SHOP TEST:
Charged up Miter Saws
by Chris Marshall

Excerpted from Issue 159 June 2003

The expanding world of cordless tools has a new category, and manufacturers are slowly, but surely, joining in. Next time you buy yourself a miter saw, you might find yourself telling the clerk to "hold the cord." In the June 2003 issue of the Woodworker’s Journal, Chris Marshall put this new breed of saws through their paces. One test he preformed was cutting stock to form a nine sided frame.

If you've ever cut a picture frame with mismatched miter joints, you know it doesn't take much deviation from 45 degrees to throw the last corner off. Even a quarter degree of error at each miter makes a noticeable difference. Increase the number of sides on a shape and this cumulative cutting error becomes a bigger problem.

Ryobi MS180	Makita BLS820	The photos at left depict the gap between the first and last joints of the nine-sided test polygon cut by each saw.
Makita BLS712	Bosch 3924

To test the accuracy of these cordless miter saws, I tuned up the blade, fence and table according to their manuals. Then I set each saw to a 20 degree miter and cut nine-sided polygons from MDF strips. Granted, no one cuts nine-sided figures regularly, but I was curious to see how the last joints would turn out. When the dust settled, Bosch ruled the day with a ninth joint that closed almost perfectly. Makita's BLS712 sliding miter saw earned a strong second place. The last joint was about 3/32" open -- darn respectable on the first try. The other Makita saw fared well, but the ninth joint was about 1/2" open on round one. I cut a second polygon using one of the Bosch pieces to set the blade angle, and the BLS820 left the final joint open about 1/8". The Ryobi saw (a consumer tool priced at less than a third of the Makita offerings) finished fourth. After I cut three polygons and reset the blade with one of the Bosch test pieces, the last joint was still about 5/8" open.

Ryobi MS180 18-volt
Last fall, Ryobi entered the cordless miter saw arena with this 81ž4" dia., 18-volt compound miter saw. Ryobi makes the tool more appealing by pairing it with a 1/2" drill/driver that shares the same batteries.

Makita BLS820SFK 24-volt
If you're a dyed-in-the-wool Makita fan, this mid-sized cordless miter saw won't disappoint you. It may even tempt your allegiance if you wear a tool cap of a different color.

Bosch 3924K 24-volt
If you're looking for a battery-powered miter saw sized like its corded cousins, look no further than the Bosch 3924. It's equipped with the largest saw table and fence in this test group and spins a 10" blade. With 24-volts driving the motor, this saw’s size and performance may make you look twice for the power cord.