Taper laminations

[mmattockx]

What is the purpose of the taper when laminating?

Kenny gave you the short answer, but here is a slightly longer version.

Depending on the back profile of the bow limbs the limbs will need to taper in thickness from the riser to the tips to achieve a smooth bend when drawn. Wood bowyers spend a lot of time on this because they are working with a much less forgiving medium and need the whole limb to bend properly to have a functional bow that lasts. Fibreglass is so much stronger and tougher that you can have a very non-optimal taper and still get a useful bow out of it. Wood breaks or takes massive set if you don't get it right.


Mark

[Longcruise]

What is the purpose of the taper when laminating?

Kenny gave you the short answer, but here is a slightly longer version.

Depending on the back profile of the bow limbs the limbs will need to taper in thickness from the riser to the tips to achieve a smooth bend when drawn. Wood bowyers spend a lot of time on this because they are working with a much less forgiving medium and need the whole limb to bend properly to have a functional bow that lasts. Fibreglass is so much stronger and tougher that you can have a very non-optimal taper and still get a useful bow out of it. Wood breaks or takes massive set if you don't get it right.


Mark

Good 'splain.

[Roy from Pa]

Wood breaks or takes massive set if you don't get it right.

Yes it does:)

[kennym]

Wood breaks or takes massive set if you don't get it right.

Yes it does:)

Voice of sperience? LOL 

[Roy from Pa]

Yupper....

 

[Crooked Stic]

I reckon if you a knothead you know pretty much about wood 

[Roy from Pa]

 

[Bow Bender]

This is the way I see  it. Getting the proper bend in the limb is also achieved by tapering the limb width from the fades out to the tips.  Limb width tapering isn't just for looks.  Try to imagine what the limb bend would look like if the width was parallel for its entire length. You don't want to get the limbs too narrow either especially on a flat thin recurve limb because you lose stability.  So to achieve the proper bend without losing stability the thickness is also tapered.  Proper limb bend is achieved with a balance of width and thickness taper.  Depending on what you want the limb bend to look like you may be able to achieve it with no thickness taper using parallel lams, or a power lam, or reversing the taper with the thick butt end of the lam at the limb tip or a combination of these but normally the thickness taper decreases toward the tip.

[kennym]

This is the way I see  it. Getting the proper bend in the limb is also achieved by tapering the limb width from the fades out to the tips.  Limb width tapering isn't just for looks.  Try to imagine what the limb bend would look like if the width was parallel for its entire length. You don't want to get the limbs too narrow either especially on a flat thin recurve limb because you lose stability.  So to achieve the proper bend without losing stability the thickness is also tapered.  Proper limb bend is achieved with a balance of width and thickness taper.  Depending on what you want the limb bend to look like you may be able to achieve it with no thickness taper using parallel lams, or a power lam, or reversing the taper with the thick butt end of the lam at the limb tip or a combination of these but normally the thickness taper decreases toward the tip.

Yep, and there's the fun part. Somewhat expensive , but fun... 

[Flem]

Plenty of bows have been build with untapered lams and they work. Thats not to say it's a good design, they don't have any hand shock or they are pleasant to shoot. But if you want to slap something together and you don't have a way to taper, you can still make a bow with them

[mmattockx]

Proper limb bend is achieved with a balance of width and thickness taper. 

+1. Both the width and thickness tapers work together and need to be correctly matched to get the bend right.

Plenty of bows have been build with untapered lams and they work. Thats not to say it's a good design, they don't have any hand shock or they are pleasant to shoot. But if you want to slap something together and you don't have a way to taper, you can still make a bow with them

For sure. If you go with a pyramid width taper you need no thickness taper to get it bending well. Fibreglass offers much more range on the width/thickness combinations that will work because you can concentrate the bend in a small part of limb and it will survive that with no issues. Wood cannot typically stand that much concentrated strain and needs the entire limb bending properly to work. The process of tillering a wood bow is really matching the thickness taper to the back profile to end up with a nice, smooth bend.


Mark

[Roy from Pa]

Wood cannot typically stand that much concentrated strain and needs the entire limb bending properly to work. The process of tillering a wood bow is really matching the thickness taper to the back profile to end up with a nice, smooth bend.

Yupper and it takes some time.
And thickness tapering my core lam, boo backing and tapering the width profile from 1.25 at the flares to .5 at the tips makes the tillering process easier.

[kennym]

Rody!! You using decimals now ?? 

[Roy from Pa]

Had too cause you skipped class the day they wanted to learnt ya fractions:)