Limb failures

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Boo
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Re: Limb failures

Post by Boo »

There are a lot of “experts” behind a keyboard who barf out garbage all day long.
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nchunterkw
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Re: Limb failures

Post by nchunterkw »

xpert1111 wrote:
Fri Nov 19, 2021 12:59 pm
nchunterkw wrote:
Fri Nov 19, 2021 12:49 pm
xpert1111 wrote:
Fri Nov 12, 2021 7:56 am
Are we talking a huge speed loss at 600-700 grains? I was thinking I would be shooting around 320-340 fps at this weight? I know still fast but not for me.
Speed loss with these limbs is in the 1 fps/3gr or 1fps/4gr ballpark

At 1fps per 4gr.
600gr-350gr = 250gr/4 = 62.5fps. SO 420-62.5 = 357.5fps.
700gr = 332.5fps
500gr = 382.5 fps

At 1 fps per 3gr.
600gr-350gr = 250gr/3 = 83.3fps. So 420-83.3 = 336.7fps.
700gr = 303.33fps
500gr = 370fps


Maybe a good compromise for you is a 500gr arrow flying around 375fps? Really fast and will blow through an elk, bison or moose let alone a deer.

Another thing you may consider is to make heavy arrows that do not have a really high FOC. Having a more balanced arrow (like by using a shaft within a shaft instead of just heavy inserts and BHs) will result in a much flatter trajectory even at lower speeds at the ranges you are talking about. And FWIW, (you would know better than me as you shoot deer way out there), I don't think their reaction to the shot is as violent when they are 50 yards away, versus 25 or 30. So from a "jumping the string" perspective, maybe the speed loss wouldn't be a factor if the trajectory is flatter.
I'd take 375 in a heartbeat but many are saying 500 grain still too light and will damage limbs
Well, (full disclosure...I'm an engineer)....."many" do not have the design knowledge or test data that the Excal guys have. And they are comfortable at 350gr. 500gr is a 42.8% increase over the minimum so to me that creates a lot of margin. BUt let me ask.... why do you want the speed? Is it because of deer reaction time at distance, or for flatter trajectory? Or another reason?

Flat trajectory can be handled with FOC manipulation

As for reaction time (from above examples)
a 500gr arrow @ 375fps will travel 50 yards in 0.4sec
a 600gr arrow @ 347fpw will travel 50 yards in 0.432sec
a 700gr arrow @ 318fps will travel 50 yards in 0.471sec

and for reference (since you said you are shooting a 410 gr arrow)
a 410gr arrow @ 402fps will travel 50 yards in 0.373sec

so by bumping up to 500gr, you only "lose" 27milliseconds of travel time, and 600gr only costs you 59milliseconds.

27ms is 1/37th of a second and 59ms is 1/17th of a second.

IMO if you build a flat shooting 500 to 600 gr arrow you will not be giving up much at all.
Keith
Stand by the roads and look, and ask for the ancient paths; where the good way is,
and walk in it and find rest for your souls. - Jer 6:16

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xpert1111
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Re: Limb failures

Post by xpert1111 »

nchunterkw wrote:
Fri Nov 19, 2021 2:13 pm
xpert1111 wrote:
Fri Nov 19, 2021 12:59 pm
nchunterkw wrote:
Fri Nov 19, 2021 12:49 pm

Speed loss with these limbs is in the 1 fps/3gr or 1fps/4gr ballpark

At 1fps per 4gr.
600gr-350gr = 250gr/4 = 62.5fps. SO 420-62.5 = 357.5fps.
700gr = 332.5fps
500gr = 382.5 fps

At 1 fps per 3gr.
600gr-350gr = 250gr/3 = 83.3fps. So 420-83.3 = 336.7fps.
700gr = 303.33fps
500gr = 370fps


Maybe a good compromise for you is a 500gr arrow flying around 375fps? Really fast and will blow through an elk, bison or moose let alone a deer.

Another thing you may consider is to make heavy arrows that do not have a really high FOC. Having a more balanced arrow (like by using a shaft within a shaft instead of just heavy inserts and BHs) will result in a much flatter trajectory even at lower speeds at the ranges you are talking about. And FWIW, (you would know better than me as you shoot deer way out there), I don't think their reaction to the shot is as violent when they are 50 yards away, versus 25 or 30. So from a "jumping the string" perspective, maybe the speed loss wouldn't be a factor if the trajectory is flatter.
I'd take 375 in a heartbeat but many are saying 500 grain still too light and will damage limbs
Well, (full disclosure...I'm an engineer)....."many" do not have the design knowledge or test data that the Excal guys have. And they are comfortable at 350gr. 500gr is a 42.8% increase over the minimum so to me that creates a lot of margin. BUt let me ask.... why do you want the speed? Is it because of deer reaction time at distance, or for flatter trajectory? Or another reason?

Flat trajectory can be handled with FOC manipulation

As for reaction time (from above examples)
a 500gr arrow @ 375fps will travel 50 yards in 0.4sec
a 600gr arrow @ 347fpw will travel 50 yards in 0.432sec
a 700gr arrow @ 318fps will travel 50 yards in 0.471sec

and for reference (since you said you are shooting a 410 gr arrow)
a 410gr arrow @ 402fps will travel 50 yards in 0.373sec

so by bumping up to 500gr, you only "lose" 27milliseconds of travel time, and 600gr only costs you 59milliseconds.

27ms is 1/37th of a second and 59ms is 1/17th of a second.

IMO if you build a flat shooting 500 to 600 gr arrow you will not be giving up much at all.
I'm ok with that but still concerned why 350 is ok from an Excalibur design knowledge and test data with me being on 4th set of limbs.
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Re: Limb failures

Post by DMc »

https://www.fullpotentialoutdoors.com/deer-reaction-time-jumping-string/

I thought this short article had some interesting information on reaction time vs arrow speed.
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Re: Limb failures

Post by Boo »

xpert1111 wrote:
Fri Nov 19, 2021 2:30 pm
nchunterkw wrote:
Fri Nov 19, 2021 2:13 pm
xpert1111 wrote:
Fri Nov 19, 2021 12:59 pm

I'd take 375 in a heartbeat but many are saying 500 grain still too light and will damage limbs
Well, (full disclosure...I'm an engineer)....."many" do not have the design knowledge or test data that the Excal guys have. And they are comfortable at 350gr. 500gr is a 42.8% increase over the minimum so to me that creates a lot of margin. BUt let me ask.... why do you want the speed? Is it because of deer reaction time at distance, or for flatter trajectory? Or another reason?

Flat trajectory can be handled with FOC manipulation

As for reaction time (from above examples)
a 500gr arrow @ 375fps will travel 50 yards in 0.4sec
a 600gr arrow @ 347fpw will travel 50 yards in 0.432sec
a 700gr arrow @ 318fps will travel 50 yards in 0.471sec

and for reference (since you said you are shooting a 410 gr arrow)
a 410gr arrow @ 402fps will travel 50 yards in 0.373sec

so by bumping up to 500gr, you only "lose" 27milliseconds of travel time, and 600gr only costs you 59milliseconds.

27ms is 1/37th of a second and 59ms is 1/17th of a second.

IMO if you build a flat shooting 500 to 600 gr arrow you will not be giving up much at all.
I'm ok with that but still concerned why 350 is ok from an Excalibur design knowledge and test data with me being on 4th set of limbs.
You won’t find the answer in this forum, all you’ll get is controversy. Call Excalibur and speak to the senior engineer. He would be the most qualified person to ask.
I use a “light weight” arrow in my 400 Suppressor and 385 in my other Micros. I know limbs have a limited life and I’m not looking to extend that life or have them last a long time. A bow is a tool no different from a chisel. You can tap it all day or beat on it. It’s mine to do as I see for for my intended purpose. This conversation about arrow weight will only go in circles. There is no science or math involved that bring the subject to an exact science. The same goes for all limbs of all manufacturers. Most of any data is based on calculations with an anecdotal base line.
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Re: Limb failures

Post by xpert1111 »

Boo wrote:
Fri Nov 19, 2021 1:38 pm
There are a lot of “experts” behind a keyboard who barf out garbage all day long.
You weren't referring to me were you Boo?
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Re: Limb failures

Post by Boo »

xpert1111 wrote:
Mon Nov 22, 2021 9:36 am
Boo wrote:
Fri Nov 19, 2021 1:38 pm
There are a lot of “experts” behind a keyboard who barf out garbage all day long.
You weren't referring to me were you Boo?
Absolutely not. The information from members here is largely very good. I am mostly referring to other social media sources like Crossbow Nation and Facebook.
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Re: Limb failures

Post by nchunterkw »

DMc wrote:
Fri Nov 19, 2021 2:43 pm
https://www.fullpotentialoutdoors.com/deer-reaction-time-jumping-string/

I thought this short article had some interesting information on reaction time vs arrow speed.
Yes quite interesting. I'd like to see frames 6 and 7 to see when that arrow started to enter the deer.

Very hard to make a chart like that IMO. Way too many assumptions. And deer reactions are very different from many many factors. Distance, head up head down, arrow noise, on and on. I shot a doe at 35 yards this year with a 438gr arrow going about 305fps. AT 35 I had to center where I wanted to hit between my 40 and 30 yard reticles....so not as precise of an aim point as when I can use one or the other. The hole was dead on center mass behind the leg....so it seems she didn't move. But I have shot several other deer at 30 that were on alert to me and a few of those hit the spine, because the deer did move, and one ducked my arrow completely but just as many did not seem to move. IMO you just have to judge each shot on it's own and try to make the best ethical shot you can.

However, the OP is talking about long shots (50yards) in a field. I am of the opinion that a deer will not react as violently to a noise that is 50 yards away as it does to one that is 30 yards away. And that delayed reaction will be very long when compared to these arrow speeds or the reactions times in the article.


But the point of my other post was to show that you don't really give up much "flight time" by going up in weight. Going from 410 to 500 only costs you 0.027 seconds. Or....if you fire those 2 arrows at the exact same time, when the 410gr arrow reaches 50 yards exactly, the 500 gr arrow will be about 10 FEET behind it.

The heavy arrow also carries with it a plethora of other benefits such as increased momentum which results in better penetration...especially when the shot is not perfect and only trying to go through (or between) a few deer ribs.

In the end this a good discussion IMO. Everyone being civil. Does a heavier arrow help limb life? Who knows? The way to tell would be to take a bunch of sets of limbs (100 sets) and fire 350gr arrows through them until they fail and count the shots. Then repeat that experiment with another 100 sets of limbs with 500gr arrows (or whatever gr weight) and evaluate the differences. A pretty costly experiment that IMO is never gonna happen. So we can continue debating forever. :lol:

The problem we have is we have limited anecdotal data. The OP had 3 sets of limbs fail...true...but how many other guys are out there shooting the same bow with the same weight arrow with zero issues. We have no idea. So we can't draw any real conclusions.

But on the other hand, you can draw real conclusions on how a heavy arrow performs verses a light one so I would base my choice on that data.

Here is another interesting article.

https://static1.squarespace.com/static/5d0443b188b6c900011e0ccc/t/5e9378b48f4a085e431232d4/1586722996915/2019+Terminal+Arrow+Performance+Update.pdf
Keith
Stand by the roads and look, and ask for the ancient paths; where the good way is,
and walk in it and find rest for your souls. - Jer 6:16

Micro 335 & 355
deerboyarchery.wixsite.com/trinitystrings
[email protected]
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Re: Limb failures

Post by Boo »

nchunterkw wrote:
Mon Nov 22, 2021 10:37 am

In the end this a good discussion IMO. Everyone being civil. Does a heavier arrow help limb life? Who knows? The way to tell would be to take a bunch of sets of limbs (100 sets) and fire 350gr arrows through them until they fail and count the shots. Then repeat that experiment with another 100 sets of limbs with 500gr arrows (or whatever gr weight) and evaluate the differences. A pretty costly experiment that IMO is never gonna happen. So we can continue debating forever. :lol:

The problem we have is we have limited anecdotal data. The OP had 3 sets of limbs fail...true...but how many other guys are out there shooting the same bow with the same weight arrow with zero issues. We have no idea. So we can't draw any real conclusions.

But on the other hand, you can draw real conclusions on how a heavy arrow performs verses a light one so I would base my choice on that data.

Here is another interesting article.

https://static1.squarespace.com/static/5d0443b188b6c900011e0ccc/t/5e9378b48f4a085e431232d4/1586722996915/2019+Terminal+Arrow+Performance+Update.pdf
At one of the Boofests, Anthony had 3 sets of limbs fail on him. It was a busy Boofest that year and there were lots of people shooting. I'm guessing but I'll guess 50 people whacking away at the 3D course, 100 yard course and a multiple distance range. I'm petty sure that Anthony was the only one with a limb problem. Statistically what are the chances of one guy amongst so many to have all the limb failures? I relate the story because the OP has had 3 sets of limbs fail. One thing of note is that we don't see the defects. Some splintering is no big deal to some but a big deal to others. Some will cut a splinter off, some will glue it back on. Anthony's limbs folded, a complete and utter failure but this was years ago and Micro limbs have improved a great deal.
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Re: Limb failures

Post by nchunterkw »

Boo wrote:
Mon Nov 22, 2021 11:59 am
nchunterkw wrote:
Mon Nov 22, 2021 10:37 am

In the end this a good discussion IMO. Everyone being civil. Does a heavier arrow help limb life? Who knows? The way to tell would be to take a bunch of sets of limbs (100 sets) and fire 350gr arrows through them until they fail and count the shots. Then repeat that experiment with another 100 sets of limbs with 500gr arrows (or whatever gr weight) and evaluate the differences. A pretty costly experiment that IMO is never gonna happen. So we can continue debating forever. :lol:

The problem we have is we have limited anecdotal data. The OP had 3 sets of limbs fail...true...but how many other guys are out there shooting the same bow with the same weight arrow with zero issues. We have no idea. So we can't draw any real conclusions.

But on the other hand, you can draw real conclusions on how a heavy arrow performs verses a light one so I would base my choice on that data.

Here is another interesting article.

https://static1.squarespace.com/static/5d0443b188b6c900011e0ccc/t/5e9378b48f4a085e431232d4/1586722996915/2019+Terminal+Arrow+Performance+Update.pdf
At one of the Boofests, Anthony had 3 sets of limbs fail on him. It was a busy Boofest that year and there were lots of people shooting. I'm guessing but I'll guess 50 people whacking away at the 3D course, 100 yard course and a multiple distance range. I'm petty sure that Anthony was the only one with a limb problem. Statistically what are the chances of one guy amongst so many to have all the limb failures? I relate the story because the OP has had 3 sets of limbs fail. One thing of note is that we don't see the defects. Some splintering is no big deal to some but a big deal to others. Some will cut a splinter off, some will glue it back on. Anthony's limbs folded, a complete and utter failure but this was years ago and Micro limbs have improved a great deal.

I remember that...and the root cause was determined to be an operator production issue during the huge production ramp as I recall..not a design issue But, yes...statistically speaking pretty low chance of 1 guy having 3 sets fail...but it happens. I have had my Micro 335 since the earlt pre-production run and also have a Micro 355 suppressor. Only ever had 1 limb fail...and it was an older limb (4-5yrs old) and happened during a bear hunt wherre the bow stayed cocked for 8+ hrs at a time for 4 days straight. Harsh conditions. I just replaced and kept t hunting. Killed a bear the next day.
Keith
Stand by the roads and look, and ask for the ancient paths; where the good way is,
and walk in it and find rest for your souls. - Jer 6:16

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Re: Limb failures

Post by robertyb »

Boo wrote:
Fri Nov 19, 2021 1:38 pm
There are a lot of “experts” behind a keyboard who barf out garbage all day long.
Very very true Don. :clap:
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Re: Limb failures

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robertyb wrote:
Tue Nov 23, 2021 7:58 am
Boo wrote:
Fri Nov 19, 2021 1:38 pm
There are a lot of “experts” behind a keyboard who barf out garbage all day long.
Very very true Don. :clap:
Was that meant for me?
Keith
Stand by the roads and look, and ask for the ancient paths; where the good way is,
and walk in it and find rest for your souls. - Jer 6:16

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Re: Limb failures

Post by Boo »

nchunterkw wrote:
Tue Nov 23, 2021 8:48 am
robertyb wrote:
Tue Nov 23, 2021 7:58 am
Boo wrote:
Fri Nov 19, 2021 1:38 pm
There are a lot of “experts” behind a keyboard who barf out garbage all day long.
Very very true Don. :clap:
Was that meant for me?
The deepest sin against the human mind is to believe things without evidence."
"Science is simply common sense at its best - that is, rigidly accurate in observation,
and merciless to fallacy in logic."
Thomas Huxley
Keith, you fit into the second category, not the first. Most of what you say is evidentiary based. The only time I'll disagree and think that you are off on a vector is you place as high an importance to momentum as you do. But that's a point of discussion for another time. I have the greatest respect for you as a human being and as a person who gathers evidence before speaking.
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Re: Limb failures

Post by nchunterkw »

Boo wrote:
Tue Nov 23, 2021 9:22 am
nchunterkw wrote:
Tue Nov 23, 2021 8:48 am
robertyb wrote:
Tue Nov 23, 2021 7:58 am


Very very true Don. :clap:
Was that meant for me?
The deepest sin against the human mind is to believe things without evidence."
"Science is simply common sense at its best - that is, rigidly accurate in observation,
and merciless to fallacy in logic."
Thomas Huxley
Keith, you fit into the second category, not the first. Most of what you say is evidentiary based. The only time I'll disagree and think that you are off on a vector is you place as high an importance to momentum as you do. But that's a point of discussion for another time. I have the greatest respect for you as a human being and as a person who gathers evidence before speaking.

Thanks Don, and the same goes for me towards you. Always factual and always civil. As for the momentum deal..........like I always say........"Sooner or later y'all come around to my way of thinkin' " :D
Keith
Stand by the roads and look, and ask for the ancient paths; where the good way is,
and walk in it and find rest for your souls. - Jer 6:16

Micro 335 & 355
deerboyarchery.wixsite.com/trinitystrings
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Re: Limb failures

Post by xpert1111 »

:thumbup:
Last edited by xpert1111 on Thu Feb 03, 2022 8:00 am, edited 1 time in total.
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