Creator tried this back in June, with a $100 USDK funding goal, and died (cancelled) after 40 backers raised only $6 USDK.
Back at it, with a revised (yet still very unrealistic) goal of $75 USDK for funding.
The problem with mixing .STL files with an actual product you will ship is that the actual product will take a TON of money to produce and ship, and the .STL files are already done, and ready for download (or very close to ready).
I don't think $75 USD for the .STL files is super high (it is more than I would pay), but this campaign is never going to fund. Not with those goals.
Good rule of thumb: First three days you get whatever you get. Next 24 days, you get equal to what you got before (if nothing derails). And in the last three days if you are lucky, you get between 50-100% of whatever you did in the first three days.
The more unlocked stretch goals, the more likely you are to match those first three days.
Given that metric, this campaign has raised a little over $13 USDK the first three days. Which means at most, if the metric holds, this campaign could reach $39 USDK.
Falling far short of funding at $75 USDK.
So it didn't make any difference to me how cool the .STL files were. There was no need to back, because no chance of funding.