lawnmower motor magnet broken

[mark]

After investigating a scraping noise, I found about 10% of one of the 2
halves of the magnet broken off. Removed and cleaned it up and it runs ok
except there seems to be a little vibration. I assume the field is not
balanced? What kind of glue/epoxy would work to reattach the magnet?

 

[Jeff Liebermann]

On Fri, 6 Jul 2012 05:01:31 +0000 (UTC), mark <mart87121@gmail.com>
wrote:

After investigating a scraping noise, I found about 10% of one of the 2
halves of the magnet broken off. Removed and cleaned it up and it runs ok
except there seems to be a little vibration. I assume the field is not
balanced? What kind of glue/epoxy would work to reattach the magnet?

<http://www.kjmagnetics.com/blog.asp?p=sticky-business-how-to-glue-neodymum-magnets>
I had a similar failure on a PM motor. The problem was that I could
not tolerate much of a gap on the glue line. So, I cleaned both sides
of the break with a brass wire brush and alcohol to be sure there was
no loose debris. I used high strength epoxy and clamped both halves
under as much pressure as possible using two pieces of wood and some
glue clamps. Despite all this, I still had to sandpaper the PM motor
ends to recover my clearances. 4 years later, it's still running.

Good luck.

--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

 

[spamtrap1888]

On Jul 5, 10:01 pm, mark <mart87...@gmail.com> wrote:

After investigating a scraping noise, I found about 10% of one of the 2
halves of the magnet broken off. Removed and cleaned it up and it runs ok
except there seems to be a little vibration. I assume the field is not
balanced? What kind of glue/epoxy would work to reattach the magnet?

Maybe you are confusing cause and effect. Perhaps the vibration caused
the magnet breakage.

But to answer your question: Loctite 334 Structural Adhesive, High
Performance, is designed as a magnet adhesive. But you probably will
have gaps as you glue the broken pieces back in place, so use a good,
non-instant epoxy. But recall that like poles repel each other, so the
piece you replace will want to jump out. You will have to fixture it
properly to keep it in place.

 

[mark]

Used Araldite and made a wooden dowel to clamp it - works great!

Thanks