Primitive Archer
Main Discussion Area => Bows => Topic started by: FilipT on April 28, 2018, 01:19:20 pm
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Short explanation:
Worked on my first black locust flatbow and I got the tiller even at 25" or so. I stopped because angle between tips and string become 90 degrees and if I would go till intended 28", it would be even greater. Since I before wanted a recurve, I decided to flip the tips so I could get rid of that bad angle and make my first recurve bow.
Suddenly there were lot of problems on bent shape. When I corrected them, new came in. That cycle continued for long and at the end I was left with thin bow that had torqued limbs and as a result string was not going through center like before. I threw the bow away as it didn't make sense to continue it.
How to prevent such errors in future? Any advice on when to flip the tips or how to watch shape when there are flipped tips?
Thanks
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A good way to prevent this from happening is to pull the bow to full weight the entire time through the tillering process but you have to make sure the entire limb doesn't have any weak spots in it when you start off. No part of a limb will bend too far if it is too strong or stiff so you don't have to worry about that as long as you bring it down evenly.
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How long was the bow?
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How long was the bow?
66 inches nock to nock.
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A good way to prevent this from happening is to pull the bow to full weight the entire time through the tillering process but you have to make sure the entire limb doesn't have any weak spots in it when you start off. No part of a limb will bend too far if it is too strong or stiff so you don't have to worry about that as long as you bring it down evenly.
That was probably the case. Even though I always use scale, this bow had a lot of waviness in the limbs, which I am not too experienced with so that created all kinds of trouble for me. Somewhere I probably left undulations too weak, somewhere too stiff, who knows.
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How long was the bow?
66 inches nock to nock.
If your string angle was 90 degrees at 25 inches with a 66 inch bow then something was terribly wrong with your bend.
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Pics always help to determine the problems.
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Yeah, start a new one nd post pics as you go. we will help you!
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How long was the bow?
66 inches nock to nock.
If your string angle was 90 degrees at 25 inches with a 66 inch bow then something was terribly wrong with your bend.
+1, or your handle section was much too long, perhaps
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If your string angle was 90 degrees at 25 inches with a 66 inch bow then something was terribly wrong with your bend.
I wouldn't use word terribly. I am not a complete beginner and terrible tiller doesn't really happen to me anymore. That being said, unfortunately I don't have any picture to show. But I can say this, whole limb bent, including tips. Tips were not stiff for couple of inches. That probably happened because of very thin limbs. This picture of someone's bow describes best how my tiller looked at 25". Notice the string angle.
(http://i.imgur.com/hVY6UtP.jpg)
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+1, or your handle section was much too long, perhaps
It wasn't. Handle was 4" and fades were 2" each.
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There was still 4" to 5" past the fades that was stiff.
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That is not my bow on picture; I put that picture to show you close approximation how my tiller looked like.
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If your bow looks like this one then my opinion stands. By getting those 10" or so near the handle bending the string angle will be changed and the bow can be drawn farther.
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Ok, tnx for advice, I am going to attempt another recurve, probably next week so I will post my progress.
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I renamed this thread from previous one how I failed making my first recurve. For the second attempt I decided to use deflexed hazel bend through handle longbow. Yes, you read right, I am using deflexed bow. It has not yet been on tiller tree and since it has deflex I thought I could recurve the tips so the bow basically becomes reflex-deflex bow. Here are the pictures, tomorrow I will start with the tillering.
Bow viewed from back, not the deflexed curve
(https://s9.postimg.cc/ny7imc0b3/back_up.jpg)
Belly up
(https://s9.postimg.cc/9f0dkxmlr/belly_up.jpg)
Bow resting on the side
(https://s9.postimg.cc/685u1bhlb/side_1.jpg)
Another picture from the side, not the deflex curve
(https://s9.postimg.cc/3qu2u1pz3/side_2.jpg)
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Here's how I straighten out twists in the tips.it really doesn't take much heat to make a adjustment .that said I work almost exclusively with elm.
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Luckily bow is not twisted in any way and I want to preserve that deflexed shape. Btw, anyone know if hazel responds to heat gun? I tried dry heat on black locust flatbow I mentioned in this thread and it bent without effort. I think it is in that way BL same as osage.
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I agree with Pat, way too stiff in the inner limbs. Just fixing that will make a huge difference in your string angle and everything else.
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hazel really likes the heat gun too. cheers
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hazel really likes the heat gun too. cheers
Really? Then I am lucky guy. Anybody have advice when should I introduce recurves, I mean at what draw length? I will start tillering in a couple of hours.
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I agree with Pat, way too stiff in the inner limbs. Just fixing that will make a huge difference in your string angle and everything else.
Thanks Badger, although bow you are talking about is for some time now in the fireplace haha. Anyway, I will know for the future what to do.
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hazel really likes the heat gun too. cheers
Really? Then I am lucky guy. Anybody have advice when should I introduce recurves, I mean at what draw length? I will start tillering in a couple of hours.
Before you start tillering. Some like to tiller the bow and then bend in the curves but sometimes it's better to start the bow off being its final design.
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That is an interesting idea, I must admit every time I see that people introduce recurves at 20" or so. Do you think maybe I could go for recurves when I get to brace height, instead of just at beginning or near end of tillering?
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No, put them in right away. You're already a bit whippy looking on this one too.
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Plenty of advice here so you're good.
What I have learned from recurves, wider limbs and wider recurves make things a lot easier. Less limb twisting and more successfull bows. Also helps the bow tolerate the added stress from reflex.
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When I introduced heat, I got good bend, but not on the tips. One tip cracked, and other one broke almost completely. Decided to not continue working on it. Even if I pike the bow, it would be shorter, I would have to make a whole lot a things on the wood. Since I have a lot of staves on attic, why bother further with it.
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This one is ruined too?
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I recommend boiling for recurves.
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Yes, ruined. JNystrom, I think I will go for boiling next time on whitewoods. But I think black locust might be best done with dry heat, it just becomes like a dough!
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Use steam or boiling for recurves, no matter the wood species.
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Hazel will not respond well to dry heat, boil it but set the recurve with the heat gun the next day or it will come out later. This bow would have given you a lot of trouble aligning the tips because they where too narrow and too thin. On the next one I recommend you keep the tips wide and if you are going for hazel again keep the whole bow wide.
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How do you mean set the recurve next day with the heat gun? What do I do with boiling then?
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Boil or steam it and then after it has set/dried hit it with the heat gun to lock the curve in.
Also why don't you cut the ends off this one and try a shorter one?
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i assume he meant first boil & bend & then the next day fix &stabilize the recurve with dry heat. also sorry you misunderstood my recommendation about heat treating hazel: i meant dry heat works well to improve efficiency with hazel, not bending. what you can do with hazel is bending recurves into the fresh cut wood and let it dry then. good luck!
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I'll try your advice with the next bow. Not sure what I will use though.
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I did that with my 2nd bow and it still works. Be careful, not too thick or they will crack, and while slowly bending added some dry heat. ( No warranty) >:D later stabilize it with dry heat. Edit: Dry wood certainly is best steamed.
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I floor tiller and try to get the outer limbs very close in dimensions(especially thickness)!while balancing it on the fulcrum to assure equal mass or close.sand down all hard edges to a small radius and do a dry run.
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simk
Very cool looking bow. I like the slight recurves like these, instead of aggressive static recurves. Ok, I wouldn't mind having such bow but I prefer the former.
bushboy
So you primarily worry about outer thirds where recurves will be and you try to get them equal?
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Ideally ,it's best to get both limbs equal as possible.balance at the fulcrum is a tool I use for this.i have found that it's all about the prep work,so when you go to bend it every thing move equally or close to it.i have only been using Marc's localized steam method for hooks,as you can see it works well!
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I changed the name of the thread. This has been a third attempt at making a recurve. Second one, hazel, broke at the tips like I mentioned at the previous page and this one is like the first one, a black locust flatbow. It is practically the same dimensions as the first black locust bow was, except it is a bit wider at the handle and fades.
I decided to follow PatM advice so I cut the string grooves in and immediately bent the tips. During the bending I got just a few minor raised splinters which were immediately removed and sanded down. Pictures are below. Soon I will proceed to tillering and will post here my progress. Looking forward to this adventure!
P.S. I have also one other roughed out black locust bow which is the same dimensions as the first one. So at the end hopefully I will get two almost the same looking bows. The second one will be a bit lighter in draw weight though.
Viewed from the back
(https://s9.postimg.cc/wh2nbuf73/IMG_20180511_184732.jpg)
Viewed from the side
(https://s9.postimg.cc/6yaayub2n/IMG_20180511_184904.jpg)
Bow before the recurving shown on the left, on the right is the second one I talked about above
(https://s9.postimg.cc/3q5tmd1tr/IMG_20180509_125244.jpg)
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I have yesterday bent the second bow and will go tillering next week. I will put pictures as I progress.