3river calculator center cut setup/arrow recommendations

581 Views 29 Replies 10 Participants Last post by DDD, 12 d ago

Yonas

Discussion Starter · 15 d ago

I destroyed some arrows during my practice and have only 3 now so I have to buy some and want to make a good decision because I can order just a dozen.

I tried set up the 3river spine calculator but not sure I didn’t make a mistake.
There is no Hoyt Satori in the list so I picked up a bow with a past centercut and corrected the numbers with strike plate thickness plus added my side plate thickness.
Based on spec Satori has -.44 centercut and side plate 0.261 (with the 0.03 spacers 0.291/0.321/0.621)
My calculations is the following:
Centercut with side plate only : -0.179. 1 spacer: -0.149 with 2 : -0.119 with 3 : -0.089

Is this method correct?

for the arrow selection:
i would prefer the Easton carbon legacy or platinum in aluminium. But the legacy would be my first choice if possible.

parameters: Hoyt Satori 21” riser off the shelf. Delta C3 long limbs 28#@25” riser. 28.5” DL. So ~32-33# DW on fingers

100/125 point, 13gr insert, 13gr nock, 3x 5” feathers. Legacy 600 shaft ( based on calculator cut to 29” but first I would leave uncut)

Do you think it is the right setup (just for practice) ?

thank you in advance

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CD

· #2 · 15 d ago

Yonas said:
There is no Hoyt Satori in the list so I picked up a bow with a past centercut

In 3 River's spine calculator, there are a number of bows to pick within the drop down menu. Which specific bow did you choose from the menu?

Yonas

Discussion Starter · #3 · 15 d ago

CD said:
In 3 River's spine calculator, there are a number of bows to pick within the drop down menu. Which specific bow did you choose from the menu?

3River Dalaa T/D recurve: it has -0.34375 Centercut insted of my Satori so I decreased the Satori side plate thickness with 0.09625 to fit my Satori -.44 center cut with 0.261 side plate (strike plate set: 0.19475 insted of 0.261) .
(-0.34375-0.09625)=-0,44
(-0.34375+0.16475)=-0.44+0.261

But not sure this is the right method

Nuthatch

· #4 · 15 d ago

Best to use the generic recurve option. Then put in the actual centercut value as measured to where your rest is located.

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Nuthatch

· #5 · 15 d ago

This is how I would suggest you use the calculator. Adjust the values to your specific set up.

I used the generic recurve option and then selected 0.125 for your centercut. This value may be different for you, but on my Tribute (has marked center) my strike plate is about 1/8" inside the center line. I shoot Axis shafts which are on the thin side. This centercut puts the tip of my arrow just outside the string when viewed from the belly side of the bow. See Fig 7 at the bottom of page 3 Easton Guide.

The calculated results show that a 600 spine Axis shaft would need to be 31" and need 175gr point weight to meet your dynamic spine requirement. That also makes it on the heavy side (13.2 gpp). I would suggest you consider shafts in the 700 to 800 spine range.

Here's a screen shot of the calculator results.

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c_m_shooter

· #6 · 15 d ago

Yonas said:
I destroyed some arrows during my practice and have only 3 now so I have to buy some and want to make a good decision because I can order just a dozen.

I tried set up the 3river spine calculator but not sure I didn’t make a mistake.
There is no Hoyt Satori in the list so I picked up a bow with a past centercut and corrected the numbers with strike plate thickness plus added my side plate thickness.
Based on spec Satori has -.44 centercut and side plate 0.261 (with the 0.03 spacers 0.291/0.321/0.621)
My calculations is the following:
Centercut with side plate only : -0.179. 1 spacer: -0.149 with 2 : -0.119 with 3 : -0.089

Is this method correct?

for the arrow selection:
i would prefer the Easton carbon legacy or platinum in aluminium. But the legacy would be my first choice if possible.

parameters: Hoyt Satori 21” riser off the shelf. Delta C3 long limbs 28#@25” riser. 28.5” DL. So ~32-33# DW on fingers

100/125 point, 13gr insert, 13gr nock, 3x 5” feathers. Legacy 600 shaft ( based on calculator cut to 29” but first I would leave uncut)

Do you think it is the right setup (just for practice) ?

thank you in advance

Choose based on where your arrows actually sits when viewed from the rear. The tip should sit just outside of the string, if so use .065 or .125. If you truly are shooting at centershot, pick 0.0.

Get 1816 aluminums and leave them long.....

Reactions: 2

Yonas

Discussion Starter · #7 · 15 d ago

Nuthatch said:
This is how I would suggest you use the calculator. Adjust the values to your specific set up.

c_m_shooter said:
Choose based on where your arrows actually sits when viewed from the rear.

Get 1816 aluminums and leave them long.....

thanks,
My problem is the method because I am not sure I use the right center shoot value.
Satori has -.044 without the plates and if i put everything on it still -0.089 ( .261+ 3pcs 0.03 spacer .351) and I am not sure it is correct. Data from 3river Hoyt Satori description

If I measure based on the description I got totally different numbers so I am confused which is the correct.
(measured with side plate only)

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4

Nuthatch

· #8 · 15 d ago

Remove the strike plate. Measure .44" from your riser and mark the shelf. That will be your center. Use the mark and determine the nearest value on the calculator for your cut past center.

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Nuthatch

· #9 · 15 d ago

Here's a picture of the shelf on my Tribute. The red arrow shows the measurement you need to take. The Tribute is .56" past center where you indicated that your Satori is .44".

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Remote

· #10 · 15 d ago

Nuthatch said:
Best to use the generic recurve option. Then put in the actual centercut value as measured to where your rest is located.

Wrote my reply for me. Yes, this is the way.

c_m_shooter

· #11 · 15 d ago

Nock an arrow and look at it from the back. Does it look like this?

It doesn't matter where it is cut. It matters how far the center of your arrow is out. You can use calipers and it will still be a guess.
The biggest flaw with the calculator is giving that option. .065 or .125 is what most should use.

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DDD

· #12 · 15 d ago

Satori is .370" cut past center measured.
Measure the arrow diameter then Divide by 2.
Subtract that from the cut.
= striker plate thickness to get center shot.

If you know the arrow length and brace height? I can calculate how much striker plate thickness to add to get to 1/2 or 1 outside arrow shaft outside center.
DDD

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DDD

· #13 · 15 d ago

I sell adjustable side bolts that will reach down to the Satori shelf.
DDD

DDD

· #14 · 15 d ago

Here's one on a wolf riser with my base.

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Yonas

Discussion Starter · #15 · 14 d ago

DDD said:
Satori is .370" cut past center measured.
Measure the arrow diameter then Divide by 2.
Subtract that from the cut.
= striker plate thickness to get center shot.

If you know the arrow length and brace height? I can calculate how much striker plate thickness to add to get to 1/2 or 1 outside arrow shaft outside center.
DDD

Thank you. I would use a carbon legacy O.D ~.290 or 1816/1916 aluminium .281/.297

I measured -0.36 and basically with this you answered my question

if I use the side plate and all spacers I am center cut. If I want 1 diameter out I need all spacers and if use only the side plate 1/2 with any arrow larger than ~200 O.D. Am I right ?

redfin

· #16 · 14 d ago

My head is hurting after reading this thread. Lol. I have been at this awhile and it is hard to get a tune from the charts. At least for me. Based on your original post and having shot my 21” satori off the shelf a 600 spine left long will be very close. You can trim and or adjust point weight from there. If you prefer an arrow closer to 29”….. then I would opt for the 700 spine. Either way you may have to adjust a little. If you plan on going up in bow weight then the 600’s left long make the most sense to me.

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jtrops

· #17 · 14 d ago

DDD said:
Satori is .370" cut past center measured.
Measure the arrow diameter then Divide by 2.
Subtract that from the cut.
= striker plate thickness to get center shot.

If you know the arrow length and brace height? I can calculate how much striker plate thickness to add to get to 1/2 or 1 outside arrow shaft outside center.
DDD

Correct me if I'm wrong, but if you subtract the radius of the arrow from the center cut your arrow would end up on center, or 0.0 centershot. You would add the radius to the center cut to get the arrow to point to the outside per the standard recommendation.

Beendare

· #18 · 14 d ago

Nuthatch and CM said it well….just mark actual center shot And go from there.

That is the flaw in that calculator IMO…..but I suppose they do it for folks 5hat want to tune by adjusting their side plate.

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DDD

· #19 · 14 d ago (Edited)

jtrops said:
Correct me if I'm wrong, but if you subtract the radius of the arrow from the center cut your arrow would end up on center, or 0.0 centershot. You would add the radius to the center cut to get the arrow to point to the outside per the standard recommendation.

Problem lies with the fact that archer look down a nocked arrow at brace height. Some even focus on a longer stabilizer too center the arrow shaft in the riser. If your going to use this method your better off calculating it. Then you need to know.
Cut out of riser.
Arrow diameter
Arrow lenght
Brace height

Better way is too hang the strung bow by the sting on two levels hooks near limb tips. Lets say 1/3 down from tip. So, Not to touch limbs. Must swing free, plumb. No offsetting weight on riser just bare bones.
Nock your arrow let it hang down. Make sure your nock fit is right. Tap lighty on string and shaft should drop off string. Now with the nock and hanging down, Measure the distance between inside of the shaft and riser above the lowest point of the grip. Could be on the plunger hole or not? This measurement will tell you your measured striker thickness.

Then to double check, you can calculate and add the needed additional amount to the offset striker. OR bare shaft tune from center. Better than eyeballing it. My opinion. I have had a couple riser I needed to be inside center by a fraction. Lol.
I can tell you the adjustments are small. This why you see barebow archers add or subtract a couple of clicks to their plunger. Yes it's tension, but a movement is a movement.
Example on how to calculate.
Arrow dia=.290"
BH=8"
Arrow length=30.5"
Riser cut past center=.370"
Center shot striker thickness.
.290"/2=.145"
.370"-.145=.225"
1/2 shaft outside center at 8" brace height.
8"×.145"/30.5=.03803"
.225+.03803=.26303
1 shaft outside center at 8" brace height.
8"×.290"/30.5"=.07606"
.225"+.07606"=.30106"
For off the shelf. It's simple pick a shaft diameter.
DDD

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jtrops

· #20 · 13 d ago

DDD said:
Problem lies with the fact that archer look down a nocked arrow at brace height. Some even focus on a longer stabilizer too center the arrow shaft in the riser. If your going to use this method your better off calculating it. Then you need to know.
Cut out of riser.
Arrow diameter
Arrow lenght
Brace height

Better way is too hang the strung bow by the sting on two levels hooks near limb tips. Lets say 1/3 down from tip. So, Not to touch limbs. Must swing free, plumb. No offsetting weight on riser just bare bones.
Nock your arrow let it hang down. Make sure your nock fit is right. Tap lighty on string and shaft should drop off string. Now with the nock and hanging down, Measure the distance between inside of the shaft and riser above the lowest point of the grip. Could be on the plunger hole or not? This measurement will tell you your measured striker thickness.

Then to double check, you can calculate and add the needed additional amount to the offset striker. OR bare shaft tune from center. Better than eyeballing it. My opinion. I have had a couple riser I needed to be inside center by a fraction. Lol.
I can tell you the adjustments are small. This why you see barebow archers add or subtract a couple of clicks to their plunger. Yes it's tension, but a movement is a movement.
Example on how to calculate.
Arrow dia=.290"
BH=8"
Arrow length=30.5"
Riser cut past center=.370"
Center shot striker thickness.
.290"/2=.145"
.370"-.145=.225"
1/2 shaft outside center at 8" brace height.
8"×.145"/30.5=.03803"
.225+.03803=.26303
1 shaft outside center at 8" brace height.
8"×.290"/30.5"=.07606"
.225"+.07606"=.30106"
For off the shelf. It's simple pick a shaft diameter.
DDD

I think I'm following what you are saying. Still if the string is centered on the riser, and you subtract the radius of the shaft from the center cut you would put the arrow directly in line with the string, and centered on the bow. You would need to move the center shot out a bit to get the right edge of the shaft to appear next to the string.

By simple calculation it would be a radius added to the center shot, but the length of the arrow would make it less than than that.

I would think that once you have the arrow on center by subtracting the radius from the center cut the best way forward is by hanging an arrow and visually adjusting until it appears correct. Then shooting the arrow and making more subtle changes until the arrow is hitting well. In my experience measuring gets you close enough, and fitting takes it home.

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