AIR 1800 FAQs & Troubleshooting AIR 1800 Not your product? Sort by Updated Date Popularity 5 Results 1. 06/13/2024 Differential feed adjustment 2. 11/02/2022 Thread tension adjustment 3. 11/02/2022 Adjusting the presser foot pressure 4. 11/02/2022 Locking and unlocking the upper knife. 5. 10/28/2022 To secure chains Sewing (Overlock machine) FAQs & Troubleshooting