As a staff member, you can determine the way you participate within Projectcampus . Some teachers have assistants or instructors managing the course on Projectcampus, and only step in if there is a question only the teacher can answer. Some teachers take the lead and step in on every occasion. It is really up to the teacher to decide what suits him/her and the course best. It is important that expectations on the side of the students are managed up front (at the start of the course), to prevent frustration on both sides.
Basically, this is expectation management. You just indicate in your first post or during your introduction lecture what is expected from the students on Projectcampus and what the students can expect from each other and from their teachers. Obviously, teacher presence once in a while is important. But students can go a long way helping each other if this is clearly communicated (and checked) by the teachers.
TIP: Explain your students that Projectcampus makes it easy to learn from each other. Students can help each other in the course or follow projects from other teams or students.