Neal wrote:
I have a low end Grizzly table saw which has a arbor speed of 4700. I
switched the motor and arbor pulleys so that the smaller one is now on
the motor. The saw now seems to cut much smoother and has more power.
I don't know what the arbor speed is now with the pulleys switched....

I realize I inadvertently replied while reading Lew's response so try
again...

As noted there, the speedup/slowdown between two shafts is proportional
to the pulley diameters. To clarify the calculation you need, since you
swapped pulleys, the ratio of speeds is the square of the smaller:larger
diameter since it was a speedup of L/S and is now a slowdown of S/L.

Algebraically, the new speed is S/L/(L/S) -- S/L*S/L -- (S/L)^2

As a rough approximation example using easy numbers, if S = 3" and L =
4" and motor rpm were 3450, originally you had 4/3*3450 = 4600 rpm
blade speed, roughly what you said is supposed to be.

After you swap, it 3/4*3450 = 2600 (approx)

Note that 2600/4600 = .57 which is square of the 3/4 ratio of 0.75.

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