Marble ball release mechanism cylinder version

**Danger of finger injury**
*The servo is not strong enough to cause a serious injury (I don't think), but especially for very young children with small fingers it may nip them, so It is recommended to glue tube as least longer than a finger to each entrance of the device to prevent accidents with fingers being poked into the device while in operation.*

#Marble release mechanism 2#
Revisit of marble release problem, my previous "beam engine" style device that was not reliable enough at del