Hoyt Helix true center

[alquick]

I am trying to align my new hoyt helix with the 900cx limbs. I have alignned the limb tips and the string straight with the tiller bolts. But how can I check that the string is running on the true center of the riser? With my avalon I use the 23xx arrow to check this but what can I do with the Helix?

Regards!!!!

[piphil]

Originally Posted by alquick

I am trying to align my new hoyt helix with the 900cx limbs. I have alignned the limb tips and the string straight with the tiller bolts. But how can I check that the string is running on the true center of the riser? With my avalon I use the 23xx arrow to check this but what can I do with the Helix?

Regards!!!!

I haven't had any experience with the Hoyt 'tec bows, but I would have thought lining up the string with the limb bolts should be fine. Are you trying to line up the string with the centre of gravity of the riser?

[harlequin]

The sight window should be at 90 degs to the limbs. Hold a straight arrow to this face, I use a couple of elastic bands, stand back and look along the arrow on the string side, adjust the limbs so that the sting passes through the centre of the limns and riser lim bolts. You can also check that you longrod is true to the axis, if it is, you can always use the end of the longrod as the position to align the string.

[TJ Mason]

The true centre is (I'm told) 0.41" from the sight window on the Avalon. I've never seen a figure for the Helix.

What you could do is measure the distance from the sight window to the centre of the limb bolts on the Avalon, then take the same measurement on the Helix. If they're the same distance, there's a good chance the true centre is also the same distance, so use the 23XX arrow as now. If they're different, look for some bit of tubing that's larger or smaller than a 23XX arrow by this amount and use that.

Or you could send a PM to Gtek and ask him nicely for his opinion.

[WhitehartFB]

IMO aligning a riser with the limb bolts and so called true centre of the handle is useless, unless you are really lucky and will result in a bow that is out of line.

I have yet to see a bow where the limb tips are straight and the string runs down the exact centre of the bow very very close but not exact.

For accuracy it's the limb tips being straight that is important.

I have seen many bows where great time has been spent in aligning the string using limb guages and the like and on many occassions it results in one limb tip slightly twisting west and the other east when the bow is held vertically.

See page 6 below photo 3 and the text to see what I am trying to say.

http://www.perrisarchery.co.uk/Perri...%2005%20Q4.pdf

[piphil]

Originally Posted by Whitehart

IMO aligning a riser with the limb bolts and so called true centre of the handle is useless, unless you are really lucky and will result in a bow that is out of line.

I have yet to see a bow where the limb tips are straight and the string runs down the exact centre of the bow very very close but not exact.

For accuracy it's the limb tips being straight that is important.

I have seen many bows where great time has been spent in aligning the string using limb guages and the like and on many occassions it results in one limb tip slightly twisting west and the other east when the bow is held vertically.

See page 6 below photo 3 and the text to see what I am trying to say.

http://www.perrisarchery.co.uk/Perri...%2005%20Q4.pdf

I'll give your method a try when I next get the bow out. I see what you're saying, but if the string is centered on the limbs (seen via limb gauges or riser bolts) surely the limbs would have to be straight? If one limb was east and the other west, wouldn't the string run diagonally across the riser and miss one of the bolts? Am I missing something...? :P

[WhitehartFB]

Originally Posted by piphil

I'll give your method a try when I next get the bow out. I see what you're saying, but if the string is centered on the limbs (seen via limb gauges or riser bolts) surely the limbs would have to be straight? If one limb was east and the other west, wouldn't the string run diagonally across the riser and miss one of the bolts? Am I missing something...? :P

No logically you are quite right, but and I think it's a big "but" I am yet to see a "perfectly" straight riser and in some cases even the limb bolts are not perfectly central. If you adjust the string to run down the centre of the riser and or even the centre of the limb where you have the measure (guage or tape) it is not a guarantee that the limb tips will be straight if the riser is not. Adjusting the limbs left or right to get the string to run down the centre can put the limb tips out.

BTW the limb tips can both point east or west that was just the most common example.

[piphil]

Originally Posted by Whitehart

No logically you are quite right, but and I think it's a big "but" I am yet to see a "perfectly" straight riser and in some cases even the limb bolts are not perfectly central. If you adjust the string to run down the centre of the riser and or even the centre of the limb where you have the measure (guage or tape) it is not a guarantee that the limb tips will be straight if the riser is not. Adjusting the limbs left or right to get the string to run down the centre can put the limb tips out.

BTW the limb tips can both point east or west that was just the most common example.

Ah, so this is a problem of the riser not being straight rather than the limbs being bent - that makes more sense. Tbh, it's never even entered my mind that my riser might be bent. May be interesting to have a closer look at my bow later. :-P

[geoffretired]

Could we use a bracing gauge with the short side on the flat of the limb and the long measuring piece pointing towards the bow string?
When the string is in contact with the measuring part,the zero should be at the middle of the limb width, yes?
If the limb is twisted or the riser causes it to appear twisted, the zero mark will be off centre.

[WhitehartFB]

Originally Posted by geoffretired

Could we use a bracing gauge with the short side on the flat of the limb and the long measuring piece pointing towards the bow string?
When the string is in contact with the measuring part,the zero should be at the middle of the limb width, yes?
If the limb is twisted or the riser causes it to appear twisted, the zero mark will be off centre.

The key is that the limb tips are straight with the limbs and each other what the string does at the riser is not very important.

Funnily enough Beiter are working on a guage to do something similar as they are aware of the limitations of the guages, but were having issues making it universal and allowing for different limb profiles as some are not flat. TBH for recurve if you do as suggested in the article by Jay that's all you need, as it negates any inconsistancies in the riser, even a twisted riser can be more accurate using this method I think Jay shot one for a time.