Invent Design Make

Step 5 – Bond in Magnets

So this step is a little trick… Did I mention you MUST handle the neodymium magnets with extreme care?  When I first unwrapped them and laid them out on the bench (which was carefully cleared of all metal objects), one flew across the bench and stuck to the keys in my trouser pocket.  So yeah, watch out – it is worth wearing safety goggles because they can chip if they grab at something and collide with it.

First thing’s first, prise the fan off the armature, being careful not to scratch the windings below. We need to place that into the can, it is too big to fit back through once the two magnets are bonded in place.

There are probably other bonding agents out there that would work as well but my research led me to JB Weld.  Mix up the JB Weld as per instructions and coat the outside of one arc segment magnet. Now comes the difficult bit. Putting it into the can without destroying anything. Grip it very tightly and be strong – that’s my advice.  You will find it is not actually that hard. There will inevitably be a bit of snapping into place, but the JB Weld offers a bit of a cushion :)

With one magnet in, wipe away any excess JB Weld before it sets, and prep the next one to go.  Note the fan is in position ready. REMEMBER: the other magnet must be the opposite polarity to the one that you just put in.  In other words it will attract to the magnet that is already in the can.  Use some spacers to keep it in place. I used some scraps of wood I had knocking about.

Now we just need to wait for it to dry overnight.. Dry Dry!