Do you have a chronograph? Id like help.

[sleek]

I want to do a mass experiment. Im looking for a trend and trying to remove confirmation bias, so crowd sourcing should help.

The hypothesis: A bow will not dry fire as quickly as it will fire with a poper arrow weight

The experiment: Shoot 5 times with a 3 gpp arrow and get your average speed. Then increase the arrow weight by .5gpp repeating the experiment until you are at 6gpp. Record the results.

I have this idea that a bow, like an engine, needs to be loaded a certain amount to keep the limbs from warping and loosing a lot of energy. Thats energy that will increase arrow speed and momentum. I suspect there are two arrow weight ranges that any bow will fire best at. One will be extremely light weight for max speed and the other will be heavy for max energy. This experiment focuses on maximum speed.

The premises: This deals with harmonics. Much like an out of balance tire, there are two speeds where you will find the vibrations peak, and conversely where they go away entirely canceled out. The idea carries over to bows. The tips each travel in an arc like a tire rim, weighted by the arrow. If the  rate of tip travel is at the correct speed ( tire rpm ) then the limb vibrations should cancel out or peak, and that will reflect in arrow speed.

I have seen this myself in exactly one bow before, but I was also looking for it. Its easy to find what you look for, aka, confirmation bias. So if yall have a chronograph and some time to kill, id be really interested in your help and results.

[Del the cat]

I did this some time back. Being a crossbow it had less error than shooting off the fingers, tho' admittedly it's a shorter metal bow, but vibration etc could still be relevant.
Del
https://bowyersdiary.blogspot.com/2011/11/mass-velocity-and-energy.html

[Badger]

 This is already pretty well tested. Allen is shooting his bows at about 1/4 grains per pound. I seldom test below 100 grains, but any testing I have done always shows more speed with less weight no matter how light you go. Using a chrono to estimate virtual mass is a very useful tool for a flight shooter/ bow builder

[willie]

This is already pretty well tested. Allen is shooting his bows at about 1/4 grains per pound. I seldom test below 100 grains, but any testing I have done always shows more speed with less weight no matter how light you go. Using a chrono to estimate virtual mass is a very useful tool for a flight shooter/ bow builder

1/4 grains per pound? can you clarify?


on another thought,
Does more speed out of the bow always make for a longer shot? I seem to recall a theory that an arrow needs enough weight to "carry" well.

[Badger]

     Jim Matin, another successful flight shooter, made the statement that there is not much sense in shooting an arrow much faster than its critical speed. So he adds enough weight to the arrow to bring it just a bit over critical speed. I have no idea how he determines the critical speed.

[JW_Halverson]

I have a chronograph in a box somewhere. Want me to go looking for it for you?

[sleek]

I have a chronograph in a box somewhere. Want me to go looking for it for you?

Well if you dont mind doing some shooting through it to test different arrows speeds at different weights?

[sleek]

I dont know what happened to the reply that was on here, but it asked of id need to shoot the same arrows through the same bow. The answer is no. Im looking for a trend across bows, not specifically for one bows result. I need to build a shooting machine to really get solid results across my bows.

[Badger]

    This test has been conducted countless times. Dry fire speed is dry fire. Lighter arrows may not fly as far but they will always come out of the bow faster. Lighter arrows are less forgiving and require more tuning.