Repair to Damaged Outer Serving of Cables Within an Energy Chain

Sounds like whoever originally specified the cables got it wrong - not checking the resistance to oil.

Afraid I can't help with any kind of coating for repair. I think you may be better off in the long run replacing them with oil-resistant types.

I suggest that you contact: KabelSchlepp Hose and Cable Carrier Systems

I have used their products with success over the years. (Not an endorsement)

Oh, and the correct term is sleeving (not serving), I believe.

Good luck.

Has the oils used been changed? Does the oils used meet the manufactures specs?

Over the years I've had problems with these cable chains. Not caused by strain on the cables but to much slack causing the cables to move about in the chain. May be worth a look at.

Changing the wiring every 12 mos may be part of the recommended maintenance...I would contact the manufacturer and check to see if this is so, and if there has been any solutions found to this problem, or better wire or different oil recommended....If you have the brand and model no., we may be able to assist you in establishing contact...

Have you got any dividers in the energy chain? how many cables are in the energy?With most energy chain you can insert dividers that are for segregating cables in the chain and stopping excessive sideways movement it may pay to invest in some of these. With regaurd to a coating for the cable you may be able to use a teflon based dry film lube like Molybond 122L a light coating may give you some protection.

I worked for a printer manufacturer many years ago (daisy wheel printers). We found that the carriage cable (in this case, a flat multi-conductor cable) would self-destruct after many passes because of fillers in the insulation. The more filler (Talc powder IIRC), the quicker the insulation would flake off.

Only wires with pure Teflon insulation would survive our tests.

It is possible your supplier has changed cable suppliers or specifications in an effort to reduce costs.

Just a thought.

Thanks Everybody,

You all came back with some very good advice and I really appreciate that. As with most problems there is a story behind the story and I will try and elaborate a bit on the history of this problem by answers to some of the queries raised in the replies. -

JohnDG & mrhemus- Original spec wrong: the design of control cabling for use in applications like this is quite complex having to address many factors including flexibility, resistance to damage by oils or other chemicals etc. These cables are the original spec cables supplied with the machines which come from a reputable German knitting machine company who have been in this business for more than 50 years. I know that they outsource the cable design to a company that specialises in this type of thing and also that the cables are designed specifically for this application plus there are different designs according to the various models of machine.

I have been involved in this industry for over 20 years now and have noticed a change in the material used for the outer serving (sleeving) from the original rubber like serving to the more recent harder 'plastic' serving which is the part which is breaking up. The original rubber servings (20 years ago) also reacted badly to the oils and used to get hard which probably prompted the change.

Thinking now I'm wondering if this problem could not be made a lot worse because of a reaction between dissimilar materials used for the outer serving and the inner serving?

Solar Eagle- Contact manufacturer: We have been in close contact with the manufacturer regarding this problem and their solution is renew the cables. This is the ideal solution however based on a) our exchange rate against the Euro b) the fact that the knitting industry in SA is under threat plus c) apart from the problem with the outer serving there is nothing wrong with the cables (this is basically preventative maintence meant to extend the life of the cables).

Ozzb - Oil changed: the type of needle lube-oil is the standard used throughout the industry for this application - high quality 'Kluber' (German) oil as recommended by virtually all manufacturers of knitting machines. There are some factories that have tried to use cheaper oils but these are in the minority.

Redfred, Grouchy & TonyS - Abrasion and slack in cable: the abrasion mentioned was referring to the use of silicon sleeving (silicon handles heat well but not abrasion). These cables are installed correctly in the 'energy chain' with separators installed and the cables run straight.

Lyn - Referral: thanks for the referral which I will follow up. Just a note here - the 'energy train' (cable transport system) being used on these machines is a very high quality system and is not causing the damage to the cables.

Thanks for the replies so far and I appreciate the fact that some of the 'CR4 brains trust' have taken the trouble to help with this problem - I would score everybody with a 'Good Answer'. I really look forward to finding a solution to this problem.

Thanks, Keith

Hello

Some issues are pretty well to understand. Most plastic materials as such are stiff, hard and brittle, only softener molecuels will make them soft and bendable. Nearly all plastic used for the exterior packaging of cables will loose the "softer" chemicals in the long run. I remember that ages ago I was trainee in a big German electro company, I was assigned to a QC dept. We tested cables for the performanc under heat by softly pressing a short length of the cable on a highly polished metal plate, expose them for one week to heat of 80deg.C and analyse one week later the impact to the polished surface. Only teflon did not leave visible marks. At that time we tested different material from wellknown makers. The final decision which cable to use was only based on the extend of the marks of the softener on the polished surface. And I can imagine that the fast movement on a knitting machine is accellerating the process as the energy of the quick moving is also stress on the outer sleving of the cable.

Against this only a regular exchange of the cables will help. In the a.m. case the system finally was designed that on both ends of the energy chain connectors were installed and the connecting cable was an assembly with connectors on both sides - so an exchange was quickly possible. The cost were acceptable as in this case the cable was mission critical.

Against the impact to the oil I would try to put a teflon foil into the energy chain, insert the cables over it and wrap the foil over them - if this is possible. Once I saw a nice material for this purpose which was delivered on a roll and had something like an endless zipper to close the wrap (like ZipLock kitchen bags). It was used to protect the cables from hydraulic fluid of cables also running on the same energy chain. The Zipper required a special tool to close and as I learned - should survive the motion on the energy rail. But I really can't remember the maker or brand name - I think it came from the hydraulics side of the game. Might be worth to investigate and run a trial.

Two strips of nylon reinforced black polypropylene sheet cut 3-4 times the width of the energy chain. One laid above and one laid below, then sealed at the sides with strips of Velcro, creating an envelope that encloses the whole energy chain. This protects all the cables in the chain from oil and UV but still gives you access. If it solves the problem, you have identified oil or UV as the cause. If it does not, it was a low cost test eliminating oil and UV.

The culprit is "heat generation". Thus, if heat can be disspiated somehow....things may work out. There is be a solution which wont involve too much capital investment and is worth giving a try. You can arrange a fan with a pedestal (stand) and high rpm to be installed infront/behind/suitably near the machine and keep it on running at ful speed whenevr the machine is working. If the fan can rotate swinging the air radially, it would be even better. The concept is that the inrush of air would dissipaite the heat and might also evaporate the lube oil. I think this might work, though I dont have any hands on experience.

The manufacturer reckons its normal and you just have to replace the cables.

Seems they consider it a component subject to wear with a finite service life. You, on the other hand, need to prolong that life.

Have you considered using spiral wrap tubing over the cables to protect them and possibly prolong their life or utility?

This can be applied without removing the terminations.

Unfortunately, suppliers change their way of doing things and don't necessarily inform the customer. I was using IC probes in an environmental chamber and then after ordering the same ones, they fell off.

The manufacturer changed the way they attached the insulator to the probe body. They switched from spot weld to 60/40 solder. They continued to use Sn96 for the probe needles.

They could not make them anymore with the old process. The process was decomishioned. They were able to accomodate by making the attachment with Sn96.

They never did get the fact that they left flux remnants in their process. I still had to pre-process their products for our end in-house use by boiling them in baking soda and water, drying and doing an electroless gold plate.

They would not plate the solder because it would contaminate their bath.

I could, and did, unsolder their probes, clean and re-attach with Sn96 but I did have to make a jig to do so.

Their change did not affect 99% of their customer base, but it affected me. Fortunately we didn't use many of their probes.

They were designed for use with a probe card and I designed a magnetic base with adjustable height for them. The first design was very crude. As the design got refined it became fairly elegant and simple tooling had to be created to machine the parts.

A low-profile version was necessary with a higher magnetic strength later and that was a little tough. The regular design was upgraded to the higher magnetic strength design, but it was incompatible with high temperatures. In the high temp design a mechanical means of holding the probes was designed as well.

I would agree with the exploration of a Teflon insulation and to investigate the suppliers changes of the part to to the OEM.

As an alternate possibility, consider putting the current wire so that it contacts a Teflon or even Delrin roller or hole. There are track-like supports too.

Don't really have anything to contribute here except a massive huge thumbs up to all the responders here! THIS is the way CR4 is supposed to work!!!

Good on ya guys.

Hi Yusef1,

I agree 100% with your comment - CR4 working like this is absolutely awesome!

I was so impressed with the quantity and quality of the responses that I got to my question and this demonstrated the depth of knowledge and experience available on CR4. What was also very impressive was that all the responses showed that a lot of thought was put into the answers and I was given the benefit of some very clever and experienced peoples knowledge. For this I say a big THANK YOU!

As far as the problem with the cables goes - I am going to follow up on all the suggestions and recommendations and will keep everybody updated on the results.

Great work everybody - you are what makes CR4 Rock!

Regards, Keith

Does your factory have a hose knitting machine?

If so, you could knit a sock for the harness.

If you are looking for a quick fix whilst you evaluate a more permanent option you could try this site.

http://www.techflex.co.nz/general-purpose.html

They offer lots of different quick application "sleeving methods"

Good luck