Primitive Archer
Main Discussion Area => Bows => Topic started by: paulc on September 30, 2019, 03:23:57 pm
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i've started a new bow and am hoping to have you all check my plan. Stave is 72" currently, I draw around 27-28" give or take. I am shooting for no less than 50lbs at 27" but would also like to come in over weight rather than under :-)
Limbs currently running 1.75 inches from fade to tips, 5/8ths thick from fade to tip. My plan was to leave it full width most of the way out...? Maybe narrow last 12"? Don't really know yet. I want to heat treat it before I get very far into tillering. But there is a descent sized divot in the back so I will have to back the bow-I guess you ought to back any hackberry? Anyway, I still need to make the rawhide for backing but my question is really about order of steps...
Rough out the basic outline of the limbs first and clean up the back as best I can.
Heat out prop twist and line up tips better?
Then heat treat the belly followed by rawhide backing?
Then go into proper tillering for final weight. Once I get to weight heat treat again?
Is that about right? Or is there a better order to go in? I was concerned about damaging the backing with heat treating but maybe that shouldn't be an issue if I heat treat correctly?
Thanks a bunch for the hand holding! Paul
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Where I stopped yesterday afternoon. Paul
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Try to have at least a 14" transition from fade end to fade end. You don't have that. I would seriously glue a lam on the back.
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Try to do your untwist tip lineup and heat treat all in one session. If you do your untwist tip lineup first and then come back later to do a heat treat you stand a good chance of losing your tip lineup. I just went though a bunch of that. I think maybe 5-6 heating sessions just going back and forth. If I had managed to do it all in one session it would be a done deal. Trying to figure out how to do it in one go may be tough but it beats 6-8 hours watching a heat gun. :D
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No need to back the Hack, so long as the back is in good condition. Hacks weakness is in it's compression, not it's tension. I didn't see the divot you mentioned, but if the back is dinged up and you need to put rawhide on it then do as DC mentioned. Get the tips lined up and all the heat treating done in one session. You lose too much progress otherwise. Get it bending well before the rawhide is applied. Not enough for it to come apart, but so far as you can safely go.
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Try to have at least a 14" transition from fade end to fade end. You don't have that. I would seriously glue a lam on the back.
woodly, I really can imagine a 14" fade?! could you send a pic?
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He is talking about the middle of the bow, starting at the end of a fade (toward a tip), through the handle, through the other fade. If you can visualize a three piece takedown, it would be the fat part!
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Ohhhh! I see! makes a lot of sense now!
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Try to have at least a 14" transition from fade end to fade end. You don't have that. I would seriously glue a lam on the back.
Explain your reasoning?
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Still, the fade to fade section doesn't need to be that long.
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Try to have at least a 14" transition from fade end to fade end. You don't have that. I would seriously glue a lam on the back.
woodly, I really can imagine a 14" fade?! could you send a pic?
Yep right here...……..
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That's a very atypical handle/fade layout. Not wrong, atypical and not necessary. A 4-5" grip and 1.5-3" fades is adequate 100% of the time.
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You can bet the fades on that one are moving quite a bit too.
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This is a good discussion on the handle and fades.....I put a tape measure on my blank at lunch it measured right at 12" fade out to fade out....I am guessing the proper length of handle and fades "depends" just like about everything else in primitive bow making:-)
Thanks all, Paul
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Try to have at least a 14" transition from fade end to fade end. You don't have that. I would seriously glue a lam on the back.
Why 14"? How would you go about gluing a lam onto the back of what you think is an already too short handle section?
PaulC - the one thing I would be mildly concerned about is if you intend keeping the limbs parallel for a decent proportion of their length 5/8ths out of the fades is a wee bit thin. Make sure to go gently floor tillering and getting to brace, the main thing will be getting a good thickness taper early so the fades/inner limbs aren't worked a bit hard early on.
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Bownarra, you're thinking that parallel for the full length is not the best idea..? I was thinking parallel for as much length as possible to have the load carried by as much wood as possible. Sounds like you think that might over-stress the fades/inners?
I will try to get a pic of the damage to the back of the bow later tonight.
Paul
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My opinion, 72 inches is long. 28 inch draw is average. You can go parallel. The tiller won’t be round but elliptical, bending more as you move from the fades. You will have a lot of bow in the middle not working much, but you won’t be trying to throw all that wood forward. The bend will be mid Limb out, but done right the power will be in the mid inner limbs.
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Slimbob et al...here is the damage on the back. It is of course located where the fade fades into the limb....
Thanks for the help. Paul
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If it were Osage I would sand it smooth and forget it. Just not sure on Hackberry. Where will it be on the bow? In the handle, no problem. Mid limb, a concern. I am tempted to say sand it and forget it but rawhide is a safer option. See what others offer up.
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It is pretty much the fade...the knot on left is in the handle with fade happening to the right....P
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The fade wont bend so I would sand and forget. I will caution you that rawhide is safer and doing what I suggest could fail spectacularly, but I think you will be OK.
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My two cents. Whether its actually worth that much, I don't know.
I wouldn't back it, rawhide wont prevent blow up's, just tiny splinters on occasion and its heavy and slow. That being said, all fades do bend some. Its not enough to worry. I would wrap sand paper around my finger and sand all the edges of that divot smooth and round. Then continue on and enjoy the build.
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I agree 72" is a bit long. If it were my build I would cut a few inches off one end so that it centered the divot in the handle. Of course that is assuming you have enough thickness to shift the center.
As far as the parallel limb width is concerned, I understand your line of thought behind it. However it's a flawed logic. The reason bows taper toward the tips is leverage. The load on the limbs decrease from the center outward. By leaving the limbs wide further out, you will have to make them progressively thinner to get them to work properly and yet they will still have more mass than a limb that tapers in width. Even with an elliptical tiller it will be less efficient.
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Hello All, please see attached pics. I roughed out the stave yesterday and got it to bounce a bit on the floor-In my limited understanding of all this that is floor tillering :-) I ended up tapering the limb width rather that going with parallel limbs...I honestly don't understand the physics of it but I think staying away from elliptical tiller is probably in my best interest at this point in my understanding of bow building.
I then toasted the heck out of the belly- I still need to shape the tips and cut string grooves before I start tillering on the tree. But please see the pics and comment. There is a layer of bad wood on the belly that extends from one limb through the handle and shows up a tiny bit in the other limb. There is a good bit of damaged wood on the upper limb but my hope is that is mostly scrapes off as I tiller...thoughts? Is this stave dead already? Wish I had photo'ed it before toasting as it would be a lot clearer...
Silmbob in particular, but everyone- Bob you said at some point on this board that you tend to start working tips first-get them to bend a bit and then work your way towards the fades? Is that right and can you talk a bit more about that? What are other schools of thought of how to progress on the tiller?
And the handle seems pretty clunky to me at this point-I say the handle and fades are about 12" now. I can get them down to 10" right? Simply make it smaller? General comments on current handle shape and layout?
Thanks! Paul
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2 more pics
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Not the tips first. What I mean is don't get the fades (near fade) bending early. That's last for me. I want it to bend right up to the fade when it's finished, but bending there too early is a problem. Get it bending an inch or 2 beyond the fades, all the way to the near tips (assuming stiff tips). Get that bending in a nice arc and matched limb to limb. The last few inches of draw length for me is bringing the bend up to the fade. Too early there and you will come in under weight trying to play catch up with the rest of the limb. You have to have it happen first before it completely makes sense I think.
Few additional thoughts...The bad wood is what it is. All you can do is see if you will get past it. I think you will. Just a guess though. The handle at this point should be decided and it appears to me it is. I would tiller without further regard for the handle at this point.. Read the other "Hackberry" post near this one for a description of what I would do next. I didn't invent any of this, claim that it is "THE" way, nor necessarily the best way, it's just the way I do it and it works well as wellas being easy to describe over the internet.
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Thanks so much for feedback.
Paul
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Hey, your at the "bow making" stage now. Everything before this was furniture making. This is the fun part...the difficult part...the deciding part. This part was the reason my finish work was never really good. I just lost interest when the tillering was done.
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is that wood heat treated or is that rotted, or bad wood? Cant really tell. if its bad wood just hope that you get past it. then heat treat the wood. if not to help the bow, do it to make your workshop smell good!
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It's both deerhunter....hopefully most of the damaged wood will scrape away as I tiller.
Best of luck with your hackberry project!
Paul
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You too! We shoukd do like a shoot off and see who makes the better hackberry! ;D
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Hi Paul,
I'm with Slimbob. Get to a short tillering string and brace ASAP and stay away from the handle fades until last. Focus on the mid limbs first then scrape out to tips and fades last. Heat treat as you go. Nothing you can do about that wood discoloring so...screw it, just go.
It appears you've already laid out your handle and have the width increasing out from the grip through the fades to maximum in limb length. I'll throw in my thought...it appears like an overly long design. My perspective is that a 4" grip with 2" fades is plenty. I suppose if you had monster hands maybe another inch for the grip. Even at that, I barely hold the my wood bows when shooting, really only grabbing them with my middle finger and pointer...but I'll digress.
Hope you've been well.