Author Topic: Build Along ( building by mass)  (Read 71498 times)

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Offline Pappy

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Re: Build Along ( building by mass)
« Reply #30 on: January 29, 2008, 08:05:26 am »
Nice build along Steve,Looks like you are coming right along.Lots of calculating there,
looks like a job for GregB.He like that kind of stuff.I should do more of it just don't seem
to take the time.Thanks for sharing. :)
   Pappy
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Offline Badger

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Re: Build Along ( building by mass)
« Reply #31 on: January 29, 2008, 11:46:09 am »
Pappy, I know it's not for everyone but really not as much calculating as it seems to be. I know that you make a lot of different style bows kind of like me. I make all different draw weights, all different styles from all kinds of woods. The last couple years jut to test this out I have been making them from 35# to almost 160# and from 48" long to 88" long. It's main purpose is to make sure you have enough wood to complete a design, and it will also suggest designs in a lot of cases. If you are making the same kinds of bows from the same kinds of woods it would be of little value. I can tell you one thing for sure I come up with a lot different demensions than I often see posted as suggested starting places, I also am a lot more comfortable now making longer bows, I use the formula to help me decide on a tiller shape for the long ones.
Would anyone like to post some full draw pics of some of their bows here, just give the length of the bow and the draw weight with a full draw pic and we will do a mass breakdown on it? Steve

Offline DanaM

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Re: Build Along ( building by mass)
« Reply #32 on: January 29, 2008, 11:56:04 am »
Pignut hickory, 58 ½” NTN, 42#@25”, 1 ¾” at fades straight taper to 5/8” at nocks. Has 1” of string follow after unbracing. Buffalo horn and bone tip overlays, black cordage handle wrap.

Steve I will weigh it tonight, I have an old nail scale which seems to be pretty accurate

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"Prosperity is a way of living and thinking, and not just money or things. Poverty is a way of living and thinking, and not just a lack of money or things."

Manistique, MI

Offline Pappy

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Re: Build Along ( building by mass)
« Reply #33 on: January 29, 2008, 12:03:49 pm »
Nice looking bow Dana. :) Looks cold up there. ;D ;D
   Pappy
Clarksville,Tennessee
TwinOaks Bowhunters
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Offline DanaM

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Re: Build Along ( building by mass)
« Reply #34 on: January 29, 2008, 12:05:02 pm »
Thats yer hickory pappy and ya its cold and we have blizzard warning for later today >:(
"Prosperity is a way of living and thinking, and not just money or things. Poverty is a way of living and thinking, and not just a lack of money or things."

Manistique, MI

Offline Badger

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Re: Build Along ( building by mass)
« Reply #35 on: January 29, 2008, 12:06:21 pm »
Dana, for that bow and tiller I would have used stright limbs to about mid limb. It's is pretty stiff out of the fades so I would call the center handle and fade area 10" instead of 8". Total mass projected would be a little over 16 oz and set would be about the same as you have hopefully at 1".

Offline DanaM

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Re: Build Along ( building by mass)
« Reply #36 on: January 29, 2008, 12:11:44 pm »
Dang I'm going to have to run home at lunch and weigh it ;D Do you add any weight for tip overlays or are they negligible?
"Prosperity is a way of living and thinking, and not just money or things. Poverty is a way of living and thinking, and not just a lack of money or things."

Manistique, MI

Offline Badger

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Re: Build Along ( building by mass)
« Reply #37 on: January 29, 2008, 12:23:22 pm »
Dana, I never add on for overlays, your draw length was just about right for that bow length and handle design and it only added about 1/3 of an ounce for draw length. if you draw length was 28 the mass would have gone up to 17.5 oz. Steve

Offline DanaM

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Re: Build Along ( building by mass)
« Reply #38 on: January 29, 2008, 12:46:55 pm »
I couldn't stand it I went home and weighed it, with the string and grip it weighed 17.5oz, badger I did tiller it out to 26"
as its going to a green horn and I want a little insurance. I also induced about 1.5" of reflex at the floor tiller stage does that affect the calcs?
I'd say I came pretty close to what your mass theory says it should be. This bow spits a 450g arra pretty dang good.
"Prosperity is a way of living and thinking, and not just money or things. Poverty is a way of living and thinking, and not just a lack of money or things."

Manistique, MI

Offline Badger

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Re: Build Along ( building by mass)
« Reply #39 on: January 29, 2008, 01:04:19 pm »
Dana, thats pretty cl;ose. Thats the whole idea, it realy doesn't hurt to be a little hevy on the inside limb as long as the last several inches aren't too bulky. Now if you would have stopped and weighed that stave early on and found it only weighed 15 oz instead of 17 you could have mad a little adjustment by getting it bending more near the fades and still come into weight ok with out taking set. Steve

Offline DanaM

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Re: Build Along ( building by mass)
« Reply #40 on: January 29, 2008, 01:26:44 pm »
thanks Steve this was edumakational, I'm going to have to keep the scale handy as I see the value of your theory.
You said with this tiller you would have kept the limbs straight to mid limb care to explain.
I hope in TBB 4 you go into limb shapes and designs with type of tiller, with pictures of course.

Some one else's turn to post a bow to be examined :)
"Prosperity is a way of living and thinking, and not just money or things. Poverty is a way of living and thinking, and not just a lack of money or things."

Manistique, MI

Offline Badger

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Re: Build Along ( building by mass)
« Reply #41 on: January 29, 2008, 03:36:42 pm »
Did a little tillering this morning, ran into a minor problem which is good for the buildalong but bad for me LOL. The bow keeps adding reflex as it is tillered, now right at about 4" which is way more than I like. This also raises the amount of mass I need in the stave. Normaly on a boo backed osage I will take allow myself about 10% mass less than what the formula calls for but right now I am at 20 oz. Not much wood will need to come off now as I am pretty close to final tiller but I am allready below the weight I wanted to be at and starting to worry if it will be able to take the extra strain. I have decided to get it working a bit further out to the tips and a bit closer to the handle, more working limb will allow me to build the bow lighter. I don't like to loose reflex in tillering i would prefer just to build it with less reflex and keep what i put in originaly. I think I rushed a bit for the buildalong and didnt take the belly stave down enough and as I remove wood the bamboo cantinues to pull it back into more reflex, I will probably stop the bow at 27" draw now also but still keep my 50#. Hopefully the bow will maintain 3" reflex when finished. This is where I have a lot of fun. I know the bow is a bit overstressed but if I do my job right it will come out hot!. Looks like she is going to finish at 19 oz, so I am going to go back to my formula, play with the numbers and make a final descision as to what she should look like when done.

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Offline Badger

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Re: Build Along ( building by mass)
« Reply #42 on: January 29, 2008, 03:58:17 pm »
I went ahead and braced her up picure is 1st brace and then went ahead and pulled her out to 50# which she hit at 24". right limb is just a tad stong and left limb needs a few scapes and she should be done. Bow has a super smooth draw buildng at less than 2 1/2# per inch of draw. Very high early draw weight. reflex dropped to 3" which pleases me greatly, likely will drop another 3/4 inch or so as I hit my 27" draw. Looks like she will finish at 20 oz, a little ighter than I wanted but if she hold together it will be a good thing.

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« Last Edit: January 29, 2008, 04:55:51 pm by Badger »

Offline Badger

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Re: Build Along ( building by mass)
« Reply #43 on: January 29, 2008, 04:00:56 pm »
The center limbs look stiff, but compared to the unbraced profile they are actually working quite a bit. I cut the tip of my middle finger off a few days ago so I won't be able to shoot the bow till the finger heels. Steve

Offline Badger

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Re: Build Along ( building by mass)
« Reply #44 on: January 29, 2008, 04:20:17 pm »
Ok, just got her finished up at 52# and 27" she held 2 3/4" reflex and feels like a good shooter. I will get her sanded up and finshed and try to post a finsihed full draw in a couple of days. i used a little more bend in the inner limb than I had originaly planned to make up for the lower than planned mass, looks like it worked out ok. Steve
« Last Edit: January 29, 2008, 04:56:27 pm by Badger »