Helen Howes Sewing Machines - Measuring a Motor Belt

Measuring a Motor Belt

How to measure and fit a motor belt

The picture on the left shows the parts of the sewing machine mentioned in this tutorial.

You will need the following;
Screwdrivers, or spanners to fit the bolts holding the motor and bracket.
A length of string or cord - at least 45cm or 18 inches long.
A marker pen
A ruler or tape measure

If you already have a new drive belt for your machine, go to Step3.

Step1

Start by fitting the motor and bracket

The motor can be moved up and down by loosening the bolt holding the motor bracket to the machine.

The motor can be moved in or out by loosening the bolt holding the motor bracket to the motor so there is space between the motor and light, and the side of the machine.

Some motor brackets do not have this adjustment.

Look from above to make sure there is clearance between the motor and light, and the body of the machine.

Step2

Take a length of cord, and put it round the motor pulley and the belt groove on the back of the handwheel.
Pull the cord tight, and hold it between thumb and forefinger, then mark across both ends of the cord with a marker pen.

Measure the length between the two marks with a ruler

Step3 Fitting the belt

When you have the right belt for your machine, undo the bolt holding the motor and bracket, slide it up as far as possible and tighten it enough to hold the motor in place.

Put the belt over the handwheel and ensure that the belt is in the pulley at the back of the wheel.
Pull the belt over the motor pulley, it should be a loose fit.
Undo the motor bracket bolt and slide the motor and bracket down then tighten the bolt and check that the belt can be deflected about 1cm with your finger.
Adjust the motor and bracket up or down until it has the right amount of slack.
You may need to do this a few times to get it right.

Step4

Look at the belt from above to make sure that the two pulleys line up. If they don't, the motor pulley can be moved along its shaft.
The pulley is locked on to its shaft with one or two grub screws, undo them, and move the pulley along the shaft until it is in line with the pulley on the handwheel.
When the pulleys line up, tighten the grub screw, or screws up.
After doing this, check the belt tension and adjust if needed.

Step5

The motor should be ready to try, first try it with the clutch undone, so only the handwheel moves.
Do up the clutch, ensure that there is no thread in the machine, and raise the presser foot, then try running the machine.

My address is:-
Helen Howes
Helen Howes Sewing Machines
1 Castell Farm Cottages, Thurlton Road, Raveningham, Norfolk NR14 6NY. UK
07914 676182
Email me here - helen@helenhowes-sewingmachines.co.uk
I prefer that you email me (at any time), or phone between 3 and 6 (UK time) most days