N_Cook wrote in message
...
isw wrote in message
]...
In article ,
Splork wrote:

My low tech pencil sharpener has a drive that uses a 2.2" gear to
drive
the
mechanism from the motor. The gear broke into 3 pieces.

I can probably repair it but am unsure of the composition and what to
use for
cement/ strengthening.

Cut a groove around the perimeter, deep enough to get past the gear
teeth. Wrap a steel wire around the gear in the groove, and twist the
ends to make it tight. If cyanoacrylate will stick to the plastic, use
that to get the pieces assembled before you add the wire.

Isaac

Are you saying cut a slot through the middle of the teeth into the bulk
under the teeth?
I suspect a .4mm saw in a Dremmel would end up as a melted mess and not a
slot, perhaps a heated scalpel blade in a jig

Or perhaps use some nicrome wire with some silone sleeve at the overlap,
apply a weight and some adjustable current. Hope the wire melts into the
bulk of the plastic and perhaps ypu can ignore twisting off of the wire.
May need to recess 3 pins into the disc part , then swathe in hotmelt or
something, if the 3 sections have failed with smooth edges, before doing
the
wire job



on second thoughts as its 2.2 inch there is probably quite a thickness of
bulk material. Wire and twist around the teeth to act as an alignment jig ,
then 3 pins and generally hotmelt "soldering" along all the joins, cut away
the wire.
Precede with a test that the plastic and hotmelt are compatible in the first
place.