One piece toilet difficulty of manufacture

[Hugo Lam]

I've been thinking about this question for a few days.
Generally, due to production difficulty, one-piece toilets are more expensive than two-piece toilets.
I can simply understand this concept; however, when I dive into the question, I get confused.
What exactly is "production difficulty?"
Will love to hear the answers. Thank you in advanced.

 

[hj]

They are making one "large" item out of a lot of small pieces, then firing them in an oven. That means there is a lot of latitude for warping to occur and a warped one has to be destroyed.

 

[Sponsor]

 

[Jadnashua]

Until they get to the point where they may be able to economically use a 3D printer to construct one, keep in mind that when you pour in the clay, you have to be able to remove it from the mold...you cannot do an entire toilet in one pour, so, as HJ said, adding in the tank on top of the bowl pieces is one more bit that must be manually attached, smoothed, to the bowl (that also has multiple pieces), and that takes both time and skill.

Keep in mind that the molded toilet is LOTS larger before it dries then is fired, so you have to account for those variations in relative moisture content of the pieces...if they're different, and you smooth them together, once they all dry, they'll be different and then things won't fit or look nice. Clay is useful, but low-tech.