Repairing a treadle sewing machine is like opening a doorway to the past. Isaac Merritt Singer invented the first treadle sewing machine in 1850. He thought that powering the machine with a foot pedal, like a spinning wheel, would be more efficient than the hand crank that powered the earliest machines. Treadle machines were mass produced until the 1920s, when the treadle was replace by the electric motor. But treadle machines are still on the market today, and many of them still operate.
Inspect the exterior of the machine. Look for cracks in the case or visible rust. Mix dish washing detergent with water and wipe the outside of the case. Use great care around painted words and decals. These may identify the model and date of your machine.
Open the sewing machine case by unscrewing the small screws at either the top or the bottom of the machine. The location of the screws depends on the model.
Remove debris with tweezers and a metal nut pick. Dust, lint and even insects find their way into the moving parts of an antique sewing machine. If the machine has been stored in a barn or outdoor storage building, small rodents may have nested in the machine or cabinet.
Remove old grease and dried dirt from the workings of the machine. Dip cotton swabs in kerosene and wipe the old, dried grease from the gears and shafts of the machine.
Oil the inner workings liberally with WD-40. Turn the hand wheel and watch the inner workings move. If the needle does not move, turn the hand wheel and watch which gears and shafts turn. Look carefully where the movement stops. If there is debris blocking contact between gears, remove the debris. There may be a single gear or shaft missing. Replace any missing pieces. Replace the cover.
Check the leather belt that connects the hand wheel to the treadle. If properly cared for, the leather belt can last for a hundred years or more. Look for cracks in the leather. Turn the hand wheel if possible. Watch for the staple to appear as the belt rotates with the wheel. Check the condition of the staple.
Clean the gears on the underside of the cabinet. Use kerosene and cotton swabs to remove old oil and dirt. Oil the gears.
Press on the treadle with your foot. Push the back of the treadle and watch the wheels spin. If the gears work, but the belt slips or breaks, replace the belt.
Remove the old belt. Inspect the new belt. Find the staple that makes the belt into a loop. Pry the staple open and remove. Set the staple aside.
Fold the new belt in half and slip the loop over the hand wheel. Drop the front half of the belt down the front hole in the cabinet and the back half through the rear hole in the top of the cabinet. Wrap the bottom portion of the belt around the bottom flywheel.
Place one end of the staple into its hole at the end of the belt and bend the staple closed. Pull the leather belt taut around the wheels, overlapping the ends tightly. Mark the spot on the belt that crosses the staple. Press the leather needle into the mark to make a hole. Slip the free end of the staple through the hole and bend the staple closed.
Missing or damaged shafts and gears can be replaced. Look through antique stores for partial machines. As the machine is used, the leather belt stretches. It may need to be tightened after use.
Always use care when poking around in the machine. Insects, spiders and other pests may have taken refuge in the machine. Don't stick your fingers where you can't see.