Primitive Archer

Main Discussion Area => Bows => Topic started by: Knotty on June 18, 2016, 02:43:02 pm

Title: How narrow can limbs be? (Important)
Post by: Knotty on June 18, 2016, 02:43:02 pm
Hey guys,
Today I was checking out my Guava stave and I re-checked the string alignment..
I noticed that having the string aligned through the center of the stave would leave me with EXTREMELY narrow limbs..
I'm talking about 1" handle tapering to 1/2" tips.. Wouldn't that be too narrow?
How could I compensate the narrow limbs? Maybe with limb thickness during tillering?

I read one of Manny's posts from his Guava hunting ELB in which he said that the best design for guava wood is the deep narrow one..
However mine is too narrow I think.
Should I consider throwing away the stave?
This got me a little down.. I had high hopes for my guava .

I'd appreciate any reply .
Thanks in advance. 👍
Title: Re: How narrow can limbs be? (Important)
Post by: SLIMBOB on June 18, 2016, 03:02:03 pm
I cant tell you anything about guava but, in general, string tracking imo is a little overrated on flat bows.  Once you pull the string the tips will seek  their own center.  Narrow thin tips like lever bows it is critical,but not so much otherwise.  I say this because you said the string leaves you with a 1 inch wide bow.  That means your string does lie along the handle so it doesn't sound to bad.  If a bow shoots well then I wont bother with string tracking MUCH.  You can heat and bend the bow in the handle to bring the tips in if you need. If a string lies off to the arrow pass side a little, that's ideal for me.
Title: Re: How narrow can limbs be? (Important)
Post by: Knotty on June 18, 2016, 03:09:13 pm
I'll take a picture and show you, give me 2 minutes.
Title: Re: How narrow can limbs be? (Important)
Post by: Knotty on June 18, 2016, 03:19:26 pm
Nevermind, it would look too confusing.

Anyway, do you think that at those measurements it could keep up?

I mean.. Guava is surely very tension strong and I could always heat treat the belly.
Title: Re: How narrow can limbs be? (Important)
Post by: SLIMBOB on June 18, 2016, 03:32:39 pm
Thin wood can bend into a tighter radius before taking set or breaking, so narrow thick limbs can be a problem.  I know nothing about Guava, so that is a question for someone else.  My question is why make it so narrow if you don't have to?  I have given you a way to easily tweak the string tracking????  Get a picture up of the belly with the string tied on.
Title: Re: How narrow can limbs be? (Important)
Post by: Dakota Kid on June 18, 2016, 03:39:18 pm
How wide is the stave? That's the only basic limiting factor when it comes to limb width.

String alignment shouldn't really dictate limb width. Make your bow as you had originally planned and if you need to adjust the string alignment once you have it to bow dimensions a simple steam bending should take care of it.
Title: Re: How narrow can limbs be? (Important)
Post by: Knotty on June 18, 2016, 03:47:26 pm
Alrighty then, I'll proceed as I had previously planned, and we'll see what happens, thanks for the help guys!
Title: Re: How narrow can limbs be? (Important)
Post by: Del the cat on June 18, 2016, 03:48:45 pm
I've just measured my 40# boo backed Yew ELB   0.962" wide just above the grip. So yes it's doable :)
I generally rough out a 30mm wide in the centre section for an ELB of upto 50# weight.
Del
Title: Re: How narrow can limbs be? (Important)
Post by: Knotty on June 18, 2016, 03:50:01 pm
Del , the problem is, yours is a longbow, while my stave is only 55" long.
That really changes things up!
Title: Re: How narrow can limbs be? (Important)
Post by: bubby on June 18, 2016, 03:50:58 pm
I have made plenty of bows an inch wide at 50# sounds like the problem is you need to do some alignment
Title: Re: How narrow can limbs be? (Important)
Post by: bubby on June 18, 2016, 03:53:44 pm
Knotty listen to the advice given if a longbow can be that narrow and still be stable you don't think a short bow can? It takes less wood to make a short bow besides the obvious length difference
Title: Re: How narrow can limbs be? (Important)
Post by: SLIMBOB on June 18, 2016, 04:04:29 pm
If it is the stave you have in your first post, they seem to be very knotty as well.  Short knotty narrow thick limbs might not be your best option.  I too have bows with a width of 1 inch or so.  Some are short little Plains style bows of 48-52 inches in length so yeah it's doable, but most are pretty clean and knot free.  Still comes back to simple alignment that gives you some latitude in the width.
Title: Re: How narrow can limbs be? (Important)
Post by: Badger on June 18, 2016, 04:05:30 pm
  I would make it bend through the handle, start tillering at whatever weight you are after and stop when it starts taking set, it might be 22" it might be 26". You can't get more than what the wood has in it to give thats a for sure positive.
Title: Re: How narrow can limbs be? (Important)
Post by: Knotty on June 18, 2016, 04:37:56 pm
Alright , thanks to everyone who has given me some advice!
I really appreciate it!

I guess I'll go with the 1" thickness and see what happens 😉
Title: Re: How narrow can limbs be? (Important)
Post by: Newindian on June 18, 2016, 05:30:06 pm
I have an Osage which is thinner and about 58" long and a 50 something pound draw weight, it's almost as thick as it is wide, but that is Osage.
Title: Re: How narrow can limbs be? (Important)
Post by: Del the cat on June 18, 2016, 05:30:47 pm
Del , the problem is, yours is a longbow, while my stave is only 55" long.
That really changes things up!
That should make it better!?? I think..
If it's shorter it will be stiffer than a longer bow, therefore it will need to be thinner to get the equivalent draw weight.
That means the ratio of thickness to width is less and it will be less likely to bend sideways. E.G it will be more rectangular and less square than a longer ELB.
Say the ELB is 4:3 width:thickness a shorter bow of same width is likely to be nearer 4:2 width:thickness
Del
Title: Re: How narrow can limbs be? (Important)
Post by: Knotty on June 18, 2016, 05:41:15 pm
Is it backed? If it worked with Osage , it surely works with Guava.
Title: Re: How narrow can limbs be? (Important)
Post by: mikekeswick on June 19, 2016, 03:17:59 am
Firstly stop worrying! Don't stress on the string tracking lots of tricks to sort that out and more importantly just laying a string along a non bending stave doesn't actually tell you much....string tracking can only really be judged once it's braced. The simple answer then if it's off at all is to shape the handle to the string.
Do as Badger says ;)