The hubs were designed to be used with Schedule 40 PVC pipe, but we know that lots of people have used different materials for struts. The important consideration is the inside/outside diameters. Schedule 40 pipe is measured by its inside diameter, so that users can calculate air or fluid volume through them. So ½” Schedule 40 pipe actually has an outside diameter of .84”. Similarly, 1” pipe and 1 ½” pipe have those corresponding inside diameters. Our mega hubs are designed to accommodate an outside diameter of 1.33” on the inside of the hub arms. So you need to get the specs on your EMT and find out if you’ll be using the inside or outside diameter of the hubs.
Another consideration is the lack of flexibility of the EMT. Because of the flexibility of PVC, we can get away with all 10 or 12 degree angles, even though the pure math says the angles should range from 9 degrees to 14 degrees. If your dome is big – like 20’ diameter, it won’t be as much of an issue. If your dome is smaller than that, you’re going to have a challenge getting the pipe into the hubs.