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Posted: Sat Nov 05, 2011 10:12 pm
by judaspre1982
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Posted: Sun Nov 06, 2011 12:53 am
by paulmcohen
The math works out to 2390 RPM with a 12" blade gives the same FPM as using a 10" blade at 3450. I am traveling so I don't have access to my PowerPro but I wonder if the computer had other blade sizes programmed into. I was specifically thinking of things like 6" and 8" dado blades.
Posted: Mon Nov 07, 2011 9:58 am
by BigSky
paulmcohen wrote:The math works out to 2390 RPM with a 12" blade gives the same FPM as using a 10" blade at 3450. I am traveling so I don't have access to my PowerPro but I wonder if the computer had other blade sizes programmed into. I was specifically thinking of things like 6" and 8" dado blades.
I wonder if I could impose upon you to "show your work". I am unable to come up with those calculations.
Posted: Tue Nov 08, 2011 4:55 pm
by paulmcohen
I Googled "RPM to FPM" and found several calculators. Plugged in the numbers and reported the results. I am in Mexico and don't have access to the sites I used until next Wednesday.
Posted: Wed Nov 09, 2011 1:21 am
by JPG
BigSky wrote:I wonder if I could impose upon you to "show your work". I am unable to come up with those calculations.
Distance traveled by a 10" blade vs a 12" blade = 10/12.
So 3450 x 10/12 = 2875
pi D = 3.14159 x 10 = 31.4159 in / rev
x 3450 rpm = 108,385 in/min
/ 12 = 9032 ft/min
/ 60 = 150 ft/sec
Posted: Wed Nov 09, 2011 6:19 am
by pennview
The typical arbor hole size in a 12" blade is 1", so you might have some difficulty mounting the blade on a Shopsmith without a special arbor. But you could always have one bored out to fit the 1 1/4" arbor.