Ender 3 90° heated bed cable strain relief with aftermarket springs

Model originally uploaded to Thingiverse at https://www.thingiverse.com/thing:4138892.

I modified the original design to fit the aftermarket (yellow/blue) springs for the bed.

All modifications:

• flipped the mount for the screw so now it's solid part on the bed, should be more sturdy and won't break the plastic because of the spring tension
• tighter tolerances for the cover mount (0.25mm instead of 0.4mm) - no need to reprint the cover
• enlarged the zip tie mount to fit zip ties up to 8mm × 1.6mm
• added cable tunnels for the bed thermistor