There's been at various times a couple of discussions over on the Mach forum re: whether or not to have quick blow fuses between the PS and drives and whether or not to have a large capacitor between a switching PS and the drives.
I have a copy of the (famous) STEP MOTOR BASICS guide which is a few years old now and it states YES to both the above questions.
However, all be it divided opinion seems to be NO to both the questions and indeed one poster says Mariss has argued against the use of fuses between PS and drives for years.
I notice that these sections have both apparantly been dropped from the latest STEP MOTOR BASICS guide on the Gecko site.
However the thread at the top of this sub still refers to a filter cap but doesn't state (like before) that it should be used with a switched supply so is perhaps ambiguous maybe. Also, further down, fast blow fuses are recommended.
Hence I guess the confusion. Has Mariss been mis-represented? Is there a difference of opinion between Marcus and Mariss? Do we fuse or not? Do we use caps with switching supplies?