Mag Drive 24 impeller shaft replacement?

Hey guys, a friend of mine brought me her Mag 24 pond pump because it stopped working for her. I found the ceramic shaft was shattered in the back of the magnet housing. I was able to determine that this had been caused by pump cavitation based on the reducing fitting directly connected to the 1" outlet. I'm going to remedy the cavitation by building an adjustable blow off.

The replacement part is $45! and frankly I don't think ceramic is the best part to use here anyways. I'm going to pound out the ceramic shaft that runs through the core of the impeller magnet and replace it with a different material. Probably just an aluminum piece or whatever I can find.

I recall I may have done this before in the past, but I either had a problem, or just totally failed removing the ceramic drive shaft from the core of the magnet. Luckily, these days I have more tools and a bench vice. Can anybody think of a good method for drilling/breaking/pounding/punching the shaft out?

 

Cavitation is usually associated with a local region of low pressure. A restriction on the outlet would tend to increase pressure inside a pump and reduce the tendancy to cavitate. A restriction on the inlet has the opposite effect. Having said that, I'm not convinced that the reducer fitting on the outlet is the primary cause. A reducer on the inlet or a clogged intake filter would be more suspect.

Is the cereamic shaft jammed inside the impeller magnet because it is broken into small pieces? If so, I would take it easy at first and try not to pack in the fragments even more tightly. I would suggest taking a small diameter drill bit and try to tease out some of the fragments. Do this by hand and feel. Start by inserting the drill into the magnet bore and turning it to see if it can catch or loosen any shaft fragments. Pull the drill bit out and lightly tap the impeller magnet to free up and pour out any broken shaft parts. Repeat the process if it seems like it is working. If not, then...BFH.

Aluminum is pretty soft and may wear quickly or even weld itself to the impeller magnet. Just think of what a grinding stone looks like after grinding aluminum. If it's a freshwater pond, you may be able to find a stainless steel shaft.

Best luck to you. Hope some of this helps.

 

I replaced my ceramic shafts with Carbon fiber. I am still in the test phase with these rods, but they seem to be working for me so far. I have had one in my return pump for a week now. I am going to take it offline this weekend and look to see the condition of the shaft.

My return pump shafts are $45 each. No way am I paying that anymore......

 

Thanks guys, there was some indication of clogging as well actually as the strainer was full of dried leaves. The impeller isn't shattered in tiny pieces inside the pump, it was broken off at the back end where it meets the socket in the back of the pump housing. How much we're those carbon fiber shafts Jim and where did you get them at? Let me know what you find when you take them apart. Are the mag drive pimps as well?

 

I hav a quiet one 14000 that I use these shafts in.


I got the carbon fiber rod at Dragon Plate.com but I bet you can source them in IC at a RC car hobby shop.

Paid $17 for a 4' length of rod. Over half of that was for shipping.