Is there a general guideline for how far apart Robart hinges should be placed? I'm changing out some CA style hinges for Robart's and am curious as to how many to use.

Are you talking about a round hinge point hinge? How big is the plane? I would generally get 4 in each aileron and at least 3 in the rudder and each half of the elevator in anything up to a 90 size. Maybe one more in a larger plane. Make sure you use the right size and get them glued in well.

It's actually a Superstick 40, but for some reason I've had a couple of CA hinge failures, which hasn't ever happend on any other planes I've had. I've got it setup for massive throws which makes me think it might be taxing the CA hinges a bit. Fortunately the failures haven't caused a crash...I've had several guys recommend the Robart Hinge points, but am not sure as to how many to use. My original guess was to do a 1 for 1 replacement.

I use 1 for 1 with out any problems.

Yup