Check my math and reasoning....

OK gang,
I am trying to piece together my power supply and have a few
questions regarding the rated voltage for a capacitor. I am finding
that most use 50v caps and they are cheap and available...I am
wondering at this point if I am missing something...here's where I am
and where I want to go with the PS:

I am running Sigma N42 motors on the Bridgeport and the manual says
that they are 6.8A. I would like to build a power supply with enough
juice to power these 3 steppers AND an 11A Servo for the 4th axis
down the road. I will eventually need to run 4 of these 11A servos @
70v ~ so I am thinking why not just build one supply and be done with
it?

Right now I have 2 50v (what decal says on each...but advertised as
55v when I bought them) 800VA torid transformers. I bought 2 at the
time so that I would have enough amperage to run the 4 servos. Now
comes the question of capacitors...I need caps are rated by voltage
after being rectified, right?...In this case at least 80v...not 50v,
right??? I searched around on here and didn't see any reference to
this.

So...If my math is correct, I will need (using the servo motor draw
as a guideline) Assuming 50v rectified to 70v by the 2 torids:

44Amps * 67% (from Campbell's pdf) = 29.5A

C= (80,000 * I) / V)
(80000 * 29.5) / 70 = 33691 uF

Could I get away with 3 P10653-ND from DigiKey? They are 12,000 uF @
100v +/-20%.

Did I do my math right...or am I missing something???

Thanks!!!
-Brady