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Main Boards => PowWow => Topic started by: peter61 on April 19, 2011, 03:21:00 AM

Title: Reverse Taper
Post by: peter61 on April 19, 2011, 03:21:00 AM
Hello to everybody at the forum!
Can anyone explain me, what is a reverse taper?

In the instruction for the Bingham Pronounced TD-Longbow is writen, that you have to put a paralell, a "normal" tapered and a "reversed" tapered lamination in the limb form for glueing.

Please help me, I'm confused!

Regards Peter   ;)
Title: Re: Reverse Taper
Post by: Buemaker on April 19, 2011, 04:35:00 AM
Well, A "normal" taper gets thinner in thickness the closer you get to the bowtip. A reverse taper is the opposite it gets thicker the closer you get to the bowtip. So to make it clear or perhaps more confusing; The two tapered laminations are made the same way, but the thickest end is pointing in opposite directions. Some bows are made with reversed tapers, I believe The 21st Century Longbows are made this way. Personally I would not bother with what Bingham is saying. Bue--.
Title: Re: Reverse Taper
Post by: Hootsbow on April 19, 2011, 07:08:00 AM
Why would you use a normal taper and a revere taper in the same limb? you just made a parallel
Title: Re: Reverse Taper
Post by: Buemaker on April 19, 2011, 08:01:00 AM
It is not in the bowlimb itself that Bingham recommend this, but in the bowform/mold.
Here is what they say;reversed tapers laminated to mold thin tips butted at center. Note; drawing shows the parallel laminations on top of riser and tapers on bottom of riser with the reverse tapers placed in bottom mold. Rounded design will use this arrangement with laminations laminated over the complete top of rounded surface. The traditional design can use this arrangement or you can place tapers on top of riser with parallels on bottom of riser without reversed tapers installed into bottom of mold. I guess what they mean is that if your bow to be is made with it`s back down on the mold and you use tapers here, you should glue  reverse tapers to the mold in order to even out the taper you place on the back of the bow. Wow my head is starting to spin, no wonder if you are making your first bow you could get confused.  Bue--.
Title: Re: Reverse Taper
Post by: Charlie Lamb on April 19, 2011, 08:03:00 AM
Bingham suggests doing that so that the materials glue up nice and even.

When laying tapered lams in the form, they form a kind of "hump" where they join.... because the tapered lam is thickest there.
By gluing a couple of tapered lams on the form, butted together at the thin end it allows for the "hump" and everything sits nice and flat.
Title: Re: Reverse Taper
Post by: PV on April 19, 2011, 08:06:00 AM
In the binghams design the "reverse taper" Is the same as the "normal taper" Just flip it to create a parallel limb
Title: Re: Reverse Taper
Post by: Buemaker on April 19, 2011, 08:07:00 AM
Thank you Charlie, you said it much more comprehensible than I did. Bue--.
Title: Re: Reverse Taper
Post by: Hawkeye on April 19, 2011, 02:00:00 PM
Jim Reynolds' Thunderstick MOAB uses a reverse taper lam in its construction.  Lots of people think they shoot very nicely...
Title: Re: Reverse Taper
Post by: kennym on April 19, 2011, 08:03:00 PM
The way I understand it, the pronounced longbow TD,limb  has a .002 taper, the wedge, a reverse .002 taper and a parallel, all between 2 slices of glass.

Why? Don't know, but they shoot pretty good I hear. Maybe so the thin end of the reverse taper bends over the "corner "on the wedge?

I have had a couple people build with 3 parallels with equal success.
Title: Re: Reverse Taper
Post by: Crooked Stic on April 19, 2011, 08:14:00 PM
Kenny you caught on quick. Thin bends better.
Title: Re: Reverse Taper
Post by: kennym on April 19, 2011, 08:41:00 PM
Thanks Mike!

Blind squirrel syndrome?   :D
Title: Re: Reverse Taper
Post by: David Mitchell on April 19, 2011, 11:06:00 PM
21st Century does not use reverse taper now--at least the two 21st Edge models I have from Milton do not have them.  At one time Hummingbird longbows were made with reverse tapers also but not any more.
Title: Re: Reverse Taper
Post by: 7 Lakes on April 20, 2011, 09:48:00 AM
If the bow has a .002 taper then reversing that .002 taper on the form will allow the riser to fit perfectly.  Clear as mud?

If bow limbs are tapered .002 the riser area will rock .002 on a flat form. Reverse the taper on the form to take up the .002
Title: Re: Reverse Taper
Post by: Mike Mecredy on April 20, 2011, 02:39:00 PM
I keep all the thin ends on the tip, I wouldn't see why one wouldn't.
Title: Re: Reverse Taper
Post by: 7 Lakes on April 20, 2011, 09:01:00 PM
I may have misunderstood...  Are you talking about putting the reverse tapers on the form or in the bow?