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Tip string grooves
bassman211:
Zugal... I shot first with the looped string in the original nock grooves. Then tried cutting a v notch in the existing tips which were to small, and split when I strung, and shot the bow, so I cut the tips off and ,V grooved down to sinew I had on the limb tips which would be nearly the same length as the looped string. ???
pierce_schmeichel:
Wow, that's amazing Bob!! And yeah I still think it's the mass and the reduced friction of the string on the groves, but the extra leverage hypothesis is a great one and I think you're onto something Zugul!
Also Bob did you reduce width material on the bow at all? If you haven't yet and you did you would see even more improvements!
What we need to find out is how this nock style affects the velocity of different length bows and different material bows. In being consistent, we would want the ntn length to be the same for each test, for the individual bows. For example, if you have a 55" ntn bow with side notches, collect your data and then convert it over to a 55" ntn v notch.
I am curious how this would affect woods like osage. My thoughts are that since it is a wood with a greater mass, one may see more dramatic improvements. I might be wrong though, it could very well be proportional.
bassman211:
No Pearce... no reduction on limb width. Rather narrow to begin with. What I know for sure is that this bow never shot 150 fps with that arrow, and was built in 2016, so it tells me that something is going on, but I truly have no clue. I know for sure I will be trying it on some string follow bows that I have made over the years that are longer just to see the results. Fun to experiment.
superdav95:
Pierce and zugul. I think there is a few things going on. String friction and mass reduction are the two that I see. I also wonder something is going on with the length of the string between limb tip to tip. Impressive results guys! I’ll give a try and test some of mine too. I’ve seen a 5 fps increase with tip reduction in mass. Will be interesting to see if this translates to longer bows!
Zugul:
--- Quote from: bassman211 on October 12, 2024, 04:23:58 pm ---Zugal... I shot first with the looped string in the original nock grooves. Then tried cutting a v notch in the existing tips which were to small, and split when I strung, and shot the bow, so I cut the tips off and ,V grooved down to sinew I had on the limb tips which would be nearly the same length as the looped string. ???
--- End quote ---
You eliminated the wood that was above the old nocks and made the V nocks so the string lenght and the brace height stayed the same, correct? If this is the case then you took off "dead weight" that was just slowing down the return of the limbs from full draw to brace height, plus reducing the surface area between the string and the nock thus reducing friction (I think this leads to a marginal improvement in speed). As stated inTBB1 "On bows of average lenght and strenght, 65 grains of weight at each tip affects arrow speed by about 1 fps". I think the reduction of limb tips mass is the key here, but we neeed someone else to try and replicate your results because this still isn't enough to explain such a big difference in speed IMHO.
EDIT: it's nice to see my thoughts are in line with someone that has so much more experience then me, superdav95! :BB
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