Bare Shaft Tuning?

[Desert Archer]

Need some help from the more experienced here at setting up (tuning) a bow.

I just got a set of Border Carbon limbs (Longs pulling 34# @ 28"). Since I draw 32.5" and like the adjustable metal riser bows, that poundage doesn't have much to do with anything. Decided to try them on a 23" Best Zenit riser. Yea, I realize someone with my draw should use a 25" riser but I have this mental block about hauling a 70" recurve around the field course. 68" just seems more managable. I know it's silly but humor me.

Anyway, when I first set the limbs into the riser the digital scale said I was getting 47 pounds at my draw. A bit more than I wanted for a field archery bow. Backed off the screws, fiddled around to get the tiller set dead even and ended up with 43 lbs, 10 oz. Call it 43# for conversation sake.

Easton's charts say in the ACC line I should use either 3-39 (.440 spine) or 3-49 (.390 spine). This is all at my draw length and that pull weight. Thought I would try the 3-49s as I shot them in a 43# Spigarelli and they flew pretty good with 120g screw in points.

Shot three into about 4" at 20 yards (shoulder is tired from the indoor shoot) and then tried an unfletched shaft. Missed the target & cardboard to the right and the shaft landed more than a foot off the point of impact for the fletched arrows. After calming down (not used to missing the whole dang thing) I tried 110g points, then 100g points. I'm still 6-8" right of the fletched arrows point of impact. That says my shaft is too weak. If anything, these .390 spines should be too stiff. Oh, and I went to a stiffer spring in the plunger with no noticable effect.

Can anyone out there give me an idea why what should be a too stiff arrow is acting like it is too weak? This one has got me puzzled.

Dave

[Stagmitis]

When TOO stiff the nock end hits the riser cut out and sends the shaft to the right. If it were weaker it would "Bend" enough to get it through paradox, around the shelf and fly to the left.


To discount the possibility of the shafts bein g too stiff try adding 175 grns(or more) and you should begin to see a difference.


Also, when I think I am "There" I still like to add and remove weight just to make sure. On a perfectly tuned BS it doesnt take lots of weight to get them react.

[thisbucks4u]

Dave for what its worthI have to use a 60 grain nib in my full length 300 spine carbons to get them to bare shaft.
Theres no predictable way to determine what full length shaft is going to work perfect on the first try. There is a huge difference between full length and -1 inch. Besides that you have to figure in string material, nock weight, etc-etc.
Try putting some rubber string leeches on. This will sap some energy form the string, and make the shafts stiffer. Also you can try addind several strand of material to your string ie go from 12 to 14, or 16-20.

These two tricks work, and they dont rob alot of speed.

Also try altering the poundage up or down, see what that causes.

:2cents:

[Desert Archer]

Stag,

It sounds like you are saying a too stiff shaft will shoot to the right but every thing I have read says it should shoot to the left. I can see the nock end being left from hitting the riser, which it is, but I don't get the point of impact being so far to the right at 20 yards.

tb4u,

In my case, full length shafts are just barely long enough. The ACC 3-49 raw shaft is 32" which with a insert and G-Nock just makes the 32.5" I need. I was shooting the ACC 3-39s in a lighter target bow and I have to add the halfout insert to get the extra 1/2" for them to be usable.

Dave

[Stagmitis]

DA,

I ran into the same problem some time back. I had Bare shafts hitting 18" to the right! Naturally I kept reducing point weight to correct it but it got worse. Like you it made no sense that the arrow was acting weak since the charts indicated a shaft a couple sizes weaker in spine should have worked.....It defied all reason and fooled me good until I figured it out! :sbrug:

And youre right.

If a shaft can get past the shelf "unimpeded" the stiff shaft will fly to the left with a nock right and the weak one will go to the right with a nock left.


The "degree" of stiffness dictates how "hard" the nock strikes the shelf. This dictates how severe the angle is when the shaft leaves the bow and how far to the right it will go.


Try stuffing as much point weight on the BS as you can and let me know what happens!

[Spike]

Dave, are you using a plunger? If so how is the centershot setup and the spring tension? I shoot 30" long 3-18 ACCs with 82gr point out of my gamemaster at 47# at my 28.75" clicker draw length setup. With your longer draw but lower weight looks like a 3-28 or 3-39 ACC might work.

[Desert Archer]

Thanks for the feedback guys but I'm still baffled. Just came in from the "patio range". I bare shafted everything from .390 spine to .500 spine. Everything (ACC 3-49s, Lightspeed 400s, ACC 3-39s and Lightspeed 500s) bareshaft from 8"-18" right of the corresponding fletched arrows.

I thought Stagmitis was on to something but those 500 Lightspeeds can't be so still they too are hitting the riser. And some where in the above spread there should have been something that worked. Help...it's getting worse.

Dave

PS: Thought I would add, with the 3-39 ACCs I have bare shaft tested with my 41# Spigarelli/Hoyt target bow and everything lands in one tight cluster, so I at least have done this successfully before (smiley face goes here).

[Stagmitis]

Now Im stumped!

Sometimes if your nocking point is too LOW youll get a similar effect. Now the nock hits the rest.

Can you race back to the patio range, raise the nock point and post back quickly?

:sbrug:

[Stagmitis]

oops!

One more thing! Can you take the .500 and add the heaviest head and see what happens?

[Desert Archer]

Stag,

You're going to think I am being deliberately hard to get along with (LOL). Nocking point is already at 1/2", based on bare shaft testing, i.e. the bare shafts are landing at 3-4 o'clock.

I shot the 500s with 60g, then 80g and finally 100g points. All hit to the right of the fletched arrows with the same points.

I'm running out of ideas and have no idea what arrows to shoot in this set-up.

Dave

[Larry Hatfield]

try looking at the total alignment of the bow. support the bow so you can see how the string is located on the riser for center the full length, and where the string is riding on the limbs.
the holes in the riser should be in the exact center and gives you a solid reference point.
might not be the arrows. you may have to adjust the limb pockets to align the string perfectly with the bow.

larry

[Cato]

Out of curiosity, is your set up exactly center shot, or is the shaft slightly outside the string? I've heard two different things. One is that a true center shot will call for a much stiffer arrow. But then Warf sets up this way, and says he can shoot a wider range of shafts.

Since you seem to have tried everything else, you might move the arrow outside of the string a little (unless its already there) and see if that changes anything at all.

[Desert Archer]

LOL - to get away from this before it drives me nuts, I decided to run a couple errands. While I was driving to the PO I thought of CATO's idea. The bow is currently set up so the point of the arrow lines up with the left side of the string (when it is straight in line with the limb bolts Larry - smiley face).

I wonder if I should try with the thing set for a dead center shot? Since nothing else makes sense I'll give it a try and report back.

Dave

[Stagmitis]

Being a Longbow guy I never would have guessed limb pocket adjustments! :youdaman: larry!


If its not the bow I would raise and lower the nock by an additional 1/8". Cant hurt besides im running out of ideas!


Anything different about the handle of the bow/

[Scooter]

Dave,

Have you tried tried starting with a stiff plunger? By stiff I mean a match stik inserted and the centershot set dead down the middle. I could try and detail it all here but there is a better description on the article tuning for tens. Sorry if you already did all this already. Here's the link.

http://www.texasarchery.org/Documents/T4T/TuningForTens.html

[Scooter]

Man I am away from home on a dirt slow dial up :mad: . You guys are beating me to the punch while I'm still loading. Stag might have something with that grip question. Some grips just cause you to torque and give all kinds of false tuning messages. As a last resort yank that grip off and shoot it from the bare riser.

[BLACK WOLF]

DA,

As others have mentioned...a bareshaft that hit's right for a right handed archer is most likely to stiff, but in the case where an arrow is really stiff it will also show an indication of being to weak.

Cato asked about how center shot your bow is. I would have to ask the same thing.

Based on my experience, a bow that is more center shot is harder to shoot with fingers than a bow that isn't as center shot within reason.

Ray

[van_fl]

DA
I do not re member if you shoot right or left handed. But will assume that you are right handed. If you are shooting to the right with a bare shaft move the plunger out a bet. (not more then 1/8-1/4 at a time . Of coarse if you shoot left handed do the inverse. If the original set up was not just inline . You could be moving the limbs out of line when the poundage is reset.
:2cents:

[Desert Archer]

First, I really do appreciate all the suggestions you guys have made.

I initially set this up with the medium spring in the plunger and medium tension (recommended by a couple books). Center shot was with the right side of the arrow point even with the left side of the string. The string is lined up with the limb bolts and centered in the string grooves (and limb tips are aligned). Tiller is set at zero, which I have found to work best in a number of bows and was recommended by Limbwalker. Nocking point is 1/2" above 90 degrees, which bare shafts at 3 o'clock. Brace height was set at 8.75" which was the quietest setting.

When the above didn't work with spines from .390 to .500 (all shot the bare shaft to the right) I tried setting the plunger so the center shot was dead in the middle. I tried ACC 3-39s with 100g and 80g points, both landing 12" to the right of fletched arrows. ACC 3-49s with 120g points landed 8.5" right. 110g and 100g landed 8" right. 90g landed 9" right.

I give up guys. I have no idea why this particular combination of limbs and riser will not bare shaft tune with any combination of arrow or point I have. I'm going to try the limbs on a 25" riser just to see if that some how makes a difference.

Oh, and the grip on the Best Zenit riser is the same one I used at the indoor tournament when I shot a 260 out of 300. This afternoon I was getting most of my fletched shafts to hit within 2" and sometimes touching so I don't think I was torquing the bow.

Dave

[BLACK WOLF]

Try moving the cusion plunger out away from the riser past center shot.

Ray

[Stagmitis]

Dang the Wolf beat me to it! :cheers:

Or, run a .340 through the bow and see what happens!

[Stagmitis]

DA,

Ya left us hanging!


Any more developments with the BS?

[Cato]

This is like missing the end of a movie. We need to know how it turns out.

[Stagmitis]

DA,

Did ya get to home plate yet? :cheers:

[Desert Archer]

Had to put the Best/Border bow up for a couple days to get ready for the FITA 900 round I'm shooting on Saturday (got to convert my points of aim from yards to meters).

Last night in my shop I did take the whole thing apart and re-assemple it. I'm starting over with everything. Got the tiller even closer to dead even, which rised the pull about half a pound. It is now an honest 44# at my draw length. Had to re-set the nocking point so I took the old one off and am going to re-do that to.

I was following the guidlines in the Archer's Reference and McKinney's book the first time. This time I'm going to go with the "Tuning for Tens" so I cut a plug for the plunger, to replace the spring. Set it so center shot is dead in the middle. That's as far as I got last night. Going to paper tune for knock hight as they describe, then go on to the bare shaft portion but it will have to wait until after Saturday.

Do appreciate all the suggestions and advice. This sure has me bugged as I had bare shaft tuned a couple bows prior to this without much difficulty. Either these limbs are very touchy in this riser or...I'm overlooking something really obvious and dumb. Almost wish it was the latter as I really want these limbs to work in this riser. It sure looks good and feels good to shoot.

I'll let you know next week (hopeful smiley face goes here - LOL).
Dave

PS: Since this bow is part Italian and part Scottish, does that mean it is emotional but frugal??? Maybe that's been the problem all along (LOL again).

[Cato]

My wife is Italian, beautiful, and high strung. Maybe that is your issue after all!

[Desert Archer]

Got to tell you (smiley face goes here) I have sure fallen for those Italian risers. Got three of them, two Spigarellis and a Best, and am looking at another. If you haven't seen the Best Murcery riser go to Alternative Sports web site (www.altservices.co.uk) and look at the picture. That thing is like a piece of modern sculpture. Think I'm in love, at least until I look at the price (LOL).

Dave

[Desert Archer]

Thought I wasn't going to get back to this until after the FITA 900 on Saturday but I shot over 200 arrows yesterday at 40m in the morning, then at 50m and 60m in the afternoon. Got my point of aim down for each distance. My bad back has been protesting all the time on my feet so I decided to take today off (from the serious practice anyway) but couldn't resist playing with this problem bow some more.

Set up for paper tuning like Tuning for Tens describes. Got the nocking point set - it was just a bit high - and was surprised I was getting a left tare in the paper. That means weak shaft (just what the other paper tuning was telling me but I didn't believe). Tried several times and it stayed the same. Put up new paper and decided to play along. This was with the ACC 3-49 bare shafts, starting with 120g screw in points. I thought they would need that heavy point because they were too stiff at a spine of .390. OK, so if they are weak I lowered the point weight in increments. First 110g, then 100g, then 90g and down to 80g. Still getting a left tare but it was smaller. The lightest points I have are 60g and I thought - what the heck!!! With the 60g screw in point (that's 1/2 the point weight I started with) I got one ragged hole in the paper. You could have knocked me over with a feather (except my bare shaft didn't have feathers - LOL).

The only think I can figure to explain this is these Border XP-10 carbon limbs must be either very fast or very efficient. I have quadruple checked the pull and it is staying right at 44#. A .390 shaft should be at the upper end of the spine range for that pull at my draw. Someone earlier suggested I try a .340 spined shaft. I don't have one but danged if I don't think it would have probably worked.

Now I have another problem (sometimes you just have to laugh at yourself). The tuning I've done so far, according to the instructions, has been with a little piece of wood in place of the spring to give me a stiff plunger. The next step is to shoot a good group at 18m (20 yards) and move your sight so the group is in the middle of the target. Then you replace the wood with the medium spring and go about adjusting the spring tension to get the group back to where your sight is set, i.e. the middle of the target. Problem...I don't have sights. I shoot barebow. I can't figure how I'm supposed to do the next part of this thing (LOL).

Gonna go out now and shoot a group at 20 yards and see where it lands. I guess all I can do, since I don't have a sight to play with is use the plunger to get the arrows to land in line with the point of the arrow, which is what I use for a reference in my point of aim style. Wish me luck (hopeful smiley face goes here).

Dave

[Stagmitis]

That was ME with the .340!

Thank ya very much! :cheers: LOL

Thats why I like to go to extremes with shaft size or point weight because sometimes a setup just defies reason! Been there done that....

Glad you got it worked out!

[Desert Archer]

OK guys, here's the final installment in the long and twisted saga of "Desert Archery Learns How to Tune".

I shot 6 fletched arrows at 20 yards with the solid plunger. One flyer but the other five were in a group of about 3" and 18" to the left (glad I was shooting at a 48" target - LOL). Took out the plug and put the medium weight spring in (this is a Cavalier Master Plunger by the way) and adjusted the screw so it was in the middle of its range. That moved the arrows about 6" to 8" closer to center. Then I started screwing out the adjustment (weakening the spring) per the Tuning for Tens instructions. After four adjustments I finally got the fletched arrows hiting in the center (left & right) so...the new to me limbs on my riser are basically tuned to the arrows of choice. There is one more step but I'm going to shoot it this way for a while before making the last "micro" adjustments.

This has been a long journey and a very interesting learning experience. I am reminded of a comment by Robert Heinlein's character, Lazarus Long. "If the facts don't fit your premise, take another look at your premise." I was so convinced the ACC 3-49s had to be stiff I ignored all the evidence that said otherwise and consequently did just about everything wrong.

At my age it is nice to still be able to learn something once in a while (LOL). Hope someone else might have gotten some value out of my ramblings too.

Dave