Bow Physics revisited.....Bow Finished!

[joebuck]

In 1988....I read instinctive shooting.... G Fred explained the mystery for me on how to shoot a trad Bow.....Split finger, burn a hole, follow through. I was off to the races for many years shooting a similar style..............................2018...either Jason W writings  and/or that "pushpod segment"".........I am a Crawl convert....not looking back... Mr . Quillian if still alive would scold the HELL out of me...but... this system works for me...cant wait to shoot a critter out of my Guido saddle!

enough for my background..........Since 1992...my basic TD recurve bow building has been locate the center of riser then go 1.5" up and cut my radius  shelf....Now i am gripping the string , 3 fingers, low wrist  and the arrow is 1" above my fingers for 'crawl" or "walk".......................

So long winded.....are any of you setting your risers and or limbs up different for the crawl?  I know archers have been string walking since maurice and will but now center of bow is 3.5" above nocked arrow.

[joebuck]

Too much heavy thinking on design  when i should be solving on tiller board. Just focus with tiller on board so both limbs are timed together with new grip and shooting setup

[Mark Smeltzer]

I'll be watching this one. I don't string walk or crawl..lol but have always pondered the the relationship between bow center, shelf placement and hand placement on the string. I build my bows with the shelf at 1.250  above center.
When I think about this stuff i throw in tiller also just to further confuse the issue. Even tiller or positive. On primitive bows some guys make the bottom limb shorter too.

[kennym]

"" now center of bow is 3.5" above nocked arrow ""



That seems like the bow center would be way too high?

[joebuck]

correction....The arrow nock is about that ...3 to 3.5" high of where my pressure is on the grip ( base of thumb)

[joebuck]

i think on this bow i am going to attach riser to tiller board holder to exactly the place my grip pressure is by base of my thumb would be ( not center of throat of grip), then attach pulley rope to exactly where top of my index finger for three under would be................then tiller limbs accordingly....not jack with making one limb short or riser catawambpus...etc........................

Kenny, you up to making lams out of all this persimmon?  big boards are 2x12x8'

[Bvas]

You want to attach the rope where center of your middle finger would be. This should be the focal point of your drawing hand.

Tillering for string walking, I’d imagine that you would want to attach slightly lower than that. Just guessing??

[kennym]

i think on this bow i am going to attach riser to tiller board holder to exactly the place my grip pressure is by base of my thumb would be ( not center of throat of grip), then attach pulley rope to exactly where top of my index finger for three under would be................then tiller limbs accordingly....not jack with making one limb short or riser catawambpus...etc........................

Kenny, you up to making lams out of all this persimmon?  big boards are 2x12x8'

Any number!! 

[Roy from Pa]

[stickmonkey]

I would first try just tillering the limbs to the fixed crawl so the bow appears like the one in Roys pic.

[EwokArcher]

Nice rowing machine you have there Roy, I am sure your  PT would be glad to see that vid too lol.

[Roy from Pa]

LOL

That's not me.

I have hair..

 

[kennym]

I wuz gonna say somethin but I figgered I just be quiet....

[Roy from Pa]

Yer getting mellow there ole timer.
 

[joebuck]

Here’s the real question.   Why do we set up our riser (TD) typically with the center of riser typically in the throat of the grip when the proper grip pressure point is base of thumb which is 1" +lower?   In picture , i am showing the Blue dot is relative position of that base thumb with horizontal stick showing typical center ( mathematical center of my riser)   

I am thinking if I  lengthen the lower riser to make blue dot exact center of bow ( where now the throat of grip is the center) This would line up all three.....mathmatical center of the bow with the pressure point of correct grip and in line with my three fingers under?
 

[EwokArcher]

The lower position of the thumb rotates the hand and forearm into a more pronated position. This straightens out the bow arm and makes it more in line with the arrow which is more beneficial for instinctive shooting. A trad hill style handle would have your thumb high and heel of the hand planted in the bow. I've been shooting with a straight wrist and have been making my handles with the lower thumb and higher palm swell to encourage this. This puts the pressure in the webbing of the hand at the center of the bow.

[joebuck]

I am wondering if Olympic re curves lower limbs are longer than top limbs?

[EwokArcher]

I don't know about Olympic bows. But from making wood bows you learn a lot more about tiller that tends to get bypassed with glass bows.  I think the limb length isn't as critical as even stress between the limbs. I made a hand full of asym osage bows and other than being more trouble they shot no better than a normal properly tillered design. When making wood bows I would use a mirror or camera and draw the bow by hand to more exactly replicate the proper pressure through the limbs to fine tune tiller. I am no expert I'm sure someone has less anecdotal input.

[Mark Smeltzer]

I guess they build the Yumi bow the way it is for a reason. If you figure it out let me know.

[joebuck]

Now that pic gave me a headache