Pen tool help

[so4chinate]

Working on pen tool practice. When I do another line it doesn't attach completely. So I try to use pathfinder to merge or unite. Often times my paths don't unite correctly and I can't use join path tool because the paths don't cross properly. What could be wrong with my paths that they go crazy when I try to unite? Do they need to be closed paths etc? Thank you so much 

 

[Bobby Henderson]

Paths need to be closed in order for merge or unite pathfinder commands to work. Is it necessary for the open paths to be joined together? If so you might try expading the stroke of those paths. Then those resulting paths can be merged together into a compound path.

[so4chinate]

I'm trying to make a svg someone can use on their cutting machines so I'm not sure but I'll try to look into it. Thank you so much for the help!

[Bobby Henderson]

In that case I would recommend expanding the line strokes into editable paths. The strokes will need to be thick enough and the overall size of the object large enough that it can be cut effectively. If something like roll vinyl is being cut the fine line details can be difficult to weed out by hand if the lines are too thin.