I have one giant video clip that I am trying to chop up into many clips that are all the exact same size. Is there a way to simultaneously trim the big clip in equal intervals, or do I need to manually scroll along the clip and trim it one point at a time?
(Apart from having no idea why anyone would want to do this) I can't think of a "standard" way of doing it in FCP's toolset, but there are ways you could go about it, so as a first suggestion:
make a new layer; load something inconsequential into the viewer (e.g., text); set the duration of the clip to whatever you want your length to be; edit it into the new layer as many times as you need (so you have a continuous series of clips all at the same duration with cuts); select the blade tool and check that snapping is on; run along the vision layer you want to divide up and click as the cursor jumps to each snapping point.
I expect that someone will have a better way of doing this.