gmat (anyone) help- Magdrive Impeller Silencing -

[Jim]

gnat-

You posted a fix for the mag drive impeller silencing on this Forum a few days ago.

I have found out what this little rattle you were writing about today, during an early test of my water cooling system, still under construction.

I have the Eheim 1250. I cannot quite determine how to get the guts out of the pump. I remove the disc in the front and try to pull on the white part, but no go? I don't want to ruin my pump.

Help please.

TIA
Jim

[iceheart]

You can pull out the white part safely, it's held in there magnetically. You want to glue the little impeller (bladed thingy) to the white part (with the magnet attached to it).

[Jim]

I reviewed the drawings that came with the Eheim last night and the white knob (there are two) is connected to the shaft.

Just seems to require more pulling effort than I expected. Don't want to damage any parts.

Jim

[iceheart]

My eheim (1048) looks like this:



The little black rubber thing on top is only stuck on there, if you take it off you can pull out the rotor assembly.

btw. didn't someone write an article about this somewhere, it should be posted on procooling.

[Jim]

iceheart-

Here is the link to the article.
Go Here.

Is my 1250 Eheim same as yours, more or less I mean?

Is the "rattle" sound we are talking about sort of like grinding coffee at a slow speed or like running marbles around the inside of a drinking glass by centrifugal force?

Trying to get a handle on this, whatever the noise is called I would like to eradicate it on my Eheim 1250.

Have to work on the disassembly this evening after work.

Jim

[gmat]

Your impeller shaft may be damaged or warped. If you try the pump *alone* in a basin it should be totally silent. If not then it's damaged.
Now if it's silent you're good for glueing the impeller.
The little rubber cap wont come off easily, just make sure that:
* You dont lose it
* You dont bend the shaft while pulling hard
Thats all
Tell us if it went well.

[Jim]

gmat-
Nope pump is quiet in the tub not connected to my heater core. So I guess no damage. I will check it out tonight when I get time to disassemble it.

Pump is brand new, hope no parts are bent!

Jim

[Jim]

Originally posted by gmat
Your impeller shaft may be damaged or warped. If you try the pump *alone* in a basin it should be totally silent. If not then it's damaged.
Now if it's silent you're good for glueing the impeller.
The little rubber cap wont come off easily, just make sure that:
* You dont lose it
* You dont bend the shaft while pulling hard
Thats all
Tell us if it went well.

Ok, got it apart, was just a little stubborn.

I also ran the pump under water and I can only hear a hum, no rattle, so I guess no damaged parts.

After removing the impeller from the shaft of the magnet I noticed the Eheim has splines to keep the impeller from rotating independently from the shaft, except for a very tiny bit.

In the article by Unaclocker "Magdrive Impeller Silencing", he mentions pumps where impellers can rotate as much as 3/4 a turn from the shaft (magnet) freely. Can't imagine the Eheim being able to do that with the splines that index the impeller onto the shaft.

Anyway, you guys recommend I glue the impeller to the shaft to prevent rattle so I will get it done. Noise is not desirable!

Jim

[gmat]

In the article by Unaclocker "Magdrive Impeller Silencing", he mentions pumps where impellers can rotate as much as 3/4 a turn from the shaft (magnet) freely. Can't imagine the Eheim being able to do that with the splines that index the impeller onto the shaft.

Mine could rotate slightly. This changes from one pump to another, but all those aquarium pumps have this security (so gravel / solid objects can go through without damaging the shaft).

[Jim]

Thanks for all the help gmat, going to glue her up tomorrow with epoxy, just want to let it dry off overnight (water) before applying any glue.

Thanks once more.
Jim