Overtightening of cable management bindings can cause conductor breakage, insulation damage, excessive chafing, and deformations between the conductive, dielectric, and shield parts of a cable, and no doubt a host of other issues. It is one of the classic problems with ratcheting plastic cable ties (i.e. "zipties") that they only have quantized adjustment steps and cannot be easily loosened. While zipties with a metal tooth insert do allow for smoother tightening, the possibility of this tiny metal part coming loose near electronics generally excludes their use. That zipties cannot easily be loosened or adjusted during tightening makes them more prone to being left in an overtightened state. Difficulty of adjustment might also be considered a possible strike against using the Constrictor Knot (and similar knots) for this application.
I'm not convinced by this explanation. A skilled person will do fine with a zip tie. Knots once tied should not be easy to untie in such applications - you don't want possibility of failure.
An over tightened zip tie can be quickly cut away.
The thing that seems reasonable to me is lacing works for thin cabling, but if you have a fat bundle of cables (say 5mm or more in diameter) I can't really see a big problem for zip ties.
In the Aerospace industry, special applicator guns exist to zip bundles of wire in a specified tension. [1] But the use of butchers twine and wax line in still rather common.
A few more points:
- Zip ties are also made of ABS plastic - which has a Tg of <200*F...things start uncoupling around there.
- Kapton gets brittle, and most of these cable bundles are covered in the stuff.
- Mass. There are plenty of lightweight fibers (Aramid/Kevlar, carbonfiber, nanofibers, etc) whose tensile strength is greater than steel.
- Lastly, I'm biased against zip ties after multiple recabling projects while in IT...
Have you considered consulting for NASA? They've likely put no thought into materials selection and I'm sure they'd benefit from your vast experience in the performance of zip ties in non-terran environments.
The thermal extremes of space are severe, and can easily render a simple zip tie to be useless. Another issue is the potential for materials (plastics are a particular headache) to offgass in a vacuum, which can send nasty contamination into places that it shouldn't be (like sensitive instruments). They actually test these components in vacuum chambers while thermally cycling the assemblies to figure this out.
Overtightening of cable management bindings can cause conductor breakage, insulation damage, excessive chafing, and deformations between the conductive, dielectric, and shield parts of a cable, and no doubt a host of other issues. It is one of the classic problems with ratcheting plastic cable ties (i.e. "zipties") that they only have quantized adjustment steps and cannot be easily loosened. While zipties with a metal tooth insert do allow for smoother tightening, the possibility of this tiny metal part coming loose near electronics generally excludes their use. That zipties cannot easily be loosened or adjusted during tightening makes them more prone to being left in an overtightened state. Difficulty of adjustment might also be considered a possible strike against using the Constrictor Knot (and similar knots) for this application.