Landguard1120

Greg. You are spot on !!! "Remove all holes" was ticked. Many thanks for your help

We are trying to print some basic item for children tricycles at local school. The item is a 50mm dia, 15mm high puck shape hollowed out to a depth of 10mm with walls and base 5mm thick. We have created the stl file in both Fusion 360 and Tinkercad to see if problem was at the design stage. Our problem we are slicing in Cura 4.13 & Cura 4.7 and all appears well until we print. What is happening that the printer is not creating the hollowed out part and we have ended up with a solid Puck!! We have tried 3 different printers and we get the same result. Any ideas what we can do to just print a very basic object ?? Any help appreciated