[tori]

Hey guys,

I've switched to slightly longer arrows recently - 570 ACE cut to 29.5 inch shaft length. I was shooting 28.5 inch (shaft length) 620 ACE.

I have an issue or concern. I'm getting slight scuffing on the rear node, which I assume is from plunger button contact with the shaft as the arrow leaves the bow.

Arrow flight is most excellent though, and the bare shafts are with the groups. Still, I have these *very slight* scuffs on the rear of the shaft (in front of fletches) that indicate contact with the button. I can rub these scuffs off with my finger, but sure enough, they more often than not appear again after the arrow has been fired.

I was under the assumption that there should be no contact at the rear node upon release of the arrow. Am I missing something basic ... ie; is the arrow spine too soft? Or perhaps I've got the plunger set up incorrectly. It's at or close to center-shot, medium spring beiter, backed off to a relatively soft feel.

For a solution, can I correct for the rear contact by changing center-shot plunger position to either slightly left of or right of centershot, and also adjusting spring tension?

Or, do I need stiffer shafts? If so, it's $300 down the drain for the most recent 570 ACE purchase. I'm getting subjectively very good arrow flight with these though, and bare-shafts out to 50 yards are with the shot groups ... this is why I'm very stumped.

Any insights are more than welcome. I thought I knew quite a lot about tuning, but something here is not right.

Tori

 

[Matt_Potter]

Tori

You are shooting hex-6 I'd try coming closer to center they seem to like that.

Matt


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Team Montana - we are coming for your quarters ;-)

 

[j.conner]

Tori, what is the draw weight of the bow? What weight points are you using on the arrows?

Those bare shaft results sound pretty good! Yes, you can adjust center shot and plunger tension to adjust for spine. Some experimentation along those lines is probably in order, however it might be challenging as you are already getting good flight and are timing the nodes. More details on the setup might help tell if it is trending stiff or weak.

 

[Sid]

Tori, if your still at a loose end with this, see if you can find the time to Skype us.
Might be able to talk it through???

We managed it with a Target archer in Hawaii, and one in England.

 

[everwood]

what matt said. get as close to center as you can. if its flying great.. then great.

it sounds to me like you have it right and you are simply getting contact. you can have a perfect tune and terrible clearance. fix the clearance. try lipstick on the vanes and turn the arrow until the contact goes away. take note of how much wire arm you have coming out on your rest. search for points of contact. lipstick on the vanes works well and you can try some foot powder spray all over the offending area and note when it gets brushed off. one of these two methods should show you something more.

is your plunger in the middle of its tuneability(medium tension and bareshaft flying true?)?

 

[Sid]

what matt said. get as close to center as you can. if its flying great.. then great.

it sounds to me like you have it right and you are simply getting contact. you can have a perfect tune and terrible clearance. fix the clearance. try lipstick on the vanes and turn the arrow until the contact goes away. take note of how much wire arm you have coming out on your rest. search for points of contact. lipstick on the vanes works well and you can try some foot powder spray all over the offending area and note when it gets brushed off. one of these two methods should show you something more.

is your plunger in the middle of its tuneability(medium tension and bareshaft flying true?)?

AH, YES... no need to run conventional cock feather position. It can be anywhere you want as long as its not contacting the bow.

 

[tori]

Hey guys, thanks for the tips. I have been able to completely tune out the contact, which is a great relief. I backed off the limb bolts a few turns; as I think it was simply too much energy for the ACE 570 to cope with. The severe paradox on the rear node is now OK; and I'm not getting the slight hits against the plunger as the arrow passes.

This has quietened down the bow a LOT, I really should have sorted this issue before now. I also moved the plunger to the right - close to center - and raised the brace height slightly (7 and 3/4 inches). I may have lost a couple of FPS by lowering the pre-draw with the limb bolts, but what I loose in speed, I am gaining in control. It's great that I can hold the bow at draw with ease, and it gives me time to settle to anchor, get sight picture/aim correct, and let that arrow fly to the bulls.

My point on with the 29.5 inch (shaft length) ACE 570's is 55 yards, and I'm very happy with this for my IFAA game. I've increased the point weight of the arrows slightly - to 90gr up front, and total arrow weight is 285gr.