Standard Spoked Wheels:

When engaged, the balancewheel transmits the power fromthe handle (or treadle) to run themachine. The combined weightand spinning motion helpssmooth out the action.

When disengaged from the maintransmission, the balance wheelis used to drive the bobbin winder.

(1) Slacken the small pin screw in the face of the shiny knurled hub disc - known as the stop motion screw.

(2) Unscrew the stop motion screw hub disc.

(3) Remove and clean the oddshaped clutch washer.

(4) Draw the balance wheel off its spindle then clean and oil spindle and wheel bearing.

If the wheel is tight on the shaft,try easing it by liberally applyingpenetrating oil.

If the outer rim of the balancewheel is badly pitted or rusted, areplacement wheel may be thebest solution.

(5) If the balance wheel is really stuck, place a block of wood beneath the needle bar.

This prevents the machine fromturning while you work the bal-ance wheel free. Do not useexcessive force because there is adanger of disrupting the timing.

(6) If the wheel is still seizedon the shaft, turning itslowly whilst tappinggently with a fibre malletshould dislodge it...

(7) ...or, if you have one, use a Gear Puller like the oneillustrated above.

You may need to reverse the armsso the hooks are pointing out-wards and can lock on the rim ofthe balance wheel through thespokes.

Solid & Larger Size Wheels:

Machines with spoked balancewheels are designed for use withhandles and/or treadles.

(8) Some very early machineshave balance wheels with a thickrim like the one shown. This cansometimes preclude the oppor-tunity of inter-changing handlesfrom some other later models.

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Some machines are designed tobe driven solely by a belt andhave a solid balance wheel likethe one shown.

(9) Dismantle and draw a solidwheel off its spindle in thesame way as a spoked one.

These solid balance wheels havea larger diameter flange for thebobbin winder to work on thanthe spoked wheels.

We cannot therefore just substi-tute a spoked wheel, as the bob-bin winder cannot be adjusted toengage with the spoked balancewheel.

(10) Check if the bobbin winder attaches at the top of the machine.

If so, the balance wheel and thebobbin winder can be changed asa pair. If you do not have spares,note it on the refurbishmentrecord on the outside of the caseand Netley Marsh will change it.

(11) In most cases you will findthat the bobbin winder attachesby screws at the side of themachine behind the balancewheel.

All is not lost in this case, as wecan use any long base machine -15K, 66 or 201- for a treadle base,releasing a spoked balance wheelmachine for conversion to hand.

Again, a few solid balance wheelshave an indented notch cut inthem to allow a handle to be fit-ted.

We do not recommend that thisconversion is attempted on othermachines such as 99 and 185.

(12) The picture above shows theBalance Wheel (stop motion)bushing on the end of the end ofthe driveshaft.

What concerns us is the opera-tion and adjustment of the clutchmechanism which is common toall the machines we send.

(13) Here we see the end of thebushing, projecting through thehub of the balance wheel. Noticeparticularly the notches at theend of the bushing.

(14) Now the clamp stop motion(or clutch) washer has beenadded and you can see how thetwo inside lugs fit into the twonotches at the end of the shaft.

Notice how these lugs bend out-ward from the bushing. This isimportant because it provides acreeping action for tightening theclutch.

In other words, the clamp stopmotion washer acts like an ordi-nary spring washer except that itis not designed to lock into posi-tion.

If the lugs are pointed inwardthere is no give to the washer atall. It locks almost instantly and islikely to work loose when themachine is working.

Exact adjustment of the stopmotion washer is an easy matterif the clutch is understood.

(15) This picture shows thereverse side of the hub disc andthe stop pin screw that threadsthrough the hole.

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(16) When threaded into positionthe end of the screw projects farenough through the hole so itcan strike against the outside earlugs.

When winding a bobbin it isdesirable to have the balancewheel run free, and not turn thedriveshaft which operates themachine.

Imagine you could see what washappening behind the disc...

To help you understand, theaction the following photos aremirror images.

(17) The hub disc is unscrewed(anti-clockwise) releasing thepressure until the pin clicksagainst an outer ear lug, stoppingthe hub from undoing completely.

When the bobbin is wound, theoperator turns the clamp stophub screw clockwise and, in sodoing, tightens the clutch.

The white lines added to photo(16), show where the tips of theprojecting sprung lugs rubagainst the inside surface of thehub screw.

(18) If, when the hub is screwedin to its maximum, it is still nottight enough - you will have toremove the clutch washer andturn it through 180 degrees.

The dotted lines show how bydoing this you get six times moremovement between the pin andthe ear lug which allows thethread of the hub screw to bitedeeper and increases the pressure.

When you replace the stopmotion screw, you can have noidea whether you have locatedthe washer correctly.

However, it will soon becomeobvious. If it isn't right, take offthe screw, turn the washer round180O and try again.

(19) It is much easier to fit thewasher and screw if you tip themachine up on to its end.

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