apex7 problem

[jmarlowe]

I have a new apex 7 and had been shooting it for two weeks now and it shot good however, when i inspected the string and cables i noticed that the cam is eating-up the serving in my cable and the string was already exposed so I stop shooting the bow. Is this a common problem with apex7 or it is only my bow that is having it? Any advise from apex7 shooters or from any mathews technical staff... thanks...

[New Tricks]

Very common problem to the extent of being what I would class as a design flaw. Take the worn cable off and reserve it with the toughest serving you can get. I served mine two days after getting it and it is pretty much unworn 4 months later. Not shooting it is a good idea as you WILL break strands.

This problem is so pronounced, we got a brand new Apex not the 7 but the same cam, which had never shot an arrow but only drwn as it was shelf stock and took a look and it too already had wear showing. If you look close up at the cam, you can see where it wears and Mathews know this obviously as they have added a little bit of rounding to try and alleviate the problem. The wear is much worse on the shorter ATA Apex 7 as due to the roller cable guide, the cable runs at a steeper angle over the edge that does the wearing.

If you get 'custom' strings like winners choice or Vapor Trail, make sure you reserve the same part on them as the cam will eat them for breakfast particularly Winners Choice as the serving on them is like dental floss.

In summary. Yes, it is a known common problem. Don't shoot it. Go and get it served ASAP.

Good bow though so don't let this little problem put you off it.

[OldDog]

Rad Rhoid is right on the rissole. The stock cuda strings are about as junky a string as i have ever seen in archery. Mine lasted all of 4 days before it chopped through at the cam and then came undone at the roller guard as well. (unheard of prior to the cuda string)
I replaced mine with vapor trail and havnt had a problem since. Me thinx the diameter of the string has a bearing as well.

[apexrob]

Yep, this is a problem everyone is facing no matter what kind of string you put on. I have found 28 strand cables will wear quicker, then 24 strand cables. I also found DiamondBack .018 wound super duper tight also helps.

[krisfarm]

Mathews Apex/Apex7 Cable wear problem.
11th April 06

Soon after buying an Apex bow I found that the cable wear was extreme, within 200 shots my original cable showed signs of scuffing. This soon progressed and a strand wore through before I had shot 1000 shots. I tried different serving materials and tensions to extend the cable life and did achieve a limited success. However none of the trial servings achieved what I considered a satisfactory life.
After my last cable serving started to rub through, I decided to remove the cam from my bow and get to the cause of this problem. I originally thought that the cable was failing due to a combination of the tight curve that the cable takes leading on to the flat section that acts as a draw stop and the angle that the cable is forced to follow caused by tension from the roller guard and cam angle. Upon close inspection this is not the cause. The abrasion is caused by a combination of ballistic bouncing of the cable upon release and the large rectangular shaped lightening hole that is adjacent to the cable track just before the bend leading on to the draw length stop wall section of the cam.
When we release the arrow there is a difference in speed that the string, cable and limbs achieve before they reach brace height and achieve brace height tension, this allows the cable and string to move around quite a bit as they have little tension on them. We have all seen the high speed video shots of bow string behaviour. The cable bounces up and down a lot of times each time we release as well. As the cable has quite an amount of side tension, due to the roller guard pulling on it, Newton

[Marcus]

Rad Rhoid is right on the rissole. The stock cuda strings are about as junky a string as i have ever seen in archery. Mine lasted all of 4 days before it chopped through at the cam and then came undone at the roller guard as well. (unheard of prior to the cuda string)
I replaced mine with vapor trail and havnt had a problem since. Me thinx the diameter of the string has a bearing as well.That's the experiance I had with my switchback (in my review I wrote this time last year)
The Barracuda string didn't even last the Nationals before I had chopped through most of the serving. This is not isolated to the Apex

[No eye deer]

Yep, I got 5 months out of my VT string.Not a lot of shots,but a few.I took the cable off yesterday,pulled off the chewed serving, and found a broken strand and 3 nearly broken strands.
I put on the original Barracuda till my new VT cable arrives.

Mark

[apexrob]

I noticed that there was a small burr around the hole that is cross drilled through to the axle. The cable actually runs over it . I deburred this with a heavy 45 deg chamfer, made a new cable , and relised after 100 shots this was not the problem. My opinion is that the machined angle near the draw stop is causing the wear. Iam so over it, my Apex 7 is constantly in the press at the moment trying to work it out. I've found 24 strand cables are lasting the longest served with diamond back .018.

[krisfarm]

Apexrob.
Try my solution described in my earlier message,I am sure you will solve your problem.

Bob Rawlins

[apexrob]

Yeah , I'm re-serving mine tonight i'll let you know how it goes

[New Tricks]

You party animal rob. Serving strings on a Friday. Next thing you will be posting on the internet. Oh..wait..

[beetle]

Me thinx the diameter of the string has a bearing as well.

Yer. My 'cuda cable dosesn't even have a circular cross-section. It appears to have been twisted up and then simply folded in half and then served without trying to mesh the two halves into one. The miss-shapen result must cause all kinds of wriggling as the cable smacks over the cam. A bit of fore-thought would have prevented this. Curiously, the spare 'cuda cable I've got looks to have a much better shape.

Anyhoo, I've simply re-served the in-use cable with ultra-tight 0.018 Diamondback. Time will tell.

[apexrob]

Next thing you will be posting on the internet. Oh..wait.. :o

[apexrob]

[quote=krisfarm]Mathews Apex/Apex7 Cable wear problem.
11th April 06

Soon after buying an Apex bow I found that the cable wear was extreme, within 200 shots my original cable showed signs of scuffing. This soon progressed and a strand wore through before I had shot 1000 shots. I tried different serving materials and tensions to extend the cable life and did achieve a limited success. However none of the trial servings achieved what I considered a satisfactory life.
After my last cable serving started to rub through, I decided to remove the cam from my bow and get to the cause of this problem. I originally thought that the cable was failing due to a combination of the tight curve that the cable takes leading on to the flat section that acts as a draw stop and the angle that the cable is forced to follow caused by tension from the roller guard and cam angle. Upon close inspection this is not the cause. The abrasion is caused by a combination of ballistic bouncing of the cable upon release and the large rectangular shaped lightening hole that is adjacent to the cable track just before the bend leading on to the draw length stop wall section of the cam.
When we release the arrow there is a difference in speed that the string, cable and limbs achieve before they reach brace height and achieve brace height tension, this allows the cable and string to move around quite a bit as they have little tension on them. We have all seen the high speed video shots of bow string behaviour. The cable bounces up and down a lot of times each time we release as well. As the cable has quite an amount of side tension, due to the roller guard pulling on it, Newton

[krisfarm]

Apexrob
Nice to hear that you have your cable problem solved.The original cable on my Apex was 30 strands which was served for a short length this made the string way to thick for the cam groove and resulted in the string being deformed to fit the cam groove- a bad idea.It only lasted a very short time.Why Mathews made this cable this thick we will probably never know as they do not respond to emails sent to them.I make my cable out of 16 strands of BCY 450 Plus and serve tightly with 3D serving and it fits the cam groove perfectly and keeps the cable nice and round for maximum strength. I think Mathews should eliminate the oblong lightening hole which would help.My cable has around 3000 shots on it now and still showing no scuffing.Thanks for the feedback.
Regards Bob Rawlins

[StuNVA]

[quote=krisfarm]Mathews Apex/Apex7 Cable wear problem.
11th April 06

Soon after buying an Apex bow I found that the cable wear was extreme, within 200 shots my original cable showed signs of scuffing. This soon progressed and a strand wore through before I had shot 1000 shots. I tried different serving materials and tensions to extend the cable life and did achieve a limited success. However none of the trial servings achieved what I considered a satisfactory life.
After my last cable serving started to rub through, I decided to remove the cam from my bow and get to the cause of this problem. I originally thought that the cable was failing due to a combination of the tight curve that the cable takes leading on to the flat section that acts as a draw stop and the angle that the cable is forced to follow caused by tension from the roller guard and cam angle. Upon close inspection this is not the cause. The abrasion is caused by a combination of ballistic bouncing of the cable upon release and the large rectangular shaped lightening hole that is adjacent to the cable track just before the bend leading on to the draw length stop wall section of the cam.
When we release the arrow there is a difference in speed that the string, cable and limbs achieve before they reach brace height and achieve brace height tension, this allows the cable and string to move around quite a bit as they have little tension on them. We have all seen the high speed video shots of bow string behaviour. The cable bounces up and down a lot of times each time we release as well. As the cable has quite an amount of side tension, due to the roller guard pulling on it, Newton

[Jbird]

It would be a great help if you could post a picture here so we can all see how to do it.
Thanks,
Jbird

[apexrob]

I'll try and post something soon guys!

[krisfarm]

StuNVA/Jbird

When I wrote the original article on this problem I did have a picture included showing details,unfortunately Archery Forum would not accept it direct from myself. To identify the problem area if you lay your bow on its side with the cable side of the cam pointing upwards then follow the path of the cable starting from the attach peg on the cam,approximately 90 mm from the peg you will see a rectangular shaped hole with rounded corners.This hole is almost on the bend that the cable takes to reach the draw stop and is the one that chews the cable.You have to end your serving just short of the start of this hole .Hope this helps.Apexrob will hopefully add a photo to help.
Regards Bob Rawlins

[StuNVA]

So your saying not to serve the cable that will rest against the draw stop groove in the cam ?

If this doesnt fix the problem straight up then the cable would have no protection at all and be cut to bits in no time ???. :o

I was thinking about a 452X 16 strand cable with 2D serving, but I'm having trouble convincing myself to finish serving prior to the current ware spot ?

[OldDog]

stu dude there are plenty who have shot thousands of arrows through these bows.
The advice you have been given is sage. To date it is the only thing that has worked.
Give it a burl, you will be surprised.

[2Dogs]

you will be surprised.

You sure will, when your string snaps at full draw

:rofl:

[StuNVA]

I'm getting a 452X cable made served as above to try next week, I'll chop it to bits instead of the VT cable, if it works I'll reserve the VT cable to suit.
I'm still wondering why the hole is even there the cam is waffer thin at that point anyway I cant see any advantage in the hole being there anyway, unless they envisaged more ware would happen with the cable rubbing on the cam itself ?

I'll let you's know when / if the trial cable snaps or wares next week.

[dbjac]

Is it possible to cover/fill in the hole? I say this without ever having looked an Apex 7, so be gentle :oops:

[beetle]

Is it possible to cover/fill in the hole?


Yes..sort of. I saw a different approach to this isssue at Manly. A small piece of duct tape was covering the hole. Seemed to be doing the job.

[dbjac]

well that would seem too easy to actually fix the problem... what's the catch... :-?

[beetle]

well that would seem too easy to actually fix the problem... what's the catch... :-?

Dunno. But I'm going to try it. Nothing to lose, eh? :D

[beetle]

I tried the duct tape fix today. I installed a brand new Barracuda cable first (for a good baseline). I applied the tape and shot about 80 arrows. It's way too early to tell, and I expect to have to shoot a few hundred arrows before I know anything. I tried taking a pic of the cable but the serving is too reflective for the flash. The cable looks like you'd expect - a slight discolouration and deformation where it bends over the cam, plus flattening of the serving material itself. No separation yet and no scuffing. Wait & see.

here's the 'fix'

http://members.iinet.net.au/~mxb/A7_cam.jpg

[Patchy]

couldnt you just debur the problem?

[Marcus]

This is a great thread, thanks everyone, good info.

[beetle]

couldnt you just debur the problem?

The hole doesn't have burrs. It's just happens to be razor sharp around it's entire edge due to how thin material of the cam is at that point. Actually, the hole isn't necessary. As previously mentioned, the amount of weight saved by machining this hole is negligible.

[Jbird]

My latest A7 came with the new powder coated cam on it. The buss cable serving separated after less than 200 shots. I took the cable off and reserved it with BCY .018 62XS with the cable under a lot of tension. Have shot the bow about 600 shots and so far no scuffing and no cable separation. We'll see how this holds up. One thing I am sure of is that the gray serving that comes stock on the buss cable is junk.
Jbird

[StuNVA]

Just shot a 14 Target field round with the hole covered with duct tape and noticed no increase in scuffing, it might just be that simple.

[dbjac]

wow, that was pretty simple then... and a lot cheaper than new cables every thousand shots... :-?

[krisfarm]

StuNVA
Placing a piece of duct tape over the hole will give tempory protection but if it rains and gets wet it could fall off. My Apex cable has now shot over 3500 shots with no sign of scuffing. The cable does not need to be served at the draw stop position as no wear occurs in this area and the cable should not break provided there are no burrs or sharp edges.Serve a cable as per my original post and you should have the problem solved with a more permanent fix than duct tape.
Bob Rawlins

[beetle]

This pic was taken after approx 160 arrows. You can see the usual flattening and slight separation of ther serving that you would expect due to the cable bending over the cam, but so far it hasn't got damaged. I would think that at least another 300 arrows will be needed before I would consider this a success, but so far it is quite promising. It's not as elegant as krisfarm's fix but that's not why I'm trying this.

http://members.iinet.net.au/~mxb/A7_cable1.jpg


http://members.iinet.net.au/~mxb/A7_cable2.jpg

[StuNVA]

http://forums.mathewsinc.com/viewtopic.php?t=32701&postdays=0&postorder=asc&&start=25

This is basicaly the same thread on the Mathews forum, it appears the tech guys at Mathews have finally (well maybe) acknowledge it's worth looking at, if anyone has pics of the cable ware post them on that forum or email them to me on sdolbel@bigpond.net.au and I'll post them on it. Would really like to see a "Mathews" fix made public on this matter.

[Marcus]

I complained about this issue last year with a Switchback.
I shot teh Nats with one and within a few hundred shot the cable was worn through the serving totally.
I got the bow back from the customer who had bought it and reserved it, and put tape (clear) around the cam area. After a few hundred shots there is no sign of wear.

[jmarlowe]

Go to the mathews forum at the archery tech portion... you will find out that the mathews technical people are as confused like anyone of us regarding the problem and my most interesting observation is that, it seem they don't want to acknowledge the problem and come out with a mathews solution...

[Patchy]

All they have to do Is turn out the cams without the effecting holes on both the apex cam and cobra cams.

[StuNVA]

Shot a full IFAA field and 1/2 hunter today (dont ask the scores I'd rather forget them). plus practise shots, duct tape is still good and cable looks fine.

[Patchy]

I know the tape thing works, and it looks like Mathews isnt going to do much to solve the problem but what if you shim the roller guard out? this would get the cabble away from those stupid little holes a mm or so

[krisfarm]

Patchy,
The problem that causes the cable wear is the amount of bouncing the cable does on the cam every time you shoot.The cable is loaded and unloaded quite a few times with every shot.The large rectangular hole in the cam is big enough to let the cable engage in it during this bouncing. My solution of ending the serving just short of this hole gives the unserved part of the cable just enough clearance to avoid entering the cam hole. The masking tape does a similar job but is not as permanent a solution.To shim out the roller guard would not provide sufficient clearance.One of my cams actually angles away from the cable (there is quite a tolerance in stock Mathews cams) and it gets chewed just as much as the others.Mathews should never have made this cam with this hole in this location.I am sure they are aware of the problem,but choose to ignore it.
Regards Bob Rawlins

[OldDog]

News Flash!!! the prob may not be as first thought. Mathews techs looked at the prob in slowmo and it would appear that the cable actually vibrates on the corner of the cable track rather than the hole.
Same prob and same fix tho. :o

[StuNVA]

Curious to as how the duct tape has an impact if it's all cable groove ware Old Dog ?? When I first saw it I thought it was not retracting evenly into the groove where the sharp curve is into the draw stop, but the duct tape fixes it, how could it if the groove is the problem.

[beetle]

Now with over 300 arrows and still no abnormal wear.

:D

[Bobmuley]

I've sent mine back to the factory for "observation" since they couldn't find any bows with this particular problem. So I'll let you know if they find anything out.

I did a lipstick test on mine and the worst rubbing appears to occur on the draw cycle, moreso than the shot cycle. The worst rub was at the very small step on the inside of the cable groove (between the rectangular hole and the bend in the cable track).

I'll let you know how it turns out in Sparta.

[beetle]

Another 80 arrows. Still looks good. I knew I liked duct tape. :D

[dbjac]

that has to be the cheapest fix ever. maybe we should patent it?

[StuNVA]

I reserved the cable with 3D the other day but the diamondback I used as an emergency patch was not frayed at all just seperating where it goes over the hump no mark or anything else on the cable. I must have been up around 2500-3000 arrows.

I'll stick with the duct tape until they send us all new cams..............yeah right.

[stejac]

Hi Guys,

Have been put on to this thread by dbjac.

My thoughts are that the hole you think of as a lightning hole is actually required by the machining process to manufacture the cams.

Looking at the way the cams would have to be machined I think the holes are used so the cam blanks can be secured (by dowel pins) for the CNC routing/Milling machine to profile the cams.

If that is the case then it might be possible to machine up a plug for the hole and loktite it in position. hole goes away ....problem fixed ???? maybe!

Cheers Steve

[krisfarm]

I had a good look a a new cam that Mathews are fitting to the Apex line of bows.The cams are not anodised like the originals but finished with a plastic type of finish that helps round all of the edges.The retangular hole that has been cutting the cable is still on the cam but has been moved further away from the cable groove and its angle of orientation in relation to the cable has been changed also.Lets hope this fixes the cable wear problem.I also noiced that the cam is no longer fitted with two bearings,it has one bearing and one "plastic" bush. This could be an improvement as the original bearings were a loose fit on the axel anyway and therefore only worked as a bush.My cable served as per my original post has now shot 4500 shots and is still OK.
Bob Rawlins

[apexrob]

Here is my Apex 7 cable after 3500+ shots. I've found a new material to use on this section and with correct application it's working great. I'm not using the powdercoated cam or duct tape. Results are no seperation, minimal wear.

http://img443.imageshack.us/img443/892/cable2ay7.jpg (http://imageshack.us)


http://img518.imageshack.us/img518/1615/cable1dr1.jpg (http://imageshack.us)
http://img518.imageshack.us/img518/1615/cable1dr1.47d73c2399.jpg (http://g.imageshack.us/g.php?h=518&i=cable1dr1.jpg)

I have now used the same stuff on 9 of my customers Mathews ranging from Apex, Apex 7, Con4 , Ovation and Con 3 and the feedback has been great.

Keep in mind correct setup of the bow is required, as untuned bows do wear strings and cables out alot quicker then a tuned bow.

I'm selling these cables seperate for $45 each.

[GuyDawg9]

yeah since i put my new string on i have had no wear so far rob.... keep it up

[beetle]

Nice work apexrob. :thumb:

[pyroarch57]

The serving wear is due to the fact that the cam radius is having a pushing/dragging effect on the cable when drawn, also the diameter of the cable has a bearing on it.
On thicker cables the wear will be more apparent, simply because of the tighter fit in the groove.
I just fitted a new cable (24 strand 452X and 3D serving) i have drawn it up around 30 times without shooting the bow.
The cable is already showing signs of wear around it`s whole circumference where it contacts the bend.
Apex rob has the best solution.

[DKW]

Apex rob has the best solution.

Yes, and It works very well. I've had a string of his now for ~8 months and
the cable is only just starting to show some wear, there is still no sign of
serving separation though. By this tme on my last set of srings (Zabras),
the cable was rat sh't!