Primitive Archer

Main Discussion Area => English Warbow => Topic started by: cool_98_555 on April 09, 2013, 10:57:16 am

Title: Bamboo Backed Osage Warbow?
Post by: cool_98_555 on April 09, 2013, 10:57:16 am
I have just acquired a very good osage board at 1" thick and 72" long.  Grain is very good, with only 2 runoffs on the back.  Thinking of backing it with bamboo (strip is 1/4" thick).  For this warbow I want 100# @ 30".  Thinking of having handle area at 1.5" wide by 1.25" thick (bamboo backing included) and tapering out to .5" wide by .5" thick tips.  Is .5" thick enough to start tillering for 100#,  or should I start with .75 in thickness at tips?  Any other recommendations for width at handle are encouraged.  Thank you for your help!
Title: Re: Bamboo Backed Osage Warbow?
Post by: Del the cat on April 09, 2013, 11:26:07 am
You would probably be fine with those dimensions for a boo backed laminate.
With a stave it's better to keep some extra width to allow you to move the nocks from side to side if necessary to stop any sideways bend/twist.
I normally rough out to 30mm square at the grip and 20 mm square at the tip. keeping the 30x30 for about 6" or so either side of centre and then taperinging out to the tips. I also go by the rough guide of 2mm thickness change every 6" along the limb.
Once it's flexing then it's down to eye and feel of course.
Roughing it out square gives some extra thickness and prevents you coming out light, and when I say 30x30 I mean that's where I draw the line, and I say outside of it, not on it.
The boo will need to be nice and flat on the gluing face and prob a bit thinner at the tips.
Hope that helps.
Oh, and glue it up with 1 or 2" of reflex, 'cos it'll pull a bit out when you tiller it.
Del
Title: Re: Bamboo Backed Osage Warbow?
Post by: adb on April 09, 2013, 05:20:37 pm
Your bow will end up 70" ntn once you cut the nocks on a 72" stave. That's ambitious for 100#@30". Certainly possible with bamboo/osage, but your tiller will have to be spot on throughout. I'd go with 1.25" wide, not 1.5", especially if you want a rounded belly.
Title: Re: Bamboo Backed Osage Warbow?
Post by: Del the cat on April 09, 2013, 05:26:55 pm
Your bow will end up 70" ntn once you cut the nocks on a 72" stave. That's ambitious for 100#@30". Certainly possible with bamboo/osage, but your tiller will have to be spot on throughout. I'd go with 1.25" wide, not 1.5", especially if you want a rounded belly.
Why the heck would you lose 2" ???
If you do a horn nock correctly you can easilly just come down less than 1/2" at each end, even allowing a second groove for a stringer on the top nock.
If you are really careful you could probably get away with 71.5" ntn !
You can glue a block on the back of tips for temporary nocks during tillering.
Mind I agree that a bit more length would be nice.
Look at my Horn Nock Instructional ob myblog, you can see how close the gooves are to the tip.
http://bowyersdiary.blogspot.co.uk/search?q=horn+nock (http://bowyersdiary.blogspot.co.uk/search?q=horn+nock)
Del
Title: Re: Bamboo Backed Osage Warbow?
Post by: adb on April 09, 2013, 05:33:44 pm
I usually lose 3/4" to 1" off each tip when I add overlays and cut the nocks.
Title: Re: Bamboo Backed Osage Warbow?
Post by: Del the cat on April 09, 2013, 05:58:37 pm
I usually lose 3/4" to 1" off each tip when I add overlays and cut the nocks.
Yeah, that's the advantage of a horn nock that goes right round the tip and adds support and strength, you can almost treat it as an extension on the tip of the bow.
I make sure the groove is actually cut where there is still wood underneath but it can get pretty close to the tip of the wood.
I daresay it would be possible to take it out beyond the wood, but I wouldn't want to try it on a 100# bow!
Del
Title: Re: Bamboo Backed Osage Warbow?
Post by: adb on April 09, 2013, 06:37:36 pm
Even with glue on horn nocks (which I don't do often), I don't extend the nock groove beyond the wood, especially on warbows.
Title: Re: Bamboo Backed Osage Warbow?
Post by: Del the cat on April 09, 2013, 06:57:08 pm
Even with glue on horn nocks (which I don't do often), I don't extend the nock groove beyond the wood, especially on warbows.
That's what I said diddle I? *
There's a world of difference between "Not extending beyond the wood" , and throwing away an inch of limb tip!
I'll quit now while I'm behind ;)
Del

*From an old English Joke:-
Man goes into the butcher's shop and says"I'll have a pound of kiddly please"
Butcher says, "Kiddly? Surely you mean Kidney?"
Man says "That's what I said, diddle I?"
 ::)
Title: Re: Bamboo Backed Osage Warbow?
Post by: toomanyknots on April 09, 2013, 09:46:21 pm
Look at my Horn Nock Instructional ob myblog, you can see how close the gooves are to the tip.

One thing I hate about making the nocks super close to the wood, is that my hitch knot always will dig into the wood right below the knock and make a dent. This every happen to anybody?
Title: Re: Bamboo Backed Osage Warbow?
Post by: adb on April 10, 2013, 02:42:44 pm
Even with glue on horn nocks (which I don't do often), I don't extend the nock groove beyond the wood, especially on warbows.
That's what I said diddle I? *
There's a world of difference between "Not extending beyond the wood" , and throwing away an inch of limb tip!
I'll quit now while I'm behind ;)
Del

*From an old English Joke:-
Man goes into the butcher's shop and says"I'll have a pound of kiddly please"
Butcher says, "Kiddly? Surely you mean Kidney?"
Man says "That's what I said, diddle I?"
 ::)


I don't throw away an inch of limb tip, but I do measure  in 1" from the end of the tip overlay to cut my string grooves. What do you do?
Even with horn tips, I still measure back at least 1" into the wood of the limb tip on each end. This means my bows become 2" shorter ntn than when they started. Like I said, what do you do? I don't think extending any tip overlay or horn nock beyond the wood of the tip is good practice. In my books it's too weak, but I've been wrong before.
Even looking at the Mary Rose bows close up, I could see the remnants of the string grooves at least an inch down the limb from the tips.
Title: Re: Bamboo Backed Osage Warbow?
Post by: Del the cat on April 10, 2013, 02:53:20 pm
I've already posted a link to a blog entry showing exactly what I do as a 2 part 'how to do horn nocks'.
It took a good deal of time and effort to video and post it.
Here's the link again...
http://bowyersdiary.blogspot.co.uk/2013/02/horn-nock-instructional-part-1.html (http://bowyersdiary.blogspot.co.uk/2013/02/horn-nock-instructional-part-1.html)
Del
Title: Re: Bamboo Backed Osage Warbow?
Post by: bubby on April 10, 2013, 06:54:44 pm
I've already posted a link to a blog entry showing exactly what I do as a 2 part 'how to do horn nocks'.
It took a good deal of time and effort to video and post it.


I think this means we better watch it ::) :laugh:
Title: Re: Bamboo Backed Osage Warbow?
Post by: adb on April 10, 2013, 07:05:56 pm
I've already posted a link to a blog entry showing exactly what I do as a 2 part 'how to do horn nocks'.
It took a good deal of time and effort to video and post it.
Here's the link again...
http://bowyersdiary.blogspot.co.uk/2013/02/horn-nock-instructional-part-1.html (http://bowyersdiary.blogspot.co.uk/2013/02/horn-nock-instructional-part-1.html)
Del

Sorry, Del... didn't see your link, but I'll definitely check it out! Thanks.
Title: Re: Bamboo Backed Osage Warbow?
Post by: adb on April 10, 2013, 07:11:13 pm
OK... checked your link... awesome. That's how I do it myself. But, as far as I can see, you're still 'using' at least an inch of each limb tip to fit your nock, thereby ending up with a bow about 2" shorter than the stave you started with. Yes?
Title: Re: Bamboo Backed Osage Warbow?
Post by: Del the cat on April 10, 2013, 07:20:02 pm
No,No For pities sake NO! :'(
Look at the picture of the temporary nock and the groove filed into the back of the bow!!!!!!, it's about 1/4" away from the tip!!!!!!
I stick some tape on the back of the bow and measure 6" from the temporary nock and draw a big pencil line .
When the horn is stuck on I measure the 6" back from the pencil line and file the groove into the horn... so it's still 1/4" from the end of the wood.
Ok there is an extra 1" of horn sticking out the tip, and maybe 1" on the grip side of the groove, but nock groove to nock groove is exactly the same as it was before I stuck on the horn.
I'm not sure if you are teasing me now ::), or if you need to go sit on the naughty step ;)
Del
Title: Re: Bamboo Backed Osage Warbow?
Post by: adb on April 11, 2013, 02:42:00 am
No, I'm not messin' with yah Del. As you can obviously figure, I don't do horn nocks very often. I mostly do tip overlays, and I don't make the overlay go past the tip of the bow limb, so I lose an inch off each tip when I measure back to cut the string grooves.
Title: Re: Bamboo Backed Osage Warbow?
Post by: mikekeswick on April 12, 2013, 04:31:27 am
Even with overlays there is no need to measure a full inch in off each tip and with proper horn nocks you would only need to 'lose' 1/2 off the whole bow or a 1/4 per tip. Del is spot on. Horn nocks take a little perfecting to get them just right and i've done hundreds of the beggars....
Title: Re: Bamboo Backed Osage Warbow?
Post by: Pat B on April 14, 2013, 01:45:25 pm
I would make the bamboo no thicker than 1/8" at the crown at the handle. Most of the strength in the boo in in the closely packed power fibers just below the rind. Shape the outline of the bow on the boo and cut it out. Then thin it to 1/8" at the handle and thin it more as you go towards the tips. You can leave the backing 1/8" its full length also.