Tip string grooves

[pierce_schmeichel]

Billy from Primitive Pathways, came out with a new movie and he had some piaute bow fragments. They had a strange V notch at the tip. Billy said he thinks it was there to wrap the sinew around the tip and I don't think he is wrong at all. In fact I think he is very much correct, but I think it may have also served another purpose. A string groove that you can wrap the string around! I have done some testing and it has a lot of benefits actually. You are able to reduce the weight at the tips significantly, it wears less on the string, and you can leave the string tied onto the bow from both ends.

Here is the bow I tested on, before I changed the tips to the piaute v notch, I had just normal side string socks. It was 46" ntn and 40lbs at 23" draw. It flung a 400 grain arrow 130fps, not awefil but not great either. Then I cut the tips off and did the piaute style v tip notch and it was still 46" ntn and 40lbs at 23" draw, but now it flung a 400 grain arrow 150fps! A major increase in speed. So if somehow that is not what it was for, i found a new way (new to me at least) to string a bow.

[pierce_schmeichel]

Here is a screen shot of the bow fragments and a picture of how i string it and then a picture of how i unbrace the bow and can still have the string tied on both ends

[Pappy]

That’s pretty cool,  never seen that done before, thanks for sharing. May give that a try. Pappy

[superdav95]

Well that’s neat.  I may also have to give that a try. 

[GlisGlis]

that's something really interesting! kind of make me think to brush nocks on steroids
It has the potential to use the true FULL length of the bow
Leaving the string always knotted is also another benefit
I wonder if stronger tips are needed

[pierce_schmeichel]

that's something really interesting! kind of make me think to brush nocks on steroids
It has the potential to use the true FULL length of the bow
Leaving the string always knotted is also another benefit
I wonder if stronger tips are needed

Yes you definitely need to wrap sinew just below the tip so it doesn't split the bow upon the release of an arrow. I had that happen on one of my tests but the sinew holds it together great!

[bjrogg]

Really interesting.

By the way beautiful full draw

Bjrogg

[ssrhythm]

I love it when I check in for the heck of it just to skim the forums and stumble into a gem like this thread.  Looking forward to doing this soon.  Thanks.

[pierce_schmeichel]

Hey thanks everyone!! And let me know what you guys find out in your own tests. The more data the better!! Also I found you can make the tips thinner too.. reducing limb weight even more. The tips only have to really be about a couple millimeters wider than the string. Then you can put rather small string groves down to hold the loop. As the string wraps from the back to the front it has some mechanical advantage and does not need as much to hold it down.

One could probably get the limb tips 1/4" to 5/16" thick, depending on your strings thickness.. if you were trying to push the performance even more that is. I don't know how historically accurate that would necessarily be.. but it would work.

[GlisGlis]

one thing that puzzles me is the pronounced V notch shape of the pajute bow fragments
It seems to me that a U shape would be more appropriate and would reduce the risk of the tip splitting

[pierce_schmeichel]

one thing that puzzles me is the pronounced V notch shape of the pajute bow fragments
It seems to me that a U shape would be more appropriate and would reduce the risk of the tip splitting

I was thinking that exact same thing, but if you're using stone tools making a U notch is a little more tricky, definitely doable. When you wrap sinew inside the v notch it mellows out that V more into a U shape and then when you wrap the tip laterally with sinew it doesn't have a chance to break.

The sinew wrapped at the tip laterally also has a second purpose. It gives the string loops a little more to grip onto. Kind of like a traditional sinew nock.

[mmattockx]

How would one go about using this with a synthetic string? It seems to me the loops can't be served if they need to bend back on themselves to come back over the tips to the belly side.


Mark

[pierce_schmeichel]

How would one go about using this with a synthetic string? It seems to me the loops can't be served if they need to bend back on themselves to come back over the tips to the belly side.


Mark

If you're doing an endless loop string you could take the loops and flip them in on themselves to turn them into slip knots. I'll post some examples of what I mean(forgive the ugly polyester sting haha, it's all I had on me)

And regarding the serving I'm not exactly sure but it should hold up. I think if you served it normally you would still be fine. Maybe I'm wrong cuz I'm not a huge expert on synthetic stings but the compound bows I've looked at have aggressive curves and bends like that in them and they seem to hold up fine.

[bassman211]

What puzzles me is the physics behind it. I can't see how you are getting 20 fps more not that I don't believe you, but the difference in speed could only be marginal in my mind. Guess I will have to try it to prove it to myself.

[pierce_schmeichel]

I was able to remove a lot of mass from the width of the bow as well. Since the singular V notch only really needs to be about as wide as your strings diameter, you can remove a loooooot of mass. You can get the tips as narrow as a pencil. I didn't get them that thin on this bow, but you definitely can.

The string also may be experiencing less friction due to its singular contact point at the tips. Maybe not on that one idk just a thought.

Another note, I could see this string nock style benefiting heavier woods like osage because reducing mass is more crucial on those heavy woods.