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.

It is an Amber waxy looking/feeling material and it scrapes like wax.

What is this??

TIA

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

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

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.

The Lady from Philadelphia advises you to purchase a new pencil-sharpening
instrument.

William Sommerwerck wrote in message
...
The Lady from Philadelphia advises you to purchase a new pencil-sharpening
instrument.




You've just posted that 'reply' to a thread with repair in the title on a
board with repair in the title

On Oct 29, 7:42*am, "N_Cook" wrote:
William Sommerwerck wrote in message

...

The Lady from Philadelphia advises you to purchase a new pencil-sharpening
instrument.

You've just posted that 'reply' to a thread with repair in the title on a
board with repair in the title

But common sense has a place even in a repair group.

You've just posted that "reply" to a thread with repair in the title
on a board with repair in the title.

You're rather missing the point.

The reference is to a character in Lucretia Peabody Hale's short stories
"The Peterkin Papers". Said lady was a fountain of common sense, giving
simple solutions to what appeared -- to the Peterkins -- to be complicated
problems.

http://en.wikipedia.org/wiki/The_Peterkin_Papers

N_Cook wrote:

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


what is a waxy plastic gear? I can't picture any gears being made of wax
or material soft like wax?

Jamie

Jamie t wrote in message
...
N_Cook wrote:

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


what is a waxy plastic gear? I can't picture any gears being made of wax
or material soft like wax?

Jamie




I've come across them but don't remember where, glossy looking as though
covered in oil , hard white material but not PTFE , and slippery to the
touch but no oil film. IIRC quite coarse teeth and pitch as though not very
structural plastic.

On Mon, 29 Oct 2012 10:37:59 -0500, Jamie
t wrote:

N_Cook wrote:

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


what is a waxy plastic gear? I can't picture any gears being made of wax
or material soft like wax?

Jamie


Thanks to all the replies!!

The unit is at least 20 years old.

The gear is brown Bakelite in color. I say waxy because it has a soapy feel and
I can scrape the material with my thumbnail and get some to come off. Like very
hard wax. Odd for a drive gear material so I suppose it changed in nature over
time. The exterior seems most changed so perhaps there is some material
strength remaining.

The teeth are about twice as wide as the body and none have broken off. A clean
3 way break. The body is too thin for making a groove around the perimeter.

Adhesive would be required in and around the breaks for adequate strength.

I cannot think of an adhesive for this material so I posted here hoping for
anyone familiar with it to chime in.

As an alternate to a lost wax reproduction, I thought of reassembling the gear
and wiring it to stay put, some holes could be drilled through the disc (several
on each segment) and a 2 operation repair then be undertaken. On one side a
layer of JB Weld between hub and teeth, then a repeat on the other side. Would
give a metal sandwich with the holes ensuring the teeth remain in roper position
and are driven. Will look over the unit to see if any special clearance need be
observed. Likely the best option in hand.

Just discovered someone who has cloned the gear and is selling them $12 or so.

Splork wrote:

On Mon, 29 Oct 2012 10:37:59 -0500, Jamie
t wrote:


N_Cook wrote:


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



what is a waxy plastic gear? I can't picture any gears being made of wax
or material soft like wax?

Jamie



Thanks to all the replies!!

The unit is at least 20 years old.

The gear is brown Bakelite in color. I say waxy because it has a soapy feel and
I can scrape the material with my thumbnail and get some to come off. Like very
hard wax. Odd for a drive gear material so I suppose it changed in nature over
time. The exterior seems most changed so perhaps there is some material
strength remaining.

They call it micarta
http://en.wikipedia.org/wiki/Micarta

Jamie

In article , "N_Cook"
wrote:

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?

Yup. Exactly.

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

Just use a coping saw.

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

Something to hold it together long enough to get the groove cut would
make it easier. Even clamping the pieces between a couple of washers
might do it.

Isaac

On Sat, 27 Oct 2012 20:47:30 -0400, 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.

It is an Amber waxy looking/feeling material and it scrapes like wax.

What is this??

My guess(tm) would be Molybdenum disulfide lubricated nylon gears.
Search google for "self lubricating plastic gears".

However, glue is not going to help. No glue will stick to a plastic
gear that is impregnated with some manner of wax or grease. Your best
bet is to temporarily stick the gear together with some manner of
cyanoacrylate adhesive (super glue), and make a lost wax plaster mold
in order to clone the gear.
http://en.wikipedia.org/wiki/Lost-wax_casting

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

"Splork" wrote in message
...
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.

It is an Amber waxy looking/feeling material and it scrapes like wax.

What is this??

TIA


Knackered, I'd say ...

Arfa

Splork udtrykte præcist:
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.

It is an Amber waxy looking/feeling material and it scrapes like wax.

Perhaps you can find somebody with a 3D-printer who will print a new
gear?

Somebody who has made their own 3D-printer might be looking for
interesting stuff to print.

But then again, get a new one, unless you have lot of free time and no
money.

Leif

--
Husk kørelys bagpå, hvis din bilfabrikant har taget den idiotiske
beslutning at undlade det.