faster than one with more so how would reducing it till it flexes, just enough so you can see it, have any negative effects? The lever is still very stiff relative to a normal bow limb and also has less mass. Also I never see the transition area doing any sort of flexing even several inches on either side. If its not bending at all how can you be sure that the area isn't carrying excess mass? You can't.

Offline toomanyknots

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Re: A different type of "Molly"
« Reply #33 on: December 25, 2012, 06:24:51 pm »
I think more often than not people think that if the levers are stiff then that's all that's necessary for this design. Without seeing a slight bend there is no way of knowing they are reduced as much as possible for optimization,

Oh thats just a bunch of hooey, making the levers bend is basically killing the leverage advantage that a molly or holmegard bow typically has, making the typically smooth draw of a molly or holmegard bow stack in the last couple of inches, where it would of had a beautiful force draw curve to begin with if you would of left them stiff.

EDIT: I guess if you wanna go all flight shooter and every single fps is your goal then I might see your reasoning, but a molly is already going to shoot pretty quick, so why take a quick shooting bow that draw incredibly smooth, and turn it into a quick shooting bow that draws a little less smooth?
« Last Edit: December 25, 2012, 06:29:05 pm by toomanyknots »
"The way of heaven is like the bending of a bow-
 the upper part is pressed down,
 the lower part is raised up,
 the part that has too much is reduced,
 the part that has too little is increased."

- Tao Te Ching, 77, A new translation by Victor H. Mair

Offline Weylin

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Re: A different type of "Molly"
« Reply #34 on: December 25, 2012, 06:35:24 pm »

Oh thats just a bunch of hooey, making the levers bend is basically killing the leverage advantage that a molly or holmegard bow typically has, making the typically smooth draw of a molly or holmegard bow stack in the last couple of inches, where it would of had a beautiful force draw curve to begin with if you would of left them stiff.


If the levers bend ever so slightly how could that make the bow start to stack if it wasn't stacking with non bending levers. stacking is a factor of the string angle. I don't see how this question of totally stiff levers vs. slightly bending levers has much if anything to do with string angle. I think the biggest concern with slightly bending levers is that you are likely pushing the boundaries of safe lateral stability on the levers.

Offline toomanyknots

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Re: A different type of "Molly"
« Reply #35 on: December 25, 2012, 07:26:33 pm »
How could making the levers bend in all possibility not effect string angle? And in terms of leverage, I would rather try to pry a door open with a stiff metal crowbar than a bendy rubber crowbar, if you see what I'm saying.
"The way of heaven is like the bending of a bow-
 the upper part is pressed down,
 the lower part is raised up,
 the part that has too much is reduced,
 the part that has too little is increased."

- Tao Te Ching, 77, A new translation by Victor H. Mair

Offline PEARL DRUMS

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Re: A different type of "Molly"
« Reply #36 on: December 25, 2012, 08:29:59 pm »
Good looking bow and good looking tiller for sure.
Only when the last tree has died and the last river has been poisoned and the last fish has been caught will we realize we cannot eat money.

Offline RyanY

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Re: A different type of "Molly"
« Reply #37 on: December 25, 2012, 09:28:10 pm »
Tmk, your assumption about bending levers is of an extreme bend which is not what I mean. The bend should barely be noticeable just enough to show that the levers are reduced to a good degree. Any change in string angle or leverage wouldn't be noticeable. Weylin is correct that lateral stability can be a concern but rarely do I see tips made narrow enough to worry about it.

blackhawk

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Re: A different type of "Molly"
« Reply #38 on: December 25, 2012, 09:48:48 pm »
So Ryan..how much firsthand experience have you had testing this hypothesis out? Id sure like to know so I can build a Molly "right".  >:D

Offline RyanY

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Re: A different type of "Molly"
« Reply #39 on: December 25, 2012, 09:58:21 pm »
I don't think you have anything to worry about Chris. You make the exceptions. ;)

Offline PatM

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Re: A different type of "Molly"
« Reply #40 on: December 25, 2012, 11:31:48 pm »
Ryoon, That's part of the fine-tuning and learning process. If it's bending, you screwed up.  It's the same reasoning that makes guys put an I-beam configuration in a handle. Absolute rigidity IS desireable.
 It makes no sense to reduce the levers until they bend.  You have to make several bows to figure out where that line lies. We don't make every bow style and fine-tune past the tipping point.
 Do you make a nice full compass longbow and then overdo the ends until they are too whippy in order to prove that optimimum reduction has taken place?
 For someone who wants the best performance possible, it seems odd that you will sacrifice potential gains.

Offline RyanY

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Re: A different type of "Molly"
« Reply #41 on: December 25, 2012, 11:43:45 pm »
Why is absolute rigidity desirable and how could you possibly know that you've reached a good amount of mass removal without some sort of bend? A barely noticeable bend in the levers has absolutely no ill effects but a definite positive of mass reduction. It is still stiff by any measure and still keeps string angle low, mass is reduced as much as possible with no issues of safety to the bow with such miniscule bend. Your comparison to the full compass longbow is not accurate. Of course in that situation mass reduction can take place in the width during the tillering process if the bow is showing absolutely no signs of stress.

Offline steve b.

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Re: A different type of "Molly"
« Reply #42 on: December 25, 2012, 11:48:13 pm »
It takes about 60 grns. of weight change at the tip of the average bow to change the average arrow speed one FPS.  60 grns. is a VERY noticeable amount of material but one fps is not.

Offline RyanY

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Re: A different type of "Molly"
« Reply #43 on: December 26, 2012, 12:38:29 am »
Steve b., for me, going for that 1fps is a challenge that makes building bows so fun for me.  :D

Offline rps3

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Re: A different type of "Molly"
« Reply #44 on: December 26, 2012, 12:42:47 am »
I like the bow and the conversation about design, very informative.