Here’s a fun project. My uncle asked if I could cut down some ceiling fan blades to be about 38mm shorter. Without knowing the material or how I would do it I said “Sure, I’ll give it a try!” and he was fine with that. I guess he purchased a new set for his fan thinking they were shorter but they were the same length as the existing blades, so it was low-risk if I failed.
My first idea was to build a jig and laser cut the ends off. This would (in theory) make sure all the cuts matched exactly. Since the cuts are curved, I thought this would be a good idea. The blades are plastic though, and I didn’t know what plastic. I gave up on this idea. (I think they might be ABS, but I don’t know for sure.)
So what I did was used my desktop scanner to get an image of the blade, then printed a paper template I could tape to each blade to do a cut on the bandsaw. (Note: I have a pretty low-quality bandsaw at home, which is fine for rough cuts of thin materials, but not exactly precise.)
I taped the template to each blade and cut them one by one. I did better on the first two than the third, and probably better on the first one than the second, so I had three cuts that were not exactly matching. No matter, on to the disc sander!
Did I mention the blades are plastic? I ended up taping all three blades in a stack so I could sand them evenly. It mostly worked. I had to take breaks to allow the plastic to cool and use a razor to keep cutting off the gunked up plastic on the bottom of the stack, but I think I got them really close to being even with each other. (Apologies for the lack of process photos, I was concentrating pretty hard on getting them right.)
I cleaned up the edges a bit with a razor, but didn’t actually shape them like the original ends were. Hopefully these will work. If not, it was a (somewhat) fun challenge to do something I’d probably never otherwise do…