The good thing about mechanical hazards is that they don't need to rest or eat or post guards or any of that other distracting stuff that makes living opponents vulnerable to some sort of cleverness from the PCs. They just go about their lethal business regardless.

They can, however, be avoided in many cases simply by walking around them - assuming there's any safe region around them. So if you're going to use them, make sure you use lots of them.

Transcript

Pete: You're lying on the conveyor belt. What do you want to do?
Padmé: I stand up.
Pete: That's a one-round action. Wait while I move the machinery.
{Several panels of moving conveyor belts, crushers, welders, guillotines, steel pouring, etc.}
[SFX]: Ksssssssh.....!
[SFX]: Whump!
[SFX]: Kra-chunk!
[SFX]: Pzzz...sshhhh!
[SFX]: Ka-chunk!!
[SFX]: Zzzzt! Zzzzt!
[SFX]: K-chunk!!!!
[SFX]: Slice!
[SFX]: Wham-paff!
[SFX]: Krrrzt! Krrrzt!
Anakin: This could take a while.
Pete: I'm just doing it slowly the first time so you can learn the crusher sequence.
[SFX]: Kzz-zorch!
Pete: You are paying attention, right?