Tuning questions

[Will_m]

So, couple questions for those more experienced than myself:

1) I'm having to move my rest inside of centershot (closer to riser) to get broadheads to hit with my fp at 60+ yards, they are consistently left and still somewhat left.

Are my arrows under spined? Elite impulse @80 with a 27 inch CX piledriver PTX 350 @28.5" and a 100 grain tip. Should I try a .300 spine?

2) What is the effect of moving the cable guard outward to get clearance for my blazers?

 

[5MilesBack]

Two things first.......if you're getting any fletching contact, that's going to skew your tuning efforts. Secondly, turn the bow down to 75 or even 70 pounds and see how it shoots.......after fixing the fletching contact. I just turn my arrows so that the fletching avoids cables that may be in the way.

If it shoots better after turning it down, then it might very well be the spine. Or, you could have some cam lean throwing things off as well. Does that bow have a yoke?

 

[Brendan]

So, on my bow if broadheads are hitting left of field points, I move the rest left to fix (If I'm using the rest and not the yokes). That's been my experience on every bow I've tuned, although I've heard some people say the opposite (including someone shooting a Mathews Halon). I'd try moving the rest back to centershot, and left to test what happens for different adjustments.

With that said - you're coming up underspined when I run a CE Piledriver PTX 350 (330 Spine) through OT2 with your bow, DW, DL. Bumping up to a 300 spine Easton Axis (for example) - you're still on the weak side of "Good".

 

[doverpack12]

So, couple questions for those more experienced than myself:

1) I'm having to move my rest inside of centershot (closer to riser) to get broadheads to hit with my fp at 60+ yards, they are consistently left and still somewhat left.

Are my arrows under spined? Elite impulse @80 with a 27 inch CX piledriver PTX 350 @28.5" and a 100 grain tip. Should I try a .300 spine?

2) What is the effect of moving the cable guard outward to get clearance for my blazers?

Moving the cable guard farther from the arrow will help with the rest and may actually bring you back to centershot. I highly doubt your arrows are weak as I have a friend that shoots them In his 80# obsession with a little longer arrow and draw. It could also be your draw length is a little short but if rest movements are shrinking the distance then draw length should be good. Could also be your grip. Start by moving the cable guard away from the arrow a little since it shouldn't be close enough to give your blazers clearance issues anyway. Before you move the guard put a mark where you are. The cable guard moves a lot easier if you can unhook the cables from the slide first. Just loosen the screw and rotate it

 

[Beendare]

Will, so you are shooting a 350 spine/420ish gr arrow in an 80# bow? You are getting some poor advice my friend.

Even on the CX chart you are borderline underspined and my guess is you didn't measure total length inc BH...which means, YES you are underspined and you will have a hard time getting BH's to fly. [but of course a couple high FOC guys will chime in to contradict]

You don't want to be underspined or close to it with Compound bows and BH's. Many guys get fooled because compounds are more forgiving of FP's...but screw a BH on there and you are asking for a lesson in frustration when it comes to tuning.

5 miles had a good suggestion as did Brendan.. Drop your #'s to 65-70 and those arrows will shoot like a dream....or bump up the spine...and while you are at it shoot for the 550gr arrow weight range and you will love that bow.

 

[DWhitt]

You should be moving your field points to the broadheads....so If your a right hand shooter then if your BH's are impacting left of FP's the you should move the rest out away from riser...

 

[ndbwhunter]

As others have stated, you are definitely under spined at 80lbs. I'm at about 72lbs with a 31" draw and shoot BE rampage 250 with a 56 grain insert and 100 grain head.

 

[mfllood3800]

I am a high foc guy (18-20), but I agree, you are under spined
I'd go to 250 or 300 at the minimum

Foc, fletching all play a part, a smaller than advertised part

I'd adjust my hand group or check yoke

Dropping draw weight will help determine if spine is main issue

If I have to move my rest more than .12", I look elsewhere for gecko, usually my form, spine, spin test arrows or cam lean

Sent from my SM-G935V using Tapatalk

 

[Will_m]

Will, so you are shooting a 350 spine/420ish gr arrow in an 80# bow? You are getting some poor advice my friend.

Even on the CX chart you are borderline underspined and my guess is you didn't measure total length inc BH...which means, YES you are underspined and you will have a hard time getting BH's to fly. [but of course a couple high FOC guys will chime in to contradict]

You don't want to be underspined or close to it with Compound bows and BH's. Many guys get fooled because compounds are more forgiving of FP's...but screw a BH on there and you are asking for a lesson in frustration when it comes to tuning.

5 miles had a good suggestion as did Brendan.. Drop your #'s to 65-70 and those arrows will shoot like a dream....or bump up the spine...and while you are at it shoot for the 550gr arrow weight range and you will love that bow.

464 grain arrow at .340 spine. The arrows have a 44 grain outsert.

It looks like it was largely my hand grip as moving that around brought everything together for the most part.

I do feel as though I'm probably still underspined, nonetheless.

As far as center shot, I'm now 3/4" inch out from riser to the center of the arrow, but if you look at it from the top limb the arrow still seems to be skewed right. Would centershot not line the arrow up deadcenter to the limb bolt when viewed from above?

 

[Brendan]

Elite specs list the centershot as 3/4" - 13/16" for the impulse. That may or may not have the arrow dead down the center, because elites don't have a yoke system you can tune out cam lean with. So, to counteract cam lean, you may have an arrow that isn't running straight parallel to the riser. I do know you can get into shimming the cams for the same effect as yoke tuning, but you need to be able to press the bow and take it all the way apart, as well as have the shims in hand.

I've never owned an Elite, so this is worth what you pay for it, but what I'd try is to keep the arrow in that 3/4" - 13/16" range and see if you can get it to tune there or within 1/16" of that. I'd start by dropping poundage down to 70 or by trying stiffer arrows to see if it's truly a spine issue that's messing you up before doing anything else, and then try cable guard adjustments to see if that helps.

 

[doverpack12]

464 grain arrow at .340 spine. The arrows have a 44 grain outsert.

It looks like it was largely my hand grip as moving that around brought everything together for the most part.

I do feel as though I'm probably still underspined, nonetheless.

As far as center shot, I'm now 3/4" inch out from riser to the center of the arrow, but if you look at it from the top limb the arrow still seems to be skewed right. Would centershot not line the arrow up deadcenter to the limb bolt when viewed from above?

If the skew bothers you try moving the rest slightly left and then adjusting the cable slide toward the arrow if you have any room to do it without hitting fletchings on the cables. Your grip can play into how the bow tunes for centershot as well. Sounds like you mostly fixed broadheads hitting left with the grip though. You can also probably tune the bow to the grip you prefer or closer to it using the rest and cable slide adjustments. If you watch the arrow on the rest at full draw and play with grip pressure you will see the tip of the arrow move left or right in relation to the bow riser which will tell you which way you need to go with your grip or rest to match the preferred grip. Three adjustment options (grip, rest, cable slide, and really draw length combo of length, release and loop but if BH and FP are really close at 60 now this is a non issue) if the new grip is one that you can repeat every time consistently then you can play with rest and cable guard to get arrow pointing straighter out of bow but I will say your grip may twist the riser so this is actually straight at full draw so try checking it on a draw board or have someone look from behind and above when you are at full draw which is probably the better option because this will account for your grip.

 

[Will_m]

So, on my bow if broadheads are hitting left of field points, I move the rest left to fix (If I'm using the rest and not the yokes). That's been my experience on every bow I've tuned, although I've heard some people say the opposite (including someone shooting a Mathews Halon). I'd try moving the rest back to centershot, and left to test what happens for different adjustments.

With that said - you're coming up underspined when I run a CE Piledriver PTX 350 (330 Spine) through OT2 with your bow, DW, DL. Bumping up to a 300 spine Easton Axis (for example) - you're still on the weak side of "Good".

Thank you for running that through the software, while I don't have access to such, my research has showed essentially the same. So on that note, I've gotten my hands on some Axis 260, but haven't gotten a chance to shoot them yet.

While I had essentially remedied the problem with my two blade stingers out to 60, once I hit 70 the broadheads began walking left again. At 80 I was too far left to ignore the underlying problem.

 

[5MilesBack]

It's funny. Six years ago the owner of our local pro shop called me to ask if I was interested in some .300 spine FMJ's. He said he couldn't sell .300 spine arrows if he wanted to, just way too stiff for most everyone then......just 6 years ago. But he knew I shot 32 1/2" draw so wondered if I'd take them at cost.

I know what OT2 says, but if you look at your setup 28.5" draw, 80lbs, 27" arrow, Piledriver 350........that equates to a 32 1/2" draw at 60lbs with a 27" .350 spine arrow. At 32 1/2" draw and 60lbs I shoot a CX Maxima Hunter 350 at 30 3/8", and they shoot lights out, even at long range. That's over 3" of extra arrow length. There's no way you're under-spined.

 

[doverpack12]

It's funny. Six years ago the owner of our local pro shop called me to ask if I was interested in some .300 spine FMJ's. He said he couldn't sell .300 spine arrows if he wanted to, just way too stiff for most everyone then......just 6 years ago. But he knew I shot 32 1/2" draw so wondered if I'd take them at cost.

I know what OT2 says, but if you look at your setup 28.5" draw, 80lbs, 27" arrow, Piledriver 350........that equates to a 32 1/2" draw at 60lbs with a 27" .350 spine arrow. At 32 1/2" draw and 60lbs I shoot a CX Maxima Hunter 350 at 30 3/8", and they shoot lights out, even at long range. That's over 3" of extra arrow length. There's no way you're under-spined.

I would agree with you 5 miles and say the piledriver PTX 350 should be just fine with the OPs setup. OP I would look at your draw length and try lengthening it a little if the problem keeps coming back and amplifying that much. 260 axis arrows will be extremely stiff from your setup but they may shoot.

 

[Will_m]

I would agree with you 5 miles and say the piledriver PTX 350 should be just fine with the OPs setup. OP I would look at your draw length and try lengthening it a little if the problem keeps coming back and amplifying that much. 260 axis arrows will be extremely stiff from your setup but they may shoot.

What is the downside to overly stiff arrows? Or what will my arrows do so that I can be on the lookout for it.

 

[doverpack12]

Not a huge downside but if they are overspined and everything else is lining up but they don't shoot Broadheads and bareshafts will shoot left or tear right through paper.

 

[Brendan]

The 350 is weak. And with a 100 grain tip that is a light, fast setup. You might be able to get it to tune, but to be honest, you're better with a stiffer and heavier arrow anyways shooting at 80lbs.

All of my arrows are significantly stiff for my setup, and only once have I had an issue - and that was really extreme. Off the charts stiff. I currently shoot a 338 IBO bow, 28.5" Draw, 27.5" 250 spine arrow and it shoots and tunes great.

If it were me, I'd use the Axis, up the insert weight to 75 grain brass and add a 125 grain tip and you'll have a hammer of a setup.... Spine should be about perfect in that case.

 

[Will_m]

The 350 is weak. And with a 100 grain tip that is a light, fast setup. You might be able to get it to tune, but to be honest, you're better with a stiffer and heavier arrow anyways shooting at 80lbs.

All of my arrows are significantly stiff for my setup, and only once have I had an issue - and that was really extreme. Off the charts stiff. I currently shoot a 338 IBO bow, 28.5" Draw, 27.5" 250 spine arrow and it shoots and tunes great.

If it were me, I'd use the Axis, up the insert weight to 75 grain brass and add a 125 grain tip and you'll have a hammer of a setup.... Spine should be about perfect in that case.

It's a 27 inch draw but my speed is around 285 fps chrono'd. The 260 axis won't be a change in weight from the piledriver ptx's (which are no longer made I see) +/- or so grains. I do think it largely has to do with my grip but to be honest, I wouldn't know to recognize an over or underspined arrow.

I walk back tune after eyeballing and everything looks good -- I normally don't paper tune. As for visible arrow flight, generally it looks fine but I notice some arrow oscillation at times, and this is normally at the end of shooting sessions so I attribute that to form breakdown.

Either way, my two blade broadhead are consistent with my fp out to 60. My four blade is always significantly left. At 70, my two blades begin walking left but sometimes land with fp's. At 80, they are far enough to demonstrate a real issue.

While on the surface it does appear to be a form issue, and it very well may be, I am now genuinely curious about the spine issue. On easton's chart's, including my 2 inch broadhead, I land anywhere from .250 to .300 spine. This is fairly consistent with other charts, and now for those that have the software, the programs suggest this too.

I can understand the issues created by an arrow flexing too much -- not recovering, etc., loss of energy. But what happens to an arrow too stiff?

 

[5MilesBack]

The 350 is weak. And with a 100 grain tip that is a light, fast setup. You might be able to get it to tune, but to be honest, you're better with a stiffer and heavier arrow anyways shooting at 80lbs.

That arrow is a 10.32gpi shaft, not exactly a light arrow shaft. Going stiff probably won't hurt him, but it isn't a cure for whatever else is the problem......it's just a band aid to mask over the problem.

 

[Brendan]

OP: Earlier you said:

Elite impulse @80 with a 27 inch CX piledriver PTX 350 @28.5" and a 100 grain tip.

Was that supposed to read 27" Draw and 285 FPS?

Going stiff probably won't hurt him, but it isn't a cure for whatever else is the problem......it's just a band aid to mask over the problem.

Agree with this...