Primitive Archer
Main Discussion Area => Bows => Topic started by: nclonghunter on February 17, 2010, 10:06:19 am
-
If you make a bow from a small tree or sapling, perhaps 1 1/2 or 2 inches around, would it be better to de-crown the back or remove the belly leaving the crown on the back?
-
I would leave the back as is and be sure the belly is flat. Check out Jawge's site. He has info on sapling bows on there.
-
i should probably know this. what means the term--"CROWN". any pictures to illustrate?
-
Luke, the crown is the high point along the back.
The glossary in the back of TBBIV says... "The low or high arch on the back or belly of a bow".
-
Make the belly flat, probably pretty much across the diameter of the sapling for maximum width, but with a bit extra removed to work past the pith.
Then remove as much crown as you need to get to floor tiller weight, the tiller the belly as usual.
Hope this makes sense.
The principal as I see it is to maintain maximum width.
Del
-
Del the Cat, what you said makes sense and I was thinking the same thing only backwards....remove the back just past center pith and then tiller from belly...I will just have to try both ways and see what happens.
I am thinking the compression issues on belly would make flattening the belly first, the best option, but I suspect flattening the back first will spread the compression out when you begin to tiller the belly....I would also think reducing the belly first would give me more handle in the belly...I just like a flat backed bow, if possible. This will be a good project for 2010.
Any pictures of sapling bows would be great..
-
I don't remove the crown when I make a sapling bow. Most of the woods I use are stronger in tension than compression so decrowning is unnecessary.
-
Decrowning is not necessary and leads to potential back splinters. A flat belly is more important I believe. The less you do to the back the better.
-
And make it a little longer than usual.
-
This bow was made from a very steeply crowned log, if I had not de-crowned it, it would have ended up much narrower, or an undrawable weight, or it would have taken more set.
The original game plan was to have it as a bark-on bow.
(http://i411.photobucket.com/albums/pp195/Del_the_Cat/de-crownedbow.jpg)
De crowning doesn't do much harm as the lines of 'ring violation' run pretty much up the length of the bow along either side of the limb parallel to the edge, they don't cut across the limb. (Except where there is some twist in the limb, as you can see in the pic)
This was the 'bad half' of a split log, which was a sort of rounded triangle in cross section, so the 'good' half had a very flat back and this bow had a very pointy back, which I just had to decrown to make it work.
The bottom line is you just have to listen to the wood, and ya cannae use wha' ya havnae got!
(http://i411.photobucket.com/albums/pp195/Del_the_Cat/Birchbow.jpg)
It turned out to be one of my favourite bows.
(http://i411.photobucket.com/albums/pp195/Del_the_Cat/fulldraw.jpg)
BTW, that bark up the edges is still on there , and looks really good.
Del
-
Del, did you worry about making sure you had parallel lines in the rings you cut through? Or did you go for even thickness instead? Not too many proponents of decrowning around here, even though it's recommended in TBB1, so it's good to hear the voice of experience. Ever lost any bows because of decrowning?
-
If I don't use a Quarter Sawn Board.... I decrown all my Staves for my Paddle Bows...unless they come from very Large trees...because I want the Backs as flat as Possible...and I have very seldom had a Problem with Splinters lifting...but I have on two...and them ...I just Sinewed....
-
Here is one I just posted a while ago.it depends on the wood I know hickory is best with a crown on the back and a flat belly.
The thickness of the handle was the thickness of the tree.Hickory is so strong in tension that it can overpower the belly and cause excessive set.But heat treating can help that some.
[attachment deleted by admin]
-
Great info coming out here...Simple Hunter, I am wondering what the approximate thickness (across the base end) of that hickory bow was, to begin with. It looks great!
-
Decrowning is ok but not easy to do right. An easier solution is to leave the stave an inch or 2 longer than you normally do. LOL. At least that's what I do. I also leave the belly flat. Jawge
-
Del, did you worry about making sure you had parallel lines in the rings you cut through? Or did you go for even thickness instead? Not too many proponents of decrowning around here, even though it's recommended in TBB1, so it's good to hear the voice of experience. Ever lost any bows because of decrowning?
I just zipped a spokeshave down it and then worked the belly, it was bound to come out pretty parallel . Probably only took off aa quarter of an inch.
The back was slightly weird, (you can sort of make it out in the pic of the bare stave) the top had a steep crown and lower down there was a sort of groove down the middle (maybe it had been up against another limb?) so it was like a V at the top and a W at one point .
I've losts loads of decrowned bows, but not since I was about 11yrs old ;D (they were waaay too narrow and the wood was green... :-[ )
Del
-
Heres an interesting thought, or at least to me.....maybe the TBB folks can jump in here.
If you split two stave's from the same log and they are are removed side by side, then you de-crown one and leave the back alone on the other, making everything else the same, would they perform the same or not?
Tillering both bows to 55# @ 28", would they both have the same speed/performance?
-
Del, did you worry about making sure you had parallel lines in the rings you cut through? Or did you go for even thickness instead? Not too many proponents of decrowning around here, even though it's recommended in TBB1, so it's good to hear the voice of experience. Ever lost any bows because of decrowning?
Here's a pic of it near the handle. If I hadn't de-crowned it, it would probably ended up being as wide as the white section...
(http://i411.photobucket.com/albums/pp195/Del_the_Cat/detail.jpg)
Del
-
so if i split a 2 1/2" log in half should i use the inside of the tree to be the back or the outside to be the back?if the outside should i decrown it?
-
There's not enough wood for splitting. Make sure the string falls on the handle. Use a marker to mark belly from back. Choose the best side for the back. Remove belly wood with a hatchet. Actually get the limbs bending an inch or 2. Put it aside for a week. Remove the bark. Let it dry. Leave the stave an inch or 2 longer. The back is the back. :) Jawge
-
let's say hypothetically... ::) i already split it, then what?
-
The back is the back. Hypothetically of course. Leave it a couple of hypothetical inches longer. :) Jawge
-
let's say hypothetically... ::) i already split it, then what?
I think you've had the answer allready.
There are options, all of which are good depending on the actual wood and the required draw weight.
If you do what George says, you still have the option of taking a whisker off the crown later on if the draw weight is too high and you dont want it to get narrower.
It's the process we all use, do a bit, stop and think, if it's not right think of what the options are to move it towards the desired outcome..
AAAArrrgghhh no, I'm begining to sound like one of those dire middlemanagement presentations.
Think I'll quit while I'm behind.
BTW, Check out the 1hour bow, that was a small diameter branch...http://www.primitivearcher.com/smf/index.php/topic,16984.0.html (http://www.primitivearcher.com/smf/index.php/topic,16984.0.html)
Del
-
It seems like the answer to the decrowning question depends on the type of wood more than anything. You would not want to decrown hickory or black locust especially, but you may want to if it is a tension weak wood.
-
It seems like the answer to the decrowning question depends on the type of wood more than anything. You would not want to decrown hickory or black locust especially, but you may want to if it is a tension weak wood.
a tension weak wood like ash?
-
I don't think it is ever an option for most. When you decrown you have to still follow the grain so that the longitudinal fibers are not violated. I did it once but only to fix a splinter and then backed the bow. But everyone is free to experiment. :) Jawge