If all projects are Maven projects, and they are all on the same computer, you can simply run mvn install to “deploy” them to your local repository. This is usually located in .m2/repository in your home folder.
After running mvn install in the component projects, copy the groupId, artifactId, and version from each project, and add them as a dependency in your main project.
As long as they have versions ending with -SNAPSHOT, when you make changes to them Maven will update them in your main project without you having to change the version number.