I have not field tested jet, but it looks to work really well. The mechanism will not activate when you hold it upside down but that will be a rare case. to hold your marker in anyways.
when you print the parts just make sure that the parts can move freely. And place in a detent and your good the go.
link to video
Supports:
Yes
Category: Sport & OutdoorsThe author marked this model as their own original creation. Imported from Thingiverse.