You can have multiple campaigns for the same project! Many campaign owners with big budgets find it easier to break their goal down into small chunks. For instance, a film project might have separate campaigns for filming, production, post-production, distribution... etc.
How to Launch a Follow Up Campaign
Create a new campaign using a similar title as your old one. E.g. "Campaign XYZ Part Two"
In your Pitch, refer and link to the old campaign, with some information about what the funds were used for. For example, "Thanks to everyone who contributed to our project in Round 1. Your contributions helped us....[fill in the blank]."
Make sure to describe how the NEW campaign will build on the old one. Why do you need the additional funding? What is the new project timeline?
On your OLD Campaign Homepage, send an update to let everyone know that the project has been re-launched. Make sure to include a link to the new campaign