Ramblings about Strain Relief...

Ramblings about Strain Relief...

• Strain Relief is the most overlooked aspect of 3d printer toolhead cable installation.  The wires need to be in a neutral position where they enter the connector and not subject to any movement relative to the connector.
• Molex recommends 2cm between the strain relief and the 16-pin connector.
• Between strain relief and the connector, there should be no movement. (redundant statement here, but it's that important).
• Strain relief should allow the non-connector side of the cable to move in an arc.  It should not sharply pivot in any direction from strain relief.
• Zip ties are okay for strain relief, but there should be sufficient cushioning between the tie and the wires so there is no damage to the conductors or insulation.  Strain relief should be distributed over a small length of the cable, say 2 to 3cm in the case of this 16-conductor cable.  That is, a single zip tie or securing point will create a pivot and contribute to premature failure.
• Cable glands are generally good, though they can be more complicated to install.  A cable gland that meets all requirements of 'good' strain relief is good strain relief.  They can look nice too.
• Typical good-practice strain relief is to wrap the cable in harness tape (cloth/fiber-backed adhesive electrical tape) prior to securing it to a 2 to 3 cm long strain relief spur.  Sufficiently wrap the cable and add additional supporting material as necessary to ensure that the cable doesn't 'pivot' from the strain relief point, but rather arcs away from it.