Question edited for clarity.
Do you mean the embroidery unit. If it is secondhand and has been stored for a long time, sewing machine oil, or worse WD40 goes 'gummy'. You would need to clean all the out. WD40 is a good solvent, so spray, leave it to soak, spray again and agitate with a brush. The wash it all off with hot soapy water. Dry thoroughly and after a few days, lubricate metal parts with sewing machine oil and any plastic parts with a dry silicone spray like Jigaloo. Test Jigaloo on a flat piece of plastic first as it is also a powerful fast drying solvent.
Embroidery Unit, Singer #052007
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Guaranteed to fit Singer Sewing Machine Models: CE-150 Futura III, CE-250 Futura III, CE-350 Futura III, SES1000 Futura III, SES2000 Futura III.
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