Small extruder gear shifts on motor shaft - Solutions?

[jonjude 0]

Hi,

Launched large print yesterday but found on return last layers missing because small extruder gear position on

extruder motor shaft had shifted such that little gear no longer meshed with bigger gear - hence no extrusion for last layers.

I note there is no grub screw to hold small gear in place (!).

Anyone ever had this ? Any solutions tried ?

What about this from thingiverse ...

http://www.thingiverse.com/thing:4472

??

Best Regards,

JonJude

[billdempsey 0]

Hi,

Launched large print yesterday but found on return last layers missing because small extruder gear position on

extruder motor shaft had shifted such that little gear no longer meshed with bigger gear - hence no extrusion for last layers.

I note there is no grub screw to hold small gear in place (!).

Anyone ever had this ? Any solutions tried ?

What about this from thingiverse ...

http://www.thingiverse.com/thing:4472

??

Best Regards,

JonJude

I had that same problem at one point. What I did was change the number of washers between the big wooden gear and the extruder. It seemed like the wooden gear was slightly toward one side of the plastic gear, which caused it to slowly push the small gear further onto the shaft. I changed the spacer washers so that the wooden gear and small gear lined up perfectly and haven't had trouble since. When I did this, I had to unscrew the knurled shaft very slightly and tighten the lock nut more to hold the big gear in the right position. This made the black clip on the opposite end slightly more difficult to snap in place, but I finally got it to stay put. As I said, I've had no problem with that small gear moving on the shaft since then.