I made my first bow as a red oak board bow from poorfolkbows. That bow was awesome. It recently wore out after a few thousand shots, probably due to my poor bowyery.
I decided to try an osage board from 3rivers with a planed piece of bamboo for backing. The board is just over 2" wide, but the bamboo varies from 1-1/2" up to 1-3/4" in places.
I don't have any experience working with bamboo, and it looks like I have a lot to learn.
Here is my plan gleaned from TBB and lurking online:
1. Trace out bamboo strip on bow's back, shorten board width to that amount (around 1-1/2").
2. Rough out limbs, keeping full width to mid-limb, then taper to 1/2"
3. Trace new bow outline to bamboo strip, remove marked excess
4. Now thin bamboo from 1/8" in the handle area to 1/16" at tips
5. Do glue-up, followed by riser, tillering and finishing.
Questions:
1. How far off base am I?
2. When people measure thickness of bamboo, are they referring to thickness at the crown, or on the edges?
Thanks for any guidance.
You are in the ball park.
You can shorten the steps some.
1. Trace or lay out your bow limbs etc. on the flat part of the bamboo. Cut to line, I use a bandsaw.
2. Reduce thickness of bamboo so edges are not more than 1/8 inch. Taper as desired.
3. Take the osage reduce to desired thickness and taper..
4. Prepare form. Glue on bamboo to belly slat. Glue in reflex and or deflex. Next tillering.
So much of importance gets missed this way, I'm hesitant to help. I don't mean to he a smart@$$, but it's like 'simplifying' brain surgery by condensing it into 5 simple steps. As long as you do them all, you're golden.
1. Knock patient unconscious.
2. Open skull.
3. Find brain and repair.
4. Close skull.
5. Wake patient.
My advice, in the absence of more specific questions, would be to get Dean Torges' dvd, "Hunting the Bamboo Backed Bow"... review, rinse and repeat... then ask any questions you have.
@macbow, Thank you. I wanted somebody who knows something to confirm that I'm not standing somewhere in the parking lot.
@Bowjunkie, smart@$$ is exactly what I'm looking for, because currently I am a dumb@$$. I will purchase that DVD - thank you for the reference.
I thought the thread said, "my first BBQ bow" guess that's why I am supposed to wear glasses.
Youve got more bowyering experience than I do seeing as I've got 0 successful bows to my credit, but I did notice at least one step that you either overlooked or possibly thought it was so obvious that it didn't warrant mentioning.
When you back a bow with bamboo you are supposed to make sure the nodes are spaced in a particular way. This guy explains it better than I ever could since Ive never attempted it and don't exactly understand the process http://poorfolkbows.com/ipe2.htm
Also be sure to wear a mask when you work with bamboo, it can wreak havoc on the lungs
The Dean Torges video is basicly what I follow.
I measure the bamboo's thickness from the crown. When you cut it to your width, you'll probably have to rasp it down a little. You want the edges of the bamboo to be a knife edge or just a hair thick. It's hard to explain, but I hope that makes sense.
Here's a good build along to follow. He used Ipe instead of Osage, but the method is the same. I referred to it a lot for my first BBO.
http://tradgang.com/cgi-bin/ultimatebb.cgi?ubb=get_topic;f=125;t=009703;p=1
@Kohlqez - thanks, I had seen that description but hadn't studied it (didn't stick on the first read), but after your comment I have read it more carefully and I get it now. The piece of bamboo I got is exactly 72" long so I don't have much wiggle room for centering the nodes. It's stored in a different location so I will have to measure it tomorrow to see where the nodes fall. If they aren't centered then I will need to either ignore it or shorten the bow. Let me see where they turn out.
@macbow, yes, that's going to need to be required viewing for me before I pick up any hand tools. I really want to not screw this up, so I am slowing down considerably to learn as much as I can beforehand. I may screw it up anyway, but I don't want it to be because of some dopey blunder.
@takefive: that is helpful, and yes, that makes perfect sense. That's a great build along, thanks!!
The last two I made had me scratching my head because the nodes were so unevenly spaced. I wound up with one node well inside the fade and the other at the edge of the fade to keep them more evenly spaced at the tips.
(http://i376.photobucket.com/albums/oo207/okdoak/Wooden%20bows/bbotrilam4_zpshxu5rw07.png)
I kept them more even at the handle on the other one, but wound up with nodes a couple of inches from the tips.
(http://i376.photobucket.com/albums/oo207/okdoak/Wooden%20bows/bbocurve6_zps1bxdow0l.png)
The node spacing is cosmetic anyway. Sure it looks nice with evenly spaced nodes, which is how I lay mine out when possible. But it's no big deal.
(http://i.imgur.com/zFhVnFs.jpg)
Takefive, those look great.
Could you post a close up of your handle, arrow pass design.
@takefive and Roy - D@mn! those are mighty fine looking bows. I tell you: if mine ends up looking even half as good as either one of those, I'll be a happy man.
I didn't measure the nodes on my boo until today: the uppermost node is 11.5" from the end, while the lowermost is 13". So it's pretty close already, but I could cut 1.5" from the lower end to get them exactly evenly spaced from the tips. If there aren't tangible design benefits then I probably will just leave it alone. The nodes aren't a constant distance between, so it's going to be unbalanced somewhere regardless of what I do on the tips.
I believe I read somewhere that the nodes are the weak point in the backing system, so I can see an argument where those optimally would be balanced from the ends, which might help tillering or something else...? But there's a difference between theoretical optimality and "plenty good enough" and for my first BBO I would prefer to err on the good-enough side.
@takefive, I would like to second macbow's request for additional closeups.
Roy - is that something silver I see in the handle area? What is that? Is it an attached arrow shelf of some kind, or is that just an illusion in the picture?
After tillering the bow on the tree, I put about 100 arrows through it, then recheck the tiller. What you see is the leather arrow rest with a piece of tape over the top to keep the tung oil finish from penetrating into it, which would make it harder than what I want it to be.
I see - that makes sense. Repeat: mighty fine bow.
Finished riser with a leather arrow rest, same bow.
(http://i.imgur.com/lbvAjFh.jpg)
(http://i.imgur.com/viZhYQu.jpg)
Jeez, I miss a day or two on here and suddenly Roy shows up :)
Here are the links to the bows and pictures of the offset handles. I got the idea from Stim Wilcox's book "The Art of Making Selfbows". Except for the handle, honestly, I try to copy Roy's bows the best I can.
http://tradgang.com/cgi-bin/ultimatebb.cgi?ubb=get_topic;f=125;t=013286;p=1#000000
http://www.primitivearcher.com/smf/index.php/topic,58003.0.html
Thanks for posting the pics.
So the offset is done during the layout?
I don't lay it out until it's almost completely tillered. I have a better picture that shows how I lay it out. It was a pyramid bow 2" wide at the fades, so I could get the arrow pass just about center shot.
(http://i376.photobucket.com/albums/oo207/okdoak/Wooden%20bows/offsethandle1_zpskednsrz5.png)
Love it will have to put this on my to do list for a special friend.
I bought the Dean Torges DVD. It arrived today, and I watched it. I now see why you recommended it. I'm going to need to watch it several times.
In the meantime, I have some questions. The bow Dean outlined was a bit shorter than (64" NTN) and not as wide (1-1/4") as I expected. That's fine, and I don't mind to make a bow just like that, and if it looks like his, then it will be a great bow. He also described putting some reflex in the tips, which I hadn't planned on, but after watching the video I very well may give it a try.
But he didn't quantify the draw weight of the finished bow. I was wanting something in the 50# range. The trick is that my draw length is shorter than most (24-1/2"). That means I'm looking for a bow that would be something around 60# @ 28", though I'd never draw it that far back.
Would I need to change the given dimensions (longer/wider limbs, etc) to get a bow like I want? Not having experience with this wood/boo combination, I'm really flying blind on how stiff these things are at the floor-tillered stage.
Any guidance would be appreciated. I have other questions, but overall bow dimensions are pretty close to the front.
I have made about 50 BBOs, my method is simple.
Draw your finished bow pattern on the belly of the bamboo, cut out the pattern outside your lines and sand carefully to your lines. Thin your bamboo edges to 1/16" from the handle to the tips keeping the belly flat in the process.
Cut out your osage core leaving it oversized in width. I taper my core from fade to tip and floor tiller it.
Draw a center line on your core, butter up the pieces with glue, line up the bamboo with your core centerline. I like to tape everything together before apply the clamps.
(http://img.photobucket.com/albums/v181/ekrewson/bow%20making/frankenbowglueandtape.jpg) (http://smg.photobucket.com/user/ekrewson/media/bow%20making/frankenbowglueandtape.jpg.html)
When I remove the glue-up from my clamps I use a belt sander to thin the osage to the edge of the bamboo.
I have found no matter how well you line up your bamboo with the centerline it will be a little off after glue-up. I leave my bamboo tips a little wide, sight down the limb and even and center the limbs on a belt sander so I have clean matching limbs side to side with even tapers to the tips. I narrow my tips to a little less than 1/2".
I have found 2 1/2" of reflex on the glue-up table yields an straight limb to 1" or so reflex on the shot in bow.
(http://img.photobucket.com/albums/v181/ekrewson/bow%20making/bboglueuptable.jpg) (http://smg.photobucket.com/user/ekrewson/media/bow%20making/bboglueuptable.jpg.html)
(http://img.photobucket.com/albums/v181/ekrewson/bow%20making/bbooutofclamps.jpg) (http://smg.photobucket.com/user/ekrewson/media/bow%20making/bbooutofclamps.jpg.html)
Thank you, Eric, that is very helpful. You make is sound *so simple*. :-) If I ever make it to 50 bows, maybe I will feel the same. It's probably the other way around: only people who find it easy ever make it to 50 bows!
Please correct me if I am wrong, but it looked like the bow that Dean built was for shooting off the knuckle (and it looks like yours is too, at least at this early stage). There's something about this idea that intrigues me, and I am strongly tempted to give this a try too. I only have cedar shafts 45-55#, so it might mean a headache when it comes time for arrow tuning.
But Dean didn't seem to be having any trouble... all of his shots were bullseyes! :-)
I make mine very simular to Erics.
Once tillering is almost complete I then add shelfs as the handle is shaped.
Or shoot off the knuckle.
I glue on a rest and cut the sight window in about 1/8 to 1/4".
(http://img.photobucket.com/albums/v181/ekrewson/bow%20making/newboo.jpg) (http://smg.photobucket.com/user/ekrewson/media/bow%20making/newboo.jpg.html)
Here is my current plan for the bow. The design is based on the closest I can figure from Dean's recommendations. I rounded mine out to 66" from his 65-3/4" so the numbers would work out better. Note that the upper limb is 1-1/2" longer than the lower limb, because he said it layed better in the hand and was quicker to point-of-aim that way.
(http://gkerns.people.ysu.edu/screenshot.png)
An open question to me is where the tapers should start. Right now they are proportionally sized with the longer/shorter limb having the longer/shorter taper. Dean left that question open, and maybe it's a matter of personal taste. I would guess that the decision affects strength/stability/hand shock/cast.
Here is how it looks laid out on the bamboo.
(http://gkerns.people.ysu.edu/eru/IMG_20161126_231147030.jpg)
I haven't made any cuts yet.
(http://gkerns.people.ysu.edu/eru/IMG_20161126_233815240_HDR.jpg)
The blue dashes on the diagram are the recommended guide marks for the bamboo nodes. It turns out that for my bamboo there are two nodes equally spaced from the center of the handle (which isn't the center of the bow), and the other nodes are similarly spaced on either side in relation to the marks. Note that there was only one (1) bamboo configuration such that it worked out that way. When you try to wrap your head around the unequally spaced nodes on the bamboo, the proportional marks different on each limb, the unequal limb lengths, etc., it's sort of spooky that it all works out just like that, exactly like Dean said it would.
By the way, I made my pattern from a roll of drawing paper that was sitting around for the kids to use.
(http://gkerns.people.ysu.edu/eru/IMG_20161126_172510031_HDR.jpg)
I drew the pattern on with a carpenter's square and covered it on both sides with laminating/contact paper.
(http://gkerns.people.ysu.edu/eru/IMG_20161126_205412837_HDR.jpg)
Eventually I'd like to transfer the pattern to a length of wood. But for the time being, this will do.
(http://gkerns.people.ysu.edu/eru/IMG_20161126_205429468_HDR.jpg)
Thanks to all for the guidance so far. Please let me know if you notice any blunders on my part.
What you have should make a,good bow.
There are two schools of thought on doing the shorter lower limb.
I like to make mine even where the center of the bow is the center of the handle. Math and layout is much easier.
Others are in the shorter lower limb so that the arrow pass is closer to the center line.
I've made both and stick with the equal limbs.
I'm sure others will give their thoughts on the two.
Do a search on Bowjunkies and Roy from PA posts using the tillering tree and tillering for equal limb strngth and timing. Use this method for either type of design.
I like the top limb longer for the reasons Dean mentioned, I prefer how it balances in the hand while carrying, and how it points, cants, and moves braced and drawn... it balances more like an airplane propeller and rotates on an axis at my bow hand's middle finger location, which is where that hand's dynamic fulcrum is for me. This helps make it feel like a natural extension of me.
I also like how it's easier to tiller the limbs for good dynamic balance earlier on in the process because the string hand is drawing closer to bow center. Dean covers this in greater detail in his article "Tillering the Organic Bow" on his website.
Like Dean too, I like a convex taper from dips to tip, as opposed to a parallel inner limb leading to a straight taper to the tips... and lay the bamboo out with this profile after flattening, but prior to thinning and tapering.
BTW, none of that is to infer other ways won't work, just that there are other ways to skin a BBO bow.
Question on method.
Would it be the same if layed out for even limb length. After glue up just cut 1 1/2" off bottom limb.
Same thing, except you're cutting off a bit of the reflex and pushing the apex of the deflex out toward the tip a little more relative to the limb's length... which might make it look a little odd, or make one limb shaped a different than the other. But it would be minor and wouldn't hurt anything.
I design them asymmetrical from the get go, and glue them up so the reflex is equal and lowest point of deflex is proportional. In other words, even though one limb is shorter, the mid limb posts are both 1/2 way between dips and tips, or 2/3 or whatever.
Thanks