Please tell me where I am/ if I am going wrong

[stuckinthemud]

Ok, so I tiller on a tillering tree with callipers and a gizmo, I take the bow about an inch past brace height, going slow and careful. Usually get here with next to no set, curve across the bow is a sweet one.  Measure make and fit the string and brace the bow.  Both limbs have sweet curves but are massively out of balance, lose maybe 10lb getting the bow back into a sweet curve.  Why is the curve of the bow so different when it’s braced compared with when it’s on the tree? How can I avoid this?

[Mo_coon-catcher]

Are you using a fixed bow holder that holds the bow solid or a loose one that lets the bow tilt? If it’s a solid holder is the pull rope pulling to one side or the other? At short pull distance it wouldn’t take the rope hooking moving much to show a strength discrepancy. The loose hood style shows the difference pretty quite since it’ll tilt the bow without much weight difference. That’s about all I can think of. Other than that, it’s wood, under stress it seems to just do what it wants and we just have to figure out what it wants to do.

Kyle

[stuckinthemud]

I use a fixed hold, rope pull is straight back.

[Bob Barnes]

could you post a picture of your bow being puled on the tree?

[willie]

I take the bow about an inch past brace height

how hard are you pulling to get to brace plus 1"?
also what is your target draw weight?

[stuckinthemud]

I’m above target weight, the design I’m having trouble with is ELB bend through handle, arc of circle.  I can’t get the gizmo to measure the centre 4 inches as the tillering stick is in the way. My shortest gizmo is 4”.  I’m fairly sure that is where the problem lies.  Any suggestions?  Currently my idea is to keep practicing…

[willie]

I’m above target weight,

that not much to go on, but I have seen these sort of issues when.....
bracing too early, you could be overstressing the stave when bracing 
not working the bow after adjustments

dont worry about getting the handle bending too much this early in the tiller

a tiller tree with a backboard you can trace the curve on would help

         

[Selfbowman]

I haven’t read  it all but guessing string angle and at brace you have tension pulling the ends together.
This is a pic of my best 50 pound bow strung and traced on the board. The force draw below is of the same bow. It’s in two inch increments. When on a long string the bows bend does not match up. And I may not be understanding the question at all. Sometimes I don’t. Lots of useful info on that board for those that don’t already know it.

[stuckinthemud]

I reckon you might be right about bracing too soon. I hear lots of opinions on when to brace, I am experimenting with different approaches.  Used to be I’d wait til I got nearly to draw length but currently am stringing the bow when pulling just past brace height.  The overstressng/too early to brace does make sense.

I don’t tend to worry about draw weight until the bow is properly tillered and pulling close to draw length

[Selfbowman]

I agree about bracing. That’s what I do. Long string till it gets to bending to where my tips line up to the drawing of the braced bow tracings. Even bend then I brace. That might be the right way but I’m not sure.  🤠

[Selfbowman]

The thing strange is you can tiller a hundred pound bow to that same braced profile.

[superdav95]

I’m above target weight,

that not much to go on, but I have seen these sort of issues when.....
bracing too early, you could be overstressing the stave when bracing 
not working the bow after adjustments

dont worry about getting the handle bending too much this early in the tiller

a tiller tree with a backboard you can trace the curve on would help

       

Yes to all he said.  I also will add that I use a long string just after basic floor tiller but make it as short as I can.  I’ll have it almost touching the handle even.  I also use the wooden yard stick method and gizmo too on some builds.  I’ll measure the mid point of each limbs bending section and use this as a reference when holding the yard stick up to the bend looking at the arc of the bend to see if it’s balanced on both halves of the bending part of the limb.  I do this with each limb individually and then comparing with each other.  I’ll measure the depth from the belly at the mid mark to yard the stick as it’s held up to the limb to view the bend and compare to other limb.   I find this works well for me to get to brace and have it be spot on with little balancing needed at all normally.  I’ll use this method to get to low brace around 5.5-6” and then do this till I hit around 20”.  I’ll then decide if recurves of heated reflex or heat treatment is done.  No hard fast rule I guess and depends on the build I’m doing.   

[Kidder]

So I’ll chime in with a couple thoughts. First, make sure that your long string is as short as possible. Too long of a long string Will drastically change your bend from brace. Secondly, your handle section should be the last area to bend so don’t worry about getting your gizmo in there until after brace anyways. Finally, and I don’t know if this is ideal or not, but I continue to floor tiller as I long string tiller. The purpose being to exercise the limbs good but more importantly to have a very good feel for balance of the limbs. Since I’ve started doing that my initial short string has been far more balanced. Also when I initially string a bow on a short string I only leave the string on long enough to judge the next moves, which is usually just balancing the limbs a bit. This might mean the bow is only strung for 2-3 seconds. Until I’ve got the bow well balanced and with a nice brace I won’t leave the string on for any period of time. It all takes time and practice. Keep at it and remember to have fun!

[Badger]

You are guessing at when to brace it, there is no need to guess. You can weigh a bow before it is braced. Simply pull it down and weigh it like you would a braced bow. When you are hitting the target weight at about 23" go ahead and brace it.

[stuckinthemud]

What if you are trying for the highest draw weight the bow will give ? I guess, get to 23” then brace it?