setting tiller weight goals for mystery wood ......bow finished, pics added

[willie]

I got a chance to put a little time into this bow, and got it on the tillering tree.
I am aiming for 70 lbs. but have not pulled it that hard yet

still takes 80 lbs to deflect the tips 5'' floor tiller

got it to a short-as possible long string, kind of a semi brace at zero with strong string tension, and it takes 45 lbs  to pull from zero to 5" draw. seems to have a nice early weight by feel. left it on the tree drawn to what would be 5-6 inches for a half hour and lost 1/2 half of my 3/4" glued in reflex just unstrung. Does this seem like a lit to loose just getting it to a "normal brace height?

How far do I need to get the bow drawn to establish a benchmark of "no set tillering"

thanks
Willie

[wizardgoat]

Post photos for better advice

[Pat B]

Project 3# per inch of draw and estimate where your bow is now at full draw.

[Badger]

   If I put a long string on a bow I don't pay much attention to how far the limbs are moving. I still just look at where the string is on the measure. If it weighs say 70# at 22" with a long string it will weigh close to that braced with the short sting. It doesn't even matter how much the long string is hanging down within reason.

[willie]

Pat B

I am at zero brace with a short string I am pulling about 2.75 to 3 lbs per inch of pull.

first 6 inches took 18#
6 - 10 took 11# more
10 - 14 took 11 # more

doing that caused me to loose  an eigth more reflex.

thanks
 willie

[Badger]

  Willie, sounds like you are at 40# at 14", it will be about the same if you brace it. What is your goal weight. As for set, start measuring it once you get it braced, some of the early shape just might come out because it wasnt hard set in the first place. Instead of measuring the set, monitor how much draw weight you are loosing by increasing the draw, thats what you are trying to avoid. If it looses draw weight it will also take set. If you start having losses early like where you are now you may want to lower your draw weight expectation, I don't think you have real bow wood you are working with anyway.

[willie]

Badger-

39@ 14 is what I have. Hoping for  70#@27". I have lost about 1/2" of the 3/4" glued in reflex I started with. I am having a miserable time trying to get this bow properly braced few inches. Just got back from the hardware store with a turnbuckle. when I put it in the string and braced at two inches, the string slipped, and then I noticed that I have to come up with something better for a temporary  nock as I am crushing the soft wood. yesterday I broke a nock and had to wait for some glue to dry on my latest idea.

when get a workable string and a consistent brace I will start pulling and rechecking weights. Assuming  tiller is even, how far past 14 would you pull it to get a measure, or to put the question another way, how much  poundage loss off the 39@14 benchmark,  would you tolerate before retillering for a lower goal. I am not shooting for a real high stressed bow here. Maybe loosing the original reflex plus another inch or so, by the time I get to  my design draw length of 27?

thanks for you patience

willie

[Badger]

  If I started loosing more than 1#at 14" I would dial back my target weight all the way to 40#. If I was getting close to full draw and it started loosing a   little like maybe 1# @ 24 annother 1# at 25  I would keep creeping up on my goal. I have seen bows loose more than 10# and only take about 2" set, for a 70# bow a 5# loss would be too bad. 

[willie]

Badger

If I read that right, loosing a pound at shorter draws like 14" indicates a lot more strain and damage than loosing a pound from a benchmark closer to your final draw length like say 25"?

willie

[Badger]

Thats the way I look at it yes. I don't like to loose any weight early on, maybe 2# but no more than that.

[willie]

thank you Badger, I think I understand the monitoring approach better, your input has been top shelf

I have to shorten the bow some and work on the taper some more, add better string nocks.........

will post more with a pic or two after a few days when I get to final tiller, and as time permits that I have time to work on it



willie

[willie]

got a chance to work on the bow some more and got it to a low brace of about 2"

the bow got shortened to 70" nock to nock and weight was reduced some.
it presently pulls 43 @ 14"
it pulled 45 @ 14" before I pulled it to 17"
thought I had the bends balanced pretty well before I made the pull, but I have to go back and get the left bending more now.

any ideas how much I should drop my weight goal?  the bow is only 1.25 inches wide

thanks for looking

willie

[Badger]

  Its already loosing weight but you have a lot more wood you can get working in the center of the bow. I think I would settle for around 50#@ 28. What is the physical weight of the bow?

[willie]

Badger
21.5 oz
it took some set mid limb but not in center. the tips droop  1/4' more than before I pulled it

willie

[willie]

got the tillering pretty much where I want it and  I the bow ended up at 1 1/4 wide by 71 ntn  45@27" with 2" of total set. Larch is kind of pretty but soft. I don't know if the pics show it too well. Kind of cloudy and snowy for good pics. A thanks to Badger for helping me learn a bit more about how to set tillering goals for unknown woods. Any comments on tiller will be appreciated