[skray775]

Here is a rough drawing of the top plate and pulleys'. Excuse the drawing I am not a 3d master! LOL

With the ratios as drawn I would have a 1:1 and 1:1.8.

2HP 3 phase motor.

3" SPINDLE - 3" MOTOR = 1.0 DRIVE RATIO = 1725 RPM
WITH A BELT LENGTH OF 20.16"
@ 50% under speed I would have = 862 RPM
@ 50% over speed I would have = 2587 RPM

2.5" SPINDLE - 4.5" MOTOR = 1.8 DRIVE RATIO = 3107 RPM
WITH A BELT LENGTH OF 21.9"
@ 50% under speed I would have = 1553 RPM
@ 50% over speed I would have = 4660 RPM

I am not that up to speed on VFD so I used a conservative number of 50%.

I am fine with those numbers so if 50% is to low everything above 4660 would be a bonus.