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Main Boards => The Bowyer's Bench => Topic started by: ProArcher on April 27, 2009, 08:08:00 PM

Title: My first attempt at a bamboo backed bow
Post by: ProArcher on April 27, 2009, 08:08:00 PM

Hi Gang I have built a Bamboo backed bow and would like some advise. The Tiller seems to continue to change the more I draw it. I have about 2 & a half inches of set. But the real problem is the upper limb bends more in one spot the the other. I am thinking about thinning out the limbs and adding a belly to bring the weight back up.
 So what do you think.

 (http://i704.photobucket.com/albums/ww42/ProArcher/0425091739a_3.jpg)

Title: Re: My first attempt at a bamboo backed bow
Post by: bigcountry on April 27, 2009, 10:21:00 PM

Serious hinges on that one.  It looks like you need to get the limbs bending much more mid limb to the handle.  And don't draw it with those hinges like that.

Title: Re: My first attempt at a bamboo backed bow
Post by: bjansen on April 27, 2009, 10:36:00 PM

Well it looks like a great start..here are my suggestions...you will definelty reduce the weight a bunch to get the tiller right but that would be better than a broken bow...you might be able to temper the belly to get the weight up a bit, to chop off an inch or two after you get it tillered.  

So to tiller that better, imagine more of a circular tiller (right now it is extremely eliptical).  I tried the point this out...sorry its a little sloppy (and hinge is spelled incorrectly)

Good luck

   (http://i492.photobucket.com/albums/rr287/bjjanse/untitled.jpg)

Title: Re: My first attempt at a bamboo backed bow
Post by: Pat B on April 27, 2009, 10:53:00 PM

Like said above get the inner limbs working more. Get the tiller right first. You can add a belly slat later and retiller to get your weight. I have successfully done it on two bows.
   What wood is your belly?

Title: Re: My first attempt at a bamboo backed bow
Post by: Eric Krewson on April 27, 2009, 11:20:00 PM

Yikes, those are some serious hinges.

You need a tillering gizmo.

Here is how to make one.

 http://tradgang.com/cgi-bin/ultimatebb.cgi?ubb=get_topic;f=125;t=001047

Title: Re: My first attempt at a bamboo backed bow
Post by: ProArcher on April 28, 2009, 08:21:00 PM

Thanks guys I will try everything. Eric I will start on a gizmo Thanks.


Sorry I for got the question

 (http://i704.photobucket.com/albums/ww42/ProArcher/Bamboobacked.jpg)

Title: Re: My first attempt at a bamboo backed bow
Post by: ProArcher on May 04, 2009, 08:01:00 PM

Ok I have 2 boards I can cut down for the belly Witch would you recommend. I have A nice piece of walnut and also a nice piece curly maple. Both have a great end grain and flat grain pattern.

Title: Re: My first attempt at a bamboo backed bow
Post by: Pat B on May 05, 2009, 12:50:00 AM

Find a belly wood that is strong in compression like osage or ipe.

Title: Re: My first attempt at a bamboo backed bow
Post by: Jeremy on May 05, 2009, 08:17:00 AM

Curly maple definitely does NOT have flat grain.  If it did, it wouldn't be curly maple.  Good for risers and veneers under glass, but not for anything that'll be working.

Get the tiller correct (and the belly flat) then add the belly wood if you really want a heavier bow.  It can be done, but it'd be easier to just make a new bow.  Like Pat said, osage or ipe would be great (you can get ipe flooring boards from most big lumber yards/hardware stores), but a really good piece of maple or even oak would be fine.  Walnut seems to be real sensitive... if the tiller isn't spot on you'll have problems.

Title: Re: My first attempt at a bamboo backed bow
Post by: ProArcher on May 14, 2009, 10:12:00 PM

Ok guys here is a shot after retillering. What do you think?

 (http://i704.photobucket.com/albums/ww42/ProArcher/retillered_bow_1.jpg)

Title: Re: My first attempt at a bamboo backed bow
Post by: bigcountry on May 15, 2009, 07:17:00 AM

Much more to be taken off the area fades to mid limb, but better.

Title: Re: My first attempt at a bamboo backed bow
Post by: John Scifres on May 15, 2009, 09:06:00 AM

Start with the basics.

Trim that riser down.  Get it working closer to the handle.  Think circular tiller.  After you have a few bows under your belt, you can start playing with big risers and a cut in shelf.  But you have to learn how to tiller first.  Tiller is everything in wooden bows.  EVERYTHING.

I highly recommend getting the first Traditional Bowyer's Bible.  Many libraries carry it or you can find used ones pretty cheap.     It\\'s $15.61 on Amazon Right Now! (http://www.amazon.com/Traditional-Bowyers-Bible-1/dp/1585740853)

Title: Re: My first attempt at a bamboo backed bow
Post by: ChristopherO on May 15, 2009, 11:19:00 AM

That would be a heavy duty eliptical tiller.  Meaning way over done eliptical tiller.  
John is right, it needs to bend closer to the fades.  You will probably be under draw weight by the time it is correct but that is the joys and trials of wood bow building.  The Traditional Bower's Bible 1 is seconded as the manual to go to.

Title: Re: My first attempt at a bamboo backed bow
Post by: Cody Roiter on May 15, 2009, 01:05:00 PM

I would like to know some more info on your bow there.. Is that a all wood lam bow or is that glass and what is your core wood... What glue did you use to glue it up with....

Cody

Title: Re: My first attempt at a bamboo backed bow
Post by: ProArcher on May 15, 2009, 03:26:00 PM

Thanks guys I'll keep working on it.
 As for the Bibles I have vol. 1 thru 4.
Still reading 4

Cody the 3rd picture shows The Red oak and Bamboo
The glue was Titbond III

Title: Re: My first attempt at a bamboo backed bow
Post by: ProArcher on May 27, 2009, 09:19:00 PM

Well I just thought I would add some more shots to see what you think.

 (http://i704.photobucket.com/albums/ww42/ProArcher/tilleredagain.jpg)

 (http://i704.photobucket.com/albums/ww42/ProArcher/upperlimb.jpg)

 (http://i704.photobucket.com/albums/ww42/ProArcher/lowerlimb.jpg)

Title: Re: My first attempt at a bamboo backed bow
Post by: razorback on May 28, 2009, 08:05:00 AM

Putting those clamps in the fade area will not give you a clear picture of the tiller. That bow needs to bend into that area and the clamps will stop that. Try to make a cradle that will fit the handle area and recheck the tiller. It isn't broke so still has potential. Keep working at it and a good bow will present itself.

Title: Re: My first attempt at a bamboo backed bow
Post by: ProArcher on May 28, 2009, 07:21:00 PM

Thanks Razor but the clamps are clamped to the fence not the bow. The bow is just hanging on them.

Title: Re: My first attempt at a bamboo backed bow
Post by: Dano on May 28, 2009, 07:46:00 PM

Both limbs seem to bend pretty well, I just can't stand to look at that riser, it's way too long for my tastes. You did well to get the limbs evened out.

Title: Re: My first attempt at a bamboo backed bow
Post by: Eric Krewson on May 28, 2009, 07:59:00 PM

Still way too hingy at mid limb. I will send you a gizmo if you want one.

Title: Re: My first attempt at a bamboo backed bow
Post by: bigcountry on May 29, 2009, 02:32:00 PM

From an untrained eye like my own, still need to take off material close to the fades and relieve that mid limb area.  But again, very untrained eye here.

Title: Re: My first attempt at a bamboo backed bow
Post by: ProArcher on May 29, 2009, 07:13:00 PM

Thanks again guys. It's always good to get the scoop on what I need to do. Dano the riser is a half inch shorter the pattern I got from 3 Rivers.

Eric That is way too kind of you. I have the instructions to make one. I just have to make time to go to my parents house and use their shop to make one. I have some tools here but can't get to them right now so what you see here is done by hand mostly.

Bigcountry all eyes are helpful to me. This is my second attempt at a bow. The first one exploded on me while pulling it on the tiller rack. I knew it was going to because as I filed and scraped a crack appeared in the base wood. But I continued on working on it anyway till it broke.

Title: Re: My first attempt at a bamboo backed bow
Post by: ProArcher on June 13, 2009, 08:23:00 AM

Well I think it's time to start over. I was sanding ion the bamboo belly and found bubbles in the glue. Well at least it didn’t brake apart.

Title: Re: My first attempt at a bamboo backed bow
Post by: bigcountry on June 13, 2009, 09:16:00 AM

Quote

Originally posted by ProArcher:
Well I think it's time to start over. I was sanding ion the bamboo belly and found bubbles in the glue. Well at least it didn’t brake apart.

I am at a simular point also with an IPE/Boo bow.  Learned a ton and will apply to a second one.  

One thing for sure,  your post shows the strength that bamboo can handle with that first pic