Model: Orion Delta 3D Printer
Manufacturer: See-Me-CNC
Electronics: RAMBo, USB B port
Firmware: Orion 0.91 Firmware, Repetier-Firmware based (source)
Official Website: http://seemecnc.com/
Support Website: http://seemecnc.com/pages/support
Baud Rate: 250000, typically. Make sure that you are using the very latest OctoPrint release (that has a PySerial update to permit 250000 baud rate). After you confirm that, you may need to change the onboard setting on the Orion to this rate and push it to the firmware before you attempt to connect.
Port: /dev/ttyACM0