Pfaff 138 Sewing Machine Instruction Book – 1970s

This Pfaff Instruction Book covers setup, operation, routine maintenance, and basic repair checks for the 138, including Model A for lightweight materials and Model B for medium-weight materials.

Printable Files and On-Screen Reading

Text search and navigation: Neither PDF has embedded searchable text or PDF bookmarks. Small part numbers on the wearing-parts plate benefit from enlargement. The final English troubleshooting sheet is sideways and requires rotating the view.

The ZIP contains 40 pages across two printable PDFs, with 20 pages in each file. This comprises the 39-page instruction book, including its cover, plus one unnumbered English troubleshooting sheet already included in the total. The main book presents German, English, French, and Spanish text.

Threading, Stitch Controls, and Sewing Attachments

The following selected topics outline the operating and maintenance coverage rather than reproduce the complete contents.

• Needle setup: Needle-and-thread selection chart, subclass-specific needle systems, needle installation, and adjustment of the twin-needle gauge.

• Bobbin winding and threading: Step-by-step instructions for motor- and treadle-driven winders, bobbin-case installation, needle threading, and thread-tension balancing.

• Stitch controls: Forward and reverse stitch length, needle-position selection, straight and zigzag stitching, and locking a preset zigzag width.

• Presser-foot and pedal controls: Material-pressure adjustment, hand and knee lifting, Stop-motor needle positioning, and pedal-operated reverse sewing or backtacking.

• Cleaning and fault checks: Hook-area cleaning, hook-gib removal, lubrication diagrams, and troubleshooting for skipped stitches, thread breakage, needle breakage, and poor feeding.

• Specialty sewing: Standard and gimp buttonholes, cording, button sewing, quilting, roll padding, blindstitching, darning, embroidery, and bias binding.

It is suited to instructed operators and experienced sewing-machine owners using illustrated setup guidance; electrical-equipment work is reserved for electricians or appropriately instructed personnel.

Subclass Identification and Twin-Needle Setup

The needle-system table helps prevent a common setup mistake: selection depends on the full subclass designation, not simply on the Pfaff 138 model name.

Needle-system matching: The table assigns 438 KK to -6/21, -6/21-915/02, -34/01, -45/01-915/02, -45/02-915/02, and -66/01. The -6/21-915/05, -45/01-915/05, and -45/02-915/05 versions use 130 B; -275/01 and -277/01 use 134 EK.

Twin-needle adjustment: The -915/02 has individually adjustable needle-holder jaws, while -915/05 uses screw adjustment. Cording coverage for -45/..-915/.. machines identifies the required needle bars, needle holder, cording foot, and cover plate, with separate component references for the applicable needle systems.

The presser-foot section also addresses the top roller on -905/.. subclasses. The pedal-function chart distinguishes -913/52 needle-up/down positioning on Stop-motor installations from -911/01 reverse sewing and backtacking.

Thread Formation, Lubrication, and Troubleshooting

The threading illustrations identify the guides, tension discs, thread-check spring, take-up lever, and needle. Stitch cross-sections show correct thread interlock and the effects of excessive or insufficient upper and lower tension.

The control instructions explain how reverse stitch length corresponds to the forward setting and how a preset zigzag width can be restored after a temporary change.

Machine care: Oiling-point layouts identify the hook raceway and machine-head lubrication points. The specified products are Pfaff sewing-machine oil 280-1-120 144, or an acid-free equivalent meeting the listed requirements, and soda-soap grease 280-1-120 243 for the bevel gears. Cleaning instructions address packed lint and thread jams requiring access beneath the hook gib.

Repair checks: The fault tables connect sewing problems with needle installation, hook timing and clearance, thread-check-spring adjustment, feed-dog height and tooth condition, presser-foot pressure, and lint buildup. They identify a bent needle being struck by the hook point as a cause of needle breakage and warn that jammed thread can upset hook timing.

These are fault-reference tables, not detailed hook-timing or internal overhaul procedures.

Attachment Setup and Wearing-Parts References

Standard buttonhole instructions include a stitch-layout illustration. Eyelet-end and gimp buttonhole coverage identifies foot 91-041 420-05 and edge guide 91-041 427-91. It explains when the guide must swing clear of the presser bar; incorrect guide alignment can allow the needle to strike the guide sleeve.

Buttons and quilting: Accessory references include button-sewing foot 91-041 047-05, straight-stitch quilting foot 91-026 242-93, and zigzag quilting foot 91-041 296-93.

Darning and binding: Cover plate 91-041 251-25 is shown for darning and embroidery. Bias binder 91-041 894-23 is paired with foot 91-041 895-04, with fitting and alignment guidance for the binding.

Roll-padding and blindstitching coverage explains guide selection for different fabric thicknesses and centering the attachment relative to the needle throw.

The wearing-parts plate provides gauge-part views and an exploded hook/shuttle assembly. Parts coverage is a limited reference rather than a complete parts catalog. This is an operating and maintenance book, without wiring diagrams, motor repair procedures, or full internal disassembly and reassembly instructions.

Disconnect the machine from electrical power before threading, changing gauge parts, cleaning the hook area, or performing maintenance, and never operate a motor-driven installation without correctly fitted belt guards.

Examples of Lubrication and Attachment Settings

The oil specification includes a density of 0.865 g/cm³ at 15°C. Oiling frequency is twice weekly in normal use, daily in sewing factories, and twice daily under extreme conditions such as heavy lint or high-speed operation.

For roll padding and blindstitching with attachment 91-744 700-91, the setup specifies maximum stitch width and a stitch length of approximately 3 mm.