Circular saws

Posted by admin on Jun 14, 2010 in Carpentry Advice and Tips | 1,607 comments

Whether you are looking to fashion your first piece of dining room furniture and a chair for your den. You may need to use a circular saw.

A good circular saw should have enough raw power to slice through everything from wet lumber to dense hardwood without bogging down. “When the motor slows, the blade heats up and dulls quickly,” explains Tom Silva, This Old House general contractor. This not only produces a poor cut, it’s dangerous because the blade can climb out of the kerf and push the saw back toward the user.

However, evaluating power from the motor ratings can be misleading. Amps indicate only the amount of electricity a motor draws, not the power it sends to the blade. Horsepower accounts for torque (rotational force), but not necessarily under working conditions.

In the end, the most reliable appraisal may be price. A dependable sidewinder — the more compact design, in which the motor sits alongside the blade — starts at around £100. There are many saws on the market under this price, but they’re not as powerful, nor are they built for a lifetime’s use. Professional-grade sidewinders, which run quieter and cut through dense wood better, cost between £125 and £150. Master carpenter Norm Abram prefers this tool, noting that buyers should choose one based on balance and manoeuvrability. “I’d never buy a saw I didn’t have a chance to hold first,” he says.

On the other hand, a good worm-drive saw, Tom’s choice for framing because of its high torque output (its beefy spiral gear transfers power to the blade more efficiently), will set you back at least £200. Either way, a top-of-the-line saw, if treated with care, should still be cutting well when you’re ready to hand it down.

Saw Styles

Worm Drive

The motor is in line with the blade, delivering enough torque to carve up wet lumber or saw through concrete, which makes a worm drive ideal for framing or major renovation jobs. With the handle farther back, a user can better resist kickback and steer the 16-pound saw through long rips. As on most full-size worm-drive saws, the blade of this Skil HD77 sits to the motor’s left — in easy view for right-handed users.

Sidewinder

The motor sits alongside the blade, making for a lighter (11 pounds or less) saw, which is more manoeuvrable over a long day than a worm drive. The helical gearing on higher-end sidewinders, such as this Milwaukee 6390-20, beefs up the torque, making these models worthy competition for worm drives.

Small Sidewinder

Weight, balance, and handle size are all key features to consider when choosing a saw that fits you. For a slight-bodied person, a small pro model like this 7.7-pound Makita 5740NB may be more appropriate than a full-size sidewinder.

Cordless

Battery-driven models have increased in size as their power packs have gained voltage, making them convenient tools out in the field or when the electricity’s not on. This Bosch 1660K sports a 6 ½-inch blade and a 24-volt battery — the largest in its class. However, cordless models still have limited run times and generate less torque than corded saws.

Trim Saw

For finish work or panelling, Norm Abram prefers a small trim saw; blades range from 3½ to 412 inches. This Porter-Cable 314, with a 4½-inch blade, is the one worm drive on the market — all others are sidewinders.

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