Hi All, I’n new here… and a beginner Rhino user.
Q: How can i stable move an oblect with Osnap ON, in one dimension without it jumps into the other.
( I move it in FRONT, but it also snaps into TOP 
)
Thanks to al readers and reactions,
Rocketship
Hi Rocketship - set Project on the osnaps tool bar - that removes the CPlane ‘Z’ component from the snap.
Any luck?
-Pascal
YES YES 
Super thanks,… but now I have a second ‘small’ Question Pascal 
How to project , ‘different positions of object’ (floating) onto one plane?
( 10 objects in the air, need to align onto the floor),… select all objects and… hmmm ???
Hello - if the obects are curves that need to be squashed flat to the Cplane, use ProjectToCPlane (See also SetPt) But if you want to move objects down, but not flatten, then Move > Vertical, snap to the lowest point (if that is available) and then type in 0 and Enter.
See also, (Help file) “Tab direction lock”, Ortho, SmartTrack.
-Pascal
OMG YES I managed it also,… Thanks Pascal, Today You are my Hero 
Greetings Rocketship