Balance in tillering

[burchett.donald]

 DC,
            I use the area on my hand that feels the most pressure...For me it is where my middle finger is touching...
                    Don

[Dances with squirrels]

DC, you can tell exactly where the fulcrum is on any bow, at any point in its construction, at any point of its draw by allowing the bow to tilt or pivot as it's drawn. Hanging it by a narrow leather strap will work, or resting on a piece of wood or something under the handle that contacts it in only one spot. I use a short piece of a half round mill file that I cut off for this purpose and place it on the tillering tree saddle. Just move your pivot point left or right until the bow balances on it. That's where the fulcrum is. You should be pulling the string from your string hand's fulcrum when you do this. If that bow hand fulcrum spot isn't where you want it to balance, weaken the stronger acting limb until it moves to where you want it.

[leonwood]

I tiller to about 20” on the tree and from that point on only in the hand. I use the window in my backyard a lot as a mirror and start shooting it a bit for finetuning.

[DC]

DC, you can tell exactly where the fulcrum is on any bow, at any point in its construction, at any point of its draw by allowing the bow to tilt or pivot as it's drawn. Hanging it by a narrow leather strap will work, or resting on a piece of wood or something under the handle that contacts it in only one spot. I use a short piece of a half round mill file that I cut off for this purpose and place it on the tillering tree saddle. Just move your pivot point left or right until the bow balances on it. That's where the fulcrum is. You should be pulling the string from your string hand's fulcrum when you do this. If that bow hand fulcrum spot isn't where you want it to balance, weaken the stronger acting limb until it moves to where you want it.

Doesn't that just find the physical balance point? You know, equal mass on both sides. I've had a few bows that just refused to balance mass. I tried my best to keep the limbs equal tiller-wise and also reduce the mass on the limb that hung low and it was no-go. I wound up with a weak heavy limb. Not a billet bow either, a self bow, all one piece.

[burchett.donald]

DC,
         My fulcrum on the handle is where I "decide" to place my hand...It's a "choice" depending on your grip and handle design...Once I'm satisfied with  my grip choice on the bow I mark where my middle finger is on the bow...That would be my fulcrum point, some use exact center, some don't...If I shoot heel down I would mark lower, high wrist and I would mark higher...Not a whole lot either way...
         At brace I set a nocking point .25" above 90 degrees and place my leather 3 finger simulator below the nock, I shoot 3 under...
         Draw your bow in the mirror and drop heel down or change to a high grip and the bow will move and tiller will change...
                                                                                                                                       Don

[Dances with squirrels]

DC, no. Not all bows balanced in strength will be balanced in mass weight. Balance, as far as mass weight is concerned is determined mostly by geographical center. If you want a bow that balances at the same spot in both mass and strength throughout the draw, you have to plan it/design it/tiller it that way. It's not hard.

[PatM]

Wouldn't that require knowing the wood characteristics from each limb first? 

[Dances with squirrels]

Good question. I haven't found individual limb idioms to part ways and create adverse effects nearly as much as when string fulcrum distances itself from bow center.

[Bob Barnes]

I use tree straps for balancing when tillering.  You can find them for about a buck a piece online.  I think mine are 1.5" by 12"

[JWMALONE]

Hello guys, been following this thread while building my latest bow. The previous bows ive built I used a hard wood cradle and tillered using a yard stick to measure and get them perfectly symmetrical, that's all I knew to do. All of them felt balanced in the hand but three more so than others and they shot better, blind luck. With this one I didn't want to rely on luck so I changed it up.
 This cradle will pivot if one limb is stronger even by a fraction and because the strap (old work belt) is about the same size as the area of my hand I grip with it worked out ok. I put it in the strap and placed three fingers were they should be during the draw, if it tilted to one side I removed it and drew the bow and could feel the out of balance (barley). Then I just added a few extra full length scrapes when removing flat spots or what ever from that limb.
 I didn't use a pulley and rope, but if you did this set up may well indicate good balance while looking at tiller? As already said nothing replicates the bow in hand, but this helped me to get a good start toward good balance right away as opposed to tillering it symmetrical and then playing catch up later on when it felt crappy in my hand but looked good on the tree.
Don't know if this helped any one but you guys sure helped me. This one came out feeling great in the hand, maybe still some luck involved but I don't believe it was blind luck.
 Thanks guys.

[JWMALONE]

Oh yea, I put a couple of the oak bows that don't shoot as good as others in here just for kicks. Even though they feel pretty good in the hand,in this set up I can see the tilt, just slightly. The sweet shooting bows, no tilt. And that's not placing the bow dead center of handle its placing it were I want my hand to be when its finished. I cant pull the bow a thousand time while tillering because of my left shoulder, So this helps out a lot.

[Dances with squirrels]

That's dynamic balance in a nutshell. You're on your way.

I like the pulley directly/plumb below the string fulcrum, and a line on the wall to indicate optimum string fulcrum or nock point travel. That way there's no guesswork, nothing left up to sense of feel, and no chance I'm doing anything but pulling perfectly straight down.

Did you check it the whole way to full draw? Some bow's balance points shift as they're drawn, and some more than others... so if you're only checking it at a partial draw, you may not be getting the whole story.

[JWMALONE]

I checked during the entire process and scraped accordingly. By the time I got to full draw it was close to perfect, just a few licks with the scraper and it was fine. Really wont know until ive done a few with this method but it seems promising.

[Dances with squirrels]

Nice 

[BowEd]

Good topic.I hook my poundage tester on the string where my bow hand pressure is.Most times that is a shade above center of handle and the pressure on the handle while drawing is at that spot.I watch the hook on the poundage tester to see if it travels in a straight line.When I do that it feels balanced in my hand when drawing with even pressure from both limbs.I have to tell myself to hold the bow straight up and down while drawing which is not my normal way of shooting.I shoot a bit canted.I take a pic at full draw and study it.