General aviation fixed wing pilot reported a near miss with a helicopter at S50 non-towered airport during a training flight in VMC conditions. The Instructor performed an immediate turn to avoid the conflict.

Narrative

I was conducting private pilot training with focus on landings at S50 with a student. On third consecutive lap and making calls on each leg of the pattern; Aircraft Y [helicopter] reports departing Taxiway A south departure. We are currently in downwind for Runway 34 and I spot the aircraft starting to depart but lose them shortly there after. After turning base and reporting turning base. I still did not see the aircraft. As we neared final they appeared off the nose. We made an immediate turn towards the runway to avoid further conflict. The helicopter's position was aligned with Final for runway in use; 34. After avoiding conflict and stabilizing aircraft I asked over the radio that the helicopter avoid flying up final with traffic in the pattern. They responded with that they were not and that it was my fault for being so close. I spoke up and advised that we turned early because they were on final. They responded with to contact the airports manager if I had a problem with them. I believe that this was a very hazardous attitude to take with safety and that the pilot did not really care who he cut off and that it was the planes responsibility to move for him. If the pilot had departed into the wind and followed a standard departure there would not have been a conflict.