ORS § 14.270
An affidavit and motion for change of judge to hear the motions and demurrers or to try the case shall be made at the time of the assignment of the case to a judge for trial or for hearing upon a motion or demurrer. Oral notice of the intention to file the motion and affidavit shall be sufficient compliance with this section providing that the motion and affidavit are filed not later than the close of the next judicial day. No motion to disqualify a judge to whom a case has been assigned for trial shall be made after the judge has ruled upon any petition, demurrer or motion other than a motion to extend time in the cause, matter or proceeding; except that when a presiding judge assigns to the presiding judge any cause, matter or proceeding in which the presiding judge has previously ruled upon any such petition, motion or demurrer, any party or attorney appearing in the cause, matter or proceeding may move to disqualify the judge after assignment of the case and prior to any ruling on any such petition, motion or demurrer heard after such assignment. No party or attorney shall be permitted to make more than two applications in any action or proceeding under this section.
ORS 14.270