This is a spur gear made for a pasta machine by a company called "Modern House", however I suspect the same machine is sold under many different brands and manufactured en-masse in the same factory in asia, so this gear may very well fit other brands.

The internal hexagon has an internat dimension of 15mm at the widest part. The spur gear itself has an external diameter of 31mm.
I made it spur-shaped to match the broken one in my machine, but this shape may need to be developed further for optimal functionality.

How well this replacement holds up has yet to be tested. I have only checked that the gear fits and interacts reasonably with the remaining gear. Strength, longevity and durability is do be determined, but a reasonable filament with 100% infill should suffice for the immediate future.

I printed my gear at 102% scale, since my prints has a tendency to shrink after completion. Know you own printer and adjust any scale accordingly.