Joining Metal Cable

[pdybeck]

I have an interesting design problem and was hoping someone out there would have a suggestion or experience in joining metal cable. I understand there are many cable clamps and crimps available to join cable, but the cable in this design regularly rides over a pulley with a somewhat small diameter. This causes a high stress concentration around the device used to clamp the cables together and ultimately the cable fatigues right at the interface between the cable and clamp because the clamping device is to rigid to bend around the pulley in the manner that the cables do. Numerous methods have been tried to reduce this stress on the cable because of this phenomenon - including different clamp types, trying to blend the cables and clamps together, trying to weave the cables together etc. - all to no avail. The pulley size is fixed and cannot be increased in size as the larger radius of curvature would provide a lower stress in this interface. Does anyone know of some good methods to join cable to avoid this problem? I hope I have explained the situation well enough. Please post if you need more info.

The pessimist says the glass is half empty. The optimist says the glass is half full. The engineer says the glass is twice as big as it needs to be.

 

[MadMango]

Why can't you increase the length of one part of the cable so the clamp/connection does not interface with the pulley?

If you've already tried various clamps, crimps and weaves, i can't offer anything beyond this. or perhaps you could change your cable material to some form of plastic or teflon cable?

MadMango
"Probable impossibilities are to be preferred to improbable possibilities."
Have you read faq731-376 to make the best use of Eng-Tips Forums?

 

[GregLocock]

If this is a steel cable you are going to find this very hard, but it is possible to splice them. Perhaps it would be wise to do a two part splice, steel to (say) kevlar to steel. This will reduce the rigid length of the splice.

Talk to the cable manufacturer - they often have experience with terminations.



Cheers

Greg Locock

 

[MadMango]

Thanks for the inadvertant correction Greg, I meant "kevlar" above instead of "teflon".

MadMango
"Probable impossibilities are to be preferred to improbable possibilities."
Have you read faq731-376 to make the best use of Eng-Tips Forums?

 

[MechEng13]

What about the possibility of welding the cable ends together. Working in the wire and cable industry in my prior job we would join 2 ends together by welding. Now of course this was copper or Tin Coated copper, but I would think you could weld steel cable together as well. It leaves a rather small rigid area if done properly. Like Greg said I would contact the cable manufacturer.



Alan M. Etzkorn
Manufacturing Engineer
Hoffco/Comet Industries Inc.

http://www.hoffcocomet.com