Idea for Silencing Rattling Powerheads

[Brett]

I just picked up a wavemaker today and I'm using four Hagen Aquaclear 201's with it (because those are the powerheads I already had in the tank, and because I much prefer hagen's clip on mouting to suction cup mounting) Of course, I've run into the same issue that pretty much every one seems to have - the power heads rattle when they are turned on. Now... anyone who has looked at a powerhead impeller assembly has probably noticed that the impeller can spin nearly 360 degrees in either direction before it's forced to turn by the magnet. Apparently this is what causes the rattling - the impeller bounces back and forth a bit before it finally starts spinning. What I'm planning to do is to simply fix the impeller to the magnet. I'll probably just take the impeller off, put a drop of silicon on the shaft, then replace the impeller. Before I do this, though, I was wondering if anyone else had tried this. Also, I'm wondering if anyone knows why the impeller spins freely like it does, and if it's necessary for the powerhead to operate. Personally, I can't see any reason for it, but since every powerhead and pump I've seen (regardless of brand) has this design I imagine it's gotta have been done that way for a reason. Unless anyone has a good reason not to, I'll probably try this tonight when I get home from work. I figure the worst that happens is that I have to spend a few bucks at the LFS for a new impeller assembly. I'll let you all know how it goes.

Thanks,
Brett

[Brett]

Well... for those who care, I just tried it and my idea did not work. As I was going to get the silicon my eyes fell on my roll of teflon tape. It occured to me that it would be easier (and less perminant) to try to use the tape to fix the impeller to the magnet. So, I took apart the impeller assembly, wrapped several layers of tape around the shaft and reassembled it. When I put the powerhead back together and tried to start it, however, it wouldn't start. I still don't know why the impeller must spin freely like that, but clearly it is necessary. (Maybe this is why I don't design powerheads) ;)

It did occur to me that something soft put next to the stop that the impeller hits might soften the blow and make it quieter, but I'm not sure what could go there. I did try to wrap only one or two layers of teflon tape around the shaft... not enough to bind the impeller, but enough to keep plastic from hitting plastic. That did seem to help things a bit... the powerhead still starts and while it does still rattle it's definitely not as loud. I'll keep working on it, I guess :)

Brett

[Brett]

I managed to come up with something that works... here's the thread... http://archive.reefcentral.com/vbulletin/showthread.php?threadid=13972

Brett