View Full Version : 3rd axis leveling
05-24-2011, 07:05 AM
Most top-end bow sites have 3rd axis leveling options. I am not really familiar with what this actually is. Can someone enlighten me as to what the "3rd axis" is actually doing? How does it work? I have been thinking of getting a new site and was wondering how important the 3rd axis leveling would be. Thanks for your feedback.
05-24-2011, 01:31 PM
Reflex, 3rd axis leveling really comes into play out to yardages past 40 yards, while this is my opinion from first hand experience, it is based on years of practical findings.
If you bolt on a 3-5 pin sight and shoot out to 40 yards, 3rd axis rarely makes a difference. However, when you are pushing the limits of your equipment for practice sake, 3rd axis can assist you in providing more than the basic elevation and windage adjustments common to most low end sights. Often used in conjunction with a bubble leveler or pin wire, 3rd axis allows you to fine adjust the left to right pitch of the entire pin gang.
If you have top 20 pin set and bottom 80 set and all pins from top to bottom are in line perfectly, 3rd axis allows you to set the gang in paralell with the riser...
For instance, if you took the above description and 20 was hitting to the right and 80 was to the left, 3rd axis would allow you to pull the pins into form along your riser...
3rd-Axis adjustments can be adjusted so that the entire sight housing can swivel inward (to a position less than square) or outward (to a position beyond square). At first glance it would seem that setting the sight for a perfect 90º would be best (center sight in photo). But that isn't always the case. Most shooters hold their bow with some degree of hand-torque (slightly twisting the bow's riser to the left or right). The 3rd Axis adjustment helps to compensate for that. And since everyone shoots a little differently, a proper 3rd Axis setting is actually unique for each individual shooter. For some, dead square is still correct. For others, it's not.
I hope I didn't confuse you further!
05-24-2011, 04:44 PM
Good description Graylight. I shoot the SDP and it is not set up with 3rd axis, however due to the exact issues you described, above, my 20 pin and 80 pin dont shoot the same line as the sight is set up with. It has the wire that supposedly shows your pins are in line and level. However I have set my pins different than the wire. the 20 is slightly inside it or right of it as i see it and the bottom pin 70 yard pin as i set it up, is slightly out of the wire or left of it.
So in a way, the pins adjust in left and right independently, and is a similar adjustment for a third level adjustment.
However, EBJ had a nice article about it all some time back. I read it, understood it, and found it more or less useless for 90% of archers.
A sight with only two axis of adjustment is plenty. As an archer, form is more important. Making sure you pay attention to every single muscle you hold during a draw and shot sequence plays the part of the shot, not so much the sight.
For example, I picked up my bow this last month for more or less the first time over winter. My bow and sight have sat untouched. It shot perfectly for me last season, however I was all over the place.
My shoulders and mid back muscles are not in shape, I shook, and my grip was random.
I started all over again going through the mental routine and started noticing all the form malfunctions I had from not shooting. Give me a month and some string time and I can work that out.
No sight on my bow can fix that.
05-24-2011, 06:06 PM
You are right... Form and conditioning is 90% of it for sure! 3rd axis only helps if you know the form is right!
05-24-2011, 06:38 PM
Thanks for the info. I understand it now. I have been looking for a 7-pin sight for some time now. I currently shoot a 5-pin Cobra sight and routinely practice out to 60 yards. I would like to extend my practice sessions out to 80, which is why I want the 7-pin sight. I like the Spott Hogg sights, but I have heard good things about the Montana Gold sights. Last year, David Long did a review of G5's new line of sights in EBJ. They had a 4-pin sight with 3 fixed pins and 1 floating. I like that concept, but haven't heard anything else about that sight beyond his review.
05-24-2011, 07:07 PM
Reflex... Again, lot's of opinions so only take this for what it is worth... Many times in the field, animals move or simply put, you could forget to readjust your float pin and shoot for the wrong yardage inadvertently... Not that it will but in the heat of the moment it could happen... This was one reason behind why I went back to a 7 pin sight...
Spot Hogg's are indestructible, with the new bullet proof pins... Watch out! Deadly and bomb proof :) Happy hunting
05-24-2011, 07:32 PM
Thanks again for your input. I just got done doing some research about the G5 sight. It didn't have that great of reviews....lots of people complained about the fiber optic breaking. Not good on a backcountry hunt. I might have to stick to the Spott Hogg.
05-25-2011, 09:39 PM
Yeah I would say a good majority of people don't understand what third axis really is. Graylight is correct in that under 40 yards in most hunting situations it probably isn't needed as your difference in impact would be marginal, at longer distances and the steeper the terrain it's much more critical. As you draw your bow back the load is shifted from the string to the cables and the cables are pulled to the right by the cable slide. This causes torque in the limbs which transfers into the riser and then into your sight. There are other factors like deflection of the riser and your grip which all add to this as well.
First in order to adjust third axis the second has to be set. Second axis is easy, put the bow in a vice put a level from limb tip to limb tip and when it reads level your sight should read level. If not adjust it so it does.
So your sight housing (with the bow at rest) should be perpendicular to the string. Imagine putting a carpenters square along the front of the sight housing, it would run straight back to the string. Now when you draw the bow back all that torque causing the riser to twist translates into the sight since they are mounted together. This is easy to visualize if you think of a 4' stabilizer being mounted on the bow and as you draw back the stabilizer will actually point to the right of the target you are aiming at, your sight is doing the same thing but since it's only 6" in front of the riser it's hard to see. So now if you go back to the carpenters square and put it on the sight housing at full draw it would actually be pointed towards the left of the archer.
None of this matters on flat ground because when shooting flat level is level. But if you hold a level in your hand with the level twisted (like your sight is) and rotate the top of the level forward (like shooting downhill) the bubble will slide to the highside of the level. If you aren't adjusted for third axis when you go to level the bow up you won't actually be level.
So for 99% of right handed archers with a most bows on the market the sight housing will need to be rotated in towards the riser. Meaning if you are holding the bow in your hand the left edge of the sight housing will need to be closer to you than the right side. Bows like the new Prime Centroid with torque reducing cable guards/slides help with this but it still needs to be done.
How much this affects arrow flight depends on a lot of factors. Go down the to range and shoot 70 yards with your bubble all the way to the left. You should shoot 6-10" to the left of the target. This is actually a great trick when shooting in a crosswind. Tilt the top of bow into the wind direction and you can just shoot at the dot instead of holding to the right or left or where you are aiming.
Sorry for the long post, it's not easy to explain through writing. Hope you're not more confused now.
05-26-2011, 12:11 PM
Thanks! You had a great explanation. It sounds like adjusting for the 3rd axis might be difficult though. Is this the case or is it fairly easy?
05-26-2011, 12:31 PM
S&S did a great job of explaining it... His second paragraph will get you close to where you need to be... From there, it's a little more tricky...
05-26-2011, 01:23 PM
I've been meaning to sit down and write a in depth article on this subject for a long time. I am going to get that done today and I'll post up a link.
05-27-2011, 01:05 AM
Here are some good videos by Tim Gillingham on 3rd axis leveling.
05-28-2011, 11:55 PM
Here are some really good videos by Tim Gillingham on 3rd Axis Leveling.
06-26-2011, 08:39 PM
Look into HAMSKEA archery solution's easy third axis sight level. It is a truly incredible product. I first saw it a year or two ago back in an EBJ as featured hot new products from the ATA show. I got one and it makes a huge difference. low cost, light weight, and very packable it and a spare archery release are the only tools I pack in for my back country hunts. My local bow shops know very little about the science and effectiveness of 3rd axis so I learned to do it myself through the easy to follow instructions that came with the HAMSKEA easy third axis level. Hope this helps and enjoy.
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