Elna Air Electronic Tension Disk Cover

thingiverse

This part was created to replace the plastic tension disk cover found on Elna SU electonic sewing machine models made during the 1980's. This includes the SU Electronic, Carina, 500 and Jubiee. I found the simplest way to remove the metal guide was to push forward on the top of the arch while pivoting forward. To install, put the two ends of the guide into the grooves of the guide, press against the back of the loop while pivoting down until it clicks into place under the small tab. The screw that secures the cover is self-tapping. The hole is sized to allow the screw to be easily inserted. Keep it straight and turn the screw slowly. The 3D part is not identical to the original. Some wall thicknesses needed to be increased to strengthen the part. Also the top surface lacks the slightly raised circle. Since the part is printed upside down, the supports that would be needed can mar the surface. I printed the final with 100% fill. Lower fills should also work just fine. After the metal guide ring is snapped in place, carefully trim back the excess tab at the top so it is flush with the ring. Otherwise the tab will interfere with the tension disk. Also, file or trim back the ramp at the back if needed for the thread to freely pass under the cover to guide up to the top tension disk (when doing 2 needle sewing). Moving the metal tab protruding from the tension disk up and down when tension is set to a low number is a good check to ensure the disks are not touching anything. Since the part is printed to fairly exacting tolerances, slight differences between 3D printers may result in slight changes to the part proportions in the XYZ axis. If you need the part, I hope it works for you.