https://districtadministration.com/coronavirus-free-teaching-resources-free-education-services-covid-19/

3D-printed respirator mask lessons and videos 
Detailed lesson plans and videos on how to print the first NIH-approved open-source 3D printed respirator mask with materials readily available at the local hardware store are now available through a partnership between pi-top and Maker Mask. Masks. Printed masks  have the lifetime equivalent use of 300 N95 masks. Educators and students can access the free lessons, created by pi-top. Start printing masks.