Why many cables are constructed of 7 cores with 7 strands ?

[DrWhoF]

Magic 7

Why many cables are constructed of 7 cores and each core has 7 strands?
Is it because 7 is a lucky number?

DrWho

 

[echo47]

Magic 7

Grab a handful of equal-size round coins. Try arranging them into a nice compact pattern. How many coins did you use?

 

[IanP]

Re: Magic 7

Arguably, I would say that in this case 6 is the magic number ..
Stranding is based on the recognition that for circles of equal diameter, 6 will almost exactly fill the space around 1; next, one can see, that 12 fill the space around 6, 18 around 12, and so on ..
So, one needs to add 6 to the number in the outer ring each time to fill the next ring ..

Regards,
IanP

 

[GonzoEngineer]

Re: Magic 7

Seven strand planetary stranders are much cheaper.