Limiting Factors for Print Bed Size?

[catlover]

Can someone elaborate on what the main limiting factors are for print bed size? I know most people don't want huge printers taking up space in their homes, but I imagine there are other factors that prevent more larger print beds from being used? Are there print issues with larger build areas? If so, what?

[MK-X]

Depends on what design. Cartesian, you go too large you'll get rod flexing, belt stretches. Frame rigidity. All contribute to speed issues. Not to mention need. I could build a 1m^3 printer, but to print something that large and have it not fail would take weeks upon weeks of nonstop printing.

[RobH2]

There are a couple of issues that I know of regarding larger print sizes or beds. With an 8" bed you can frequently have a print time of 10-15 hours if you use the whole bed. Even more time if you print a high (thinner layers) resolution print. If you had a 16" bed you could conceivably be looking at 60 hours. Remember, a bed 16" on a side is 4x larger than an 8" bed, not just double size.

The other issue is warp. Even with 8" beds, warp is a problem with large and tall parts. Many larger parts are made by printing smaller components and then putting them all together. That helps with the warping issue significantly. It doesn't necessarily ease the print times because you still have to print all the parts.

What we have to keep in mind is that as cool as 3d printing is, it's not the perfect solution for ALL situations. We need to use it for what it's good for and not try to use it for everything when there is better traditional manufacturing method. I don't think we all want to have 3d printers large enough to print huge items that might take days or weeks to complete and still be of lessor quality and finish appearance than a traditionally manufactured item. Imagine if you had a huge print that used 8 spools of filament. That $300 to $400 in filament alone. Imagine having to clean up the "support" material on a print that large. To me, the benefits become overshadowed by the downside of prints that large.

We need try to resist the temptation to think that 3d printing is going free us from being consumers and that we'll never have to buy anything again. That won't ever happen. There are just so many things that 3d printers don't do well, and, never will. They are just one more tool in the manufacturing toolkit, albeit, a really amazing and powerful tool.

I think that the "smaller than a toaster" print bed size is sufficient for that large majority of home users and 99% of the knick-knacks they'd want to print.