I haven't watched the assembly videos yet. But I see that the Arduino board doesn't align with the mounting holes because the port holes for the USB and power have very tight tolerances. I don't think it's the printer because I've printed other stuff much smaller that fit pretty snugly based on my designs.
I had to scrape around the ports to remove at least 1 mm of material before the Arduino would align with the mounting holes.
Has anyone had similar issues? If there is indeed a tolerance problem, a remix could be avoided if the original could be modified and republished.