Primitive Archer

Main Discussion Area => Bows => Topic started by: helmet on August 09, 2015, 01:54:44 am

Title: stack?
Post by: helmet on August 09, 2015, 01:54:44 am

 I realize this maybe a very basic question. I just finished up my first short bow, it is 46" long white  oak, 50lbs at 19". while tilling it I could not get past 19" at 50lbs. I was hoping for 22" at 50lbs. After removing wood the till would change and the early draw wieht would change, but at 19" it would still be 50lbs. So is this waht is called stack, caoused by the tip and string angle relation?

Title: Re: stack?
Post by: wizardgoat on August 09, 2015, 02:16:00 am

Sounds like you've hit the wall. Hold a ruler in your hand pointing up and pull it back like a bow limb.
Now hold it horizontal and try to pull it back...doesn't bend too much any more.
If you recurve your tips a bit (and tiller is close), you could maybe get another couple inches

Title: Re: stack?
Post by: Del the cat on August 09, 2015, 02:40:29 am

A simple solution which may not work is to get more bend at the grip.
Imagine it this way.. if the limbs were rigid and the bow just bent in the centre (big rubbery hinge in the middle :laugh:)
The string angle will be a lot less than if the outer limbs do all the flexing and the tips are bending back towards you.
The risk is that the bow will snap in the middle...
Now has anyone ever seen a bow break in the middle? I've seen a splice break, but all the actual limb failures I've seen were mid limb...
Just sayin'
I'll do a quick pic if it helps
Del

Title: Re: stack?
Post by: bowandarrow473 on August 09, 2015, 12:12:20 pm

Is it a stiff handled bow? If so then either make it bend in the handle so you can get a few more inches or flip the tips to reduce the string angle.

Title: Re: stack?
Post by: simson on August 09, 2015, 01:20:56 pm

What Del said, good explanation sketch there!

Title: Re: stack?
Post by: helmet on August 09, 2015, 03:28:54 pm

Thanks for the info guys. Yes it is a bend through the handle design and I am tempted to flip the tips. We will see.

Title: Re: stack?
Post by: tallpine on August 09, 2015, 05:55:05 pm

I hope I'm not hijacking your thread Helmet but this is a timely thread for me as I have been trying to build an Osage pony bow with not much success. They all where tillered bend in the handle similar to Dells drawing and both took a lot of set. Anyone have a picture of a correctly tillered sub 48 inch bow that will pull 24 inches? I am now working on my third attempt and intend to sinew this one

Title: Re: stack?
Post by: helmet on August 09, 2015, 07:53:05 pm

Tallpine, I would also like to see that.

Title: Re: stack?
Post by: bowandarrow473 on August 09, 2015, 10:10:07 pm

Tallpine, run a search on this site and I'm sure you'll find plenty of pictures of well-tillered short bows.
How much did your pony bow bend in the handle, any set in the handle is magnified at the tips so a bow with no set in the limbs and a smidge of set in the handle can have a tip deflection that is surprisingly large.