Horn nock inserts

[kevinsmith5]

How many of us ever make an arrow knowing we'll only shoot it once?

[WillS]

Has anybody had horn nocks break while shooting?  I recently finished a set of 12 arrows for a 60# ELB with 2" horn inserts, cut with the grain so that the nock was at 90 degrees to the grain.  Within an hour of shooting two of the arrows had broken at the nock, both the same way - the horn and adjacent wood had completely split and blown off.  Surely the whole point of going through hours of work making inserts is to avoid this happening?! 

[adb]

I've never had this happen, even with 100s of shots from heavy (100#) war bows. What type of nock insert are you using, what kind of glue are you using, and how precise are your horn to arrow shaft tolerances?

[Del the cat]

... that the nock was at 90 degrees to the grain...

Sorry... I got totally the wrong end of this ... I thought we were talking bows not arrows...

But back on track, my guess would be the nock being tight on the string and it splitting like a wedge in a log.
I always go for a slight keyhole effect with the bottom of the slot well rounded and open so it's loose on the string, but with the other end of the slot just tight enough to stop the arrow falling off the string.
Arrow diameter, insert width? Pic might help.
Del

[WillS]

I'll add some pics a bit later, but the arrows are 11/32, 40# spined boyton pine.  The inserts are buffalo horn, the glue is 2 part epoxy and the tolerance is the best I could do without machining.  They're pretty darn accurate I think. 

It might be what Del mentioned I guess.  I cut the string nock with a multitool saw which is almost the identical width of the string.  I then use a file to smooth and widen then nock until it requires a minute effort to "click" the arrow onto the string.

[Del the cat]

I'll add some pics a bit later, but the arrows are 11/32, 40# spined boyton pine.  The inserts are buffalo horn, the glue is 2 part epoxy and the tolerance is the best I could do without machining.  They're pretty darn accurate I think. 

It might be what Del mentioned I guess.  I cut the string nock with a multitool saw which is almost the identical width of the string.  I then use a file to smooth and widen then nock until it requires a minute effort to "click" the arrow onto the string.

Maybe you need to go up in arrow diameter, I got some poplar ones about 3/8" for the 90# warbow I made from Richard Head (got points too)
I think 11/32 is maybe a tad skinny.
Del

[WillS]

I've figured out that it is indeed the fact that I cut the string nocks too narrow.  Just checked over every arrow, and every single one of them has a split starting from the throat of the nock.  That's 24 arrows, all with horn inserts and hand-cut fletchings and bindings that I will have to scrap and re-make.  Fun!

[kevinsmith5]

How much room did you leave between nock and fletching? How long is the fletching?

[WillS]

1.5" between nock and fletching, and the fletchings are 6.5" long. 

[kevinsmith5]

Room to trim the self nocks off and recut? Have a 1/2" shorter arrow?

[WillS]

Possibly on some, but on others I think by the time I get down to clean unsplit wood I'll need to remove all the fletchings and such.  I think I'll chop off a bit of the end, and taper them to fit plastic nocks (blasphemy!) so that they're at least shootable.   I draw them to the head anyway, so losing more length would be a bit of a problem!!

[Loki]

I've had a few break on me at the nock, from arrows i've made my self and from arrows made by others. I can only think it came from over use..?

[WillS]

Mine were definitely down to me cutting the string nock too tightly.  I'm gonna try taping three hacksaw blades together and see if I get a better fit without having to muck about filing each one until they're ok.

[Loki]

I found a tile saw to be the best thing for cutting nocks.