Cable worries

Hi Guy's.Trying to get into the Crossbow scene and also trying not spend too much of my pension, I bought, or thought I was buying, one of the 'Venom Taipan' Crossbows. Well, turns out it wasn't a 'Venom Taipan' but something called 'Zhaoshi'and if the name sounds revolting, then one look at this Crossbow will reveal all. I suppose it is the same model as the NCStar, but the finish was really Yuk!. The thing is, I have been using it for about a week and it is not taking to the punishment very well. There seems to be a thin coiled spring wrapped round the compound bow cable. When cocked, the bolt fits into it. I notice that it is wearing very fast and is almost in three pieces. Can this spring be replaced, does anyone know? If not, then the next thing to wear will be the main cable and that would be disastrous. I am hoping that one of the talented membership will know this model and be able to sugest something that I can do to save it from an early death. Many thanks. Regards from Walt.

Walt, I am not sure what you mean. Some photos would be immensely helpful to troubleshoot your problems, and there are generally always solutions to any problem. Could we see what is wearing out? And remember being on a budget doesnt mean you cant have fun.

Hello Stoneagebowyer. Many thanks for your encouraging reply. I was indeed having fun, a great deal of fun, but as I said, the imminent demise of this protective spring wrapped around the main cable, is going to demolish that fast. So I have stopped using the crossbow until I can find a solution. Okay so I have taken a few photographs, some with close ups of the offending item, but now find that I cannot upload them in my reply. Now that really is sad. It seems that there is no provision for doing this, which stuns me as most every forum I know will allow you to slot your pics into the message. Now I am left wondering how I can get you the photo's. Hmmm! How to do it? But many thanks again for being so kind. Regards Walt.

It is not hard, Walt, it may seem cubersome a bit at first, but not hard at all. Open up a free photo web hosting account. I used Photobucket. You upload your photos there, and then it is a snap to post them here. You see the little row of icons above the posting window (which I am typing into right now)? The 7th one from the left looks like a little TV screen or computer monitor screen. Hit that, you will get a little window, and you past the link from the photobucket for that photo into it, and voila, done. If you dont know Photobucket, once you post pictures into that site's album, you can right click it and copy the URL for that photo.

I hope that makes sense. It took me a while to struggle though it, but it really is easy. Ivo, our moderator, probably has a tutorial around here somewhere, and he may help you too. The guy is cool and totally helpful.

All this modern technology...

Hello again Stoneagebowyer. Seems like I managed to get the Photographs into Photobucket okay and got the pics to you.Just hope that you can make some sense out of them and be able to come up with a solution to my problem. Now that would put a smile on my face.



Thank you for all the help you have given me in this. Regards Walt.

That looks like serving thread that is coming loose. Is it a kind of nylon line, or is it more substantial, like plastic covered wire? Don't cut into it to find out!

If it is serving, this is really a simple, inexpensive fix. Serving only serves to protect the bowstring from excessive wear where the bolt / arrow contacts the string, plus where the string rubs against the top surface of the crossbow. I actually just had a string re-served by a bow shop last week, a Horton Scout. With these modern crossbows, you should be applying silicon lubricant regularly to prevent surface wear, which this looks exactly like. You also should get a little tube of lubricant for the bow string itself. They look about the size of little lip balm tubes, and last a long time, and are far cheaper than a broken string.

Any bow shop can do this repair for you. It cost me about $10 for my repair. They offered to do it later that day, but I left it in the shop and it was ready the next day, good as new.

You can attempt to re-serve it yourself, but that means removing the string, having a jig to put a lot of tension on the string, a serving tool and practice to get it right. Paying a small fee to a shop may be a lot easier.

Wait for others to chime in on this, too. Lots of expertise here. But, dont worry, the crossbow is fine, and you will be shooting again soon. And it looks like a nice crossbow, and fun to shoot.

Dane

Hi Dane. Thank you for the swift reply. The serving thread on my Crossbow happens to be a very stiff strong wire, coiled tightly round the string, which happens to be wire cable. At present the cable is undamaged, but I fear that a few more shots will see the serving fall to bits and the cable badly damaged.
I take what you say about letting a gunshop technician have a look at it and maybe effect a repair. But here in Hull we now have no gunshops, apart from one which is in disarray and soon shutting up for good. The owner being very old and infirm. Isn't that just great?
I have toyed with the idea of carefully unravelling the remaining wire from around the cable and maybe wrapping the cable, where it would come in contact with the top surface, but what to wrap it in that could withstand the abrasion that firing the Crossbow would subject it to? Thats the million dollar question Dane. The wire cable rests on the top of the stock and presses down onto it very heavily. It takes force to lift it free, so whatever is wrapped round it is going to take a lot of hammer.
I think I will listen to you and hang fire until others have had a chance to maybe pass on their opinions. Maybe one of the members will have experienced this self same problem. Meanwhile I am so pleased to be a member of this community. I am just starting out and will soon aquire the knowledge I need to be a halfway decent Crossbow user. Again Dane. Many thanks. Regards Walt.

Geezer here checking in on the steel-cable string. While I'm a medieval-bow guy, not an expert on modern pulley-bows, I can say you get what you pay for. Steel cables are heavy, not very flexible, and surprisingly stretchy. You say your cable has oodles of down-pressure on the track... and no doubt that's why the manufacturer opted to go for a steel-spring serving (which adds even more weight) You are NEVER going to get good performance out of that bow unless you can engineer some way to relieve the pressure of the cable on the top of the stock. IF you can do that, you'll be able to replace the steel cable with a modern fiber and serve it with another modern fiber, or even heat-shrink tubing. Short of re-mounting the prod so it works freely, you're stuck with Bad Design.
Then again, I'm just one of the medieval-bow crowd. Maybe some of our modern-bow experts will have more hopeful device. Geezer

Hi Geezer. Kind of you to come in with comments on my problem. I can see where you are coming from and would heartily agree that the cable is coming down too heavy on the rail. I will have a look at it and see if there is any way that it could be lightened, perhaps by engineering the attachment at the front end. I could probably shim the prod to make it tilt slightly, enough to clear the rail, even by a micron or two, but this might alter the flight path of the bolt to a dangerous degree. Its worth looking into though and I will.

No matter what I wrap round the cable, as it stands now, is not going to last more than a couple of shots. That is no good at all. Not whilst I have the metal rail. Another idea would be to remove the metal rail and take it back to the plastic stock, but that would not be such a great idea as the cable, situated as it is, would soon chew the top to pieces. Not only so, but the metal rail is not as I would have designed it. It wraps around the stock and is essential for the rigidity of the whole Crossbow. Take it adrift maybe and get a local engineer to cut the top edge down below the plastic stock top. But that still brings in the wear from the cable.

No I think engineering the prod to angle upwards a couple of mm seems to be the best idea. I will hang on a bit to see if anyone has a better idea, other than binning the thing and starting to save up for something better. Thanks for being so kind and putting some ideas about. Regards Walt.

I would do as you have said and shim the riser (the bracket the limbs are bolted to) to tilt it up. Then reserve the cable or better yet replace the cable with more modern string materials.



Todd

Thirty years ago, my first crossbow was a home-built with aluminum prod, steel cable string with steel spring serving, and aluminum rails on the track. The bow had been used very little before I got it, and after I made just 50 or so shots with it, the spring serving had carved deep grooves into the aluminum rails. Then I had a misfire where the string missed the butt of my arrow, and that steel cable broke in a spectacular fashion. When I got my nerve up again to mess with it again, I smoothed out the rails and mounted a modern fiber string, and even without adjusting the prod angle to reduce the downforce, the improvement in performance was imediately apparent. Good luck with your tinkering, Walt, and happy shooting!

Gnome

Hi Gnome. Thanks a lot for the comment. I have tried shimming the riser. Went up to a whole 1/4 inch and the bow was very unstable, but still that steel cable pressed on the rail. Couldn't leave it like that, far too dangerous, so back to the drawing board. Ended up wrapping the steel cable in insulating tape and first attempt was a bit overdone as it shoved the bolt restraining spring up and the bolt would not stay in. Ha Ha! But trial and error got me sorted out. It will last for a few shots and then then I shall have to renew it.

Think you have the best idea Gnome. Cut the steel cable off and replace it with string, nylon or something else equally durable. The rail is as smooth as glass, that's what bothers me. How can it cut like that? Ah well, maybe as I progress with the Crossbow, things will start to gel. Now, the next thing is what best to replace the steel cable with? Get back to you all when I have it sorted. Thanks to every member for their help. You are the best. Regards Walt.

Walt, my bad for not realizing that entire cable is steel, not nylon such as B50. I do hope you can come up with a solution, as money may be tight. Let us know what transpires as you work through the problems.

Dane

cypher000 wrote:Hi Gnome. Thanks a lot for the comment. I have tried shimming the riser. Went up to a whole 1/4 inch and the bow was very unstable, but still that steel cable pressed on the rail. Couldn't leave it like that, far too dangerous, so back to the drawing board. Ended up wrapping the steel cable in insulating tape and first attempt was a bit overdone as it shoved the bolt restraining spring up and the bolt would not stay in. Ha Ha! But trial and error got me sorted out. It will last for a few shots and then then I shall have to renew it.

Think you have the best idea Gnome. Cut the steel cable off and replace it with string, nylon or something else equally durable. The rail is as smooth as glass, that's what bothers me. How can it cut like that? Ah well, maybe as I progress with the Crossbow, things will start to gel. Now, the next thing is what best to replace the steel cable with? Get back to you all when I have it sorted. Thanks to every member for their help. You are the best. Regards Walt.

maybe a bit late, but how about wrapping a thin peace of rough leather round the string were it slides on the rail? I did this to my first bow because the string whas cutting into my rail. First i wrapped( glued)the whole metal string, it is a steel cable and wanted to make it authentic looking. Glued with epoxy. The leather holds on to the wax more easy and reduced my friction a lot! But it did get a lot thicker. That whas no problem for me, but cant speak for u. this is the only picture i have, ends are not covered with epoxy but u can imagine.

Hi Ferdinand. Many thanks for the input and yes, I think what you have done is a great idea and one which I shall file away for future use. As you know I have tried wrapping the steel cable round with an insulating tape serving. This has stood the friction for a dozen shots, but needs taking off now and renewing. However I have come up with what I think might be a much better idea.

I have ordered a supply of 80tex KEVLAR thread, which is abrasion proof as well as heat proof. It is immensely strong and difficult to cut or break. Its only failing is that strong UV lowers its strength quite a bit. But UV is the least of my worries. I intend making a new serving by wrapping it around the steel cable several times until it is fairly thick, but not thick enough to lift the bolt retaining spring out of its setting. Then what?

I have also ordered some Zardox NotWax, which is pure liquid Teflon. This is a very special lubricant which will even lubricate snowboards and ski's. Guaranteed to last and last and not lose its slipperyness. I think this will lubricate the top of the stock and the slide rail making a frictionless area for the bolt and the steel cable to speed along. The only thing I am not sure about is.....do I lubricate the serving with Zardox or just leave it to the inherent strength and abrasion resistance of the Kevlar? I would appreciate advice on this point. Thanks again for all that you are doing for me and for the advice given. I do so appreciate it. Regards Walt.

Okay, disappointed that no one came along there to help out, so on with the motley, alone.
Okay so I went along with my plans to use Kevlar for the serving over my compound crossbows steel cable. As you will remember, the original spring steel serving, wore through after 20 shots and that was hard to take. How could it be wrecked so swiftly?

Whatever. Off came the remnants of the original steel spring serving and on went a new serving of tightly wound Kevlar. Decided to wind on four layers and seal the loose end with super glue. Looked nice and neat when finished, but what would happen when I got to use it?

You all know the answer. Whereas I got a total of 20 shots out of the steel spring serving, I found that after the same 20 shots, the Kevlar serving showed no wear at all. Today I have taken it through 100 shots and still there is no visible sign of wear and the steel cable beneath is undamaged. I think I have vindicated my decision to use Kevlar instead of anything else.

Thank you for reading this and for sharing with me ( a rank newbie in all things Crossbow) as I try to learn more. Regards to one and all. Walt.

Walt,

Very glad to hear you chose and successfuly implemented an elegant solution! Now I want to obtain some kevlar thread, sounds like interesting stuff to work with.

Gnome

Hi Gnome. Nice to hear from you again. Just checked on Ebay.com and there are some bobbins of Kevlar thread even stronger than what I have used. I used 80tex but I see there is some at 90tex. Going cheap too for 100 yards. Hope it works for you Gnome. Regards. Walt.

Hi Guy's. Must share this with you. You know that in desperation to find a serving that would last and enable me to use my crossbow without incurring damage to the steel cable, I decided to buy and use Kevlar 80tex thread. Well I did and was surprised to find that instead of averaging 20 shots with various inferior servings I got in 100 shots with no signs of damage whatsoever. I just thought that the members would be interested to know that since I wrote that, I have notched up another 100 shots, taking the total to 200 and still there is no sign of wear on that Kevlar serving. On careful inspection, all I could find was two black marks on the underside where the serving seems to have rubbed into the slide rail lubricant. Thats it! I now know that I can have every confidence in the Kevlar for serving my bows steel cable. Thanks for bearing with me guy's, you are all the very best and I am so proud to be a member of this forum. Regards Walt.

Walt, it is fantastic to hear you solved your problems. Happy shooting.

Dane

Thanks Dane. Just thought I would come in here for a quickie and let you know a little more on the Kevlar serving angle. To date I have notched up 432 shots and my Kevlar serving is like it was the day I wound it on. S few black marks where it rubs on the slide and where it rests in the trigger area. Thats it. Guess I shall not be using anything else, it's Kevlar for me from now on. Good hunting guy's. Regards Walt.

Hi Guy's, just couldn't resist coming back and telling you the good news. My Kevlar thread serving has just put me through my 1000th shot. Thats one thousand arrows and the serving is as good as new. Well I just know that no one is going down the Kevlar road, but that is a shame as it is one humdinger of a serving material and I have proved it over and over again. So off I go with the same original Kevlar thread serving, maybe for another 1000 shots, who knows. Best regards to one and all. Walt.

That is good to know and thanks for sharing with us all. Will have to try on future projects.



Todd