[johnmaguire2013]

There is a local team (not my team) which, by the students choice, is 99% student-run. Most of the students actively try to prevent mentors from working with them, as they prefer a product which was built completely by themselves. They are always on time, and have a decent robot by the end of build season. It works.

Our team has a lot of students (maybe too many,) and a fair amount of mentors. For the marketing teams (PR/Media, Website, etc.) the team mentors usually assume a leadership role, making sure that things are taken care of, and if no students can solve an issue, they will come in to help. Additionally, with the website team, our mentor manages the hosting (we're on a type of AWS,) and domain, although even this could be done by our students. Some of the teams hardly get any leadership input (like the website team, which has mostly been a product of a couple students creating and coding a design, and a handful more adding content,) while others rely on it quite strongly (the PR/Media team, which has a couple mentors organizing things, and also handling purchases, etc.)

When it comes to our build teams (mechanical, electrical, effector, etc.) our mentors have a larger role teaching students to use equipment, monitoring safety, and overseeing things. Additionally, they will help out with the actual cutting, use of machinery, etc. both to save time, and to provide examples of the correct ways to do things. Again, they also handle purchases of wood, and other materials.

This works for us. It's not a sure-fire strategy, and every team is different. We also have a student leader, who manages a lot of the sub-teams, and he is pretty much able to do his own thing, regardless of our team coach (a mentor.) I think, as many others have said, it's up for the team to decide the type of involvement.