Bamboo Backed Osage Issue/Question

[U.P.dragon]

Hi guys,

I'm building a bamboo backed osage trying to follow Dean Torges' Hunting the Bamboo Backed Osage DVD. I think I've got it to where I can put a very low brace height string on it.

If I put a string on it so its tight, but not flexing the limbs much, the string perfectly bisects the center of the handle. If I put a few more twists in the string to put it at a ~2 inch brace height, it'll try to pull the string to the back of the bow...almost like it wants to be strung backwards.

Did I mess something up or can this happen if the bow is too stiff/needs more wood taken off? I'm stumped. The only other thing I can think of is my nocks aren't exactly perfect side to side yet and the string loop is sliding off to one side?

Any ideas?

[Pat B]

Will you post pics of the tips with string grooves with the string in the grooves?

[Mad Max]

Will you post pics of the tips with string grooves with the string in the grooves?

x2

Normal for a low 2" brace for tillering with reflex, I'm not familiar with his DVD

[dbeaver]

I've had this experience with a highly reflexed glass bow and I thought I'd never get it strung.  The bow was too heavy and was stretching the slack in the string until it reached the point it would flip over.  With the right string and a bit of work on the profile to reduce weight It simply won't flip like it was.

[U.P.dragon]

Thanks guys. I did put some reflex/deflex when I glued it up.

Sounds like I just have some more work to do before I brace it. I think the bow is stretching the string quite a bit too and I'm skeptical of the bowyer's knot I have in one end.

I'll post some pics of the string grooves and the bow tonight. How do you guys do your string grooves? I've just been measuring down from the end on the belly and back where it looks like the connecting line would be ~45 deg. I've been using a chainsaw file.

[Pat B]

I do my string grooves just like you do. Be sure the grooves are deep enough, at least 3/4 the string thickness, more would be better. If a bowyer's knot is properly ties it shouldn't be a problem of pulling out. That's how I have always made my strings and have never had any trouble with them.
 How much draw weight do you estimate the bow pulls now? Side profile of the bow's R/D would be helpful.

[U.P.dragon]

Got some pictures uploaded. I see there is a crack in the bamboo on one nock. Looks to just be a splinter on the very outside layer of the bamboo. Dean Torges has you scrape that layer, hopefully it comes out and doesn't go too deep.

I've only built one other bow. Hackberry self bow that turned into a kids bow. So hoping to not repeat that, but if I do, oh well.

[U.P.dragon]

Oh and I bet its at least 100 pounds right now if not more. I doubt I could pull it back very far at all and don't want to, but floor tillering its pretty heavy.

[dbeaver]

I'm under the impression that glass bow I spoke of was over 100 pounds.   From where I started to how thin the limbs are now is extreme. Almost as skinny as I will take them and the bow is still 61 pounds at 28.

I'd pour thin super glue in the tip Crack amd wrap it in plastic and then with electrical tape or inner tube to keep it tight

[Pat B]

I'd say to get the bow down to a workable weight before trying to bracing and drawing it. Then the bowyer's knot isn't properly done even though it probably will still work. And, you need to remove all sharp edges around the nocks. The sharp edges is why the boo split, the string pulled that edge instead of laying over a rounded edge.

[Mad Max]

Take the string off and put some super glue in the crack and push it back in place.
No problem

[U.P.dragon]

Thanks for everyone's help thus far. I haven't gotten a chance to work on it this week, but will send some more pics once I get it down in weight some more.

[U.P.dragon]

Okay, I got to work on her some more. I added some nock overlays, partially to deal with that crack I put super glue in and I rounded everything off to a more finished state.

I worked on the tiller a bunch more. This is from about a 6" brace height and about 20 inches. Where would you focus on scraping? To me the left limb looks stiff on the very tip and the right maybe might be a little stiff? Its a asymmetrical bow the right limb is the top.

[Pat B]

Yeah, you could get both outer limbs bending a little more(leave the last 6" stiff) and the right limb right out of the fades.
 You did a real nice job with the tips. 

[U.P.dragon]

Thanks Pat! I scraped some more on it today. I'm at 49# at 29 inches which is about what I was shooting for, so I"m afraid to scrape anymore. To me maybe that left limb is a little stiff right in the middle? I took off 3 scrapes right there after taking this pic, but I think I'm just going to go forward with it though.

[Mad Max]

Picture is to big

[Roy from Pa]

Not looking too bad.

[U.P.dragon]

Thats a cool trick. I haven't heard of the elliptical deal. Is that what you should shoot for? Would you scrape where the gap is bigger or the opposite?

[Mad Max]

Thats a cool trick. I haven't heard of the elliptical deal. Is that what you should shoot for? Would you scrape where the gap is bigger or the opposite?

If you are at your weight I would leave it alone.
If you could cut the yellow ellipse in half and slide each side over a bit you on.
The black screw driver handle sticking up behind the left limb, it looks flat to the left (scrape some) ,---and a little hinge to the right.

[U.P.dragon]

I finally got this bow finished up. My first bamboo backed osage bow and my first successful "self-ish" bow. I built one other true self bow out of hackberry that ended up a kids bow.

Thanks to everyone for their help and advice. I hate the internet, but the one good thing is the access to experienced people who are willing to help and pass on what they know.

64 inches 49#@29"