Author Topic: holy smokes...you guys are awesome! Flatbow question  (Read 3489 times)

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Offline redboard

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holy smokes...you guys are awesome! Flatbow question
« on: April 10, 2014, 12:48:39 pm »
Hello to all of you amazing people!

 I'm new to all of this and have 2 RO board bows under my belt. First one lasted 150 shots, the second lasted about 300! I'm hoping this next one will go for 1000!
 I've chosen a true flatbow design from a screamin good rift-sawn 1x2, of which 71" of it have zero grain runout! Riser will be 8" total with a 5" handle and 1.5" fades. I'm going to glue up an oak handle after tillering. That leaves me with a limb of 31.5 inches. Here's where it gets tricky for me. I started the taper at 19.5" from the fade from the full 1.5" to 3/8" at the tip. None of this is actually cut you, I'm just getting the rough layout.

My questions are these:
Are the tips too narrow?
Should the thickness be tapered or static?

my last bow was a half pyramid/flatbow hybrid with thickness tapered limbs and flipped tips. I really like the way it shot, but the toasted belly overpowered the back, and the Cedar riser was too weak...I know, Cedar was a bad choice.

 I checked out the rough profile  chart that someone put up, and if I understand correctly, the thickness taper starts from the fade to where your width taper starts, then back up slightly to the tips, making the tips a touch stiffer than the working limb.

Any and all advice is more than welcome!

Cheers

Offline Blaflair2

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Re: holy smokes...you guys are awesome! Flatbow question
« Reply #1 on: April 10, 2014, 01:00:31 pm »
U need to glue the handle on before tillering. If it bends at all it will pop off. So usually the glue on block doesn't go into the limb past the fades. Part of the fade taper into the handle has to be the limb wood.
Nothing ventured nothing gained

Offline Josh B

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Re: holy smokes...you guys are awesome! Flatbow question
« Reply #2 on: April 10, 2014, 01:04:19 pm »
Welcome aboard!  Your tips will be fine at that width, but a touch delicate if not done correctly.  As far as limb thickness goes, you will establish that as you tiller.  Put all ideas of a preconceived  dimensional thickness out of your mind.  There's only four things two worry about when tillering.   1.  Remove wood where it needs to bend more.  2.  Don't remove wood where it is bending too much.  3.  Maintain an even thickness across the WIDTH of the limb at any given point.  4.  Make sure the limbs maintain balance with one another throughout the process.  There are an entire plethora of other little things to keep in mind as well, but these four basics if followed throughout should yield you a good shooter if the wood is sound.  Josh

Offline Pat B

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Re: holy smokes...you guys are awesome! Flatbow question
« Reply #3 on: April 10, 2014, 01:41:06 pm »
Start out with the tips 1/2" or so and reduce the width to 3/8" after you see how the string tracks at first brace.
 The thickness will be determines by tillering the bow.
Make the most of all that comes and the least of all that goes!    Pat Brennan  Brevard, NC

Offline Onebowonder

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Re: holy smokes...you guys are awesome! Flatbow question
« Reply #4 on: April 10, 2014, 03:06:45 pm »
<snip>There's only four things two worry about when tillering.   
1.  Remove wood where it needs to bend more. 
2.  Don't remove wood where it is bending too much. 
3.  Maintain an even thickness across the WIDTH of the limb at any given point. 
4.  Make sure the limbs maintain balance with one another throughout the process. 
<snip>

This is awesome tillering advice in a nutshell!

I should have this tatooed to the back of my right hand so I can read it before I destroy more wood.  Hey, then I could literally say that I know tillering like the back of my hand!

OneBow

Offline redboard

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Re: holy smokes...you guys are awesome! Flatbow question
« Reply #5 on: April 10, 2014, 05:01:24 pm »
hmmm.
Thanks so much for the advice y'all.

As far as asking about thickness goes, I'm really just curious about a starting point since 3/4 seems a bit big. But I shall do as you advise and tiller away!

Anyways, here are some rachedt fotos of my other 2 that broke. The first was a linen backed RO pyramid, 68" NTN with a 10"Riser, 2.5" at the fades with 5/8" tips. I shot it in to #45 at 30"
The second was a 1/2 pyramid/flatbow 67" NTN with a 9" riser. 1 3/4 at the fades, 1 1/2 at the tapers to 1/2"  flipped tips. That one shot in to #53 at 30"

Offline bubby

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Re: holy smokes...you guys are awesome! Flatbow question
« Reply #6 on: April 10, 2014, 06:25:13 pm »
if you havn't cut into it yet try a pyramid layout  and go straight from fades to tip, then get a even limb thickness of 1/2" to start and tiller from there
http://www.primitivearcher.com/smf/index.php/topic,35312.0.html maybe this will help
failure is an option, everyone fails, it's how you handle it that matters.
The few the proud the 27🏹