How to make and model this tube with curves?
Use the FollowMe tool.
When I draw the curves with the bow and use followME, the bottom of the tube is open.
Share your .skp file so we can see what you are getting.
What version of SketchUp are you using? Your profile says it’s version 10 which isn’t possible.
Your path is poorly drawn.
My guess is that your model is too small. Share the file as requested for assistance.
to illustrate what @Anssi described:
Perfect, I was having trouble drawing the curves, you guys are amazing. Thank you very much