3 Sheet Build Plate Shelf

You will need two types of magnets - 40x10x5mm for the bottom to hold the shelf stable. 9x2mm circular to hold each build plate upright. Links below - 

The supplied G-code is for the CoreOne, you will have two opportunities to insert magnets. The first is for the back 4 magnets, and the next pause is for the front 8 magnets. 
The large square magnets don't need to be placed mid-print. Those can be slid in from the back after the print is completed. 

Print with a 0.4mm size nozzle or smaller. Any material will work, I printed with PETG. 

Links - https://www.amazon.com/dp/B0CM61NTT4?ef_=ppx_hzsearch_conn_dt_b_fed_asin_title_1

https://www.amazon.com/dp/B09Q8KD7DC?ref_=ppx_hzsearch_conn_dt_b_fed_asin_title_3