Thank you for the quick reply! I have been using a regular glue stick, so that may be the issue. I have the nozzle height pretty close, so I am not sure it is the distance. Can I ask what you recommend cleaning the glass with after printing? We use a scraper to lift the prints - and they come up easily, but there is some residue on the glass. Maybe I should try heating the glassbed and cleaning?
I am new to 3D printing and we have an older model Ultimaker 2. I have read some of the forum/expert posts and am a little overwhelmed as to why some of our designs will print find and others will fail after 1 hour of printing. I tested a few small designs, and the PLA and nozzle seem to working fine. When I tried this design, it started loosing its layering after about 1 hour into the 3 hour printing. Is this something I can prevent with my Cura settings? I think I had them set as the default, with 20% infill.