We're checking out a new online repository for printable 3D models: grain. There are many such repositories sprouting up recently, so what makes grain different?
grain's current inventory of models is a little thin, but that's totally understandable given that it launched only recently. But there's another twist we haven't seen before: they don't actually sell 3D models!
Instead of buying the STL files, which typical repository sites provide, grain lets you select and purchase a GCODE print file for selected 3D printers. For example, you could buy a file that would print on your Cube. The GCODE is detailed machine instructions that tell your 3D printer to warm up to such-and-such temperature, move the extruder to position x/y/z, etc. They're bulky as they usually contain hundreds of thousands or even millions of instructions.
We see several problems with this approach. First, GCODE files are created using various print parameters, including your desired layer height, which can vary considerably depending on your needs. A rough item prints fast, while a finely detailed item prints slow. You should be able to choose such things whenever you want to print. GCODE also makes assumptions about the print material, typically PLA or ABS. In grain's paradigm, you have to buy BOTH a PLA and an ABS file to be able to print both materials.
Another major issue is the longevity of the files. Should a firmware upgrade occur on your 3D printer, your grain file might no longer work. Usually such issues are handled by simply re-slicing the model with the manufacturer's updated software. But you can't do that with grain's GCODE files. And what happens if you replace your 3D printer with another one? That's right: Buy the files again, assuming grain supports it.
Perhaps this is the reason grain's products are typically priced very low: you may have to re-buy them several times. But that won't help at all if you need to reposition your print to a particular spot on your print bed.
Aside from these issues, grain's approach does simplify your 3D printing workflow: you don't have to slice your model. Nevertheless, please check out grain; you might find an object you can't find elsewhere.