Author Topic: Build Along ( building by mass)  (Read 71519 times)

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Offline Badger

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Re: Build Along ( building by mass)
« Reply #15 on: January 27, 2008, 05:42:06 pm »
Inbetween the rain I am working on the bow here is where I am at so far.

Picture#1 is showing the mulberry stave and the osage boo parts i will use for the 2 bow build along.

Picture#2 shows the guide I use to run my bamboo through the bandsaw for it's initial thinning

Picture# 3 shows me running the boo through the bandsaw.

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« Last Edit: January 27, 2008, 05:47:51 pm by Badger »

Offline Badger

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Re: Build Along ( building by mass)
« Reply #16 on: January 27, 2008, 10:04:40 pm »
Here are a few more pics,
#1 is just tracing the boo to match the roughed out belly stave
#2- the belt sander I flatten everything on before glue up
#3- The slices I cut off the belly I reused on the handle
#4- Total mass at this point is 32 0z, I actually lightened it a bit more on sander before glue up so it is now actually 27 oz.

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« Last Edit: January 27, 2008, 10:08:47 pm by Badger »

Offline Badger

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Re: Build Along ( building by mass)
« Reply #17 on: January 27, 2008, 10:13:41 pm »
Here is the glue up, I use tightbond 3 and bicycle innertubes. I like to leave a little gap inbetween each wrap. It has to be pulled very tight to get the deflex reflex as you see here and in the middle of the limb I will ofyen have to make several wraps just to get it pulled down. I will let it dry in the house and in the morning take the wraps off and clean it up a bit, I will take it to floor tiller but wait one more day till I strat really stressing the bow as it has been pretty wet lately and the glue may not cure strong enough overnight. Steve

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Rich Saffold

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Re: Build Along ( building by mass)
« Reply #18 on: January 27, 2008, 10:39:22 pm »
Ingenious little jig for trimming the bamboo Steve... This rain is driving me nuts!

Rich-soaked

Offline Badger

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Re: Build Along ( building by mass)
« Reply #19 on: January 28, 2008, 10:55:18 am »
The mass formula in the how to section is wrong! I didn't know it was there. It doesn't adjust for working limb in relation to draw length at all.  maybe I cna get them to remove it. Steve

Offline DanaM

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Re: Build Along ( building by mass)
« Reply #20 on: January 28, 2008, 11:02:31 am »
I deleted the mass theory thread in the How To section Steve, Being as you started the thread you also could have deleted it.
"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 DanaM

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Re: Build Along ( building by mass)
« Reply #21 on: January 28, 2008, 11:07:38 am »
Steve I will repost your excel spreadsheet so its readily available for folks.
I believe you said this is correct.

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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 Badger

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Re: Build Along ( building by mass)
« Reply #22 on: January 28, 2008, 11:28:25 am »
Thanks Dana, I use the calculator so much I almost cant remember how to figure it with out it anymore.
I am also working on the mulberry stave, yesterday I reduced it and took off the 3/4" thick sapwood, The stave looks good and I will see how it comes out as a broadhead shooter for flight. So It will finish as follows, 68" long 50# at 27", I will likely set the tips back just a smidgeon. So I will be looking for a finish weight of about 19 to 20 oz of mass. I am debating wether or not I should drop the weight on the boo backed bow to 50# and use it for flight as well. I really like the way it is looking when I took the wraps off this morning. If I do drop it to 50# it will just come in around 1 oz lighter than I projected. With backed bows I figure about 10% less mass than stave or board bows but this one here has a heavy handle section so should come in about the same. Steve

Offline jwillis

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Re: Build Along ( building by mass)
« Reply #23 on: January 28, 2008, 12:31:56 pm »
Badger, I just realized that you have a chapter in TBB4.  You must be pretty excited!  ;D I can look forward to pointing to the book and telling my family, "Hey, this is one of my friends on the internet!"  I've been borrowing a friends copies of volume 1 and 2 for about a year, so I hope to return them and buy the complete set.

One question... Did you thickness taper the osage lam before glue up?
Jim

Offline Badger

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Re: Build Along ( building by mass)
« Reply #24 on: January 28, 2008, 02:05:44 pm »
Jim, I don't really thickness taper it, I just tim it to abpot a 3/8 thickness, noraMLY I tiller the limb a bit but when they are side tapered limbs they are pretty much tillered allready with even thickness. In a few minutes I am goig to go outside and clean the glue off and get it to floor tiller. Post some more in about an hour or so, Steve

Offline Badger

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Re: Build Along ( building by mass)
« Reply #25 on: January 28, 2008, 03:07:54 pm »
Photo 1 is present weight after cleaning up and floor tillering, shaping handle etc. Weight is 23 0z, target weight is 22 oz so it looks like I am right on target. I was hoping it might be just a tad further off so I could show how using the sides to adjust weight actually works.

Photo 2 is right out of the rubber bands, weight was 29 oz instead of the 27 I mistakenly posted yesterday.

photo 3 is glueing on some osage tip overlays

photo 4 is shoing how the reflex will often increase durring floor tillering, in this case from 1 3/4" to 2 3/4".

Going to let it sit till tomorrow morning before completing the tillering.

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« Last Edit: January 28, 2008, 03:18:11 pm by Badger »

Offline Badger

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Re: Build Along ( building by mass)
« Reply #26 on: January 28, 2008, 04:17:22 pm »
Might as well talk about tillering while I am waiting for the glue to cure. This year I started using the long string method of tillering a bit but got back away from it. I still use the long string for a couple of things. The long string is a good way to tell at what weight your bow is at for a given draw length. It is also a good way to tell if you fades are going to bend too much for the weight of the bow you are building, this is particualry useful for glueups. The look at your tiller on r/d bows especially is too misleading on a long string to be of much value. Now days I simply sight down the limbs looking at the bend of each limb as I floor tiller and then right before I go to brace the bow I hook it up to a string about the same length as the bow and pull it to full draw weight, when I am with in 4" of full draw weight with a long string I go a ahead and brace it. I then hold the bow on my lap braced and use a scraper to get both limbs looking the same at brace, excercising it inbetween scapes. Once the braced tiller looks good i proceed to the tiller tree to finish it off at final weight. Every time I pull the bow an additional inch of draw length I note before that pull the draw weight at a lower drawn length, after the pull to the new longer length I go back and check the weight at that lower draw length and see if it changed, if it changed the bow is picking up some stresses and the wood is fatiquing, tipping me off to getting some more wood bending usually near the fades. The particualr bow I am working on right now has more reflex than I actually wanted but at the same time I don't like to reduce reflex by breaking a bow down too much. I will try to limit the set the bow takes to less than 1 1/4" giving me a net reflex of about 1 1/2". I like to look at every bow as potentialy the best or fastest bow I have ever built, this keeps the adrenalin flowing until the bow is actually tested. Steve

Offline Marc St Louis

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Re: Build Along ( building by mass)
« Reply #27 on: January 28, 2008, 08:59:12 pm »
Nice build along Steve. I like the simple guide you use for thinning the Bamboo.
Home of heat-treating, Corbeil, On.  Canada

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Offline mullet

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Re: Build Along ( building by mass)
« Reply #28 on: January 28, 2008, 10:06:15 pm »
  I like that guide also. I will have to try it. I've been using a 12" disc sander and did not like all the dust.
Lakeland, Florida
 If you have to pull the trigger, is it really archery?

Offline Badger

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Re: Build Along ( building by mass)
« Reply #29 on: January 28, 2008, 11:50:55 pm »
Eddie, it will take me about 2 times as long to run a clean growth ring on the mulberry stave than it will to finish this whole bow. I just about have it ready to start tillering. I have about 1 1/2 hours invested in the glue up so far and about 4 hours into running a ring LOL. I still prefer the stave bows by a big margin. steve