Hi All,
About 2 years ago, I ordered a custom bow. I finally had the opportunity to shoot it more than once here and there. During the past sessions, i have had the string come off the bow while the arrow was being released. This has happened 4 times now. At first I thought that I had somehow rigged it wrong. Since the string came back and cut my left wrist,(i'm right handed) and left a couple of welts, I made sure that the string was properly secured and centered in the notch as well as checking the brace height every single time. Still, this is the third time the string has come off, despite checking everything and even changing string. I know that there are expert bowyers on this site and want to get feedback on the notches specifically. Do you see anything wrong with one of them or both? This is getting to be frustating and its' starting to create bad shooting habits.
Recurve or longbow?
reflex deflex longbow
I'm by no means an expert, but I have built a few. I'm guessing that is a recurve. The top picture looks like the nocks were not cut in evenly. That will eventually result in severe limb twist, which can cause the string to jump off. Also, from the picture it appears the nocks were filed at a 90°. That is why you have those cracks in the glass. I'd be surprised if your string loops aren't badly frayed. Eventually you are going to get moisture in there and have a delamination at the tip. I'd get a new bow.
Quote from: jrstegner on December 14, 2020, 06:13:13 PM
I'm by no means an expert, but I have built a few. I'm guessing that is a recurve. The top picture looks like the nocks were not cut in evenly. That will eventually result in severe limb twist, which can cause the string to jump off. Also, from the picture it appears the nocks were filed at a 90°. That is why you have those cracks in the glass. I'd be surprised if your string loops aren't badly frayed. Eventually you are going to get moisture in there and have a delamination at the tip. I'd get a new bow.
Seems your advice is correct but couldn't the angle of filing be feathered in at this point and the shoulders evened out? Also, Frog send this post to the Boyers Bench forum for more advice. Sure hope you hear what you want to!
thank you. Much appreciated.
Is the limb twisting as the bow is drawn?
not as far as i can tell
Besides what has already been said, you might be torqueing the bow handle causing the limbs to turn, hence unstringing itself.
What does the other side of limb nocks look like?
Also do you have a picture looking down the string belly side from one end to the other when it is braced so we can see if the string runs down the center of bow?
Quote from: Kelly on December 14, 2020, 07:00:14 PM
What does the other side of limb nocks look like?
Also do you have a picture looking down the string belly side from one end to the other when it is braced so we can see if the string runs down the center of bow?
What Kelly said..
Here you go. Thanks again for the help.
other batch of pics
The nocks could be worked a bit on the belly side of the bow. I don't think they need to be made deeper, but the sharp edge/angle should be reduced. It looks like the glass is already beginning to splinter on one of them. That's a precursor to delamination. Reduce that angle and put a little super glue in the cracks if they remain.
How long is the bow and how long is your draw length? If it's a short bow and if you have a very long draw length, you could just be pulling the string right out of the nocks at full draw. Of course, a severe torquing of the bow or a severely twisted limb could also cause the string to come off. However, I don't see anything in the way the nocks are cut that would cause it. String wear and potential delamination, yes, but not throwing the string.
One other thing. Smaller loops would help keep the string on the bow. Strings can go through some very unusual ocilations at the loose. If the loops are big enough, that flopping around of the string (even though you can't see it) could cause the string to come off the bow.
last pic
Quote from: Orion on December 14, 2020, 07:31:35 PM
How long is the bow and how long is your draw length? If it's a short bow and if you have a very long draw length, you could just be pulling the string right out of the nocks at full draw. Of course, a severe torquing of the bow or a severely twisted limb could also cause the string to come off. However, I don't see anything in the way the nocks are cut that would cause it. String wear and potential delamination, yes, but not throwing the string.
One other thing. Smaller loops would help keep the string on the bow.
Thanks for the tip, the bow is 56. #50 @ 28". I actually draw at 27-2.75
Pretty short, but I doubt your draw length is causing it.
I don't think I torque it. I hold the bow with thumb and index and the 3 other fingers are seentially curved in, not grabing the bow.
Quote from: Orion on December 14, 2020, 07:31:35 PM
One other thing. Smaller loops would help keep the string on the bow. Strings can go through some very unusual ocilations at the loose. If the loops are big enough, that flopping around of the string (even though you can't see it) could cause the string to come off the bow.
Duly noted. Thanks again
Loops are too Big on string. Try them where they're just able to get over the nock.
When the string returns to brace its causing a forceful slack in the loops and then it will drop past brace before returning. So it's causing the loops to slack and pop off. Simple fix
I would agree with overspined that one loop looks way oversized. Is it coming off the upper limbs nock?
What is the brace height of the bow? Is it within the bowyer's recommended range? Sometimes, if the brace height is too low, the string will come off during the shot.
--Mike
Looks like mighty big string loops on that string for a longbow.
I think your problem is the string and not the bow.
Maybe but none of my bows have the loop notches that look so poorly done.
Picture bow6 shows the nocks are not cut at all evenly. Right side being way higher than the left.
It's an optical allusion of having crooked nocks. I have already spoke with the bow owner and without a shadow of a doubt, his brace height was considerably too low when the strings came off and when the string hit the back of his wrist. This is a common mistake with the forward handle bows although I have never ever had anyone tell me that they had issues with their string coming off.
Now I have been wrong before, just not lately! :biglaugh:
This is one of my builds, and while I'm sure it's not perfect, I know what it isn't.
BIgJim
One of the problems in trying to help out folks with various problems is that we seldom know the OPs experience level and almost never have all the facts/information to offer definitive answers. But that doesn't stop us from speculating, filling in the blanks and doing the best we can.
Thanks for straightening it out Big Jim.