Minimum T/D butt wedge thickness

[Mad Max]

Never stop learning
60" Recurve
Just been playing around with drawing Take down butt wedge.
This is what I been drawing
8" x .200 thick finished length on wedge, 4" limb pad, 4" tapered @.050 per inch, 1  .005 lam (changes to .002) and a parallel. (.005 lam adds thickness to the butt end of the limbs --------.250 stack = 48@28")
or
8" x .250   .0625 taper per inch.
What do you think


I've been using the .005/.002 lam in other bows.



Here is the bend on the .005/.002

[Crooked Stic]

I am using a 11 in.wedge on my recurves. .250 to .000.
Sort of a working wedge. Thanks to Mr. Kirk old salt got a bit of no how. 

[Mad Max]

I am using a 11 in.wedge on my recurves. .250 to .000.
Sort of a working wedge. Thanks to Mr. Kirk old salt got a bit of no how. 

.250 to zero in 11" =.0027 taper per inch, I thought it may not work well with my taper lam

[Crooked Stic]

Have used .001. Latest is parallel.
Now in my TD longbow am using straight taper wedge with Kennys .001 superman. Wedge is only 7.5.

[Kirkll]

I am using a 11 in.wedge on my recurves. .250 to .000.
Sort of a working wedge. Thanks to Mr. Kirk old salt got a bit of no how. 

.250 to zero in 11" =.0027 taper per inch, I thought it may not work well with my taper lam

What I like about long lean wedges is that allows you to put more preload in the limb without creating a hinge and pushes the working portion out further. Those wedges are loading up when you string the bow in increases the preload before the limb is drawn, and also works like an overload spring does at the tail end of the draw. Shorter wedges stack up earlier in the draw cycle than longer wedges do.

With that being said…. I’ve built quite a few using just power lams in the past, or a laminated wedge system with great success too…. But the added time milling of power wedges (.128 to nothing in 12”) is too time consuming for take down limbs.
But I still use the power wedges on my one piece bows to lengthen the fades out.

Actually I pretty much quit milling the short power wedges completely. I no longer offer the custom one piece recurve bows, but still build the one piece long bows, and I have a double ended power wedge I use on the back of the riser instead of putting the shorter PLs on the belly ramps. Those move around too much on the belly ramps.

That one piece bow on the tree you posted has a nice bend to it, as well as a decent string angle. Is that a 28” draw?

Kirk

[Mad Max]

Yes 28"

[Kirkll]

Yes 28"

What's it do when you draw it to 30"  to  32"? and what is draw weight difference for each inch from 28-32"
That will tell you the story..... Looks good at 28"     

I'm not sure what you are saying about the .005/.002.... Are you running a compound tapered lam of /005 changing to .002? or a straight taper .002 Forward taper through the limb with a .005 taper on the wedge?

Kirk

[Mad Max]

Yes 28"

What's it do when you draw it to 30"  to  32"? and what is draw weight difference for each inch from 28-32"
That will tell you the story..... Looks good at 28"     

I'm not sure what you are saying about the .005/.002.... Are you running a compound tapered lam of /005 changing to .002? or a straight taper .002 Forward taper through the limb with a .005 taper on the wedge?

Kirk

yes compound taper .005 coming out of the fades and changes to .002 later. no tip wedge
I need to do a FDC on it one day

[Kirkll]

So what is your philosophy behind the compound taper rate on the lams? I’m just curious….. It seems like you would be be locked into a set location where the transition occurs, and wouldn’t be able to shift your lams back and forth for any stack height adjustment at all…..

With a straight taper rate pair of .002 lams milled at 36” length, I can flip one in a reverse position to give me a par limb and have .024 of stack height adjustment. Ive often done this on my static tip RC at lower draw weights, and it sure makes it easier. I can do the same with mixing an .001 & .002 to come up with a .001 FT and have .012 adjustment.

Kirk

[Mad Max]

I said .005 coming out of the fades, I should have said From the butt end to out past the fades and changes to .002 later
.005 is thicker out of the fades and makes the recurve (4.75 Radius) open up, I get the whole limb working.
It's long on the tip and butt, and you add a parallel also

I have .001, .002, .003, .004 sleds also
all kinds of overlay/wedge/power lam sleds too. .005, .010, .025, .036, .050, .083, .125

[Kirkll]

I’m a bit confused bro… a .005 forward taper rate is a faster taper than an .002 . In 8” it’s going to drop .040 thickness , where a .002 will be thicker and only drop .016.   So you lost me on your reasoning there….  Kirk

[Mad Max]

You would have to look at it from the tip back towards the fade.
A .002  from the tip coming back to the fade.
A .002 from the tip coming back towards the fade but change to a .005 would get thicker.
So maybe this will help you understand,  the .005 only goes out 6 or 8"

I try to grind them down until the tip end is about .020 so my parallel won't be thinner than a veneer.
I have thought about making two .0025/.001 lams and leave the parallel out.

[Kirkll]

Ok…. So you are running a reverse taper then. Not a forward taper? Typically when guys talk about taper rates it’s forward taper towards the tips.   Kirk

[Mad Max]

Ok…. So you are running a reverse taper then. Not a forward taper? Typically when guys talk about taper rates it’s forward taper towards the tips.   Kirk

No

A .005 is a fast taper but it also has to be thicker because its a fast taper.

Let’s get back to the topic
What’s the minimum thickness for a butt wedge on a take down bow

[Kirkll]

Honestly…. I’m still lost on your reasoning with the compound taper .005/.002.
But…. That’s ok….

The answer to your question is there really is no minimum thickness on a butt wedge…but it depends on wedge materials used and length of the wedge too.

on lower draw weight bows using say curly maple long lean wedges , and a long limb pad on the riser , you can get some flex on the limb pad going using less than .025 to nothing in 11”-12” milling.

Some guys run a 3/8” flat portion that extends past the riser, then has a fast taper into the fades like the ones Binghams Projects sell at 8.5”to 10.5” lengths.

I like using a long straight taper wedge that I mill at .300 to nothing in 12” this gives me a finished wedge thickness at the limb butt at about .500- .600 . And pushes the fade tips out away from the riser  quite a bit.

 Using decent hardwood for wedges, or even walnut or other lower density vertical grain wood with good stiffness works well. Rock hard maple makes excellent wedges for recurve limbs. This high density ChomaPly makes a stiff wedge too.

Draw weight can determine the type of material you want to use  for wedges too. If you are using bamboo cores with a bamboo wedge at 60# draw weight, you are going to have more flexibility at the fades than using a maple wedge with a maple belly lam. The compression rating on these two products are quite different.

I’m sorry bro…. There is no answer to your question. Length, taper rate, and type of materials used, as well as limb pad length, will determine your minimum butt thickness.   Kirk