Hi. I'm making a tool to vacuum form a part but the cavity hasn't given too sharp an edge for the tool to work. Basically what i'm needing to do is have the outer edge of the tool flat but i have no idea how to about doing this. What i also haven't been able to do is have extra material around the edges to allow it to be trimmed. The part wont allow the offset of the sketch I have used but i'm wondering if there is another way to extend a solid. I hope I have explained this understandably. I've attached both the part the tool and the assembly. Thanks to anyone that can help with this.