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