Primitive Archer
Main Discussion Area => Bows => Topic started by: snag on August 17, 2011, 01:53:52 am
-
This is a 66" ntn osage bow that is from spliced billets that Gary Davis did. At the fades it is 1.5" wide. It pulls 50#@23", I'm shooting for 50#-55#@28". At 6 3/4" brace height the left side has 1/4"+ tiller over the right side. So I'm thinking the right side is going to be the top....? But the right limb has too much bend in the outer 1/3...dangerously too much it looks like to me. I've been using the Gizmo and only taking off the high spots on the right limb and finding I can take it off evenly off the left limb. What do you guys think I should do from here?
-
This is at 23" draw.
-
That right limb is a little whip tillered, but I would not say it is dangerously so. If that limb has not taken set you are not in the danger zone yet. If it were mine I'd work the outboard part of the left limb to even up the tiller a little, then take thickness of the entire left limb and just inboard on the right limb until you make draw length. Then, make the right limb the upper limb as you discussed. If it really bothers you, or you don't make weight, it might be possible to stiffen that limb up a little by piking an inch or 2 off it. I personally don't think it's that bad though. I'm curious what the other guys think. Not sure you should proceed with just my thoughts.
George
-
Yup, I think you and George have already hit the nail on the head.
I'd just add, the first few inches out of the fade on the right limb don't seem to be doing anything.
I think I'd take a tad off there (and work evenly along the left limb) to slowly edge towards draw weight.
As the right limb works more near the grip it will take some load off the last third and it won't look so whippy.
If I have to be picky I'd say the left maybe has a slightly stiff spot just left of centre?
Slow and steady wins the day (Other platitudes are also available).
Del
-
I would go with what Del said,it really looks pretty good to me especially since you have 5 more inches to draw length. Slow and easy,that should make a fine bow. Not sure what you are seeing that look dangerous ?
Pappy
-
My advice is that AS SOON as you see a problem unbrace quickly and work on it. ;)
You can see when it is braced that there is a problem, you really shouldn't be pulling it at all until you have got the limbs bending an even amount. Personally I wouldn't have braced it until certain that the limbs are even. Also there is no need to brace a wooden bow so high, remember strain goes up a lot with increses in brace height. I never go higher than 6 inch and find that for a lot of self bows that somewhere between 5 and 6 inches max works best.
-
All good advice. Thanks, I needed that..... ;D
-
The brace picture suggests that the right limb is a bit weak, but I don't really see that in the full draw picture. I think you're fine - keep working it down.
-
I took more off the right limb at the fade and more off the left limb evenly to get it to bend more.
-
I think taking some off the fade on the right limb took the stress off the out 1/3 and made it bend a little more evenly.
-
Yup, that looks very nice now. :)
George
-
Can't remember who does this with the eliptical shape superimposed over the bow....but it helps me to see the shape of the bow better. I pulled it to 24" and got 50#. At 4 more inches to go do I just watch it's shape and keep pulling several times at each inch? 30-40 pulls to each inch mark up to 28"? Is there anything you would do to get the outer 1/3 of the right limb to bend more evenly? Take a little off the area out near the tip? Or just before the area that was bending too much?
-
:-\?
-
I think your tiller is looking good now, but I like to leave my tips a bit stiff, just like in your last picture. But to answer your question, I would just keep removing wood evenly now, making sure your tiller doesn't do anything funny along the way. If you want to get exactly 50lbs @ 28, you could tiller it to 50 @ 27 and the last 2 or 3 lbs you'll lose from final sanding and shooting it in, which will put you pretty close to 50 @28.
-
Thanks Cameroo, I'll take that path until I reach 28" and 50#+. Then I'll work on the handle.
-
I did a little light scraping and sanded the belly and edges. Got it to 58#@27". Now I'll shoot it in and see where it ends up. The top limb has about 1" of string follow. Guess that happens...? Thanks to all that tried to keep me on the straight and narrow. Got a lot to learn! Sure is fun to learn here at the Selfbow School of Learning though! haha
-
Awesome looking bow.
-
The extra set in one limb is because it was pulled too far before the limbs were even.
A good idea is at every increase in draw length that you take put the bow on a flat surface and really really eyeball it to see if it's taken any set (even a fraction) anywhere. If it has and it isn't evenly distributed along the limb then that area is weak and shouldn't be touched until you take off wood everywhere else.
-
Thanks Mike. Haven't heard that one before. David
-
Shot it a little last night. Other than needing to eventually make some lighter spined arrows for it they came off the bow quiet and fairly quick. Still needs a little more sanding.
-
Looking really sweet.
If you alread have arrows, you might consider adusting the arrow pass to match the arrows. E.G, make it closer to centre shot, just a few extra mm off the pass will make quite a difference.
I have two lots of arrows 70 grain points about 30 spine and 100 grain points about 40 spine. On the Osage I just made the 100gn felt best but shot a few inches left at 10yards, about 3mm off the arrow pass made 'em group about the same as the lighter softer arrows.
Dunno if that is of any use to you.
Del
-
Del, that's interesting. These 70#-75#'s are hitting about 4"-5" stiff or left of the mark. Should I just file off a little wood at the top of the handle, the narrowest point?
-
Del, that's interesting. These 70#-75#'s are hitting about 4"-5" stiff or left of the mark. Should I just file off a little wood at the top of the handle, the narrowest point?
Yup, that's the way to do it... terms and conditions apply, if the baw falls in half. it's now't to do with me ;).
Don't go mad, the other trick is ro rub a pencil along the arrow where it will rub on the bow, you can then check exactly where it's making contact. Mine was actually rubbing close to the belly at first so as well as removing a bit I also radiused it with a tad more off the near the belly so it now rubs plumb centre.
On my blog I mentioned 'tweaking' the bow after I'd shot it for a morning and a few people ticked the 'explain more box' so I did a blog entry explaining all my tweaks, here's the link.
http://bowyersdiary.blogspot.com/2011/08/tweaking-bow-set-up.html (http://bowyersdiary.blogspot.com/2011/08/tweaking-bow-set-up.html)
Have a go and tell us what you find.
Del
-
Thanks Del, I'll check out the "tweaking" area of your site.
-
No comments from me.... other than your tiller turned out spot on in the hand ;)