Cast vs Speed

TexasStick81 · March 26, 2014, 05:03:00 PM

I ran across a recent thread about being more concerned with cast than speed. Can someone explain the difference for me? In my mind I assumed the faster bow would have a flatter cast and a slower bow would have more arch to the cast, or more drop. What am I missing? Is cast related to how efficient the bow is at transferring the energy?

Dale in Pa · March 26, 2014, 05:23:00 PM

Cast refers to how far the arrow carries. Assuming the same arrow,the faster arrow will always go further.

Every now and then I hear about a bow that isn't particularly fast but has great cast. Just doesn't work that way.

RIng · March 26, 2014, 05:52:00 PM

Something to think about . Bow A has a 500 gr. arrow leaving the bow at 150 f.p.s. with 0 lb on the nock from the string . Bow B has a 500 gr. arrow leaving the bow at 150 f.p.s. with 30 lb. of force on the arrow nock . Which has better cast ?

hybridbow hunter · March 26, 2014, 06:07:00 PM

Ring it Is a non sense. If you add 30 lb of pushing force you will get just ...a faster arrow.
The kinetic energy of the arrow is what make it fly. Then assuming same arrows from different bows, the one which goes further is the one with higher kinetic energy out of the bows.
KE= 0.5 * mass * speed 2
More speed means more energy and more flight ( cast) for a same arrow, and that's all

ChuckC · March 26, 2014, 06:07:00 PM

It would seem that once the arrow "leaves the bow" it is on its own and none of the other things matter. If A and B are really off the bow at the same speed, they will go near the same distance.

If you mean it takes 30 pounds of force to remove the arrow nock from the string, I'd say that is gonna be one noisy bow with arrow flight problems.

ChuckC

Sixby · March 26, 2014, 06:10:00 PM

If the aerodynamics of the two projectiles are exact and weight is exact the bows are equal in cast but perhaps not in efficiency. The arrow is traveling exactly the same speed so the cast is the same.

God bless, Steve

longbow fanatic 1 · March 26, 2014, 06:30:00 PM

Where are the TG physics teachers to settle this?

Bjorn · March 26, 2014, 06:40:00 PM

Speed is a four letter word cast is not! LOL Go figure :p

Pat B · March 26, 2014, 07:26:00 PM

In the glossary in the back of TBBIV the definition of cast is..."Sometimes the distance a bow sends an arrow, but more accurately the speed of the arrow leaving the bow". There was no definition for speed.

McDave · March 26, 2014, 07:48:00 PM

Two arrows leave their bows at the same speed. One arrow weighs 600 grains and the other weighs 300 grains. One arrow has 5" feathers and the other arrow has 2" vanes. One arrow wobbles and the other flies straight. Which will go further? I dunno, but I can guarantee you they won't hit in the same place, by a substantial margin. Why? Wind resistance. The arrow with more inertia (weight), the arrow with a lower profile (vanes), and the arrow that doesn't wobble will have less wind resistance and therefore a greater cast, even though leaving the bow at the same speed.

TexasStick81 · March 26, 2014, 08:05:00 PM

Hybrid: are you saying that cast is more accurately KE? Which would make it related to speed but not equivalent.

Pat's definition suggests they are one and the same, cast is referring to how far the arrow will travel or the relative drop in flight but that's purely based on speed (all else with the arrow being equal).

I hear what you're saying Steve, two arrows an have the same cast/speed but one bow maybe much less efficient in producing the same result. I guess when people are typically referring to cast (or speed for that matter) the assumption is that all of the other variables are equivalent and held constant.

jackdaw · March 26, 2014, 08:24:00 PM

I always took "cast" to be the flight path of the arrow....i.e. ....trajectory. I believe weight/cast ratio to be more important than speed/cast. Arrow weight..(penetration) far outweighs speed where killing potential is concerned...JMO

Easykeeper · March 26, 2014, 08:26:00 PM

I think "good cast" and "excellent arrow flight" are mutually inclusive terms.

March 26, 2014, 08:27:00 PM

Speed is what my wife does when she drives the car.

Cast is what is on my arm after she whacks me for complaining about her speed!

Stumpkiller · March 26, 2014, 08:55:00 PM

Dale hit it.

Cast refers to how far a bow will launch an arrow. It is a distance measurement.

Speed is a measurement of distance traveled over a period of time.

They will be directly related as a bow that throws an arrow further will move the same arrow faster than a bow with less cast.

Neither means squat if you can't hit what you want.

John Havard · March 26, 2014, 11:46:00 PM

It's simple. Faster bows cast an arrow farther. Speed of a precisely weighed arrow from a bow with a precisely weighed draw weight at a precisely measured draw length is an immutable measurement. Bows that have higher speed MEASURED PRECISELY will always out perform slower bows ceteris paribus.

How far an arrow carries gets us into flight shooting. And there, how well tuned the arrow is to the bow is much more important than the bow by itself. So it's possible to have an "inferior" bow "cast" an arrow farther than a "superior" bow with less-well-tuned arrows.

Flight shooting is a fun sport but it tells little to nothing about the bow. Flight shooting contests are conducted in varying winds with imperfect (human) inputs. It's an interesting contest but is not by itself a definitive measurement of how well a bow performs.

ishoot4thrills · March 27, 2014, 06:08:00 AM

QuoteOriginally posted by Bjorn:
Speed is a four letter word cast is not! LOL Go figure :p

Exactly.

ishoot4thrills · March 27, 2014, 06:09:00 AM

QuoteOriginally posted by Bisch:
Speed is what my wife does when she drives the car.

Cast is what is on my arm after she whacks me for complaining about her speed!

Awesome!

killinstuff · March 27, 2014, 07:24:00 AM

Cast is what guys with slow bows like to say. Cracks me up whenever someone writes, yeah but it casts a heavy arrow well, as if a faster bow wouldn't a do a better job of it.

Hermon · March 27, 2014, 07:47:00 AM

Well if a person doesn't have a chrono and wants to compare two bows, cast is the best way. I have shot bows that I would have thought were much faster than another, but when they where chrono'd side by side, the one that "seemed" faster wasn't. Think it went was because the one that seemed faster actually had more hand shock/vibration. I feel that sometimes a exceptionally smooth bow may "seem" slower that it actually is. That is one reason I don't put much stock into claims that a bow is faster without a chrono.

I agree that a fast bow will always cast an arrow farther than a slow bow (given well tuned arrows is each) but don't discount cast as a way to compare bows if you don't have a chrono.