# Cordless (Battery Operated) Circular Saws - Your Opinion?

 Forum topic by BDFan1981 posted 11-20-2012 05:57 PM 4437 views 0 times favorited 33 replies
 BDFan198199 posts in 2357 days 11-20-2012 05:57 PM Topic tags/keywords: circular saw cordless circular saw battery operated moto-tool Here is my theory of why the cordless (and I mean battery operated) circular saws don’t work well: With regards to the OSHA standard that the maximum blade tip speed limit that is 18,000 SFPM, a max RPM of 1000 on the smallest saws in the category don’t do justice. Henceforth, for example, would you have envisioned a cordless saw with a 3-3/8” dia. blade as having its motor spin 20,000 RPM to equal the efficiency of the larger, corded saws? I repeat: 1000 RPM is not enough and especially so for a blade size as small as 3-3/8”. Case in point: even cordless battery-operated “Moto-Tools” can spin between 10,000-30,000 RPM easily. SAW BLADE SPEED CHART (all figures calculated using the max of 18,000 SFPM)3-3/8” (86 mm) = max RPM is 20,3724-3/8” (111 mm) = max RPM is 15,7155-3/8” (136 mm) = max RPM is 12,7925-1/2” (140 mm) = max RPM is 12,5016-1/4” (159 mm) = max RPM is 11,0016-1/2” (165 mm) = max RPM is 10,5787-1/4” (184 mm) = max RPM is 94838-1/4” (210 mm) = max RPM is 833410-1/4” (260 mm) = max RPM is 6708 Is there a reason that the early cordless motors can’t do 20,000 RPM efficiently (on the 3-3/8” cordless saws)? ~Ben

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