Bow tuning issue

[Kidder]

So the last bow I build has been a nice shooter right up until around 300 arrows. Suddenly it seems that the arrows are kicking off the bottom of the shelf and going rather wild. I’ve got probably too much positive tiller. It’s settled at 1/4 inch positive and my top limb has taken a bit of set. Do I need to retiller it to about an 1/8 inch positive? Will that solve the kick? I shoot split fingers. Or is this just a string stretch issue? Thanks!

[Badger]

 You could retiller or just raise or lower the nocking point on the string.

[Del the cat]

Bows do change... have a look at it and you decide if it needs re-work. I had similar thing on Sunday... took just one shot... noticed the bow looked weak in the lower limb. I'll re-tiller it.
Del

[bassman211]

Heat treat the weak limb, adjust nock ,and check tiller.

[Eric Krewson]

first check your limbs for weak spots, if you have any deal with them first, then slowly sand off wood from your bottom limb, sand and shoot, sand and shoot until you find the sweet spot.

Almost all my bows change tiller during shoot in and need to be adjusted.

[BowEd]

It could be this too.I'll go down the line as to causes.
When tillering and it gets to full draw and your satisfied with the tiller of the bow and all stiff spots are removed the bow should be pulled at least a few dozen times or more to that draw length to be sure the wood is stressed enough to show its' tiller.Less dense woods will show it quicker than denser woods.Most times laminated bows will show it later too.Leave it set overnight.Do it again the next day.A person cannot hurry this process.
Shoot it in with at least 200 arrows and check again.If any slight changes adjust it.I find the spot it shoots the best and from the school of hard knocks is the same for me every time.All this before any good finish is applied.
Another thing where your pulling from on the tillering tree should be very close to where your pulling from on the string.Could be gripping style too with bow hand.I shoot split finger with string hand and pressure of bow hand is on webbing between index finger and thumb at mid area on bow or just above mid area.Speaking about a symmetrical bow now.Nocking point of arrow shaft is app.3/8" above shelf with shelf app.1.5" above mid on bow.Some call that a high wrist style.These are gripping proximities for me on a bulbous type handle.Can't speak for a pistol grip type handle.
It's very rare any of mine change even after 1000's of shots doing it this way.In fact it's nonexistent even 12 years later stringing it up.
Another thing is I stabilize mine at 50% humidity all though its' life from a roughed out stave to finished bow and store it that way too.I like to store my bows horizontally.The only thing different that happens with mine is that in the summertime draw weight can be slightly lower than in the winter time and that's because of drier less humid air.
Either way Steves' suggestion is probably your solution now.

[Kidder]

Heat treat the weak limb, adjust nock ,and check tiller.

Can’t - it’s a boo backed ERC.
Will tillering effect nock travel/limb timing on a traditional bow like cam timing on compound will? Or am I just convoluting the issue in my head?

[BowEd]

Personally I could'nt tell you that.I've never owned or shot compounds.
Sounds like it'll just have to go down in draw weight a little bit from adjustment and it'll be fine.
Red cedar can be a little fickle type of wood.

[Eric Krewson]

Limb timing is exactly like adjusting the cams on a compound, the difference is knowing what limb needs what, it is often not as obvious a out of time wheels.

[silent sniper]

Kidder, several years ago I had the same issue with a hickory backed ERC. In total I ended up re-tillering the bow 3 different times until it finally stopped shifting. This re-tillering isn’t common but it definitely happens from time to time with both laminated and self bows. Since that experience I now brace and  shoot the bows several hundred shots over a 7-10 day period before I commit to putting a finish on them. Good luck on the bow 👍🏻
-Taylor

[bradsmith2010]

I have an osage bow,, the bottow limb kept shifting weaker, the design was a bit overstrained so I was not surprised,
just kept shooting it and tillerering,, and it settled into a nice shooting bow,,, sometimes the wood has a mind of its own,,
or is not as consistant as we expect,, and thats ok, you can get the arrow to fly on that one,,

[bradsmith2010]

Eric, Im hoping there isnt anything on my self bow thats like a compound,,

[Eric Krewson]

The mechanics of the limb or wheel travel are the same although I quit worrying about wheel travel in 1989 and concentrated solely on limb travel. Injuries and old age may shift me to a cross gun if I want to hunt but I wouldn't want one with even a hint of round things on the end of the limbs.

[George Tsoukalas]

kidder, do you use a rope and pulley?
By the time I am done tillering the bow is pretty much stabilized.
I exercise the limbs 10-12 times after each little wood removal.
i think you just fiddle with the nock point as Badger said
Jawge

[Eric Krewson]

I also shoot a bow between tillering scrapes ,usually a dozen or so short draw arrows, I check where the bow hits the target poundage and draw is an inch or two less. For me this snap of the bow makes the scrapes register better.