[Coco] Loose plastic gears - CGP215 & PC2 Printers

[George Ramsower]

----- Original Message ----- 
From: Rogelio Perea

<snip>directly attached to one of the electric motors, has a crack on the 
gear's
pit,it is hardly noticeable when the gear is installed on the motor shaft,
but a close inspection with a good light reveals the shaft metal glimmering
through the crack. This gear sits rather loose over the motor so when it is
time to excercise some force to spin the other gears around, the shaft will
slip and then the whole printer mechanism becomes really confused
----------------------------------------------------------------------------------------------------------

 Rogelio,

  I've had varying degress of success using several methods, depending on 
the size and shape of plastic gears and pulleys.

 If there's room on the broken part, JB weld is okay(use JB Quick), 
Plasti-pair is good too. These have to be applied while the gear is NOT 
installed on the shaft.
 The JB Weld or Plasti-pair is applied on the body of the gear in the area 
between the teeth and the hub boss. Use as much as room will allow and make 
sure it is clean before you begin.
 On extremely small parts where there is no room for the above, Super Glue 
works, depending on the material.  However, you have to do all this with it 
off the shaft, as the shaft spreads the part, increases the gap in the break 
and makes the part imperfect.
 When using superglue(not the Gel), you have to force the part to open the 
break a tiny bit so the glue can seep into the gap, then relax the part so 
it may close.
 Then, after the glue dries, massage the insid of the part  where the shaft 
goes with some abrasive (Fine grit sandpaper, for example) so that there 
will be no tighntess. This reduces stress on the repaired part. The repaired 
part will have to be glued to the shaft for a good connection.
 If you leave the stress on the part, the repair will fail. Originally, it 
relied on pure force of tightness to make it stay on the shaft. That 
friction fit has to be eliminated and replaced with an adhesive.

 If that's clear as mud, let me know and I'll try and say all this 
differently.

George