Quality DIY Printer frames? (Page 2 of 2)

by the age of two my daughter had been taught that 'hot burn' meant dont touch, we did this with a cup of warm drink, just hot enough to be uncomfortable when held, then made her hold it saying hot burn while we did, she soon learned that hot burn wasnt pleasant, and after that when she went to touch things she wasnt supposed to we told her hot burn, and she learned not to touch those things. things like electrical outlets were hot burn.
especially when you have things that can get as hot as the beds and nozzles of 3d printers, you have to have some safety rules laid down, even at 2 years old, its either that or move things out of reach..
As for frames, it depends what you want, but box sections could work, corner connectors could be  designed and then printed up, and runners made up for box section as easily as round (though bearings might need to be mounted to run on the faces of the box section).