Is there a pendulum expert in the house?
08-27-2003, 08:24 AM
#1
Nontypical Buck
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Join Date: Feb 2003
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Posts: 2,994
Is there a pendulum expert in the house?
Pendulum sights are advertised as " sight in on the ground from x yards and your dead on 10' -30' up in a tree out to about 30 yards or so" ...
How does one calculate the variables given the geometric nature of the sighting process?
If my pendulum says sight in at 20 yards on level ground, the distance I can shoot accurately out to from a tree is dependent on arrow speed. How do I calculate maximum dead on holding yardage for a given arrow speed?
How does one calculate the variables given the geometric nature of the sighting process?
If my pendulum says sight in at 20 yards on level ground, the distance I can shoot accurately out to from a tree is dependent on arrow speed. How do I calculate maximum dead on holding yardage for a given arrow speed?
08-27-2003, 09:05 AM
#2
Join Date: Feb 2003
Location: Florence AL USA
Posts: 53
RE: Is there a pendulum expert in the house?
Well, I' m a mechanical engineer, and I can assure you that there are too many variables to allow you to develop some kind of " rule of thumb" that could be applied correctly in every instance.
First, you have to realize that the amount of " adjustment" made by a pendulum sight depends on the pendulum radius (distance from pin to pivot.) I' m not sure if that' s the same on all different brands or not.
The other problem is that the pendulum adjustment is strictly made by the relationship of the riser sight holes to horizontal. So, you can' t make any " rules" about distance unless you' re hunting level ground from the EXACT same treestand height every time. Even if our bow setups were exactly the same, if you hunt at 15 feet from the ground and I hunt at 30, our " rules" won' t match.
First, you have to realize that the amount of " adjustment" made by a pendulum sight depends on the pendulum radius (distance from pin to pivot.) I' m not sure if that' s the same on all different brands or not.
The other problem is that the pendulum adjustment is strictly made by the relationship of the riser sight holes to horizontal. So, you can' t make any " rules" about distance unless you' re hunting level ground from the EXACT same treestand height every time. Even if our bow setups were exactly the same, if you hunt at 15 feet from the ground and I hunt at 30, our " rules" won' t match.
08-27-2003, 09:51 PM
#4
Nontypical Buck
Join Date: Feb 2003
Location: Crosby TX USA
Posts: 2,599
RE: Is there a pendulum expert in the house?
I' m by far no expert, but when I tried out my first savage it proved accurate at the variable heights and distances I shot it at. From 15' up to 23' up from 5 yards to 30 yards. And that was with a slow 235 fps arrow.
I have the newer savage pendulum supermax and will tell you IMHO, your not missing anything with your older design. The round sight housing is too small to actually make the circle fit the outside of my peeps circle. The wing nuts will not get it tight enough to hold true without further tightening down with an Allen wrench (my horizontal kept moving on me).
I did spring for the tritium pin and was shooting by moonlight the othernight. Really impressive groups to boot. Although I know of no game animal wearing all white with a round circle in it' s kill zone
(like my targets face).
I need to try it out before season to see if all is well from varied distances. If so, I' m gonna leave the mathmatical questions to someone else and just hunt. If it works, it works!!
I have the newer savage pendulum supermax and will tell you IMHO, your not missing anything with your older design. The round sight housing is too small to actually make the circle fit the outside of my peeps circle. The wing nuts will not get it tight enough to hold true without further tightening down with an Allen wrench (my horizontal kept moving on me).
I did spring for the tritium pin and was shooting by moonlight the othernight. Really impressive groups to boot. Although I know of no game animal wearing all white with a round circle in it' s kill zone
(like my targets face). I need to try it out before season to see if all is well from varied distances. If so, I' m gonna leave the mathmatical questions to someone else and just hunt. If it works, it works!!
08-28-2003, 04:37 AM
#5
Join Date: Feb 2003
Location: SCHENECTADY New York USA
Posts: 302
RE: Is there a pendulum expert in the house?
I have been shooting a KELLER for over 10 years.LOVE my accuracy with that sight.It does what it claims to do,,PERIOD.I would have to say the only thing,,,ONLY THING,,that has me looking at any of the newer pendulums is the fiber optics.MAN,,if the KELLER was rigged fiber optic,,well that WOULD be all she wrote,,because the fat lady has sung [
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08-28-2003, 07:07 AM
#6
Join Date: Feb 2003
Location: Florence AL USA
Posts: 53
RE: Is there a pendulum expert in the house?
I don' t mean to sound as if I don' t think the pendulum sights " work." It' s just a definition of " work" . I' ve never used one, but I know they' re not " magic." I' m not familiar with the claims the manufacturers make, but the functionality of the sight HAS to be a " close enough" and not an " exact" at every distance (just like the one pin I use for " every" range shot.)
I know this because, for instance, the angle that the bow is held for a 25 ft (8.3 yd) distant shot from an elevation of 10 ft is the same angle the bow is held for a shot 100 ft (33.3 yd) distant from an elevation of 40 ft (assuming perfectly level ground.) The position of the pin on both shots is the same, because the pendulum always hangs straight down. And, I know from years of archery shooting that a pin cannot be positioned to hit " dead on" at 8 and 33 yards simultaneously. Therefore, I can safely say that someone could not shoot the these two shots mentioned, while placing the pin directly on the bullseye, and have the arrow impact at the exact same spot on each target.
I know this because, for instance, the angle that the bow is held for a 25 ft (8.3 yd) distant shot from an elevation of 10 ft is the same angle the bow is held for a shot 100 ft (33.3 yd) distant from an elevation of 40 ft (assuming perfectly level ground.) The position of the pin on both shots is the same, because the pendulum always hangs straight down. And, I know from years of archery shooting that a pin cannot be positioned to hit " dead on" at 8 and 33 yards simultaneously. Therefore, I can safely say that someone could not shoot the these two shots mentioned, while placing the pin directly on the bullseye, and have the arrow impact at the exact same spot on each target.
08-28-2003, 07:18 AM
#7
Join Date: Feb 2003
Location: Northern NY
Posts: 148
RE: Is there a pendulum expert in the house?
Capstone, I realize your argument, but that doesn' t hold any real meaning. Obviously by changing two variables (height and yardage) that is going to effect accuracy. Taking an 8 and 33 yd shot from the same height is what is relevant. I do realize what you' re trying to show but I don' t see that it really matters too much...
08-28-2003, 10:14 AM
#9
Join Date: Feb 2003
Location: sardis ms USA
Posts: 561
RE: Is there a pendulum expert in the house?
i am no expert but currently use the predator pendalum with no peep sight and used simple cobra prior to that.i hunt strictly from a tree from 15-20' and have no problem taking deer from 10-30 yds.
08-28-2003, 10:47 AM
#10
Nontypical Buck
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Join Date: Feb 2003
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RE: Is there a pendulum expert in the house?
Cap, most manufacturers recommend a treestand height of 10-30' to get the pinpoint accuracy out of a pendulum. Range from the tree from just about right under to out to " around 30 yards" . The around is based on fps, so I assumed there should be some way to figure it out mathmatically.
In your example above, your second shot was above the 30' upper range for stand height, so it doesn' t count
In your example above, your second shot was above the 30' upper range for stand height, so it doesn' t count