MChronicleSword

one of the blades on my ducted fan jet broke off and i discovered, after testing my new fan blades, that it doesnt even fit in the duct. when i turn it by hand the blades scrape the wall on every rotation.
so do i sand the edges of the blades until it fits?

SoCalSal

My Feedback: (16)

I would not do that... you will never get it right. Did you get the replacement blades from the maker of the fan unit???? if so contact them about this issue. Perhaps they will replace the fan with one that is supposed to work with no modifications. You see balance is of critical importance in a ducted fan and by sanding your fan you will almost never get it balanced right.

TFF

Does it hit the housing every rotation in the same place or is one blade scraping all the way around?

MChronicleSword

oh never mind. it works now..
they sent me 4 replacement fans and i tried each of them. they all scraped the housing. but just one blade out of three makes contact, on one specific part of the tunnel.
then i took one of the 4 fans and just kept fiddling with it - just fit it into the motor at different angles until it doesnt touch the housing at all

should i have done anything otherwise? don't want it to disintegrate my jet in midair when i actually fly this thing...

JohnW

My Feedback: (6)

That's wierd. Not sure what you mean by different angles. Did you have the fan slightly cocked on the axis of the motor shaft? Hard to tell from your description if the shroud is out of round, or if the part is, or it just wan't seated correctly until you fiddled with it. If it seems OK now, what I would try, with caution, is to run the motor slowly and see if you can detect excess vibration. Work your way up to higher throttle. Just be careful and be prepared to killt he motor if someting doesn't seem right. Good chance you are fine, but it is better to play it safe and do the test. -cheers