A Study of Flatbow Profiles

[gstoneberg]

... when it exploded, it was so LOUD that my dog peed in 2 rooms at once...

I don't care who you are, that right there is FUNNY!

Really, when you first start building bows the most important thing you need to learn is how to tiller.  The frontal shape of the bow is pretty much irrelevant at this stage in your development.  I also find it interesting that you've already determined the depth of the bow when what you will discover is that you can have a design thickness in mind but once you begin tillering all that goes out the window.

George

[Wooden Spring]

... when it exploded, it was so LOUD that my dog peed in 2 rooms at once...

I don't care who you are, that right there is FUNNY!

Really, when you first start building bows the most important thing you need to learn is how to tiller.  The frontal shape of the bow is pretty much irrelevant at this stage in your development.  I also find it interesting that you've already determined the depth of the bow when what you will discover is that you can have a design thickness in mind but once you begin tillering all that goes out the window.


George

Yeah the hard part is that I was trained as an architect, so I' ve always built stuff from exacting plans. Learning how to build from feeling is going to be like learning how to walk again. But ive been there too so if i can relearn how to walk then i should be able to build a bow!

[BowJunkie]

As Ed Scott said " It's a matter of having a sense of rightness, a sense of ratio and proportion,
what feels right, you either have it or you don't"

[steve b.]

You can build from exacting plans but, just like an architect, you have to be a little open minded for the variables.  You can measure everything out but if there is an imperfection in the wood then you might have to deviate a little from the plan to compensate, or fix the problem.
Personally, I really enjoy not measuring at all, except for the center of the stave.  I just start working and adapt my "plan" as I go.  It works really well for me as serendipity always shows up.

[JackCrafty]

I thought architects hired engineers to mess with the "efficiency" stuff? 

As a drafter, I can tell you that diagrams are nice but they can ruin the building process if they are not complete or accurate.  There should be a side profile for each front profile, for example.  Also, the most efficient design calls for stiff outer limbs, which is not possible with the side profile that you have shown.

[Wooden Spring]

I thought architects hired engineers to mess with the "efficiency" stuff? 

As a drafter, I can tell you that diagrams are nice but they can ruin the building process if they are not complete or accurate.  There should be a side profile for each front profile, for example.  Also, the most efficient design calls for stiff outer limbs, which is not possible with the side profile that you have shown.

Nah, when you work for a small homebuilder with "little dog syndrome" in the Atlanta home market, you wind up doing ALL that fun stuff...

Well, I just ordered my copy of "The Bent Stick." Hopefully that will shed some light on the subject for me.

[George Tsoukalas]

hstanley, don't feel badly. I spent my entire life working with wood. My father was a carpenter and woodworker. It still took me 3 years and 14 tries before I got a bow I could hunt with. A good place to start is a bow that bends in the handle similar to the board buildalongs on my site. Jawge

[Sidewinder]

 Well, I started with a pyramid style because Tim Baker said that it was a bit easier to tiller and performed well. It worked. I would say pick a style and build a few. They tend to get better and better as you get more familiar with the tools your using and your eye gets better at discerning an even bend in the limbs.
  I also like what Jawge says" If you ain't breakin you ain't makin". There is some truth to that. I haven't broken one in a few years now but that doesn't mean it can't happen, its just not likely since I have settled into a comfort zone for now.
  I have graduated from a pyramid style to the parallel to mid limb and then taper to the tip. Alot of that is due to the less than straight wood I am working with that requires I navigate some side to side movement in the wood. Its hard for me to get an even side taper on less than straight wood so the parallel to midlimb alllows me to follow the grain evenly on the sides.
 If I were you I would also consider starting to harvest your own wood as soon as you can so that when you get a comfortable amount of proficiency you will have a good supply of materials to work with.
 You have come to the right place for guidance that's for sure. There are some very talented bow makers here that are more than willing to share their knowledge. If you have the desire, patience and perseverance you will succeed. Just get to makin shavings my man and we will follow your journey.   Danny
 

[UserNameTaken]

Speaking from a beginner's perspective, I would start with a flat board and a pyramid profile. Having just gone through all of this myself, I feel that this is the quickest and least frustrating way for a beginner to be successful. You won't learn all that there is to learn, but you will have gained a little confidence--rather than getting frustrated and quitting all together. 

[UserNameTaken]

There's a guy on YouTube that does a pyramid build-along that is about as fool-proof as it gets. User name: primitivearcher101

[adb]

I think, in typical newb fashion, you're over thinking this. ALL of your design profiles will make excellent bows, and I've made bows using all of them. Pick one... the straight taper true pyramid will probably be easiest for a beginner. Stop thinkin' about it so much Mr. Architect Boy... and start makin' some sawdust!  You'll learn this game by doin', not lookin'!!  You're not designing a suspension bridge... if the bow breaks, you've probably learned something!

[Wooden Spring]

Outstanding! Thanks for all the encouragement - it's nice to know I'm not strange for breaking most of what I've made so far... And you're right - I've learned so much about what NOT to do. In the meantime, I've got a flatbow in process in my shop right now.

Hickory
5'9" ntn
4" handle, then 1-1/2" to fades
1-1/2" wide at fades, then parallel for 12", then tapered to 1/2" wide nocks
Thickness is 11/16" at fades, and 3/8" at nocks - this could change during tillering

 My hopes is that this recipe will give me a bow of 50-60# @ 28"

[Dictionary]

didnt know there were recipes to make bows. Usually it all just comes together

[Weylin]

Be careful about setting any sights on your thickness. That's a good way to end up with a kids bow. You want the thickness to be just enough to slightly bend the bow when pushing a tip into the ground. From there you will go through the tillering process and whatever thickness numbers you had in mind are completely irrelevant from that point on. The shape of the tiller, the draw weight and the draw length will dictate your end thickness, not a predetermined measurement. Even bows that have the same design and the same draw weight, draw length and even the same wood species can have different measurements because every piece of wood is different.

[oscar3b]

Hey Stanley!  It sounds like the new stave you have in the works should be a great start.  After reading through your post, it doesn't really sound like you did anything wrong.  Ipe has the reputation of being an oily wood.  Lots of people on here report similar results.  You just have to clean it really well before gluing or use a heavy epoxy from what I understand.  Either way I think you front profile should be fine and that wasn't what caused the problem the first time around.  It was the wood.  As long as you tiller the bow the right way, the front profile shouldn't affect performance too much.  I would say you are off to a good start. 

A couple tips from what I've learned.  Use floor tillering to make sure the bow is bending evenly and with a smooth arc.  Once you press it to the floor and the tips move about 4" with a smooth arc then put it on a tillering stick or tree and use a string that is far too long (the string should hang off the bow).  With boards I also round the corner where the back meets the sides so that the wood doesn't lift a splinter there.  Then start flexing the bow with the string.  If you can, never pull it past draw weight or it will take excessive set on you.  Once the tips bend about 12" at the desired draw weight (some people may disagree) shorten the string to where it is taught when in both nocks, but not really loose anymore, repeat the process.  Shorten the string to brace and finish tillering out to about an inch short of full draw.  I found that if I don't do this my bow is always too light after I sand the tool marks out and shoot it in. 

The bow shouldn't be sluggish because the thickness will have to be reduced to get the bow to bend enough.  As long as the bow doesn't follow the string too much it should be fine and shoot fast.  I usually try to keep it under 2 inches of string follow but if it comes out with more set it just does.  If it's your first bow, the as long as it shoots and stays together I say be happy and try another one using what you've learned to guide you toward improving (whatever that improvement is is up to you; don't worry about what anyone says but rather work toward what you like).  Hope that helps.  That's just my two cents gathered from what I've read and my experience with the bows I've built.  Happy tillering!  If you need help post pictures and ask.  There are lots of people who know a whole lot on here (FYI I don't include myself in that).