Twisted nocks and other shapes

Cereleste

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In some "blue sky" thinking, I was wondering if you could get a bareshaft to spin via some modification to the nock. If the throat of the nock had a twist of, say 60 degrees, from the base of the throat to the ears, then when the arrow disconnects from the string it would be forced to rotate. I couldn't come to any conclusion about whether it would do so at any reasonable speed, or if it would be more likely to just break the nock, or if any rotation would quickly dissipate, so figured someone else must've thought about it before online.
Surely enough, Easton has a similar patent from 1992 covering a range of "offset" or "bent" nocks here US5186470A - Offset arrow nock - Google Patents . Their explanation is that it "permits the use of a lighter weight less stiff arrow by countering and diminishing the normal bending of the arrowshaft as it is propelled forward by acceleration of the bowstring at the moment of release."
Now, I've never seen or heard of anything like this for sale, so if they ever developed them into a product it likely have flopped quickly and quietly. At the same time, patents cost money so they must have thought there was some value in protecting it.
So,
- has anyone ever seen or heard of any nocks like these that were offset or purposefully bent or twisted or any other non-standard geometry, and if so, how did they work and why aren't they in use? I think ACEs were in common use then but the X10 had yet to be released.
- any thoughts as to how a forced rotation as the arrow leaves the string would affect flight (or not)?
I have a few spare nocks that I could carefully warm up and twist the ears on, and then test at short range from 20lb limbs (and full PPE in case it explodes).
 


bimble

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Ironman
Turbonocks are what you want... I wouldn't recommend them myself. There is an interesting thread about them on a different Archery Forum all the way back in 2014!
 


Cereleste

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It goes to show there are no new ideas - it looks like the only seller is the manufacturer, and besides the intense flurry of interest in 2014 (56 pages of what looks like bickering on archery talk!) it doesn't seem like they caught on or there'd be more recent posts from people using them. It sounds like centre serving wear, increased sensitivity to spine, and clearance may have been issues. Some compounders (and barebow, but not recurve?) got smaller groupings at long distance with them, (or at least showed off images to that effect) but either that wasn't repeatable or there was some other fatal flaw given there's hardly a peep about them now.

What was your impression of them?

Thanks for the archery forum link; I'm imagining space archery as the next niche sport now.
 


AndyW

Active member
I nearly ordered a set from him a few years back after getting his recommendation. I decided against in the finish as i came to the conclusion it was a solution to a non existent problem.
 


Aleatorian

Member
Bareshafts don't travel straight, they already have a spin component to their flight already. This is partly due to the serving-nock interface, which way they spin is dependant on which way your string is twisted and then subsequently served.

This can be tested by marking a bareshaft and shooting up close and seeing which way the mark starts to move. As a compound archer, I would then use this to decide which way I offset my vanes to compliment the spin. I have ran against the natural spin and seen no difference in grouping, but it just seems sensible to go with it after seeing a slow mo where an arrow stops rotating the natural direction and then restarts spinning in the direction enforced by the vanes.
A recurver may be forced to go with vanes by handedness, especially if using spin wing style vanes.
 


Cereleste

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Thanks, having not read much about compounds I hadn't heard about this before. After reading up more on the "natural rotation" of a bareshaft it seems like more of a slow rotation than a spin - something in the order of 2-3 rotations in 18m based on fairly limited data from a barebow and a compound, compared to 5-15 for various fletches. There's almost no information on any forum about how it works with recurve - if the theory about the serving direction making the nock ears rotate holds then I'd expect a Beiter nock to give zero rotation in flight.
I've got a string in need of a new centre serving though and a spare that twists the other way so will mark some bareshafts and see what rotation I get.
 


Aleatorian

Member
Jake Kaminski (American Recurve) clocks his arrows, though I think he's a Vane user rather than spin wings.

Interesting point on the Beiter Nock Point, it's rare that you see any though, even on the world stage
 


Del the Cat

Well-known member
After consultation with Clarence N Hickman I have concluded that the way forward is to have the arrow nock mounted on bearings such that the shaft is free to rotate while the nock is still on the string. This allows the shaft to be spun up to speed via a small DC electric motor with a rubber pressure wheel, this would be attached at the riser and would replace the arrow rest and clicker assembly.
Mr Hickman used this technique to spin stabilise rockets to great effect.
The high rates of spin imparted to the shaft would be of great advantage to manufacturers and sellers of unnecessary archery equipment.
Del
 


geoffretired

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DEL, it sounds OK but it will never sell very well in my opinion.
It's just too simple. The world needs things to look like they belong to a hundred years time and looking scientific, cad/cam 3-D printed etc.
 


Cereleste

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After marking 4 bareshafts and shooting them each several times from 1-8 meters into a new solid foam boss, I can say that for my ACEs, there is no trend other than the "personality" of the arrow since each arrow followed a distinct and repeatable pattern - one does make a clear counterclockwise rotation with a full period in 6m, but the others make a small rotation in a random direction in the first meter then wobble near that angle for the next 7m. I'm shooting them in random order so as to not bias myself and when I reshoot a distance I get the same set of angles for each shaft to within a few degrees.
This is using the thickest centre serving material I had around, so if the "twist" of the centre serving could impart a noticeable spin to these arrows from a recurve bow I'd expect to be seeing it. I tried the same with my old centre serving last night (the thinnest halo with two strands padding underneath so it was about as smooth a surface as it gets) with the same results.
I've been trying to understand the role and significance of fletches better - that they "stabilise" the arrow and make it fly "better" doesn't mean much in itself. I did a Portsmouth on these bareshafts earlier this week and ended up halfway between my two other indoor scores in the past year, which are 4 points apart - I'd need a lot more scoring rounds of each type before I could find anything statistically significant.
 


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KidCurry

Well-known member
I did a lot of testing, for compound, recurve and arrow type, a couple of years or so back and posted the results on AI. I found no correlation to serving or string twist. All initial spin was due to arrow type. Pure carbon/C1s imparted more twist than Protours, but Aluminium imparted the least. Most were around 1/4 turn in 3m. All initial twist was corrected by fletchings within a couple of metres. Conclusion... unless you shoot GMB upwards you might as well ignore it.
 


AndyW

Active member
After consultation with Clarence N Hickman I have concluded that the way forward is to have the arrow nock mounted on bearings such that the shaft is free to rotate while the nock is still on the string. This allows the shaft to be spun up to speed via a small DC electric motor with a rubber pressure wheel, this would be attached at the riser and would replace the arrow rest and clicker assembly.
Mr Hickman used this technique to spin stabilise rockets to great effect.
The high rates of spin imparted to the shaft would be of great advantage to manufacturers and sellers of unnecessary archery equipment.
Del
It's been half done.
Thunderball magnetic nocks. You just need the motor assembly now.
 


Del the Cat

Well-known member
Try to keep it on topic please...I'm getting complaints.
Perhaps the complainants should have the bottle to reply to the posts in question?
... otherwise, how do we know which posts are being referenced, it also gives those accused a chance to respond (or apologise) as I am struggling to find any of the posts which don't reference the spinning of arrows. Also note the OP states "blue sky thinking" effectively soliciting ideas/comments.
Is the complaint from the OP? If not then I don't see its relevance.
There have been previous threads about the lack of active posters... this sort of generic criticism surely just discourages participation?
Should we all simply delete our posts for fear of "upsetting" someone?
Del
 


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Cereleste

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I haven't complained at all, and enjoyed reading up on Clarence Hickman! I only started posting here after the post about there not being many posts, and figuring after most of a decade I've got enough background to contribute somewhat.
KidCurry - thanks for posting the data, though I've just gone through your post history and after 7 pages it says "no results found" so the update may have eaten it- if you've got access to the post could you send me a link please? Unfortunately in terms of being able to ignore these things, I got my GMB this summer and am chasing my next goal of a (ladies) 1300. I've read nearly every archery mechanics paper and done a bunch of fiddling with my bow but never anything very rigorous, so while I'm tuned in the sense that I don't need to adjust windage more than a turn or two outdoors and my bow is loud but not deafening, I've never done any "fine/group tuning" and am starting to wonder what, if anything, might be worth being more systematic about. After many years of faffing with spinwings I've been wondering what quantifiable benefit fletches give us outdoors since anecdotally I haven't found much difference (but need to score at least a 720 with bareshafts before I commit to an opinion).
Though in this thread I'm not looking for a "magic nock" or anything useful for competition purposes in this thread - as I said just blue sky wondering about what has/hasn't been done in the past and why we shoot as we do with equipment that hasn't changed significantly since the early 2000s.
 


AndyW

Active member
Cereleste, good to hear your open to a bit of chat. I now feel quite happy to carry on. Del the Cats point on the lack of posts should be heeded.
There's been a few bits and bobs tried over the years but as you say it's more fiddling than anything and niche suppliers. I guess the reason is that the bow / kit will do the job all day every day the only real inconsistency is the operator. Also, mainline supplier will not rock the boat, what sells sells - they need to put something in the marketing blurb to tempt the latest and greatest new purchase but it's generally fiddling, sounds great or/and looks pretty.
 


Cereleste

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Hi mbaker74, bimble mentioned those and I'd buy a pack just to see what they do except the size compatible with ACEs and g nocks no longer seems to exist.
Have you ever used them? If so, any comments? The other forums seem very polarised about them though most of the posts are long enough ago that if they did increase spin rate dramatically on a recurve, and that in turn also improved arrow flight, they'd be everywhere (especially at 70m where stability in the wind without extra drag is valuable).
 


geoffretired

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From what I've read on here in the past, spin rate is not that important.
If the spin is generated by the separating of the nock from the string, the energy to produce that spin must reduce the energy available to travel forwards, slowing things down.
 


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