Hickory Tillering Advice?

[Willibow]

I've been working on this hickory bow to hopefully take antelope hunting in a couple months.  I've been long-string tillering so far and am not really sure how to proceed.  I'm hoping some of you more skilled bowyers out here can take a look and offer any criticisms, advice, etc.

The images below show the bow at about 14 inches of string movement at 48 pounds.  I'm aiming for 50-55 pounds at 28# when all is said and done.  Currently it's 68" tip to tip, 67" nock to nock.  This piece comes from a board, and is scraped down to one continuous ring for the back.  Pyramidal design going from 2" at the fades down to a hair under half-inch at the tips.  Small osage tip inlays are currently in place.  Man is that stuff tough to file through!  I thought my fingers would  fall off before the nocks were done.  I need a more aggressive rat-tail file for hard inlays like this!

I always have the hardest time with the early stages of tiller like this.  I just recently broke a rawhide backed black walnut bow, and I'm in no hurry to re-live that sorrow :-)

I appreciate any help you can give.




And without the grid.


Thanks again!

[PEARL DRUMS]

Brace it up about 2" high and take a few more pics at the same draw weight you have it at now. Your well beyond long string tillering.

[Aaron H]

Chain saw files work great for cutting in nocks.   

[chef-d405]

I agree on 2" brace. It will show you more than long string pulls. Looks like you need more bend in mid and outer limbs for pyramid tiller. It is already bending well right out of the fades. Too much bend there will cause a lot of set though.

[Willibow]

So tonight I tried to string the bow at a low 2-3" brace with a new string I made up for it last night.

I always make Flemish twists from BCY B55 and have never had a problem before, but tonight it looks like the string is stretching like crazy :-(

It's 14 strand, and looks to be made at least as well as the other half dozen or so strings I've made in the past. What's happening is when I string the bow, it initially is at the desired brace height, but as soon as I take tension off of my bow stringer the tips slowly begin to return until the string is tight against the bottom of the handle. After 30 seconds or so the movement is complete.

The only thing I can think of is that the string is stretching. Where else could this movement come from?  One difference from my older strings is I'm using pure beeswax on this one, which I melt in using friction along the string with a piece of suede leather.

Has anyone else ever seen this magnitude of stretch with new B55 strings? This stuff is supposedly lower stretch than B50. How should i proceed? I'm worried about having to over stress the bow and pull it way hard in order to string it at an insane brace height so that it will settle to two or three inches at brace.

Thanks again.

[Jim Davis]

Low brace height puts more strain on the string at brace height.

I'd also suggest taking the level out of the picture when viewing the arc. It's a real distraction.

Looks like you need to thin the limbs along the full length because too much of the bend is at the fades.

Jim Davis

[mikekeswick]

Can you post a picture of it unbraced as well.

I'd recommend reducing the depth of your handle a 1/4 inch or so and blending the fades in a shallower radius.

[Aaron H]

Are you using looped ends, or are you tying a bowyers knot on one end.  I have had bowyers knots slip when low bracing

[bubbles]

Thats the reason I use FF or linen as a tillering string. Low bracing is a pain in the butt with stretchy strings.  I would suggest thickening the string a bit, just for use as a tillering string and maybe some extra wraps on the bowyers knot.

[Willibow]

Thanks for the replies. The string is a Flemish twist, no bowyers knot.

I'll take new pictures unbraced tonight after work and I'll also take the string into work and try to get it to 200 or 300 lbs of tension for ten minutes or so to properly stretch it. After doing some research, it looks like this is the way a lot of people are pre-stretching their Dacron strings.

Thanks!

[mikekeswick]

To get stretch out of your string put it under tension then get a piece of leather fold in half, string in the middle and rub it up and down until the string gets warm.

[lebhuntfish]

I use natural beeswax exclusively on my strings. I use b50 to tiller with out to about 22 to 24 Inches. Now I make FF string to do the final tiller. I make a flemish style string and add a few pieces of the b50 to the loop section. (thanks missilemaster).
When I stretch my tiller string I use a rachet  strap between two trees. My tiller string is 16 strands of b50 after stretching I've gained 6 to 8 inches at least. Patrick

[Willibow]

Good recommendations, I'll have to try these tricks to stretch the string out, or maybe just move to a FF material to save the time.

So I've stretched the string enough to get it braced at about 1.5" above the handle (2.5" above the belly of the bow).  Pictures are posted below of the tiller at 15", pulling 50 lbs.
I'm afraid I've already induced about a half inch of set since there used to be about an inch of natural reflex in the bow.  Pictures posted for that as well.

Thanks in advance for helping to share the wisdom.  This community rocks!

Unbraced with no grid:



Unbraced with grid:


Pulled to 50 lb at 15", no grid:


Pulled, no grid:


Sorry the right limb tip got cut off in the photos.  I need to rig up some way of holding the bow at draw that is more stable than my arm for photos!

Thanks again!

[Dakota Kid]

You probably should avoid holding the bow at draw for more than a few seconds at a time. Get a tripod for your camera instead.

[wizardgoat]

everything looks pretty even, Id get her braced higher