Archery Qestion about balance

Alfang

I think your chasing your tail, I don't know where you get your data or idea that one type of bow is better than another and that there's a scientific reason for it.

If you give me the horizontal cross bow which you think is harder to shoot, and let me practice for a couple weeks I'd shoot it as good as you with your choice of bows.

Maybe it's more simple, Maybe the better shooters with tons of practice and experience just feel more comfortable with a vertical bow, so that's what they shoot, they'd probably be just as good with a horizontal bow.
And help us out here, are you a competition shooter? or just plinking around with your buddies?

CWatters

This isn't an archery forum so I very much doubt many of us will have fired crossbows. I'm not even sure of their legal status where I live.

We believe the laws of physics apply equally wherever you are in the universe - so that doesn't account for any difference between H and V.

Any difference will be because not all of the system is being rotated between H and V. So no surprise if they interact differently. In rifle shooting it's well known that the prone position is more accurate than the standing. I don't see why it should be a surprise that crossbows behave differently in H and V. The reasons are likely to be complex.

JAG1118

OK,
Lets try this. Would it take less work or effort to control , lets say, a 24 oz solid rod 48" long, 1' in diameter in V or H? It seems to me that finding the center point is so critical when in the H orientation and not so in V. I am trying to establish, as a manufacturer of archery equipment, that, as all archers know and have proven, shooting a bow V is more accurate and more consistent than H (freehanded). I know this is not an Archery Forum, but I have come to you guys to see if ithis can be explained in technical terms, or am I "chasing my tail".
Sorry if I have confused you guys,
Jerry

CWatters

Ok here is an idea. For a rod the moment of inertia will be different for each axis. It will have a greater moment of inertial when rotated end-over-end than around it's long axis.

This would suggest that a vertical bow might be more stable/accurate in elevation than direction. Where as a horizontal bow might be more stable/accurate in direction rather than elevation.

If I was designing a bow I'd be thinking of adding weights on rods to increase the moment of inertial for all three axis. Google images suggests they typically only have one rod projecting forwards, but some appear to have them in other planes...

CWatters

Taking the idea to extreem... Could you mount the bow in a frame big enough for the archer to stand in as well? Obviously you wouldn't be allowed to have it resting on the ground but a big cubic frame with masses at all 8 corners would add a lot of stability in all planes.

JAG1118

CWatters,

Would the bow YOU designed be V or H, all things being equal? Obviously stabilizer rod can and are added for more stability, but we are talking bare bow. No bells or whistles.
Thank you for your participation it is greatly appreciated.
Jerry

berkeman

So my first question was about sight wander. In pistol shooting, for example, you will never be able to hold the pistol totally steady when shooting freehand. The sights have some wander to them, and your job is to minimize the wander. You typically have some goal in containing the wander, like say the 8-ring or better. So I was asking if you notice a quantitative difference in your sight wander between when you shoot your vertical bow versus your horizontal bow. Or do both sight pictures seem to have the exact same sight wander?

And then I asked about whether the jump in the hold is different as the arrow is released. Do you notice that the vertical orientation is smoother at release (it looks like you have been addressing this 2nd point some in the recent posts).

Also, is there a pattern to the difference in accuracy? Like, are the crossbow shots uniformly distributed across the target, or is the pattern spread in vertical or horizontal more?

CWatters

I can't answer that as i don't know what's required to maximise accuracy.

I have similar question to that which berkeman asked.....

Looking at google images of standard vertically fired competition bows the stabalizer rods normally seem to point forwards. If you set up such a bow and then remove the stabalizer rod would the grouping get wider or taller or both?

johnbbahm

I had never seen a vertical crossbow before looking it up just now, but if you have
ever seen a slow motion video of an arrow being fired, it appears to oscillate on the
same axes as the string.
A bolt while shorter and stiffer may still have oscillations.
If the oscillations are on a vertical plane, the inaccuracy would look like
more or less drop, if the oscillation were on a horizontal the inaccuracy would show
up as an error off the center line.
This is just an idea and may be way off the mark.
Some of the new HD video cameras have a slow motion function, it might be worth a watch.

JAG1118

No, the sights (peep and Pin) would be the same and I have tried a powered scope H and I still can not get the accuracy like in V. I have not noticed a pattern, the arrows are scattered. My groups V at a 100yds were scattered but they were grouped pretty tight. When I shoot it horizontally they are much more scatterd. It all comes down to holding the bow steady. All though as you know it all has an effect, even what you have had to eat can make a difference in how steady you can hold on the target. I experience has been consistent when compairing H to V.

berkeman

Are the H & V bows of equal power, with equal weight and length arrows?

JAG1118

CW,
Holding the bow at time of shot is going to maximize your accuracy. The front stabilizer primarly controls the side to side torque of the hand grip eliminating mostly L and R error.

JAG1118

Same bow and same arrows. everything equal.
I was speaking with an engineer buddy today and I asked him about it, he brought up a good point. If an object, lets say a rod, was vertical, anything above center would hang down and find it resting point very quickly and even if you were hold it below center it would be very easy and take very little effort to keep it straight unless it was tilted significantly. It makes since to me.
I believe that is why it can be shot more accuratly in V.
What do you think.

JAG1118

Hi John,
That is a good point, but I am shooting the same bow in V and H and the patterns are basically the same but much larger when I shoot it in The H position.

berkeman

Can you try hanging a vertical stabilizer rod from the horizontal bow to help keep it more horizontal?

johnbbahm

Hi Jag,
It's not the bow, but how the bolt is pushed out, I think the oscillation
may be lined up with the string, so the V has the error in the vertical,
while the H has the error in the horizontal.

JAG1118

I am sure that would help, I have to try it to see. I am trying to keep everything equal and adding a stabilizer is defeating the purpose of this thread, the difference in balance with H and V. I was looking for some scientific terminology that might help me with my question. There has to be test that have been done on objects for compairson. Right?
Thank you Berkman,