8 strand TS-Plus string just blew up!!!!!

[ozy clint]

steve o- that's a valid point. i wonder what forces are on a bow string when it slams down at brace height. maybe we need to look at the dynamic forces involved. if they are greater than the static forces during the draw then that is the force that strings need to be designed for.

[ozy clint]

just had a thought.
it is generally accepted that dacron stretches during the shot. so it would be logical to think that the greatest amount of stretch occurs when it reaches brace height after being released from full draw. so does that mean that the maximum amount of force applied to a string is at brace after release or at full draw. i wouldn't think a string is at full stretch at full draw. it seems we've been basing our string design parameters on the lesser of two forces.

but maybe i'm just a dumb @$$

[James Wrenn]

Well it does say an 8olb bow can generate up to 200lbs tension.I would think most of that is because of the more energy stored and cams rolling over.A stickbow would never create that much even on a heavy bow.Also the loss of 40% they speak of is not the case when you are useing flemish strings with built up loops.The loops would be stronger than the string itself.They are talking about haveing 9 strands in the loops of an 18 strand endless string.Useing this and the fact even they quote the 5 to 1 safty margin small strings of the right material should be no problem on most stickbows. Just what I get out of reading it.

[O.L. Adcock]

James, all that reenforces my point! Steve and Ozy, that was all covered pretty extensively in another skinny string thread. Max tension is at brace height before and at the end of the shot. Full draw is the least tension. That's why it's so odd one would fail at full draw. Something was amiss...O.L.

 

[James Wrenn]

Yeah OL I use 8 strand strings because with my halo serving they fit my nocks just they way I like them.No heating or sanding on nocks to get a good fit and don't have to double serv or add strands under the serving.Plenty strong,easy strings to build and makes a quiet bow.I am not concerned at all with a string breaking unless it gets cut.jmo

[katman]

One of the possible reasons listed in the BCY post for string breakage was over twisting, could it be that since some have to twist the string a lot (takes quite a few twists to change brace height with a skinny string) to get proper brace height that will lead to failure with skinny strings?

[wingnut]

OL,

That's an interesting chart.  Could you provide the rest of the information?  Like how it was developed and on what bow.  How the measurements were taken?  etc?

The chart doesn't show what we intuitivly would believe.  Of course that's not the first time that when things are properly researched and tested that the paradigm changes.


Mike

[longbowjim]

how can more tension be on the string at resting brace height.  At rest a string may only have 30 to 40 #'s of tension.  At full draw, the same bow may have 55 to 60 #'s of tension.  Common sense can tell you that much.  At brace after the string is released I completely agree.  If we are all gonna get so technical and scientific, we might as well throw wheels back on our bows and go hunt genetically altered animals.  All of this science BS is gonna end up taking the fun out of why we started doing this in the first place.  WE WANTED THE CHALLENGE.  This is a traditional hunting forum, not a science class.  I started the post to see if anyone else has had problems with TS-Plus and to share an experience that I had while out stump shooting to enjoy this great sport.  Is no one gonna be happy until someoen invents a completely adjustable "traditional" bow with 80% letoff.  JD

[Jason Jelinek]

It's not inuitive to me either, but I'm sure the measurement was taken using a tension gauge inline with the string which will show the tension on the string.  Remember that the draw weight is not on the same vector as the string or the limbs, so it may not be a proportional relationship.

At brace height the limbs are being pulled in towards the center of the bow, when drawing the bow the limbs are pulled in towards the bow and back towards the archer.  Thinking about that makes the data make a little more sense.

[wingnut]

JD,

As a bowyer I would think you would want and need to understand the science at least a little to know not just that your string broke but why.  Especially when you are sending strings with your bows.

I find that the science and innovation is what makes the traditional bow as simple as it is.

Mike

[daveycrockett]

Well said Mike!!!  

[longbowjim]

Mike-  I like understanding and expiramenting, and even trying to improve.  The only string that has ever broke is that 8 strand.  When working with wood and glass I find it more of an art than a science.  The beauty and challenge of traditional bows is what draws people to the sport, not the speed and technology.  Your bows are a work of art.  Not a work of science.  Black Widow sells more bows than any other traditional bow manufacturer out there.  They have done this by tradition.  if you are to look at their limb profile, it has changed little or none for the pas 50 years.  If I didn't build my own bows, I would probably own bows by every sponsor on this site.  Because they are works of art.  Your bow would be at the top of my "to buy" list becayse of what you have accomplish with all wood.  I would like to know the minimum breaking strength on string material, but the graphs and charts don't represent every bow.  All bows shoot and draw different.  What works for one may not work for another.  As stated on the opening page of this web site "debate is good, as one sword sharpens the other".  JD

[Carbon Caster]

JD,

Actually all of our bows (single string) DO shoot and draw the same cycle wise.  The force draw curves may be a bit different, but if you plot them all on charts, they will look the same as far as draw cycling.  The c-bows are TOTALLY different animals though.  Just because something goes against our preconceived ideas or accepted science, doesn't mean it is wrong and should be ignored and lumped into (NONTRADITIONAL).  Just because the King says he has new invisible clothes doesn't make him any less naked.  

If you don't want to be technical and scientific, you really ought to quit making those Horribly NONTRADITIONAL HIGH TECH bows you build.  Everybody knows that you are using that horribly scientific (GLASS/EPOXY/and "gasp" SYNTHETIC FIBER).  

I build 12 strand 8125 strings commercially, but have done SOME testing of lesser strand strings.  I have only seen one string BLOW up, and it was a 4 strand 8125 that I BLEW UP on my stretching jig at just over 250#.  I personally like 8-12 strands with .030 Halo, but that doesn't mean those are the only RIGHT combos.  I even shoot a 12 strand 8125 string on my Osage Self Bow with NO TIP OVERLAYS!  LOL!!

OL,

I would love to see the info that goes with that chart as well.  If you could email it to me that would be AWESOME!!!!  I knew from simple Physics that was the truth of tension applied, but have never seen real world test results to prove it.

[longbowjim]

I guess I should have re-phrased the way I worded some things.  I'm just saying for me, that that shooting a traditionl bow takes me away from technology.  I have worked around computerized machines for 18 years.  From everything in the past 5 pages I have learned not to trust ts-plus in a skinny string.  Also that BCY materials is the way to go.  Whether the string broke at full draw, or upon the releases, it still broke and I learned a lesson.  Thanks to all who gave helpful advice and pm'd me on suppliers for materials.  JD

[WIND WALKER]

Hey J.D. Im still glad that your ok and the little one! Thanks for your input.

[leatherneck]

So what is the advantage of shooting a lower strand string?

Mike

[Terry Green]

Hmmmm....lots of camp chatter lately also about skinny strings blowing.

Just because someone hasn't 'heard of anyone getting hurt' doesn't mean someone hasn't or wont...that goes for the bow as well.

"We CAN NOT trust what the manufactures tell us on the strength of this stuff.....O.L."...There you have it.  The last thing I want to worry about is my equipment being borderline.

Most jeeps don't come with a governor....but they do come with a roll bar for a reason.

I'll take the roll bar thank you....as it never kept me from getting through the mud, but sure made me feel better on the road.

[leatherneck]

Well put Tarz, well put.

[Matty]

This happened to me about a month ago on my super shrew. 8 strand Stock String.. Broke right where the string is served Upon release.. I had No Idea what Happened.. Thought I hit a branch.Then I looked at my bow.. Nothing Happened to it but... Shocked me..

[Bullfrog 1]

For me this is like shooting your bow with a 200 grain arrow. WHY take the chance??  BILL