How crucial is the Bowden Tube for a test print

[thirdsurface 0]

I am assembling my Ultimaker and have everything completed except for the missing Bowden Tube. I want to try a test print but I don't want to risk any feeding issues. Does the Bowden Tube work functionally as a guiding tool, or is it more to keep the wires and material out of the way?

 

[illuminarti 18]

The Bowden tube is critical. It acts to constrain the path of the filament, so that as the extruder motor on the back pushes the filament into the tube, it has no where to go but out the other end, and through the nozzle.

Without it, as the extruder turns, you'll jsut make an ever-bigger arch of plastic, and won't get any extrusion.