At the beginning of each construction period, have the participants discuss the events of the preceding day. Focus the discussions on the group dynamics and problem-solving methods that are being used by each group, what's working and what's not working, etc. This should take 15-25 minutes, depending on how many issues need to be brought up.
Remind the participants of how many hours remain in the construction part of the phase and that some time near the end of the phase should be spent on the development of a presentation for their device. When time begins to get short, encourage the participants to focus on the essential tasks only, and to divide them among group members to help speed up the process.
During the construction periods, keep in touch with how the groups are proceeding, taking time, when necessary, to show people how to properly use and care for tools.
Don't intervene every time the group or an individual makes a mistake. Mistakes are an important part of the learning process. Intervene only if the safety of the group is in danger or if a certain decision will prove fruitless and take a large amount of time away from the group.
Explain that any group finishing one project may go on with another small project, begin preparations for the presentation of their device or research other types of solar dryers.
Allow 10-20 minutes at the end of each construction period for cleanup of the work site and shop area.
At the end of the final construction session, plan about half an hour for a thorough cleaning of the work site and shop area.