Side plate ???

[freefeet]

Reading OL's tuning page it says that to get a more forgiving tune the arrow spine should be closer to the bow drawer weight, suggesting that one should build out the side plate to acheive this.

Question... what is considered acceptable?  If i were using arrows that are 15# above my drawer weight ( i have a 30.5 inch drawer length) is this a reasonable weight spine to tune to at my drawer length, or should i be looking 5 or 10 # spine above my drawer weight at my drawer length?

I think i can understand that getting an arrow close to one's drawer weight in spine would give a more forgiving shot, but with long drawer lengths i'm thinking there will come a point when the arrow is pointing so far left that it becomes less forgiving.  So i'm thinking there must be a sweet spot for a given drawer length, that the longer the drawer length the higher above the drawer weight the spine will be to hit that sweet spot.

Is my logic correct on this?  And is this a trial and error thing to find your sweet spot?

Hope that makes sense.

Thanks for any help.

Stan

   

[R H Clark]

This is for a right hand shooter.Build the rest out to the point that if you hold the bow at arms length and sight down the string the tip of a knocked arrow will be on the left edge of the string, when the string aligns with the center of the limbs.

[freefeet]

This is where i'm at...

   

I'm pulling the bow to 46# and i'm definitely over 53# spine already, i'm using 100gr heads and already cut BOP to the face of the bow and still getting weak spine on bareshafts.  I've just ordered some 60-65# spined to try to hopefully be able to tune to 125gr with BOP ahead of the face.  

My issue is that with 100gr heads my (BOP) FOC is only 9% and i'd really like to up that a little with 125gr heads.  I realise that i can acheive this by building out the side plate but my concern is building it out too far that it starts to affect things.  I'd rather get the side plate in the best place, wherever that is and buy shafts until i find the right spine for the side plate thickness.

On O.L.'s page it says...

   

Bows that are adjusted too close to centershot requires a much higher spined arrow than it's draw weight. This is not as forgiving as one adjusted with the arrow left of center using arrow spines closer to the bows actual draw weight. Not that they can't be shot well, they just can't be shot as well.

So am i thinking correctly that you can only go so far with it before it starts becoming unforgiving the other way?  And is my arrow in the pic above about as good as it gets?

Thanks for any help

Stan

[R H Clark]

If the angles of your picture are showing what I think I see,I would say your sideplate is fine.

I'm not certin how O.L.'s statement equates to wood arrows.I do know however that it holds true when you have a bow so far past center that you are shooting carbon arrows from it that should spine in a bow 15 lbs heavier.

I think you could take the statement to mean that you just shouldn't be so far past center that you are shooting arrows greatly stiffer than others with similar set ups.

I don't know that much about wood arrows,I think however that it is typical to shoot arrows somewhat greater spine than the actual draw weight of the bow.

Example- 65lb spine wood arrows may be near standard from a 53lb bow.

Maby O.L. will read this and clear it up.

[freefeet]

Thanks for your comments, Randy.  It's starting to make more sense now.  It's good to confirm i'm heading in the right direction and not missing anything.

I think my confusion with O.L.'s page is the 30.5 inch drawer length i have and how that affects spine weight.  If i could take 2.5 inches off my arrows it would obviously make quite a lot of difference to things, but for now, at least, i'm stuck with me long gangly arms.    :D

[O.L. Adcock]

Stan, You can go out pretty far. 1/64" on the side plate makes a sizable difference. Are you 100% certain you are weak? Do 70's shoot perfect or stiff and 125's shoot weak?....O.L.

[freefeet]

Hi O.L.

Definitely weak.  Points hitting target to the right of fletched group and nocks always to the left.  First time i had 125gr on and a shaft snapped when it hit the target at quite a strong angle.  Second time i cut an inch off the shafts so the BOP was level with the face of the bow at my drawer and changed the points to 100gr and still the same result though nothing like as drastic as with the 125gr.

I couldn't find any 11/32 70gr tips so didn't try that.

Reason i bought this up was cause i just ordered some calf skin rest/plate material to replace the leather that came with the bow and went to your tuning page because i remembered reading there about where to put the rest point for best results and while reading through the page again i noticed the bit about minimizing spine weight using the side plate.

I understand that with a drawer length of 30.5 i'm gonna have to either be higher spined than normal or build my side plate out more than normal.  It just occurred to my mind when reading your page again that there would be a kind of balancing act between the two and that there would be a sweet spot, or maybe sweet area, in there to aim for.

I had already ordered a dozen 60-65# shafts before reading your page again as i was aiming to get the 125gr back on to up the FOC from the current 9% and also get the BOP ahead of the bow face a little.  So i'll have them to play with anyway (stuck in the postal system somewhere at the moment    :(   ).