The portable electric handsaw was envisioned by Edmond Michel in 1921. A Frenchman, Michel was observing the difficult work of cutting sugar cane with machetes in New Orleans. Believing an automatic saw would increase cane harvesting speed, he began to explore different models, making several early prototypes through 1923. The result was the issuance of a patent for the Michel Electric Hand Saw on Jan. 20, 1924.
About that same time, the Skil Model 77 debuted, using an internal drive system featuring a spiral, worm-shaped drive mechanism. This design dominated for several decades and was widely copied. Art Emmons of Port-Cable pioneered the direct-drive sidewinder saw system, engineering a design that sidestepped the patented worm gear concept in 1928.
Worm Saw Design
The motor of a worm drive saw utilizes a series of gears allowing the motor to be positioned parallel to the saw blade. This design significantly increases the level of torque transferred to the blade, making it a good, heavy-duty choice for cutting difficult material. The design allows for a narrower saw, but the gear configuration develops significantly fewer blade revolutions per minute. They are a popular choice of professional carpenters and woodworkers.
Side Drive Design
The in-line drive circular saw is a more common choice for most users. The blade drive shaft is powered by the motor, which can be mounted to the right- or left-hand side. As a result, they are more lightweight and easier to handle for the occasional user. They have become so common that when one thinks of a circular saw, this design comes to mind.
Since the worm saw positions the blade ahead of the drive motor, it allows for a better view of the cutting line during use. This provides a more accurate cut and creates more torque for cutting difficult materials. The sidewinder design can be almost as accurate, with the added benefit of increased revolutions per minute. This is due to the position of the blade, which is directly in line with the drive gear of the motor, increasing the cutting rpm by as much as 2,000.
The choice between a worm-drive saw and a side-drive saw should be driven by the application. The side-drive saw is more than adequate for the home or occasional user, due to its lighter weight and ease of operation. Professional carpenters and woodworkers would be well-served with a worm saw because of its robust durability, increased cut accuracy and ability to cut through difficult materials.