The first step in involving the community in your classroom is to think about the outcomes you would like your students to achieve. The challenge is to plan each experience to support course outcomes, not just to have a fun day away from the classroom.
For example, if one of your intended course outcomes is for students to install and maintain automated machinery, you might consider it important for your class to visit a modern manufacturing facility. If a field trip is not feasible, consider showing a video in class.
If you find it difficult to see how involving industry or community resources can help your students reach your course outcomes, you may want to take a closer look at those outcomes. Ideally, outcomes should describe not only what students will learn as a result of your course, but what they will be able do in the outside world. In this light, it's hard to imagine that students wouldn't benefit from seeing the concepts they are learning in class put into practice. A guest lecturer or site visit can help students visualize the skills and behaviors they will need to succeed in industry or as a citizen in a complex technological society.
Moving beyond the classroom helps you stay fresh as an instructor. Everything you teach must have value outside the classroom. (For more information on developing course outcomes, see Module 2.)