A Study of Flatbow Profiles

[Wooden Spring]

OK, forgive an ex-architect for attempting to be more "science" than "art" when it comes to designing a bow. Since my ELB tragically committed suicide on my tillering stick last weekend, I'm turning to what folks tell me is an easier bow to build - the AFB... So, I'm pondering profile designs... In the drawing below, I've given an arbitrary width of 2" at the fades, and 1/2" at the nocks. Thickness is 11/16" at the fades, and 3/8" at the nocks. (Side profile shows a backing, but is not necessary)

Now, given all other factors are the same, which profiles would yield the most efficient bow? I don't mind a heavy bow, but I want the weight to equal speed, not sluggishness. Neither do I need a lightning fast bow at the sacrifice of accuracy or consistency.

Any ideas? Comments?

[osage outlaw]

What kind of wood will you be using?

[tom sawyer]

I tend to favor parallel out to mid-limb.  Puts wood where its most needed, and allows you to keep the inner limb skinnier for a given poundage versus a pyramid.  Having said my preference, I agree that any differences you might see are going to have more to do with individual pieces of wood and tiller.

[Wooden Spring]

Hickory, Ipe, Cherry...  I've got some friends who own a flooring company, so I can actually get my hands on some interesting species, but those three are easy to get in decent lengths.

Really? ANY profile? There isn't a single "best practice?" As I said, have patience with the newbie here if these are stupid questions.

[tom sawyer]

Parallel to mid-limb is suggested by several authors of bow-build books.  But there are examples of many different styles out there.  The pyramid bow is an easy one to tiller since a lot of the smooth bend is accomplished by the width taper.

You'll maybe be limited on the width of the flooring planks, I'd back ipe and cherry and go with the parallel to mid-limb design.  Or do the ELB design and make the bow long and fairly narrow.  That seems to be a favored design for backed ipe.

[blackhawk]

It depends on who's making the bow....I'm sure I can get all those front profiles to shoot within a few fps of each other,and yiud only be able to discern the difference with a cbrono...or make one shoot lots faster than another, and then turn around and make em again and make the one that was slower now faster than the other one ...there's a lot of other variables that contribute to speed than just its front profile alone. Either make a pyramid,cus its simple an easy to make n tiller for a novice,or the old stand by of running your width from the fade till mid limb tapering to 1/2" nocks....widths will depend on what wood or woods if you laminate them,and length of bow,length of draw,draw weight etc......

[Wooden Spring]

Parallel to mid-limb is suggested by several authors of bow-build books.  But there are examples of many different styles out there.  The pyramid bow is an easy one to tiller since a lot of the smooth bend is accomplished by the width taper.

You'll maybe be limited on the width of the flooring planks, I'd back ipe and cherry and go with the parallel to mid-limb design.  Or do the ELB design and make the bow long and fairly narrow.  That seems to be a favored design for backed ipe.

I can get flooring planks in 5.5" widths, and 8' lengths, and 3/4" thick.
I had in mind to try a design with the width carried to mid-limb, but admittedly, I'm a little wary of laminating anything on ipe. When I was trying to make ELB, I got my ipe from decking boards, and there was SO MUCH oil in those boards that no ammount of titebond 3 kept it from de-laminating... Even with planed smooth mating surfaces, the glue just gave up.

Actually, the last bow that I made didn't explode until I was bragging about it to my wife in my living room - when it exploded, it was so LOUD that my dog peed in 2 rooms at once...

[Wooden Spring]

I'm beginning to think I should take up stamp collecting instead...

[ionicmuffin]

well, its a bit hard to get started, but once you do its much easier!

[ionicmuffin]

my most recent bow that i made was 64 inches ntn and was about 1.25 inches wide. it was made of hickory and the last 12 inches on either side taper to half inch or a bit less. this design is a great one weather or not your using a short or long bow.

[blackhawk]

All you have to do is come up with a example like this..." I wanna make a hickory backed ipe pyramid,and I like a 50@28" draw"...or a hickory board pyramid or d bow or whatever....."what's the best dimensions for this" ..type of example....if you can find something that you like and be specific as to what you want to make you can then get a lot of help here and use us as a crutch to help ya get the answers ya need,and make that specific type bow you wanna make..as long as its within reason of your skill level.

[bubby]

personally a pyramid bow out of hard maple will give you a light, smooth, fairly fast bow and is almost newbie proof, some skills required , all that said all those profiles are doable, although i thought an elb was not a complicated build, Bub

[rossfactor]

No Way hlstanley! Make yourself a bow man. 

Here's the thing.  First, ignore all this nonsense about profiles (which is absolutely important and will absolutely effect performance depending on wood type and tiller profiles).  First, get you a good piece of wood, and a good set of instructionf for your first bow by either Jawge or Tim Baker.

http://georgeandjoni.home.comcast.net/~georgeandjoni/directions.html

http://paleoplanet69529.yuku.com/topic/47638/Tim-Bakers-Wooden-Bow-Reposted-Tims-Permission#.UN38c-Qvqmk

Than make youi a bow, either out of a nice red oak board, with god straught grain, or a nice straight stave of some white wood (Ash, Oak, Maple, Hickory, etc).

Than make yourself a bow with the front profile recommend by either of these two instructions. Don't worry about it too much, just start with wide near the fade and narrow at the tips .  Get a nice even tiller.  See how it shoots.  Than start wondering about how tiller shape, front profile and characteristics of wood effect design performance.  I'd say get a few built first. Not cuase those other things don't matter, or because your a novice (we are all novices here), but because bow building requires have a feel for it, not just a good scientific basis for why it works (which can also be very important). But unless you get the "feel" you wont' get hooked.  And once you got the "feel"  you will get hooked and the unlimited potential in making bows will set you on the path.

Gabe

[rossfactor]

By the way.  thats a very nice set of profile diagrams,  and I think it will prove useful to you, and others.  But as, I said, make a bow first.

I'm always game for a discussion of characteristics of wood, and the advantage of various designs, but I've learned that "feel" if the most primary thing, and its required if you wanna become a bowyer.  And you only get feel by making bows.

Gabe

[Onebowonder]

...or you could collect this stamp:  http://www.zazzle.com/archer_with_bow_arrow_stamp-172790017015413308

 

OneBow