Third Axis - Page 2



1. ## "Effects of Canting"

There is no effect on Horiz. shooting, as you have already corrected the sight adjustment for that particular angle (lets say 0° (horiz.)). This would hold true for any angle of shot, whether uphill or downhill. Shooting at the "exact" same angle for each shot will allow the arrows to "group" similarily, but the group will just be displaced. Don't forget gravities effect on those extreme up or down shots, as they would naturally be "High".

No!, If you are a target shooter and always shoot on level ground.
Yes!, If you are a BowHunter, where you may need to shoot at any angle, or any angle that may not be the same as that of which you sighted the bow in at.

Most people here are confusing "Cause" with "Effect".

The "Cause" = A mis-aligned 3rd axis. (the axis perpendicular to the riser face).
If the axis of the bubble level isn't perpendicular to the "Riser's" face, then the bubble level will have one of its endcaps pointing towards, or away from the shooter. This is not a problem shooting on level ground, because reguardless of the endcaps orientation on this horiz. plane, it is still level with the ground, and will read "true level" reguardless how you spin around. The problem is when you need to rotate the bow in a vertical manner to shoot up or down.

Lets say you are a Right-handed shooter, and the your sight bumped a tree, as mentioned earlier in this post. The impact has bent the sight back towards the shooter. The bubble level's left endcap is now closer to the shooter than the right endcap. Now, if you rotate the bow upward for a shot, you can visualize that the left endcap will be now be lower than the right endcap. The shooter see's the bubble displacement to the right, then cants the bow to the right (CW) to compensate. Thus the "Effect"

The "Effect" = Canting. (Canting (with regards to archery) = rotation about the axis of the shooting arm).

The effects of canting can be simulated on level ground.
To simulate this overall effect, and its magnitude on your shot displacement, take your bow and shoot a few arrows on level ground to establish a baseline group, keeping your bubble level reading horizontal. Next, cant your bow slightly, either right or left, like you see the Indian's doing on TV during a buffallo hunt on horseback (how is that for descriptive). Cant the bow until the bubble on your level just touches it farthest extreme. I use this example, because you will need to duplicate this canting angle for each shot if you expect to get the same size group. Don't be affraid to cant your bow 45° or more (like the Indian's), just figure out a way for you to reproduce that cant angle for each shot. Now take a few more shots. Notice that your "group" should have remained the same size, but your "Group" placement on the target has changed.

Typically, if you "cant" the top of the bow to the right (CW), the shot will displace to the right, and a left "cant" (CCW) will displace a shot to the left. In both cases the vertical shot displacement will typically be lower.

This is the same effect you have with canting a rifle, twisting it right (CW) or left (CCW) . The reason for the shot displacements have to do with the horiz. (windage) & vert. (drop) adjustments you have "dailed-in" on the sight.

Image you have "Zero" windage, and +12" of drop adjusted into your sight. Now exaggerate the effects of canting by rotating the bow/gun/sight a full 90° (CW). You now have 12" or more of right windage, and "Zero" for drop. Your shot would land approx 12" to the right and 12" low. You can see by this example, that the further the shot the worst the error, mainly due to the ever increasing trajectory corrections needed in the sight.

Sorry this was so long, but I hope this helps answer all those remaining question on this subject.

2.

3. Bow-Captain - excellent definition and description. Well done!

4.

5. Join Date
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i don't even look at my level when shooting to tell you the truth, i'm not a target shooter, just a bow hunter.but is this 3rd axis an attempt to get the sites at a 90 degree angle with the riser? b/c if so THAT i get...

6.

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Originally Posted by shec6135
i don't even look at my level when shooting to tell you the truth, i'm not a target shooter, just a bow hunter.but is this 3rd axis an attempt to get the sites at a 90 degree angle with the riser? b/c if so THAT i get...
3rd axis is so your site is accurate uphill and downhill. which of course is important for a tree stand hunter.

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Originally Posted by b_vanfossen
3rd axis is so your site is accurate uphill and downhill. which of course is important for a tree stand hunter.
we all know why it's important, that wasn't my question. my question was asking whether this 3rd axis was the need to find 90 degrees in between sites and riser. and the answer is YES it is. but like i said before i don't use my bubble level so as long as you don't either you could always have a bow that its third axis was off, and you would never know. but i understand the importance, that was never in question

9. Ok, do you have to have a third axis sight to accomplish this? Otherwise you are putting shims in, correct?

10. Great info guys. If you get an opportunity check out www.bowcast.com and www.hamskeaarchery.com. Bowcast has Tim Gillingham on their latest podcast explaining the 3rd axis topic with videos. I believe Tim G is owner or co-owner of Hamskea Archery.

Stay thirsty my friends,
G

11. Exdiver,Tim had some great info on the web cast and in the video's.Thank you
After watching and listening to Tim i had to get some into my shop.

12. G

13. Hey new to AT and just familiarizing myself and discovered this topic which recently I was dealing with. Internet surfing I discovered the Spot Hogg website and quickly realized I had found a gold rush of all things archery! Anyway they detailed 3rd axis leveling and said that it is imperative that it be done while at FULL DRAW so as to factor in the torque of the bow also. And seeing as that they were one of the first sight manufacturers to include 2nd and 3rd axis leveling I would presume they might know something about this! Nevertheless, I have used their technique and it has improved my ups and downs immensely! spot-hogg.com

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Originally Posted by nuts&bolts
LiteSpeed1:

2ND AXIS

2nd axis on your sight is basically making sure the bubble level

This presumes that your string is vertical when the bow is also vertical.
You essentially figure a way to hold your bow vertical (use a bow vise),
and then check to see that your bubble level in the sight is also reading vertical.

If not, then adjust the bubble level with the 2nd axis adjustment,
to make the bubble level on your sight read level, when the bow and bowstring are vertical.

3RD AXIS

Ok, so now we understand what 2nd axis is on your sight.

So, what is 3rd axis?

Well, what if the entire sight ring was mounted on a door hinge?

Yup. What if the entire sight ring could swing like a door?
You could swing the door towards you or away from you.

Well, let's say we swing the door towards you 45 degrees.
The bubble level still reads level, i.e., the threaded rod is still horizontal.

You know what will happen on a steep uphill shot?
Even if you aim uphill, and your bow is not tilted left or right,
the bubble level will lie to you and force you to tilt your bow.

Try this with a 24-inch level. Hold the level in your hand so that it is still horizontal, but the angle between the level and your arm is 45 degrees, as if you swung a door towards you. Raise your arm towards the ceiling.
The bubble level will not stay in the middle.

Adjust the third axis on your sight is the same as adjust the door swing so that it is 90 degrees.

3rd axis will affect uphill shots (NFAA field rounds) or downhill shots (from a treestand).

Imagine that your sight ring is a door. If you bump your sight ring into a tree, the sight ring may bend towards you like swinging a door closer to your face. Let's say the sight ring "door" opened towards you 45-degrees. The bubble still reads level when you hold the riser straight up and down.

Now, hang a weighted string from the ceiling.
Kneel down on your knees, load an arrow in a safe spot, come to full draw and anchor.
Line up the weighted string with the left edge of the riser and your limbs.

Take a look at the bubble.
The riser and limbs are vertical because you are lined up with the weighted string.
If the sight ring threaded rod is bent towards you or away from you,
the bubble will not read level even though you are not canting the bow.

Adjusting the 3rd axis of a bow restores the sight ring door swing
back to 90 degrees, perpendicular to the sight frame.
The best way to check is kneeling down on your knees,
aiming up at a weighted string hanging from the ceiling.

If you sight does not have 3rd axis adjustment,
you will need to use shims to adjust the entire sight or just the sight ring.
Text book explanation. Nuts&Bolts explains it better than I have ever read in any archery magazine.

15. thanks nuts and bolts, i was going to ask the same question about 3rd axis

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## Absolutely Necessary?

I'm thinking about going with the BG Flashpoint and it doesn't have 3rd axis. Is 3rd axis absolutely necessary? I've never used them before?
Thanks gentleman

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Centennial, CO.
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Originally Posted by Kblair85
I'm thinking about going with the BG Flashpoint and it doesn't have 3rd axis. Is 3rd axis absolutely necessary? I've never used them before?
Thanks gentleman
Watch these videos.

http://www.hamskeaarchery.com/index....id=7&Itemid=63

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Good info here... thank you for the diversified explanations.

19. Hamskeaarchery.com makes a great third axis sight level. Check it out.

20. Join Date
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This really helped me. Now I just need to get that Sure-Loc Lethal Weapon installed and setup!

21. One thing that I have noticed is the absence of the reference to the first axis.The first axis is the vertical travel of your scope/pins (up/down) the block.This is impotant because if it is not set to follow your string or arrow path then as you adjust your scope up and down you may be adding windage which will cause you to shoot left or right.A good example of this would be an archer killing the bulls eye at 20 yards but shooting left or right at 40/50 and it may not be a big left or right but enough to give you a 50/50 result because you are only catching half the bulls eye (L/R) and the further the shot the bigger the error.A 4' level on your bow dose not guarantee that your string/arrow flight and scope all line up even when the bubbles line up(in some cases it may).But as some one pointed out you may have to take into consideration shooter and bow torque.To shoot in your first and third axis is the best way (and I may be wrong).When I set up my sight I first set my scopes relationship to the block or second axis I do this using a torpedo level against the sights block which I plumb and then I adjust my scopes bubble to match my torpedo.
You do not have to shoot a big distance to set your third axis (I do because at my club I can) if you have 20y with a good angle to it then use that but first sight in on the flat and shoot a few ends to get warmed up.

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this is all good info. back up to the top

23. I thought 3rd axis had to be done at full draw, i see these bench device 3rd axis items popping up.

24. look at this,video..... hamskea.com

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Im not sure about everyone, but I rarely stare at my bubble before my shot. I used to, when practicing my form , but now I am comfortable enough without having to stare at the bubble everytime I shoot. I am sure most people dont need the 3rd axis if you shoot often and practice all yardages. JMO

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Thanks all !

I finally figured out what you all were saying and went into the garage.

BOY was my third axis off.

It's all good now.

THANKS again!!

Bill

27. ## 3rd axis

Bowhunters if you only shoot out to 30 yards at animals in normal hunting conditions for deer , don`t worry about 3rd axis, i have killed many deer before i knew that you could level a sight.But at distances past 30 yards it does make a difference and yes i am a target archer and a bowhunter.they make a handy tool and is sold by lancaster archery and it does not cost that much .i have been bowhunting before the compound bow was invented by Mr. allen. good luck Pete53

28. Join Date
May 2011
Location
Southern California
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1,989
Hey all.
FYI
I have a bench vise in the garage.
I have a Metal Carpenters square.
I have a torpedo level.

I put the square in the vise and used the level to set the metal square straight up and vertically level.

I put the back side of my bow against the level and found the second axis off.
Fixed that.

I then rotated the bow 45 degrees up with it against the level carpenters square and then 45 degrees down.
I fixed them using the adjustments on the sight.

I then took the bow to a shop and asked them to check 2nd and 3rd.

He came back minutes later and said they were dead on perfect!

WooHoo.

Thanks to all here who help.

Bill

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