Strong RC Motors LLC
Strong Engineering
Handling and Installing
STRONG Magnets
Handling Magnets
CAUTION: You have
purchased very high performance magnets.
They can attract each other, or metal objects, several inches away! As you handle magnets don't let them bang or
snap metal to metal. They could break! Impact
and temperature can weaken (demagnetize)
these high performance magnets. You can restack them, or lay them out about
8 inches apart (much closer and they bang together). When restacking them hold the stack inside
your fingers. Then you can let other
magnets be drawn to your fingers (they can snap to your finger tips just don’t
let it hit metal to metal). Then move
your fingers out letting the magnets come together slowly.
Replacement
magnets are available for 1/10 of the price of a new set.
Installing Magnets
- Start by washing your hands. That will minimize the chance of skin oil interfering
with the glue bond. Now mark the magnets so they can be placed
NSNSNS... in the can. The poles are
on the large flat faces or inside curved and outside curved surfaces of
curved magnets. N is on one side
and S on the other. You could use a compass to find out which side is N,
but the motor does not care which magnets are N or S, just that they
alternate NSN... or SNS... around the can.
No two adjacent magnetic poles can be the same. When stacked all the matching poles
point in the same direction. (Opposite
poles are together, facing each other)
So one end of the stack is N and the other is S. If you have curved magnets you will
notice in the center of the stack the polarity of the inside curved face
changes. Normally two inside faces
are together at this point. Start
at one end of the stack and mark the face of the end magnet with a marker.
Then remove that magnet and mark the next one. Slide the magnets off the stack with a
twisting motion. They are too
strong to pull straight off. If you
have curved magnets you will end up with half marked on the inside (concave)
face and half marked on the outside (convex) face.
- Wipe the inside surface of the can with alcohol or
lacquer thinner to assure the glue can get a solid bond. Now you can begin inserting magnets in the can. Spacing the magnets
evenly around the can is easiest with the aid of a Strong Magnet Spacer. Insert the spacer in the can with the machine screw
handle facing out. Then insert 12
magnets flush with the edge of the can. (Caution: Do not insert the magnets too deep. If you put the magnets too far inside
the can they could cause problems later.)
Remember to alternate polarity by having every other magnet with
the mark facing in. Now remove the
spacer and apply glue. Some
builders prefer to install every other magnet. Then remove the spacer and glue 6. Then
repeat for the 6 opposite polarity magnets. That reduces the chance of putting two
like polarity magnets next to each other.
Either way, installing twelve precisely spaced magnets takes just
minutes! Thin CA is recommended to
secure the magnets, since it sets quickest. You can fill the gaps later with
thicker CA or thin epoxy, but many builders use only thin CA. Loctite’s
Black Max is reported to be great for gluing magnets.
The spacers’ depth in the can may be adjusted
using the machine screw “handle”. In
deep cans, as used for double stator motors, turn the machine screw in and
install a second threaded wood washer or a metal nut on the tip. Use this to adjust the magnet spacers’ depth
in the can.
- Magnet spacing can be done by eye, if a magnet spacer is not
available. Insert the first magnet,
with the marked pole showing, until the edge is flush with the can
rim. The next magnet goes directly
across from the first, with the marked pole showing (like the first). The
next two magnets go half way between the first two with the marked poles
NOT showing. You now have magnets at 12, 3, 6, and