I drew these threads about three months ago and I'm trying to draw a different size now but I m doing something wrong and cant figure it out. After the first thread under the structure tab it shows up as a solid. When I do the next two threads under the structure tab they show up as surface. I can high light them and they show up but its just on the surface unlike the first thread which is cut in the solid. These are internal threads. You helped me out on this before and I printed one but I'm doing something wrong now. This is for a bird feeder cap on an ocean spray 3 liter bottle.