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A10ECGent
11-09-2009, 05:25 AM
Hi all,

You have a great forum here. I have been lurking and reading for some time now and feel I am ready to get started. I am wanting to build my own bell, I understand that it needs to be steel for the flex ring but my question is this. If I wanted to make an aluminum bell with embedded magnets with a steel flux ring pressed on the outside, contacting the magnets, would it work or would the aluminum affect it. The reason I ask is I have access to some cylindrical magnets about a 1/4 inch high and accross. very strong magnets. I can put one on top of my finger and another on the bottom and they will stay. I'm just trying to figure out if I can use them

Thanks

Greg

MustangMan
11-10-2009, 06:22 PM
I'm not sure I understand what you're thinking. If you were thinking of having a steel flux ring surrounding a layer of aluminium with the magnet inside the aluminium then I'm concerned that you'll have performance problems. The aluminium layer is like having an air gap in the flux path. Most motors have an aluminium bell end with the flux ring pressed on to a shoulder on the aluminium end with the magnets glued directly inside the flux ring. The magnets, by the way, are magnetized through their thickness, typically the smallest dimension.

I hope that helps.

A10ECGent
11-11-2009, 04:56 AM
Thanks for the reply. What I am considering is drilling through the aluminum part of the bell, centered over the stator teeth, that way I could insert the magnets have very little airgap and all the magnets would also be in contact with the flux ring on the outside

MustangMan
11-11-2009, 05:05 AM
Thanks for the reply. What I am considering is drilling through the aluminum part of the bell, centered over the stator teeth, that way I could insert the magnets have very little airgap and all the magnets would also be in contact with the flux ring on the outside
I don't think you want to do that. Outrunner motors don't have the same number of magnets as stator poles. For example motors with 12 stator poles typically have 14 magnets.

A10ECGent
11-11-2009, 05:18 AM
sorry i guess I should have said the the holes for the magnets drilled on the centerline of the stator teeth.

(in time i'll get my terminology right, until then thank you for bearing with me.)

MustangMan
11-11-2009, 05:27 AM
Ah, OK. I follow you now!