It should be okay. The one in the videos is 30″x24″ OD a bit bigger than yours. Spare z should not be an issue as long as its not more than 6″ extra. Is your dewalt mount flipped, like on the thingiverse page? Is there any reason you went so big, or can you cut it all down? If you want to do a lot of aluminum make it smaller for sure. Each time I make a new machine I make it smaller. I never do anything very big. The 3d printer parts that I want to release soon will easily be the biggest parts I will have made.
That’s why it seems like we are missing something. you machine should like its okay. How is it in wood? Fast and clean? The carving video I have it is killing it in that super hardwood. I could have easily gone full bit depth.
If you push on the tip of the cutting bit when it is all mounted up where does it move?
A few pics might really help here.