Not sure if this is the right place for this post but I did not see a suggestions box area! The 3 and 6 degree curved track STLs seem to be problematic. If I understand what the issue is, it appears that two ties are sitting flat on the bed and the rest are elevated slightly which causes the print to fail 100% of the time as most of the model is off of the bed.
I have no problems printing the straight and 12 degree curves however so I am fairly certain the issue is not on my end. Definitely willing to try out any suggestions to correct the problem on my end though.