2G Refurbishing - The Head
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Particularly bad areas for an accumulation of gummed oil and fluff are inside the Lower Bobbin housing and inside the Head. The Head is often worse because it is less frequently opened and seen. (1) First loosen the head screw (if there is one), then unscrew the thumb screw and lift off the face plate. (2) Thoroughly clean inside the head cavity. (3) Make sure the thread of the Pressure Bar Regulating Thumb Screw is oiled and the screw is easy to turn. On the 15K, 66 & 201 you will see that the the regulating thumb screw is hollow or sealed with a fibre plug. You should apply a couple of drops of oil either into the hole or onto the plug. (4) Oil all the moving parts as indicated by the black arrows. As you can see from the illustration, most of the moving parts are associated with the levers that convert the rotating movement of the drive shaft into the up and down movement of the needle bar. On top of some of these small hinge bearings you will see an oiling hole. Put a drop of oil in each of these and also on all other moving joints. Do not overoil, as the surplus oil can run down the needle bar, spoiling the workpiece. (5) When lowered, make sure the slot in the foot does not foul the cover plate hole. A swivel adjustment of the presser bar and presser foot can be achieved by loosening the spring bracket screw. (6) Make sure the needle is centred over the cover plate hole. If there is a problem it could be due to a bent needle, or the needle not locating properly in the needle clamp. Always fit a new needle. (7) To adjust the needle, first raise the needle bar to its highest point by turning the balance wheel towards you. THE HEAD [2] G - 1 2.3.2006 2 2 1 4 3 2 5 Presser Bar Regulating Thumb Screw Needle Bar Presser Bar Presser Bar Spring Bracket Screw Cover plate hole 6 7
description
2G Refurbishing - The Head
Transcript of 2G Refurbishing - The Head
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Particularly bad areas for anaccumulation of gummed oil andfluff are inside the Lower Bobbinhousing and inside the Head. TheHead is often worse because it isless frequently opened and seen.
(1) First loosen the head screw(if there is one), then unscrew the thumb screwand lift off the face plate.
(2) Thoroughly clean inside the head cavity.
(3) Make sure the thread of the Pressure Bar Regulating Thumb Screw is oiled andthe screw is easy to turn.
On the 15K, 66 & 201 you will seethat the the regulating thumbscrew is hollow or sealed with afibre plug. You should apply acouple of drops of oil either intothe hole or onto the plug.
(4) Oil all the moving parts asindicated by the blackarrows.
As you can see from theillustration, most of the movingparts are associated with thelevers that convert the rotatingmovement of the drive shaft intothe up and down movement ofthe needle bar.
On top of some of these smallhinge bearings you will see anoiling hole. Put a drop of oil in
each of these and also on allother moving joints. Do notoveroil, as the surplus oil can rundown the needle bar, spoiling theworkpiece.
(5) When lowered, make surethe slot in the foot does notfoul the cover plate hole.
A swivel adjustment of thepresser bar and presser foot canbe achieved by loosening thespring bracket screw.
(6) Make sure the needle is centred over the cover plate hole.
If there is a problem it could bedue to a bent needle, or theneedle not locating properly inthe needle clamp. Always fit anew needle.
(7) To adjust the needle, firstraise the needle bar to itshighest point by turning thebalance wheel towards you.
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Presser BarRegulating Thumb Screw
NeedleBar
PresserBar
PresserBar
SpringBracket
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Coverplatehole
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Now release the clamp screw veryslightly and check that the needleis squarely secure and pushedfully up in the clamp before re-tightening.
If the needle still fouls the holetry a new needle and if theproblem persists you will have toexamine the clamp itself whichwe explain shortly.
At this stage, if everythingconnected with the Head is cleanand working properly - and youhave successfully ticked all fiveitems on your check list you areready to move on to the nextsection dealing with the LowerBobbin Area.
If you have any remainingproblems read on:
When the face plate is removedfour areas of the sewing machineare revealed inside the Head:
1. TENSION RELEASE.
2. NEEDLE HEIGHT & TIMING ADJUSTMENT.
3. PRESSER BAR ACTION.
4. NEEDLE BAR ACTION.
1. TENSION RELEASE:
We have already discussed theUpper Thread Tension Release inthe previous section.
2. NEEDLE HEIGHT & TIMING ADJUSTMENT:
The needle height can beadjusted although seldomrequired. Most machines alsoinclude timing marks to adjustthe overall timing of the machine.However, as these features willseldom be needed, they are leftuntil the Fault Finding section.
3. PRESSER BAR ACTION.
(8) The presser bar is an adjustablespring loaded component centralto the fabric control function ofthe machine.
(9) The presser foot, attached tothe end of the presser bar, pressesdown on the fabric holding it incontact with the feed dog. Thisenables the feed dog to grip andpull the material forward for thenext stitch.
The pressure applied by thepresser foot is adjusted by thepresser regulating thumb screwat the top of the presser bar.
This knurled control is turnedclockwise to increase the amountof compression on the presserbar spring and anticlockwise toreduce it.
Too little pressure on the presserfoot (especially when sewingthick or compact material) canresult in shorter stitches than setas the feed dog fails to grip thefabric firmly.
Also, with too little pressure, thethe presser foot may not hold thefabric properly and it will pucker.
Too much pressure will impose adrag when operating the machineand induce wear on the teeth ofthe feed dog.
To insert, remove or adjustmaterial from under the presserfoot the bar has to be raised usingthe presser bar lifter lever.
(10) Feel the difference in the pressure on the lifter armwith the thumb nut screwed fully in and then fully out.
If there is little noticeabledifference in pressure, it may bethat the spring needs replacing.
(11) With the 15K, 66 and 201models the spring can be seen onthe outside of the Presser Bar.
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Presser BarSpringBracket
Presser BarBracketScrew
Presser BarSpring
Presser BarRegulatingThumb Screw
ThreadCutter
Presser Footattaches here
PresserBar
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PresserBar
PresserFoot
ThroatPlate
Feed Dog
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(12) To replace the spring, undo the thumb nut completely and slide out the old spring.
(13) With the 99 model, the top ofthe spring is attached to a rodand then encased inside a tube.
It is removed in the same way byundoing the thumb nut com-pletely. If you do not have a sparespring please highlight thecompression problem on yourcheck list and we will remedy it atNetley.
Setting the Presser Bar Lifter:
It is important that there shouldbe a small amount of free play inthe action of the presser bar Lifterwhen the presser foot is down.
This free play makes it certainthat the downward spring pres-sure is on the material beneaththe presser foot instead of on thetop of the presser bar lifter.
If the bar and foot start to liftstraight away when the lever israised you need to work throughthe following adjustment proce-dure: - first making sure the teethof the Feed Dog are below thesurface of the Needle Plate:
(14) Loosen the Presser Bar Bracket Screw.
(15) With the presser bar releaselever down, lift the presserfoot slightly by hand and insert the blade of a small screwdriver between thepresser foot release lever and the presser bar bracket.
Let the presser foot down again,check the presser foot is clear ofthe needle hole and tighten thepresser bar bracket screw.
Check that there is the requiredsmall movement of the presserbar release lever before contact-ing the presser bar bracket.
Before tightening the presser barbracket screw, make sure that thepresser foot is not fouling theneedle hole. If necessary, rotatethe foot until it is clear.
(16) The metal clip attached tothe end of the presser bar abovethe foot is a simple Thread Cutter.
It is occasionally necessary toremove the presser foot tothoroughly clean the end of thepresser bar and the foot itself.
(17) Raise the Presser Bar andthe Needle Bar, loosen theknurled thumb screw andremove the Presser Foot
(18) The standard foot has beendesigned for easy detachmentfrom the end of the presser barbecause it is interchangeablewith other styles like the HemmerFoot shown above.
There is also a range of acces-sories designed for specific tasks.These are attached to the end ofthe presser bar in place of thestandard foot and are discussedin detail in a later section.
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4. NEEDLE BAR ACTION:
(19) On occasion you mayencounter a machine with abroken or badly bent Thread TakeUp lever which needs replacing.
Because this is infrequent - and atricky operation on certainmodels - we describe the actionrequired in the fault findingsection.
Needle Clamping:
The last area we need to look at isthe needle clamp. This canusually be successfully cleaned insitu using a tooth brush. If you dohave cause to dismantle it, youshould be aware of the slightvariation between models.
(20) The illustration above showsthe simplest form of needleclamp as fitted to early 99 and 66models.
(21) A later modificationincluded a thread guide attachedto the back of the Needle Bar witha small screw.
(22) The latest and mostcomplicated system has a smallthread guide component locatedinside the needle clamp - and theclamp itself is secured to the barwith a small grub screw.
When re-assembling it is easiestto seat the thread guide in theclamp then slide both upwardsonto the needle bar - then insertand tighten the grub screw.
The thumb screw is then requiredto secure the needle. It presses onthe anvil end of the thread guidewhich in turn presses on the sideof the top end of the needle.
It is worth a reminder here thatthe flat side of the needle on the201 machines should face to theleft (away from the machine). Onall the other models the flat sidefaces right (inwards towards themachine).
If you get this wrong the machinesimply wont sew, for reasonsexplained in the first section onHow a sewing machine works..
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End ofNeedle Bar
showinglocating
groove fortop of
needle
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Thread takeup lever
