Quoted from thirdedition:We've just had our second Groot jaw motor give out. I haven't taken it apart yet, but I suspect the culprit is yet again a gear in the gearbox. I'm ordering two from the main source since they are cheaper than buying them from Marco or Pinball Life.
My question is, has anyone else had this amount of failure on Groot? Is there any known solution? It is a location game that gets a fair amount of play so I can't complain too much, but I'm curious if anyone knows that the cause is. My best guess is balls are getting stuck in his jaw and the gear is breaking when it tries to close. I'll see if I can adjust it so that doesn't happen.
There can be a lot of friction on the metal slides for the mouth. A lot of friction. I used white lithium grease on this one contact point to reduce the friction and make the motor life easier. It solved all of the problems I was having with the mouth opening and closing and that machine is now on location with no issues.