I have a 3d print of shelf for my ex wife ( still have the files as i design them myself.) not all the 3d printed item are water tight or safe ( depending on the material and how it used.) can try to pm me and i can see if I can make a design but there are free programs you can design with yourself.
One I used mostly is tinkercad and it simple and can do simple design anything more fancy would require a purchase of a lic and then they get you for renewals these days on everything. Pm me I can see if i can make some simple designs stuff for you just let me know what you want and ( it purpose ) and i see what i can make.
