Exomax String Damage

[mechanical_nightmare]

Hello,

I own an Exomax that I purchased back in 2009. It was fired probably about 10 times until last month, when I completed a homebrew target for it. Since then I took probably 50-60 shots through it, and I've been doing some pretty tight groups from 60 meters with Excalibur FireBolts.

Recently I purchased Chinese-made aluminum arrows that have half-moon nocks. I know you are not supposed to fire these out of the Exomax, but when I read about some members firing many of them without issues I decided to go for it.

I fired 5 of them and the accuracy was pretty bad. I switched back to carbon and got the same tight groups, but halfway through, I noticed that two strands on my string had snapped. I stopped shooting immediately and inspected the limbs for damage as well, but there was none. There is no way this was a dry-fire, as all the arrows were launched 60 meters, striking the target violently and sinking deep into the compressed cardboard

Is it possible that the string simply deteriorated over time, even while unstrung for a few years? I have replacement strings on the way.

From that I understand half-moon nocks are OK to use as long as the string lines up and is flush with the nock.

[Fandex]

Hi
I'm not a crossbow expert, but i read somewhere that halfmoon knocks may damage the string if not exactly engaged. And if you post a picture, we (i mean everyone who is reading your message) can see exactly where the damage is and give an advice (for exemple, if you have REDS or other stuff on your bow...).
I had too a string issue (one brand was damaged, i don't know why, but i can still continue to shoot and have an eagle eye on it).

[Kegbelly]

Hi, welcome to the forum! I've shot a few moon nocks that were given to me from my Exo. Accuracy was bad so I only shot them a couple times, just more or less wanted to see how they did. In general I wouldn't advise it.
The string is designed to ride against the top of the rail during a shot, and the flat inserts allow the string to do that and still make solid contact with the rear insert. With a moon nock, the center of the groove in the nock *could* sit above the rail somewhat and there's a chance the string can lose solid contact with the nock and there's a chance of a partial dry-fire. The larger diameter the arrow, the higher the groove will be off the rail. Also, a larger diameter string will be centered against the rear insert better than a skinny string. You said you don't think you had a dry-fire, so it could be just a coincidence that a couple strands broke when you were shooting the moon nocks, I can't really say. Could be just an old string that got weak with age. If it were me I'd toss that string. And stick with flat nocks in the future

[strum]

Don't care for the mood nocks either but Im betting the string is past its shelf life. put the new string on it an shoot away.
welcome to the forum.. pull up a chair and hang out a while

[vixenmaster]

2 things stand out on yer post. String is gettin age on it & mayhave dried out some from the wax. The other is moon nocks are not good on yer string wid high poundage models. Every one i have seen has shaper edges than i would allow to hit my string wid that force

[mechanical_nightmare]

Thanks everyone for the prompt replies. I agree that the string was getting a bit too old. Also, is there a way I can reliably cut off / abrade the half-moon nocks to a flat surface?

I have a bench grinder, dremel, and many other tools at my disposal but no arrow saw unfortunately. The archery shop I got them from are hustlers and they would probably charge me for it; if I absolutely have to use an arrow saw though I will get it done.

As for pics of the damage, I will put them up as soon as possible. Btw, what does REDS mean?

I was excited when I found these arrows for cheap but you get what you pay for. I am now planning on importing a good amount of quality arrows (and broadheads) from the US, and once I feel confident enough I will hopefully go after some wild boar!

[Kegbelly]

I may be wrong but I don't think it's a good idea to grind the moon nocks down, that would probably make them even weaker and subject to breaking when shot. You might be better off to replace them with flat nocks if you can find the right size for your shafts.
The REDS are an accessory to fit the Matrix bows. It's a string stopper system with rubber bumpers. For an Exomax you would need the S5 system:
http://www.excaliburcrossbow.com/
catalog/crossbow/s5_string_shock_sound_suppression_system

[Hi5]

......................I am now planning on importing a good amount of quality arrows (and broadheads) from the US, and once I feel confident enough I will hopefully go after some wild boar!

Where do you call home? There are custom string and arrow makers that make product in Canada? Or, are you living farther away?

[paulaboutform]

Honestly, nocks are some of the least expensive things you can buy. Stop fooling with ideas of cutting or grinding moon nocks and just get some proper nocks and/or arrows. Sorry, but that's my opinion. Sometimes looking for that great 'DEAL' just ends up costing you more $$$ plus sub standard products. Personally, I do my best to avoid anything from China, not seek them out.

[xcaliber]

I would be happy to send you a string on me, the flat nocks I do not have!

[hankenhunter]

Welcome to the forum family. If you need, I have some extra aluminum flat nocks I could spare. No charge. Ditch the old string and take up xcaliburs offer of a new string. He is a good stringmaker with a heart of gold, like most of the fine folks on this forum. Where do you hail from btw? Happy shootin,
Hank

[Horizontal Hunter]

As others have said get a new string, or better yet get two so you have a spare.

As far as the arrows go the best thing you can do for your crossbow and your accuracy is to toss them in the trash and get the right arrows for your crossbow. Do you know how much they weigh and if they meet the minimum weight requirement for your Exomax? If they are underweight it is the same as a partial dry-fire and can damage the limbs.

I build my own Gold Tip Laser II's for about $6.00 an arrow. They are not the best arrow but are more than up to the task and will shoot well out of your Exomax as well.

Bob

[mechanical_nightmare]

Hello!

Sorry for the late reply everyone... I am located in Turkey. I did not see some of the replies until now, when it was much too late, but I got 2 new excel strings, and 1 flemish string. I no longer use the cheap Chinese arrows.

Thank you hankenhunter and xcaliber, I will get in touch with you regarding the nocks. The only reason I got Chinese-made arrows was because that is what's available here (along with Chinese crossbows).

This evening I was shooting my crossbow and the same damage took place, on my new string but while using Excalibur firebolts.

Here are some pics:



This is similar to the damage that took place with the Chinese arrows, except that only 1 strand of the string snapped. Thankfully I have additional spare strings. But this whole thing makes me uneasy of shooting my Exomax. Will I have to replace a 30 dollar string every 100 shots or so?



No dry-fire events took place.. All arrows fired straight into the red dot (about 7 inches wide, from 60 meters)

I consider myself a newbie in the crossbow game, so any advice would be much appreciated. Is this normal wear-and-tear for an excel string? Can I just pull out the strand and keep using it?

[VixChix]

Your brace height seems quite low (it's resting fairly close to the riser) - there aren't many twists on your string causing excess strain on the individual strands.

I would start with a fresh string and use a higher brace height - that would give the string more twists and more strength.

The string will stretch as you shoot so for the first while you'll have to regularly add more twists to the string until it settles in.

[maine hunter]

Your brace height seems quite low (it's resting fairly close to the riser) - there aren't many twists on your string causing excess strain on the individual strands.

I would start with a fresh string and use a higher brace height - that would give the string more twists and more strength.

The string will stretch as you shoot so for the first while you'll have to regularly add more twists to the string until it settles in.

Same thing I saw, need more twists in your string. Should help a lot.