Is there a program out there that can automatically split a model up into many “building blocks”? Looking to print a 5ft tall model, but trying to see if it’s possible to not cut it up manually to save time.
I’d be surprised if you find an automatic script or plug-in, as there are so many considerations when slicing a model. I’ve seen videos using Blender and Meshmixer and it doesn’t appear to be particularly demanding. I’ve lost that piece of my mind that had a reference to a program what would create “ledges” or “rabbets” to better enable a re-joining of the split-off parts. That would be ideal for larger assemblies.
Netfabb Pro does that, but I don’t know of any free software that will.
I’ve never thought to look I’ve always chopped mine in tinkercad. ^ NetFab apparently. 
Cut, yes, but not automatically reduce to printable sized pieces based on bed size.
@Rob_Barnard Thanks, will check it out. I am aware that there’s a free netfabb version, but never tried it.
The free netfabb is pretty powerful, the cutting feature is extremely nice, although in my experience it does occasionally have problems properly closing the new faces it makes. Although the built-in model repair functions in netfabb, even free, can usually fix that.
@Shai_Schechter in FlashPrint slicer there is à “cut” option wich does exactly what you are searching for. I don’t know if it can be used with any printer but you could give it a try.
You might be able to script it using openscad, I’ve been playing with the puzzle cut script for it and I think that if it were modified it would probably do what you need?