Share 'How long do I have before chocolate sets?'

Hello everyone! I hoping that someone can help me with this issue. I'm having a problem when pouring tempered chocolate into molds/forms. It seems as though the first few trays come out perfectly tempered but the last few do not. Just how much time do I have before the chocolate sets? I rush like crazy to get them poured but I never see anyone else rushing when I watch tutorials. What might I be…