Underwood #5 Typewriter
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How to Repair Underwood Typewriters

Quick reference to locating trouble

I'm scanning and putting in hypertext format an old Service Technical Manual "How to Repair Underwood Typewriters". As new pages will be finished they will be added here.

Note: The following notes and questions are merely an aid in locating where trouble can be found with the most common troubles found in Underwood Typewriter Repairing. To adjust correctly, follow the foregoing instructions listed in contents under title of Part Affected.

 

Problems you can fix using this guide:

  1. Paper Feed
  2. Irregular Spacing Between Lines
  3. Line Space Lever Sticking
  4. Letters Running "Down Hill"
  5. Letters Drop After Caps
  6. Carriage Skipping
  7. Carriage Failing to Space Properly
  8. Carriage does not lock at end of line properly
  9. Carriage spaces when shifting
  10. Carriage binds in shifting
  11. Shift Lock does not hold
  12. Action heavy
  13. Space bar sticking
  14. Ribbon guide does not act
  15. Bichrome mixing colors
  1. Ribbon does not move
  2. Ribbon does not reverse automatically
  3. To take out type bars
  4. Type Bars sticking
  5. Spacing between letters uneven
  6. To stop Skeaks
  7. To stop rattle
  8. Alignment bad
  9. Carriage pointer going beyond one space when carriage is pulled over
  10. Pointer drops back one space
  11. Back space doesn't work
  12. Key levers lock
  13. Paper release lever works hard
  14. Tabulator out of order

To open plates in a new window, so you can look at text and images at the same time, click for Plate 2 3 4 5 6 7 8 9 10

Paper Feed.

  1. Are feed rolls stuck or rusted? Oil feed rolls on shaft and clean thoroughly with alcohol.
  2. Are slots in paper table (E Plate 3) central with feed rolls?
  3. Is the tension on feed roll hanger springs (Q Plate 3) uneven?
  4. Is paper release lever binding?
  5. Is feed roll released rod (0 Plate 3) binding?
  6. Do the feed rolls snap back against the cylinder perfectly free?
  7. Are the paper finger rolls (B Plate 3) rusted or sticking? See that there is enough, but not too much tension on paper fingers.
  8. Is there too much tension on paper clips (P Plate 3)?

Irregular Spacing Between Lines.

  1. Are the cylinder set screws loose?
  2. On late machines, does the variable line space knob (R Plate 3) push in place without a decided click? If not, tighten screw (A Plate 9) two or three turns.
  3. Is line space plunger stop (B Plate 9) set so there is play when trying cylinder after holding line space lever over? There should be a minimum of play to this.
  4. Is the rubber on cylinder loose on core?
  5. Is ratchet (J Plate 9) loose on shaft?
  6. Is cylinder untrue?

Line Space Lever Sticking.

  1. Does plunger pawl (K Plate 9) catch on carrier returning?
  2. Is stop (B Plate 9) bent too far forward?
  3. Does the line space lever bind on top plate?
  4. Is the screw (C Plate 9) loose?
  5. Is plunger spring (D Plate 9) broken?
  6. Is the plunger pawl (E Plate 9) riding over lug?
  7. Is the line space lever pin (A Plate 10) rusted, or binding?

Letters Running Down Hill.

Caused by line space lever throwing too far and ratchet pawl landing on top of ratchet tooth, jumping back when machine is in operation.

  1. Is the line space plunger stop (B Plate 9) bent forward enough to take out back play?
  2. Is there any forward play when holding line space lever over and turning forward on cylinder knob? There should he none.
  3. Is ratchet release (I Plate 9) up?

Letters Drop After Caps.

  1. Is the screw missing from end of line space adjuster (F Plate 9)?
  2. Is the right hand cylinder knob (S Plate 3) too close to guide, binding at certain places on turning cylinder?
  3. Are the motion blocks binding on inner carriage in shifting?
  4. Does the carriage bind in shifting?

Carriage Skipping.

  1. Is there 1/8" drop to space bar after escapement trips?
  2. Are the dogs too far apart?
  3. Is the spacing rack set too high in pinion wheel?
  4. Are the spacing rack teeth worn?
  5. Are any teeth on pinion wheel broken?
  6. Are pinion wheel pawl springs broken?
  7. Is loose dog pin loose?
  8. Is there too much back play when pushing end of dogs (HH Plate 5) when key lever is pressed down?
  9. Is there too much tension on main spring?
  10. Is eccentric stud set too tight binding tabular block (Z Plate 5)?

Carriage Failing to Space Properly.

  1. Is way rod properly oiled?
  2. Is the trip set correctly?
  3. Are the assembled dogs set too far to the right? Plate 5 shows correct position. Set by loosening fulcrum pin set screws and turn fulcrum screw on left side (Q Plate 5) the right amount.
  4. Is the hack space pawl (T Plate 5) catching in the spacing rack? Adjust according to instructions.
  5. Dogs carriage rub on ribbon spools? File casting on carriage if it should.
  6. Has space bar the full drop after tripping?
  7. Is the pinion wheel or spacing rack roll binding?
  8. Is the star wheel binding?
  9. Is there play between locking piece on carriage (B Plate 3) and scale plate (BI Plate 10)?
  10. Is carriage latch (A Plate 3) binding on lift rail so that carriage drags?
  11. Does carriage roll turn freely?
  12. Is the ribbon guide dust plate (A Plate 7) out of place?
  13. Is the main spring draw band (N Plate 5) rubbing on lift rail in turning?
  14. Is spacing rack fulcrum screw (T Plate 3) out of place?
  15. Are the way rod screws loose?
  16. Do paper fingers catch on wing scales?
  17. Is the carriage frame broken?
  18. Are screws in way rod bushings (U Plate 5) loose?
  19. Is screw (AA Plate 5) loose?
  20. Is loose dog stuck?
  21. Is there enough tension on loose dog springs?
  22. Is main spring or drawn band broken?
  23. Is rocker arm (Y Plate 5) loose?
  24. Is carriage latch (A Plate 3) over left rail?
  25. Are assembled dogs loose?
  26. Is bell ringer held down by clamp?
  27. Is loose dog pin loose?
  28. Does carriage bind on left marginal stop?

Carriage Does Not Lock at End of Line Properly.

Adjust according to instructions.

  1. Is bell ringing lever throwing locking rod forward at right position?
  2. Is bell ringer held down by fastening clamp?

Carriage Spaces When Shifting.

  1. Are spacing rack teeth worn?
  2. Are carriage top plates rubbing on left or right rack release levers?
  3. Is variable line space drum hitting spacing rack release lever?
  4. Is there too much play between locking piece on carriage (B Plate 3) and scale plate?
  5. Are pins in actuating lever (B Plate 7) set too far to one side in shifting bracket (C Plate 7)?
  6. Is there too little tension on spacing rack release lever spring (M Plate 3)?

Shift Lock Does Not Hold.

  1. Is comb set low enough to allow shift key to go down far enough?
  2. Are pins or lever worn?
  3. On late style shift lock keys, is the round spring broken (E Plate 7)?
  4. Is the "pick" or rub on lower and upper case unequal when trying shift lock (A Plate 8)?

Carriage Binds in Shifting.

  1. Is carriage link (V Plate 3) bent or binding?
  2. Is ribbon winding wheel (K Plate 4) set in too far, so that it rubs on shift key lever?
  3. Is right cylinder knob set in too close?
  4. Are lift hook bushings (H Plate 3) too tight?
  5. Does carriage bind on carriage guide? (B Plate 10)?
  6. Is shift lock (A Plate 8) binding?
  7. Are shift key levers binding?
  8. Are lift hooks gripping carriage too tightly?
  9. Does carriage link bind on retainer spring (N Plate 3)?
  10. Are motion blocks rubbing on skeleton carriage?
  11. Is line space lever binding on plunger at (G Plate 9)?
  12. Does left spacing rack release lever bind on top plate?
  13. Does the right release lever bind anywhere?
  14. Are the pins in actuating lever (B Plate 7) set correctly?
  15. Does actuating lever rub on universal (D Plate 7)?

Action Heavy.

  1. Are key levers binding any?
  2. Are link studs (E Plate 2) central with slots in segment?
  3. Are any type bars binding or sticking in guide?
  4. Is tension on universal spring too heavy?
  5. Is universal perfectly free?
  6. Is tension on key lever springs (L Plate 2) as light as possible without letting key levers drop away from comb?
  7. Are fulcrum pins on rocker arm (BB Plate 5) too tight?
  8. Is the ribbon pawl throwing lever (F Plate 5) binding on rocker arm?
  9. Do the ribbon spool carriers work sluggishly?
  10. Is space liar binding?
  11. Is there too much tension on space bar spring (C Plate 8)?
  12. Is space bar throwing arm (D Plate 8) rubbing on key lever?

Space Bar Sticking.

  1. Is universal binding?
  2. Are fulcrum screws (D Plate 10) rusted?
  3. Does space bar stop (F Plate 8) rub on main frame?
  4. Is the tension on spring (C Plate 8) too light?
  5. Docs space bar arm (D Plate 8) rub on key levers?

Ribbon Guide Does Not Act.

  1. Is stencil lever (F Plate 7) thrown to left?
  2. Is ribbon guide over hook on actuating lever (B Plate 7)?
  3. Are screws loose in actuating lever bracket (G Plate 7)?
  4. Are rocker arm fulcrum pins (BB Plate 5) loose?
  5. Are bichrome shifting bracket screws (C Plate 7) loose?

Bichrome Mixing Colors.

Adjust as per instructions. The throw of ribbon guide is too high or too low.

  1. Are actuating lever (G Plate 7) screws loose?
  2. Are shifting bracket (C Plate 7) screws loose?
  3. Is ribbon guide filled with dirt?
  4. Is universal (D Plate 7) loose or broken?

Ribbon Does Not Move.

  1. Is ribbon pawl's set screw loose?
  2. Are ribbon pawls away from ratchet wheel (K Plate 4)?
  3. Are spool carriers binding?
  4. Is ribbon pawl throwing arm (F Plate 5) set screw loose?
  5. Are gears (D Plate 4) loose?
  6. Are any set screws of ribbon movement loose?

Ribbon Does Not Reverse Automatically.

The following references all refer to Plate 4.

  1. Is there enough tension on shaft pawl spring (A)?
  2. Is there too much up shake to pawl (B)?
  3. Are detent (C) and gears (D) set incorrectly?
  4. Are shifting wheels (L) set away from shoulder on shaft?
  5. Are any set screws loose?
  6. Is the eyelet missing on ribbon to throw lever (H) out?
  7. Are ribbon pawls set too close together in ratchet winding wheel teeth?
  8. Is the 53...
(to be continued...)

 

 

 

Last update: 6 Jan, 2000
(c) Joan Sales
 

 

 

 

 

 

 

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