Under drawing hex 4,5,6 limbs.

Amateur Barbarian

New member
Part of the detail is missing in the smoothenss graphs posted by AB. the reasons are well known to both of us, and anyone doing some maths.
Excel uses a Polynomial line to indicate the trend in smoothness, and the more you actuall see them, everyone of them shows the same double dip, and that double dip is even more pronounced in short limbs.
We have been looking into this trait, over the last year.
If you look at the dots on the graph rather than the line, especially that flight bow limb graph that was posted a little while ago, you might see that the limbs have a two stage smoothness.
This is something we tried to play with on the hex6 and we think we have done so.
Sid is correct. We are limited by the capabilities of excel, which is limited by the capability of the math.

Look at the data points, the lines are a best representation based upon the capability of the software. You will generally see unusual behavior at the boundaries since you cannot weight the points in excel (i.e. place more emphasis for the fit on the end points). Depending upon whether you choose an even or odd polynomial, your data will either grow exponentially at the end, or loop down. I choose the polynomial that provides the the best line without an unusual behavior from high order terms I do this to help make the data more understandable. The basic profiles of the curves are very repeatable. I have tested many limbs and the shapes come out the same, the differences are in the details.
 

foudarme

New member
I dont know if you remember a thread a while ago where i asked what muscle groups were used during the draw cycle.
Basically that is the exact experience we get when we go to shoots with our stand. We had 3 Belgians on bikes arrive just last week, and on the first draw, the first guy said to the other, some thing in Belgain (could have been flemish) "compound" more Begian words...

since no single string bow at present has letoff, i do wonder how the bodies geometry and muscle loadings/ working position works.

I ask this because while the eaisest point of the draw on conventional designs that everyone is used to is about the 21" mark, the hex series has its smoothpoint at 26".
This change in loadings seems to suit the "compound" term as we have heard it alot, about 70% of the first time pulls come out with it., and on that note, id love to see how the muscles accept the loadings.
As EVC said, there isnt a MASSIVE amount in it, but enough for 70% of the people to notice it.
What we have also observed is that those that dont have a draw long enough to suit the bows length and the DFC say that the bow is not smooth infact it possibly stacks. we have had this term some 6-7 times now for "short for bow" draw lengths.


Id love to see which mucles have what loadings at which points in the draw, and as correct back tension is applied, there must be a transition from the different muscle groups. and how this works on the way the limbs load up.


We are comeing to the theory that as the loadings run though the bone structure and not all at angles where mucles have to work, the reduced climb in weight works in harmony with the bodies alignment. giving an sensation of letoff, opposed to the climb of the onset of stack working against a alinging of the arms/shoulders.

We are not anatomy experts in ANY way, we are trying to work out how the two correspond to come up with this "compound like" feeling so many people pick up on.

The only data we have is the DFC... and it shows a difference in the two limb designs and clearly people see it/feel it when we get the bow length right.
Just a few words about it:

with my 17" sky riser and my 62" hex6 ILF long limbs, I currently draw the bow at a 29" AMO draw length: at this draw length I don't feel at all the "compound letoff feeling" (big deception !) and feel as if it was stacking (what is not the case obviously)...I have tried with bolts in then out without any difference about this perticular subject...but if I intentionnaly overdraw the bow beyond my determinated draw length with this riser then the stacking feeling disappear and the compound feeling very slightly appears at around 30" of AMO draw length..

with my black douglas riser and my 64" hex6 long limbs, I naturally draw the bow at a 30.25" true AMO draw length (it's incredible but I gain 1.25" of more with this riser and it was ever the case with my hexV) and there I feel a huge "compound letoff feeling" with it...it's just like when you are againts a rock solid compound wall !

I have to add that I had previously noticed exactly the same "compound feeling" with my 90#@28 black douglas hexV limbs that I was shooting at a true 30.25" AMO draw length also !

what do you think about it (except that I should change my 17" ILF riser against a high wrist 19" one cause I WANT my "compound letoff feeling" with this BB2 limbs!) ? I think that muscles have a complete diferent way to bear the draw according to what moment the weight occurs in the draw cycle (very easy to see with the hard cams compounds; take a mathews monster, a strother SR71 and a bowtech destroyer and you will feel the absolute differences between them and how you feel them soft or not) and that the draw is identify by them (the muscles) as soft or not according their own dynamics...difficult to explain it in english for me !

I will do the DFC during the next week in order to see what is occuring exactly...
 

Kerf

Supporter
Supporter
AIUK Saviour
Hi Guys. I know this is a really thread but, as a loving owner of a beautiful pair of Hex 5s, I would dearly love to see this chart and Amateur Barbarian?s chart. Unhappily both pix on Photobucket have either expired or no longer exist -at least I can?t find them. Any chance they could be reposted or sent by PM. Many thanks in advance.
 

Amateur Barbarian

New member
I have been pulling content to create a website for test results. I have had a lot of posts spoiled by the issue with Photobucket. The upside is that I have improved my charts. I have a lot more test results on the HEX series now. Send me an email and I will create a PDF for you will HEX test results. I can create peer groups for comparisons. I have some stuff now that compares all four major HEX models. I really liked HEX5. I found that they worked really well over all four FITA distances shooting barebow. I put my rest on the target at 90 meters. The HEX6 allowed me to put my point on the target but I was never able to break the score I had with HEX5. I am now using HEX6 for field. Send me a PM and I will mail you the document. I have not been on this forum in awhile. Fortunately, I got an email from your post. I will keep an eye on my PM's.
 
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