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Offline bucksbuoy

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lam thicknesses?
« on: January 10, 2011, 01:39:40 am »
trying my hand at a triple laminante bow and was wondering if its better to have a back thats thicker then the core or belly or what?? I was thinking of having the core be the thickest lamination and the back be a little thinner and the belly be the thinnest. Or is it better to have them all the same thickness? Tapering is out of the question at the moment. any ideas would be appreciated.
thanks
Jason
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Offline adb

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Re: lam thicknesses?
« Reply #1 on: January 10, 2011, 10:21:02 am »
I make a lot of tri-lams, mostly heavier poundage ELBs and warbows. I use ash, hickory, maple, and elm as backing material, and I've used purpleheart, bloodwood, greenheart, bamboo, jatoba, and maple as mid-lams, and they usually end up being the same thickness at 1/8".
For belly wood, I usually use osage, and ipe, but also lemonwood and jatoba. The belly wood thickness will end up being whatever thickness is required to make draw weight, usually between 3/4" - 1". If you make the lams too thick, the belly wood may disappear at the tips.
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Offline Easternarcher

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Re: lam thicknesses?
« Reply #2 on: January 10, 2011, 03:09:15 pm »
Quote from: adb on January 10, 2011, 10:21:02 am
I make a lot of tri-lams, mostly heavier poundage ELBs and warbows. I use ash, hickory, maple, and elm as backing material, and I've used purpleheart, bloodwood, greenheart, bamboo, jatoba, and maple as mid-lams, and they usually end up being the same thickness at 1/8".
For belly wood, I usually use osage, and ipe, but also lemonwood and jatoba. The belly wood thickness will end up being whatever thickness is required to make draw weight, usually between 3/4" - 1". If you make the lams too thick, the belly wood may disappear at the tips.

Not hijacking the thread or anything....but,
ADB? do you ever use yellowheart as the bellywood for your ELB's? I can't get Osage or IPE that long...but can get yellowheart-purpleheart-bloodwood and the like in long lenghts(over 68in.)
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Offline bucksbuoy

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Re: lam thicknesses?
« Reply #3 on: January 10, 2011, 04:21:42 pm »
easternarcher: no prob bud
finding exotic bow worthy wood is a problem for me too. I wouldnt mind hearing were you get 68 inches of yellow heart or blood wood.
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Offline bucksbuoy

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Re: lam thicknesses?
« Reply #4 on: January 10, 2011, 05:55:39 pm »
Im going for a flat style reflex deflex bow, and honestly trying to avoid belly tillering all together. I decided to shoot for a limb thickness of 9/16 and got three lams (in 16ths for simplicity) 2/16, 3/16, and 4/16. This was my first time ripping lams so I was kinda winging it. I wouldnt mind going back and starting over making them all 3/16 but I want to try these lams first. Just wanted to see if anyone had experimented with different sized lams or had a take on how the set up would affect performance. Like I said I was thinking of making the core be the tickest, the back be the next thickest, and the belly the thinnest, but Im basing that idea on speculation.  ???   Probably doesnt even matter once the bow is glued together anyway.
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Offline adb

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Re: lam thicknesses?
« Reply #5 on: January 10, 2011, 09:45:00 pm »
I'm thinking you're trying to make a multi-lam bow without tillering? I just don't think that's possible. Unless you're using fiberglass. There is no short way around making wood bows. Wood is a natural & inconsistent material, and will bend unevenly, even when cut to precise thicknesses. Making wooden bows is not 'recipe' building, like FG recurves (x thickness and width give you y poundage). You're still going to have to teach the wood to bend evenly.
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Offline adb

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Re: lam thicknesses?
« Reply #6 on: January 10, 2011, 09:48:07 pm »
Quote from: Easternarcher on January 10, 2011, 03:09:15 pm
Quote from: adb on January 10, 2011, 10:21:02 am
I make a lot of tri-lams, mostly heavier poundage ELBs and warbows. I use ash, hickory, maple, and elm as backing material, and I've used purpleheart, bloodwood, greenheart, bamboo, jatoba, and maple as mid-lams, and they usually end up being the same thickness at 1/8".
For belly wood, I usually use osage, and ipe, but also lemonwood and jatoba. The belly wood thickness will end up being whatever thickness is required to make draw weight, usually between 3/4" - 1". If you make the lams too thick, the belly wood may disappear at the tips.

Not hijacking the thread or anything....but,
ADB? do you ever use yellowheart as the bellywood for your ELB's? I can't get Osage or IPE that long...but can get yellowheart-purpleheart-bloodwood and the like in long lenghts(over 68in.)
I've never used yellowheart as a belly wood, but it might work. If length is an issue, you can splice your belly wood. I live in a bow wood desert, so I have to pay and import bow wood if I want to make bows... it's part of the game!
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Offline bucksbuoy

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Re: lam thicknesses?
« Reply #7 on: January 10, 2011, 10:00:49 pm »
Darn! lol.
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Offline Easternarcher

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Re: lam thicknesses?
« Reply #8 on: January 10, 2011, 10:27:22 pm »
Quote from: bucksbuoy on January 10, 2011, 04:21:42 pm
easternarcher: no prob bud
finding exotic bow worthy wood is a problem for me too. I wouldnt mind hearing were you get 68 inches of yellow heart or blood wood.

Bucksbuoy, I  am fortunate to have a small wood suppliy store here in town that has some variety of exotics. IPE and OSAGE are almost out out the question, but I may talk him into ordering some lemonwood for me to build a few ELB's.(my next project).
I'm on East Coast of Canda BTW.

ADB, I've seen ELB's with hickory-purpleheart-lemonwood bellywood. Wouldn't the purpleheart over-power the lemonwood or yellowheart if I use that???
Would you have some better lam combinations for an ELB? Lastly, I thought you couldn't splice a bow together that had a slight bend-in the-handle like elb's???or can they stay stiff in the grip. Not looking for a warbow just yet either...

Sorry again Bucksbuoy.....I'll stop now.
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Offline Easternarcher

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Re: lam thicknesses?
« Reply #9 on: January 10, 2011, 10:31:19 pm »
Quote from: bucksbuoy on January 10, 2011, 05:55:39 pm
Im going for a flat style reflex deflex bow, and honestly trying to avoid belly tillering all together. I decided to shoot for a limb thickness of 9/16 and got three lams (in 16ths for simplicity) 2/16, 3/16, and 4/16. This was my first time ripping lams so I was kinda winging it. I wouldnt mind going back and starting over making them all 3/16 but I want to try these lams first. Just wanted to see if anyone had experimented with different sized lams or had a take on how the set up would affect performance. Like I said I was thinking of making the core be the tickest, the back be the next thickest, and the belly the thinnest, but Im basing that idea on speculation.  ???   Probably doesnt even matter once the bow is glued together anyway.

Like ADB says...there's no magic way around tillering. You either tiller the bellywood or make a pyramid bow and taper/tiller from the sides to achieve a smooth bending limb. It's not that bad....jsut a learning curve with minimal tools you can make some impressive weapons.
Just look around this site and you'll see.
Got any books on the subject? See if you can get hold of the first couple of volumes from the Bowyer's Bible series. Lots of excellent info there.
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