I recently replaced the motor in my PR3 Master Flow attic fan.
The fan with the the new motor vibrates significantly more than the old one. I may have been a little too aggressive trying to get the fan blade back up through the motor's suspension yoke. Some of the blades may have been tweaked…
I beliwve Master Flow doesn't make replacement blades for this model. (I've emailed them to verify.)
I could try a generic fan blade or try to straighten them – what would be the best approach?
If fixing the blade is best, what is a good way to straighten them as visually it is really hard to tell any blades are out of spec – the blades actually look fine.
If bending is just not practical, can I find 3rd party blades that will fit? I assume they usually attach with some kind of set screw?
Edit: Did get a response from manufacturer, they confirm PR3 series is discontinued, but say the closest blade they have is the X113873, so I'll need to call them and see if I can order that.
Update:
I bought a fan blade from their newer PG3 model that fits. It has 3 blades instead of five.
Since I took the other one back out anyway, I checked it on a table. Checking it was easier than I thought … it was very obvious that one blade did not rest on the surface. I bent it back into place, but did not test it.
Best Answer
Take the fan blade assembly off the shaft and set it on a flat surface and verify that all the blades rest firmly on it. Tweak if needed. You can then check the angle of the blades by cutting a piece of cardboard to the angle 0f one of the blades and then checking it to the other blades to make sure they're all the same. Good luck/