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bdickens
05-17-2010, 10:07 PM
We finished the first assembly of the electric outboard and we ran a short test at 24v. All worked fine mechanically, but we threw the magnet on the hall effect sensor. No injuries, no damage, never left the case. Just a delay to the weekend. I used a plywood disk with hole bored through that the magnet fit into, glued with west systems epoxy. The magnet was embedded in the disk and the sensor below.

The shaft is 7/8ths and will ultimately be spinning at about 4000 rpm. It was up to 1800 when it tossed the magnet. Realizing this is not an electronics question, how do you all fasten your magnets? I have a keyway, not used, I wondered about a longer bar magnet that I could bandsaw into the slot. Less centripital force etc. Use a delrin band around the shaft.

My default fix will be to mount the magnet perpendicular to the disk, with a thicker disk. Then mount the sensor to the side. Would make removal easier. But I figured someone has solved this before.

And thanks to Tom Doyle for motor minder.

Thanks