YSK the safe way to clean a 20 in. box fan
Why YSK: After seasons of use, 20 inch box fans get built up dirt on the blades. Sometimes the blades need to removed for the best cleaning or even repair of cracks. I just used a new method for getting the blade off. Rather than trying to pull it off of the motor shaft, I removed the grilles and blocked up just two sides of the metal frame clear of the blade edges and used some smaller blocks to _push_down on the plastic fan blade center. This is much safer than a technique shown on youtube by standing on the frame on the floor and trying to get leverage.