Carbon rods, Traxxas 5347 Ball Joints and a jig

Some of the critical components for linear delta 3D printer are the diagonal rods and the joints used for them.
As of January 2015 there are two "mainstream" solutions that are recognized as "working reasonably well":

1. Carbon fiber rods with Traxxas 5347 ball joints and possibly some kind of grub screw to join these, as well as epoxy glue to hold everything together.
2. Carbon fiber rods and steel balls with magnetic joints. Again, epoxy glue seems to be the preferred method to hold everything together.

I have already discarded wood, steel, aluminum and printed rods. Carbon fiber rods are easy to find worldwide, are relatively affordable even here in Barcelona and of course the weight to strength ratio is unmatched. The only caveat is that special precautions must be taken if one is cutting carbon fiber rods oneself. Dust from carbon fiber is extremely dangerous to the skin, eyes and lungs. I have found online relatively affordable pre-cut carbon fiber rods for the Delta Steel to avoid these issues altogether.

I have also decided to first experiment with Traxxas 5347 ball joints as these are easily available by mail order worldwide.

Finally, I have taken note of the need to assemble diagonal rods with exactly matching lengths, and the easiest way to achieve this is through the use of a simple jig. More on jigs later.