pecan for a selfbow?

[wazabodark]

[wazabodark]

[wazabodark]

Ok folks, here the latest set of pics of the Pecan Rollercoaster. He's been sitting in dryout land for two weeks. I only took him out to finish cutting the width to finished dimensions and do a little shaping on the limbs. Also scraped the tool marks off the back with a piece of glass and sanded with 100 grit.    I've decided to go ahead with the antler in the nocks. So do I do that now, or do I mount temporary blocks like I've seen others do? Also, I really like the wavy lower limb. I'm not gonna have to straighten that, am I?

[wazabodark]

 OK. I have the nocks mounted, tillering tree ready, and a tillering string built. What now?

[Art B]

I don't believe I've ever seen overlays done quite like that Ronnell. Probably be Ok since it's hickory, but to err on the safe side, I'd do a wrap right out in front of those overlays to prevent that back ring from lifting.

Next step, if you have the tips moving enough, place on the tillering board, using a short as possible long string, pull the bow down to about what you think is brace height. Then run a string line (affix to each end) from nock to nock to where you can stand back and judge tiller.

Once you have an even tiller, and the bow is light enough to string using a regular short string, then do so. Wood removal and sanding can all be done with the string left in place. Just don't cut the string. Easy peasy from there........Art

[wazabodark]

this is making me a little nuts. The top limb(on the right) is bending well with no tillering at all. The bottom limb isn't moving much at all. After lots of scraping this is what I've managed to get out of it. The first picture is at what I figure to be about brace height (7"). The second is 12". I'm at 15#@12". It seems that the limb is naturally inclined towards bending where the the roller coaster crowns to the back of the bow, and nowhere else. Is this normal? It makes sense to me, but should I be working to overcome this? Also, would I be better off working from the tip in or the fades out? Or from center out? I'm afraid to put the short string on it for fear of stressing the top limb.

[Art B]

For the time being Ronnell, keep your bow centered on the tree.

Looks like you need to do some more floor tillering on that lower limb to get it bending more before going to the tree.

One trick that I use that will get both limb close is to balance the bow for equal limb mass. Very simple and easy to do. Just mark the exact center of your bow. Now balance it on a pencil or something similar. Adjust limb mass until the bow balances at the center of your bow. This way, you know you at least have equal limb mass to work with. And maintain that balancing act right on through construction..........Art

[wazabodark]

I did the balance trick and the top limb is actually heavier than the bottom. Meaning the one that bends actually has more mass. Now I'm REALLY confused. It seems like taking material from the top limb is just begging this bow to come in under target weight. I'll do whatever you tell me, I'm just trying to train myself how to think about these things. As a frame carpenter I go out of my way to make sure wood doesn't move. Bowyering is the exact opposite of that.

[wazabodark]

I did the balance trick and the top limb is actually heavier than the bottom. Meaning the one that bends actually has more mass. Now I'm REALLY confused. It seems like taking material from the top limb is just begging this bow to come in under target weight. I'll do whatever you tell me, I'm just trying to train myself how to think about these things. As a frame carpenter I go out of my way to make sure wood doesn't move. Bowyering is the exact opposite of that.

[Art B]

One thing you're going to learn about full length staves is that you're dealing with uneven working properties Ronnell. So limb dimensions from limb to limb can and often does appear slightly different at times. That's why many bow makers prefer matching sister billets to work with.  

Wood removed for the sides, and perhaps tips of the top limb, will effect movement very little Ronnell. But a small amount of wood removed from the belly of the lower limb has greater consequences.  So stay with that balancing act...........Art

[wazabodark]

Got it, Art. Thanks.

[wazabodark]

Got it, Art. Thanks.

[wazabodark]

Okay. So I put in some time today and finally got limb mass equalized. I also got that bottom limb to start moving some. Now I have a couple of questions. First; what kind of arch am I shooting for with this style bow? Am I looking for a true arch or more of an ellipse? Second (and this is me thinking like a carpenter again) if the handle is centered in the cradle and the center of my string is under the peg on my tree, then I should be able to mark my limbs in 6" increments from centered and measure from there to my peg to check if I'm tillering evenly (but not necessarily properly), right? My wife (who hates my bow but is smarter than me), seems to think that the waviness of the stave would negate the effectiveness of this technique. I'm inclined to agree. Third; should the limbs bend from the fades out, or from the tips in?  oiu

[Art B]

Look for the greater bend of the limbs to be about where you started your side taper Ronnell. So you're looking for more of an elliptical tiller more so than an arc.

That's the beauty of an applied taper tillering over searching for one by scraping here or there for one. Or as Torges puts it, "stalking tiller".

If you have about 1/16" belly taper from fade to where the side taper starts, with even limb mass, first stringing will be very close to the correct tiller for your limb design.  

If you have a caliper, run it down your limbs, taking into accounts any irregularities in the bow's back, look for any high/low areas in the belly.

I think I mentioned this before, the growth rings can be a big help in determining where wood needs to be removed.

Oh, my hat's off to your wife!    

[wazabodark]

Okay, I'm back. I got a little busy building things for other people, but I've found time to indulge in my own selfish pursuits (my wife is thrilled). The limbs are bending more or less evenly so I put the short string on it.    . The pics show brace height, 12" of draw, and 16" draw. My scale shows 15# @ 16", so I'm cutting it retty close to target weight. That's not a real issue to me at this point, though. I shot a 50# bow the other day and although I could handle it, pt wasn't exactly comfortable. I'm used to a 30# recurve. Anyway, I can plainly see that there is tillering yet to be done, I'm just hoping that I can get some advice on where to start.

[John Scifres]

Right limb between the humps.

[wazabodark]

Finally got the bottom limb bending, but in typical fashion I overworked the @&%& out of it, completely ignoring the other limb. The pictures are at brace, 14", and 20". It draws 18# at 20", so I'm going to come in way under target weight. Doesn't matter though, I still have hope for it. And I'm learning quite a bit on this one.    . Any suggestions?

[wazabodark]

Finally got the bottom limb bending, but in typical fashion I overworked the @&%& out of it, completely ignoring the other limb. The pictures are at brace, 14", and 20". It draws 18# at 20", so I'm going to come in way under target weight. Doesn't matter though, I still have hope for it. And I'm learning quite a bit on this one.    . Any suggestions?

[wazabodark]

 I'll try posting that link again.

[takefive]

Good deal, this link works for me.  Your left limb looks great but the right one looks a little thin in the middle to me.  Then again, I've tillered exactly one stave bow and I know that natural humps and dips in the wood can deceive the eye a bit.  Do you have a picture of it unstrung?  A Gizmo and a cheap dial calipers are a huge help.  I also mark the side of the limbs every 6" from the fades out when I can first string it and measure each increment from the string as I do the final tillering to keep it even.  But that still doesn't stop me from making a few rasps in the wrong spot sometimes.  Hey, if your bow comes in light, but it's still shootable, give yourself a pat on the back and remember how it got that way so you won't do it again on your next one.  My stave bow came in 5# light, but I have some lighter arrows that shoot great thru it.