Feature Request: Increase size of rear Z tensioner to improve strength

[zruncho3d]

This part started as a mod to MCMben's block-and-tackle Z, which is more space-constrained.

Bumping up the width of that part to account for prints done with less-than-optimal layer adhesion seems like a nice improvement.

[zruncho3d]

The issue was improper print orientation, which was fixed with alpha-6. Closing until there's evidence of any future failures.