Compound bow - set up question

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07-29-2008, 08:48 AM

#41

brucelanthier

Nontypical Buck

Join Date: Aug 2006

Location: Southern MD

Posts: 2,520

RE: Compound bow - set up question

Quote:

ORIGINAL: GMMAT
Then how do you explain setting one up with a level and a square? If it's perpendicular/plumb to the string......it's Perpendicular/plumb to the ground. Ifyou're using a bubble level to set your arrow......what's it "level" to?

You do all that to set up "center shot". This means that the arrow is set up to be launched in the most efficient manner from the bow. Tuning the arrow and bow together refines this efficiency to the idiosyncrasies of the bow and arrow. In an idealized set up of center shot the tiller is even and the arrow is "centered" on the string.

07-29-2008, 08:53 AM

#42

Rob/PA Bowyer

Boone & Crockett

Join Date: Oct 1998

Location: Hughesville, PA USA

Posts: 18,322

RE: Compound bow - set up question

Quote:

Then how do you explain setting one up with a level and a square? If it's perpendicular/plumb to the string......it's Perpendicular/plumb to the ground. If you're using a bubble level to set your arrow......what's it "level" to?

The bow/arrow is set up at level/plumb/center in a vice, not when your holding it. That is designed for the arrow to come out of the bow as straight as possible. Then you pick up the bow, and your raising it to shoot down range.

Think about this Jeff, when you shoot 40 yards, do you not raise your bow? If you were to shoot 60 yards, do you not raise your bow higher? If you put your bow in a shooting machine, plumbed and leveled it so the arrow is level and shot it, it would not make the spot on the 20 yard target. It would not arch up, it would come straight out of the bow and start to drop immediately.

When your shooting 20 yards, your not holding the arrow level, your bow is level side to side not front to back.

07-29-2008, 08:57 AM

#43

JoeRE

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Join Date: May 2006

Location: IA/WI/IL

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RE: Compound bow - set up question

Quote:

ORIGINAL: GMMAT

Quote:

Jeff, if your at full draw and aiming at a 20 yard target your arrow will not be level to earth, it will be point high/nock low. Your arrow does not leave the bow level when shooting at targets down range, remember the arch,

Then how do you explain setting one up with a level and a square? If it's perpendicular/plumb to the string......it's Perpendicular/plumb to the ground. Ifyou're using a bubble level to set your arrow......what's it "level" to?

Your bow is not horizontal to the ground when your pin is on target. It cannot be, because your arrow is level with your bow and the arrow is pointed slightly up, therefore your bow has to be pointed slightly up as well since the arrow and the bow string are perpendicular/plumb. I dont know if you are a visual person but I am....grab a scratch peice of paper and sketch it.

Quote:

ORIGINAL: GMMAT

Also......This has nothing to do with the original question......but wouldn't the location of the target at 20 yds determine whther or not your arrow was "level" with the 20yd spot? Or....are you saying that ther eis nowhere you could put your target and have your arrow be "level"?

Your arrow cannot be level in relation to the 20 yard target. Imagine that the bow has a laser in it, coming right down the length of the arrow when at full draw and projecting out in front. This laser beam is also perpendicular/plum to the bowstring like your arrow would be. When you set your 20 yard pin on the bull, that laser beam will be high. As your arrow leaves the bow during the shot it falls below the laser beam further and further untill it hits the 20 yard target. Since it also is traveling down range at say 280 fps while it is falling we say that the arrow 'arcs' to the target as that is its path in 3D.[&:] Does that help at all?

07-29-2008, 09:25 AM

#44

GMMAT

Dominant Buck

Thread Starter

Join Date: Oct 2005

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Posts: 21,043

RE: Compound bow - set up question

Quote:

The arrows elevation on the bow at rest is set in readings that are 90 degrees to the string. The string however would not be perpendicular to the ground if you were shooting at a target 20 yards out shoulder high. The arrow would also not be parellel to the ground.

The string can't be perpendicular to the ground when you're at full draw

. Gotcha. And really.....my original question was more from the set-up. But for S's and G's.......why couldn't your arrow be level .....shooting at a 20yd target? Is there nowhere that target could be that would find your arrow level (parallel) to the gorund?

Rob said....

Quote:

Tell that to the bubbles on your level

They won't read plumb/level if the bowstring/arrow isn't/aren't.

And this....

Quote:

Think about this Jeff, when you shoot 40 yards, do you not raise your bow? If you were to shoot 60 yards, do you not raise your bow higher? If you put your bow in a shooting machine, plumbed and leveled it so the arrow is level and shot it, it would not make the spot on the 20 yard target. It would not arch up, it would come straight out of the bow and start to drop immediately.

NOW you're going where I wanted you to go. I'm simply "asking"......WHY can't the sight line line (from eye to target) and the arrow line intersect and then reconnect at 20 yds. What I'm saying is the bottome or "arrow" line......isn't a line, at all. "I" theorizing they meet at 8 or so yds (per Matt/PA).....and from there the "arrow" line is above the sight line......and it arches to meet the sight line....at 20yds. I believe it DOES start to drop fairly "immediately".....crosses the other line.....then arches to the target.

I'm not sure it "rises", though......unless someone can explain to me why it has to be set up UNlevel.

Quote:

When your shooting 20 yards, your not holding the arrow level, your bow is level side to side not front to back.

It certainly "could" be. BUT.....This will help illustrate what I'm saying.....

What if your arrow was perfectly level.......on a parallel line with a line coming from your 20yd target. Now....."I" think your arrow line would be above your 20yd target line.....and the fact that you're looking down from your sight line would make this compensation.

Heck I'm gonna draw it.....I know this is confusing...

07-29-2008, 09:53 AM

#45

rybohunter

Giant Nontypical

Join Date: Feb 2004

Location: Pittsburgh, PA

Posts: 7,208

RE: Compound bow - set up question

WHY DOES THIS MATTER SO MUCH?

07-29-2008, 09:57 AM

#46

GMMAT

Dominant Buck

Thread Starter

Join Date: Oct 2005

Location:

Posts: 21,043

RE: Compound bow - set up question

Why do you care, Ryan? I want to know why things are the way they are.

"It just is" don't do it, for me....and I'm betting there's a lot of folks who thought they knew a little more than they did about this stuff. Am I wrong?

If this isn't interesting to you..........move along. No hard feelings.

07-29-2008, 10:07 AM

#47

RuttNutt

Typical Buck

Join Date: Jan 2007

Location:

Posts: 546

RE: Compound bow - set up question

You know what's funny. You askedthequestion and here you are telling everyone how wrong they are........AGAIN...... This is pretty basic stuff. Now let's talk about hunting....

07-29-2008, 10:08 AM

#48

rybohunter

Giant Nontypical

Join Date: Feb 2004

Location: Pittsburgh, PA

Posts: 7,208

RE: Compound bow - set up question

No, its not that, it just seems like it was explained enough already to figure it out and understand. And if not, was the little bit of info gained, REALLY worth the enormous effort to obtain it?

I would think a physics book, and a chapter on projectile motion should clear things up in a hurry. As opposed to relying on 15 "mr wizards" who slept in a holiday inn last night

07-29-2008, 10:08 AM

#49

Badger_Girl93

Fork Horn

Join Date: Aug 2007

Posts: 298

RE: Compound bow - set up question

Quote:

ORIGINAL: GMMAT

Is there nowhere that target could be that would find your arrow level (parallel) to the gorund?

There is one spot, but it is below the straight line you draw from nock to tip.

Quote:

ORIGINAL: GMMAT
Tell that to the bubbles on your level

They won't read plumb/level if the bowstring/arrow isn't/aren't.

The only level I am familiar with is the one on my sight, and it only reads plumb/level in one plane...a different plane than the arrow flight travels on. Do you have a level for each of the 3 planes involved?

Quote:

ORIGINAL: GMMAT
WHY can't the sight line line (from eye to target) and the arrow line intersect and then reconnect at 20 yds.

They do...always.

Quote:

ORIGINAL: GMMAT
I'm not sure it "rises", though......unless someone can explain to me why it has to be set up UNlevel.

If the target is below that one magical spot that I mentionedfirst in this post, then the arrow will not rise. Ifthe targetis anywhere above that spot, then the arrow will rise.

07-29-2008, 10:28 AM

#50

BobCo19-65

Giant Nontypical

Join Date: Feb 2003

Location:

Posts: 7,571

RE: Compound bow - set up question

Quote:

But for S's and G's.......why couldn't your arrow be level .....shooting at a 20yd target? Is there nowhere that target could be that would find your arrow level (parallel) to the gorund?

I believe that I already answered that:

Quote:

The string however would not be perpendicular to the ground if you were shooting at a target 20 yards out shoulder high.

Sure you could shoot at something withthe starting point ofarrow at full draw parallel to the ground.

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