Pfaff 418 Series User manual

418
438
838
PFAFF
Service Manual,
innovation made by PFAFF

Contents
Page
1Preparations for adjusting 2
2Centring the needle in the needle hole (in sewing direction) 5
3Setting
the stabilizing rod parallel to the needle bar
6
4
Stitch width control 8
4.1 Zeroing the needle for straight stitching 8
4.2 Stitch width scale
9
4.3 Limiting the maximum stitch width
10
4.4
Adjustung the locking lever 11
5Adjusting
the needle in the needle hole (sideways)
12
6Adjusting
the needle throw 13
7Needle position "left, centre, right"
14
8Adjusting the needle position lever
16
9Adjusting
the stitch length scale ring
25
10
Zeroing the bottom feed 18
10.1 Adjustment with closed gearcase
18
10.2
Adjustment with open gearcase
19
11
Adjusting the bottom feed driving motion
20
12 Bottom feed liftingmotion
21+22
13
Tensloning the driving belt in the gearcase
23
14 Adjusting the hook bearing bracket
24
15
Preliminary adjustment of needle bar height
25
16 Oil distributor ring
26
17
Hook timing and hook-to-needle clearance
27
18 Final adjustment of needle bar height
28
19
Bobbin case opener
29
19.1 Position of bobbin case opener
29+30
19.2 Timing the bobbin case opener
31
20
Adjusting the slack thread control
32
21 Clearance between presser foot and needle
33
22 Feed dog height
34+35
23
Oil check valve
36
24 Tension release mechanism
37+38
25 Lubrication of zigzag eccentric
39
26
Hook lubrication
40
27 Knee lever stroke limitation
41
28 Knee lever play
42
29
Bobbin winder
43
30 Thread check spring and thread regulator
44
31
Presser foot pressure
44
Annex for machines equipped with zigzag control -716/..
32 Needle vibration 45
33 Left, center and right needle positions 46+47
34 Needle position lever 48+49
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Notes on safe machine operation:
The machine must only be usedforthe purpose It has been designed for.
When converting Itto anotherversion, all valid safety rules must be followed.
Service and repair workmust only be performed by qualifiedpersaonel.
Workon liveparts Is not permitted, apart fromexceptions according to DIN 57105 and VDE0105.
Service manual 418,438,838 appliesto the following versions:
418 438 838
418-716/.. 438-716/.. 838-716/..
For the adjustment of automatic fancy-stltch mechanism -718/01 and thread trimmer -900/.. there are
separate manuals.
Important note
Donot use a C-clamp on the needlebar of Pfaff 418,438 and 838 machines as thiswoulddamage
Its special coating. Make sure you check the hook lubrication system (see Section 27) on ma
chinesInoperationforthe firsttime or which have been Idlefor a longer period (I.e.1 or 2 months).
For shipping purposes the oilis drained from the needle vibrating eccentrichousing of the Raff 418,438
and 838. ItIstherefore necessary to fill this housing with 75 c.c. of oil (see Section26) before operating
the machine for the first time. A sticker on the machine arm serves as a reminder.
When the machine Isgiven a general overhaul put about2c.c. of piniongrease, witha dripping point of
160°C, in the bevel-gear
case of the hook. We recommend you use Molykote-Longtherm 00. This
grease can be obtained from us under No. 280-1-120 199.
Tools, gauges and other accessories required for adjusting the machines
1 set of screwdrivers with 2 to 10 mm wide blades
1 set of alien keys from 1.5 to 6 mm
1
set of wrenches with openings from 7 to 14 mm wide
1wrench with 27-mm-wlde
opening
1 metal ruler
1 cylindrical pin (5 mm dia.), No. 13-030 341-05
1 feed dog gauge, No. 91-129 995-05
1 hook bearing bracket gauge. No. 91-129 996-05
1 wrapper of system 438 needles
2 strips of white paper
1 rollof adhesive tape
Sewing thread and testing material
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1
Note:
Preparations for adjusting
To allow the machine to be blocked with the needle bar at the required position the
bearing plate (Fig.1.0.1.) has four holes.
Afterpositioning themeedlebaras requiredpushthe pinintothe appropriatehole until
it enters the recess behind the bearing plate, thus blocking the machine.
5mrn
1.0.1
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1-1 Take out screws 1 from the cast iron cover and remove the cover. (Do not remove the
needle bar lubricating wickfromits hole inthe cover sealing plate.)
.2 Drainthe oilfromthe needle vibratingeccentric housing.
1.0.2
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1.3 Unscrew the two screws in the face cover and remove the cover.
.4 Take out screw 2 and remove the presser foot.
.5
Take out screw 3 and remove the thread guide.
.6 Loosen screv^jof thejthread control and remove the latter by pulling it downwards.
.7 Unscrew alien screws 5 (do not remove cover plate 6 itis stillconnectedto oilwick9).
.8 Loosen clamp screw7 and pullstabilizing rod 8 down a little.
.9 Remove plate 6 with oilwick 9.
.10 Insert a new needle (system 438) and push itup as far as it will go; the longgroove should
face the front.
1.0.4.
1.0.3.
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Centring the needle In the needle hole (in sewing direction)
When the stitch width is set at "0" and the needle position lever is in its central position
the needle must enter the needle hole exactly in the middle (in sewing direction).
1
S'
2R
3B
4 L(
5Ti
th
6In
7C
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Setting the stabilizing rod parallel to the needle bar
Setting: Stabilizing rod 4 must be parallel to the needle bar.
Adjustment:
3.1
The lobe of eccentric stud 3 must always point downwards.
Bring the needle bar to t.d.c. and Insert the pin In hole "2" of the bearing plate (to block the
machine).
lulaking sure that lock screw 7 Is loose, loosen screw 1 (accessible from the back of the
machine arm).
Loosen jam nut 2 und turn eccentric stud 3 so that Its lobe points downwafds.
Insert stabilizing rod 4 in the loop of oil wick 5.
Position stabilizing rod 4 so that the recess at Its top end (see arrow in Fig. 3.0.1) touches
eccentric stud 3.
Hold stabilizing rod 4firmly and turn eccentric stud 3until stabilizing rod 4 Is
parallel to the needle bar (Fig. 3.0.2).
In this position tighten eccentric stud 3 with nut 2.
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3.8 Tocheck that itis paraileltothe needle barfirstpullstabilizing rod4 downand then push
it up again as far as it will go, making sure that guide 6 does not move to the side (if
necessary turn eccentric stud 3accordingly).
•9 Making sure that stabilizing rod 4 is still in contact with eccentric stud 3 tighten clamp
screw 7securely.
.10 Remove the cylindricalpinfromthe hole inthe bearing plate.
.11 Bring the needle bar to b.d.c. and tighten screw 1 which is accessible from the back of the
machine arm.
.12 Screw on cover plate 8.
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4
4.1
Setting:
Stitch width control
Zeroing the needle for straight stitching
When the stitch width control is set at "0" the needle bar must not move to the side.
4.0.1
Adjustment:
4.1.1 Set needle position lever 1 at its central position.
.2 Loosen screws 2 and 3.
.3 Loosen clamp screw 4 and let lockinglever 5 move back until itsspring is relaxed.
.4 Inthis position, tighten clamp screw 4.
.5 Move stitch width lever 6 to the right as far as it will go (i.e. towards "0").
.6 Turn on the master switch and let the machine run slowly.Move stitch width lever 6 to
the left until the needle bar stops swinging sideways.
.7 Inthis position push screw2 to the right as far as it will go and tighten it.
.8 Check this adjustment (see "Setting").
.9 Switch off master switch.
. 10 Screw 3 is still loose.
8
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4.2
Setting:
Adjustment:
4.2.1
.2
.3
.4
.5
Stitch width scaie
When the stitch width control is set at "0" the zero mark on the stitch width scale
must be opposite mark 3 of the stitch width lever.
4.0.2
Movestitch width lever1 to the rightas faras it will go.
Loosen screws 2.
Adjust the stitch width scale untii the zero mark is opposite mark 3 of stitch width
ieverl.
in this position tighten both screws 2.
Check this adjustment (see "Setting").
9
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4.3
Setting:
Adjustment:
4.3.1
Note:
Limiting the maximum stitch width
When the maximum stitch width is set, mark 2 of the stitch width lever must be
oppositethe maximum stitch width markon the stitch width scale.
4.0.3
Move stitch width lever 1 to the left until mark 2 is opposite the maximum stitch
width mark on the stitch width scale.
Inthis position move stop screw 3 which limitsthe maximum stitch width upwards as far
as itwillgo and tighten it.
Iffor certain sewing operationsthe machine is equippedwith a needle plate whose hole Is
smaller than the widest stitch width indicated on the scale, limit the stitch width according
to the width of the needle hole rather than the graduation mark on the stitch width scale.
Check this adjustment (see "Setting").
10
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4.4
Setting:
Adjustment:
4.4.1
.2
.3
.4
Adjusting the locking lever
The locking lever 2 must be adjusted sothat stitch width lever 3canbe locked inany
position.
4.0.4
Loosenclampscrew1 of locking lever2, making sure thatthe pressurespringinthe lock
ing lever does not fall out.
Pull locking lever 2forward until it presses against stitch width lever3.
In this position use ascrewdriverto turn hinge stud 4 until the locking lever has the
right amount of play and then tighten clamp screw 1 (whenat rest, locking lever2
must be more or less parallel to stitch width lever 3).
Check this adjustment (see "Setting").
11
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Adjustment:
5.1
Adjustingthe needle Inthe needle hole (sideways)
When the stitch widthlever is turned to "0" and the needieposition lever isinitscentral
position the needie shouid enter the needle hole exactly in the middle (sideways).
m
I
Turnthe needie position ieverto its central positionand the stitch widthlever to "0'
Bring the needle bar to b.d.c.
Loosen jam nut 1.
Turn eccentric stud 2 until the needle Is centred In the needle hole sideways.
Inthis position tighten eccentric stud 2 with nut 1.
Check this adjustment (see "Setting").
Replace the plastic plug on the underside of the arm.
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6
Setting:
Adjustment:
.1
.2
.3
.4
.5
.6
.7
.8
Adjusting the needle throw
Whenthe needle bar risesfrom the bottom position on the rightof its throw to t.d.c. (pin
in hole 2) it must not move to the side when the stitch width lever is moved to and fro.
coAmm
6.0.1
Loosen screws 1 of zigzag eccentric 2 just enough to allowthe eccentric to be turned on
its shaft against strong resistance.
Bring the needle bar from the bottom position on the right of its throw to t.d.c.
Insert cylindrical pin in hole "2" of the bearing plate (to blockthe machine).
Moveeccentric 2sidewayson its shaft untilthere is a clearanceof about 5 mm betweenit
and the rightwall of the casting. (See Fig. 8.0.1.).
Turn eccentric 2 on its shaft until the needle bar stops vibrating when the stitch
width lever is moved to and fro.
Check this adjustment (see "Setting").
Remove cylindrical pin from hole "2"of the bearing plate.
Screws 1 are still loose.
13
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Needle position "left, centre, right"
When the stitch width lever is set at "0" the needle must enter the needle hole in the
centre.
When the maximum stitch width is set the right and left positions of the needle In the
needle hole should be equidistant from the centre (Fig. 7.0.2).
Turn
needle position lever to its "central" position and the stitch width lever to "0".
Place a piece of white paper on the needle plate and hold it in position.
Turnthe balancewheel initsnormal direction ofrotation and letthe needlepierce the paper.
Raise the needle again a little and hold the paper in position.
Turn the stitch width lever to the "maximum" stitch width.
Turn the balance wheel in its normal direction of rotation and let the needle pierce the
paper again.
Remove the paper from under the needle and turn the balance wheel one complete turn.
Turn stitch width lever to "0" again.
Place the piece of paper under the needle again and position itso that the needle pierces
the first hole exactly as before.
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7.10 Making sure that the needle point is not in the paper, turn the stitch width leverto "maxi
mum"
and let the needle pierce the paper again.
.11 Move
needle vibrating eccentric 2 in the direction In which the two outer needle
punctures must be moved in order to obtain a symmetrical stitch pattern; make sure
that the eccentric is not rotated in the process.
.12 Inthis positiontighten screws1 and pushthe circlip (see arrow in Fig.7.0.1) up againstthe
eccentric.
.13 Check this adjustment (see "Setting").
15
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8
Setting:
Adjustment:
8.1
.4
.5
.6
.7
.8
.9
.10
.11
Adjusting the needle position lever
The left and rightthrows ofthe needle must be the same both at the widest stitch
setting and at the leftand rightneedle positions.
8.0.1
Loosen screws 1 and 2.
Tum needle position lever 3 to Its "central" position and stitch width lever 4 to the "maxi
mum" stitch width.
Tum the balance wheel in its normal direction of rotation untilthe descending needle is
positioned above the left end of the needle hole.
Place a piece ofwhitepaper overthe needle hole and fixitinpositionwithadhesivetape.
Turnthe balance wheel Insewing direction untilthe needle pierces the paper.
Turnthe balancewheel inthe oppositedirection and letthe needle pierce the paperagain.
Turnstitch widthlever 4 to "0" and push needle position lever 3 to the rightuntilthe point
ofthe needle Ispositioned exactly above the hole last made Inthe paper.
In
this position push screw 2 against its stop and tighten it firmly.
Push needle position lever 3 to the leftuntilthe point of the needle Is positioned exactly
above the lefthole Inthe paper.
In this position push screw 1 against its stop and tighten it firmly.
Check this adjustment
(see "Setting").
16
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9
Setting:
Adjustment:
9.1
.2
.3
Adjusting the stitch length scale ring
When the stitch iength is
set at "0" the "0" mark on scale ring3 must be in line with
graduation mark 4.
Turn miiied wheel 1
as far as it will go in the direction in which the reverse-feed control
moves downwards.
Loosen screw 2 and turn scale ring 3 so that the figure "0" is in linewith graduation
mark 4.
Inthis position tighten screw 2.
17
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10
Setting:
10.1
Adjustment:
10.1.1
.2
.4
.5
Zeroing the bottom feed
When the stitch iength is set at "0" the feed dog must not move fonward when the
baiance wheei is turned.
Adjustment with closed gearcase.
((t
1/
10.0.1
Loosen clamp screw 4 of actuating crank 5.
Place a27-mm wrench on hexagon torsion nut 6 and thus hoid actuating shaft 7 firmlyin
position.
Keep rotating the balance wheel and turn the wrench on the torsion nut until the
feed dog stops moving forward.
Hold the wrench in this position and, making sure the actuating crank 5 and circlip 8 are
against the casting, tighten clamp screw 4.
Check this adjustment (see "Setting").
18
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