listen carfully ok heres whatcha do buy a new one it ain't gunna fix itself unless u try some vbutter i recomend blue bonnet. lol but seriously try it.
Isaac Singer built the first commercially successful machine, which was electric powered instead of crank or pedal as all others had been.
Circular is one type. There are manual and hand crank knitting machines.
I do believe you have a 1921 model, but according to the singer website, for a machine that old, you would need to email or call them in order to get the model type.
i think it is a wheel and axle
A windlass crank is a type of wheel and axle simple machine. It consists of a wheel (the crank) attached to an axle that is used to lift or move heavy loads by turning the crank.
A lever
There are many variable to determining the value - more detail is needed, year of manufacture, you can obtain that at the singer site - all you need is the serial number. These machines can be treadle, crank or electric. Condition of paint and decals? Is is a working machine? I have purchased them for as little as $5.00 (working electrical from 1932) and seen them as high as $100.00
A window hand crank is a type of simple machine called a wheel and axle. Turning the crank rotates the wheel, which in turn moves gears to open or close the window.
a wheel and axle
The better machine shops can drill and tap the crank for you. Might be cheaper to buy a newer crank.
The purpose of the thread crank in a sewing machine is to manually raise and lower the needle, allowing the user to easily position the fabric and control the stitching process.
The lead singer has, Chester Bennington, has had small acting parts in Crank and Crank 2.