Hickory bow, sinew back

[1776J]

you may already know this (but doesn't hurt to say I reckon) ...
if you're going for long, stiff levers on that bow you'll only need to sinew back
the working section of the limbs, which shouldn't take much time or sinew.
 

Well I'm finding (I think??) that I'll have to thin out the tips a little where they begin to reflex in order to get it bending better and flexing a bit more.
.... I think??
hahahaha

[NTD]

Take your time tillering that kid.  He's kinda cute, must resemble his mother.   

BBWWAHAHAHAHAHAA!!!!   

I think with the sleep we're NOT getting I may think I was tillering the kid and changing a diaper on the bow!!?? 

I know I said it before, but it get's better   Diapers on bows...It'd be a comfortable handle wrap...just don't use the ones that should have been tossed in the diaper Genie

[1776J]

I know I said it before, but it get's better   Diapers on bows...It'd be a comfortable handle wrap...just don't use the ones that should have been tossed in the diaper Genie

Hahaha...

YIKES! 

[JW_Halverson]

Nate,1776J,  it appears you two have been up too late into the nite changing nappies.  Get off the dang computer and get some sleep!

[1776J]

The latest with the hickory bow....

Seems to look like we're at #55 @ 22" right now.

I'd like to get it to #50-#55 @ 27" but I'd settle for #45 @ 27"....

What do ya think fellas? 
Anything look like its hinging,...etc.etc?
The subtle recurves aren't even (one seemed to have pulled out a little)....which looks as if the right limb isn't bending as much?
I'm thinking of reducing the fades a little on each side of the handle.  Handle is 4"...fades approx. 1.5" long,...maybe a little more actually.

• UNBRACED •


• BRACED AT 6"•

[1776J]

Anyone think it would be alright to try and put back some reflex into the tips that I had lost...or at least even up the one limb that lost the majority of its reflex?
I don't want to push it to hard and loose a perfectly good bow....

[artcher1]

Good looking helper you got there! Congrats!

Haven't keep up with your bow build but do what Sonny mentioned.

Sinewing places more belly wood under under compression I understand so you might want to give some thought to trapping the sides of you limbs. This will save you some sinew and glue which will help with bow weight gain/loss as temps/humidity changes occur.

You do need to get your limbs set back before starting your sinew. You can heat treat your limbs into reflex, or heat your limbs and set 'em back. Build your a form or something to hold your limbs in reflex while the sinew dries.

I like to get my bows to just about where you have yours now and place a permanent balance mark at center using an awl or something similar. Once the sinew dries I recheck  the balance point, and if shifted I scrap/rasp the sinew to bring the bow back into balance. This ensures the same amount of sinew per limb. This seems to help prevent tillering chances later on.

That's a short version of how I do mine, hope it helps............Art

[1776J]

you may already know this (but doesn't hurt to say I reckon) ...
if you're going for long, stiff levers on that bow you'll only need to sinew back
the working section of the limbs, which shouldn't take much time or sinew.
 

Sonny,
thank you for the advice,... somehow I missed it when you first posted it.
I figured to only sinew that area, BUT, I was also thinking of sinewing just under the knock area, to give it some extra support.
I may indeed be "overbuilding" it, but I guess I'm just trying to be proactive?? 

[1776J]

Good looking helper you got there! Congrats!

you might want to give some thought to trapping the sides of you limbs. This will save you some sinew and glue which will help with bow weight gain/loss as temps/humidity changes occur.

Thanks for the help... I just need to figure out to what extent I need to shape the bow's side, back and belly in that trapezoidal shape.  A little,... a lot,... round out the edges of that trap shape,.. or make it a trapezoid with just the edges "just" barely rounded off???

[1776J]

Well,...
I decided to mark off 1/8" on either side of the back, and 1/8 on the sides, thus forming a perfect angle as it were.
I took it close to the lines with a fine rash, then sanded it up the rest of the way to make everything uniform.

WOW!,.... what a difference that made!!!!!!! 

It's SOOOO cool to see these theories go from paper (or screen as in this case) into physical practice and then see and feel the end result of it.

It is now braced at 6" and pulls #55 @ 27" my full draw.
I only took it to 27 maybe twice as I didn't want to push my luck. 

I can't wait to throw the sinew on later this week!!!! 

....not to mention,... I can't wait to take down a doe or buck this coming season!!! Whoohoo! 

[1776J]

Here is the bow at a full draw of 27"  (tried to get a decent photo)

[1776J]

Something I noticed that was a little frustrating...

In Bowyer's Bible #4,... it talks of Trapping.
First it lays out the positives, and it sounds great. 
Then lays out negatives and makes you wonder, "Hell, did I just do a safe thing?"...mentioning how it can be unsafe for the bow.
Lastly, in the photo illustration on the next page, it suddenly says it can be "safer" to trap a bow?

What the??!!??
 
I'm stumped.

I have a slightly crowned belly on the bow AND I just trapped it about 1/8" on either side of the back of the bow.

Of course I'm going to sinew the back so this should compensate for any "unsafe" things going on with the trapping I did.... right?
Hmmm,.....

[Pappy]

Looks like to me most of the bending is going on a few inches out of the fads. Is the 3rd picture back the un strung profile ?
   Pappy

[1776J]

Looks like to me most of the bending is going on a few inches out of the fads. Is the 3rd picture back the un strung profile ?
   Pappy

Pappy, here's the unstrung Profile.... it's 59" long


Yeah I couldn't help but notice that as well. 
The tips are a little long, (similar to the Holmegaard bow design with still long tips) however, it seemed as though no matter what I did while tillering, the majority of the bend kept coming in at those points??
Would the stiff ends have something to do with that? 
I know they are a little long,... should I thin out the tip areas a little more where they start to turn up into their slight reflex and a little past that making that area flex a little more???

I'm figuring that if its pulling at #50 @ 27" now, then even if I have to take off some more to get it bending better, after I add the sinew it should bring the poundage back up afterword.  Right?


Here's another shot of the full draw, just turned....Looks like the left side (top limb) has a stiff area right past the mid limb area.  Would you agree?

[artcher1]

Jason, when you go with the reflexed or recurves tips you add extra strain inner limbs. You have to preplan for that. A semi-pryamidal limb design or greater belly taper would have accomplished this IMO.

Your drawn profile reflects a more pyramid limb design (circular) where as your rectangular limb design should show an elliptical shape. By doing some side tapering from fades to mid-limb will allow more bending mid-limb.

For now, maintain your slightly crowned belly. Because as your sinew dries, it's shrinking properties will cup a flat belly. That will cost you poundage if you have to flattening the belly back out.

That's a good illustration of trapping in TBB#4 and a good guide to shoot for. For a 1 3/4" wide limb I'll trap in 1/4" on each side leaving me with a 1 1/4" back to sinew. Saves a lot of sinew and reduces quite a bit of physical weight also.

A naturally crowned back such as a small stave will produce the same effects as trapping a board.

As Baker mentioned, trapping becomes unsafe when MC of the bow drops. Bow becomes stiffer and adds extra strain to the back of the bow. That's where sinewing will help......Art