
The CL cap to this mini boss is CL 5.0, but Papasaw appears at level 6.6 and the minions are at CL 5.9. When you first enter the sawmill (you will have to have completed the Mon Cheri and Cheri's sister quest) nothing will happen.
If you step past a certain point (use the crates at the top as a line), the saws will start to spawn. Many crews use the top left corner next to the crates to buff up before making the saws spawn, and they usually stay there for the duration of the fight. Papa Saw has the ability to knockback, which makes the corner better because you don't get knocked back, although there is a known glitch that people get stuck in the walls.
Fire Rain [and other crowd control rings] is a very good ring to have, especially when you use it at full rage because two or three rounds of it will take out a whole wave of saws. It is
highly recommended that the whole crew stay together, because it makes Fire Rain much easier to use.
After many waves, you will know you are getting close to the end when the two Mama Saws spawn. Afterward, Papa Saw will spawn, and so will many other Buzz Saws. It is better to attack Papa Saw first and defeat it, then deal with the other saws if you still have the health and stamina. Or you can just exit the sawmill after that.