Author Topic: Share your thickness taper pls~  (Read 2212 times)

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Offline leehongyi

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Share your thickness taper pls~
« on: May 16, 2014, 06:39:17 am »
To a certain length thickness is the key to keep best recovery and least set/string follow. Dense wood usually need less thickness to gain the same poundage as those lighter woods. supporting we are going to build a BBI RD or longbow between 60-70" and aiming to achieve 50-70#. what's your experience or suggestion about the relation of total length and thickness taper? from fade to tip for a 64“ bow, 1/2"(13mm) to 1/4"(6mm) ok? i guess the working area should not be over 1cm.
Please share your amazing bows' thickness guys!

mikekeswick

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Re: Share your thickness taper pls~
« Reply #1 on: May 16, 2014, 07:25:42 am »
For R/d lam bows I like to have an 18 inch powerlam - 8mm thick in the middle. A 6mm thick belly lam, reverse taper tip lams (to keep the reflex) of 1mm to zero 12 inch long. These must be prepared perfectly for good gluelines  ;) All my taper goes into the core - normally 8mm - 2mm.

Have a look at TBB vol 4 - it has a great chapter on the sort of bow you want to make.

Offline leehongyi

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Re: Share your thickness taper pls~
« Reply #2 on: May 16, 2014, 08:06:59 am »
For R/d lam bows I like to have an 18 inch powerlam - 8mm thick in the middle. A 6mm thick belly lam, reverse taper tip lams (to keep the reflex) of 1mm to zero 12 inch long. These must be prepared perfectly for good gluelines  ;) All my taper goes into the core - normally 8mm - 2mm.

Have a look at TBB vol 4 - it has a great chapter on the sort of bow you want to make.
tri lam or bi lam? the bending area is 8mm including all lams? 2mm tip is really thin!

Offline Badger

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Re: Share your thickness taper pls~
« Reply #3 on: May 16, 2014, 10:16:02 am »
 
For R/d lam bows I like to have an 18 inch powerlam - 8mm thick in the middle. A 6mm thick belly lam, reverse taper tip lams (to keep the reflex) of 1mm to zero 12 inch long. These must be prepared perfectly for good gluelines  ;) All my taper goes into the core - normally 8mm - 2mm.

Have a look at TBB vol 4 - it has a great chapter on the sort of bow you want to make.
tri lam or bi lam? the bending area is 8mm including all lams? 2mm tip is really thin!
  I believe he is just talking about the core thickness and taper.. I just recently started building tri lams and after about 3 bows have come to about the same conclusions Mike has posted. Most of my experience has been with the self bows and hard backed bows where we simply tiller in the bend we want. On a tri lam you can easily run out of bellywood if you dont get your core thickness right.

Offline leehongyi

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Re: Share your thickness taper pls~
« Reply #4 on: May 16, 2014, 11:56:21 am »
 
For R/d lam bows I like to have an 18 inch powerlam - 8mm thick in the middle. A 6mm thick belly lam, reverse taper tip lams (to keep the reflex) of 1mm to zero 12 inch long. These must be prepared perfectly for good gluelines  ;) All my taper goes into the core - normally 8mm - 2mm.

Have a look at TBB vol 4 - it has a great chapter on the sort of bow you want to make.
tri lam or bi lam? the bending area is 8mm including all lams? 2mm tip is really thin!
  I believe he is just talking about the core thickness and taper.. I just recently started building tri lams and after about 3 bows have come to about the same conclusions Mike has posted. Most of my experience has been with the self bows and hard backed bows where we simply tiller in the bend we want. On a tri lam you can easily run out of bellywood if you dont get your core thickness right.

got it~ ;D my poor english reading~

Offline leehongyi

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Re: Share your thickness taper pls~
« Reply #5 on: May 16, 2014, 11:33:15 pm »
For R/d lam bows I like to have an 18 inch powerlam - 8mm thick in the middle. A 6mm thick belly lam, reverse taper tip lams (to keep the reflex) of 1mm to zero 12 inch long. These must be prepared perfectly for good gluelines  ;) All my taper goes into the core - normally 8mm - 2mm.

Have a look at TBB vol 4 - it has a great chapter on the sort of bow you want to make.

thanks mike!
A bamboo back lam usually is 3-4mm thick. if your bow is 64" long, the thickness from center grip to the end of power lam(9") is 18mm to 16mm, and to the beginning of tip lam is 13mm, the end of tip is 12mm. that means the bending area thickness is from 16-13mm.