This shows the needle bar and presser foot bars and their associated parts being removed, or reassembled if you look at them in reverse order.

Singer Model 66 Tear Down Index

• Singer Model 66 disassembled
• Singer Model 66 Treadle Handwheel Assembly
• Hook Driver Assembly and Feed Rocker Assemblies
• Singer Model 66 Needle and Presser Bar Area
• Singer Model 66 Stitch Regulator Assembly
• Singer Model 66 Upper Tensioner Assembly