Dr. Kathy DeGioia Eastwood (Professor Emerita of Physics and Astronomy
Northern Arizona University), have developed a tactile 3D grid that can be made from inexpensive and easily available materials. The CARDIS will also be useful for sighted learners who have trouble visualising in three dimensions.
The link below contains tables and one image of the 3d Grid CARDIS. Descriptors will be added later. Try it and write us! your kind suggestions and comments are welcomed always!If you need help with please get in touch with us at wdm@astro4dev.org we will happily assist you.