To add on to this.Yes, a Grinder is a good early way to get 3x ingots with RotaryCraft. Pretty easy to set up. The Extractor (for 5x ingots) is somewhat harder but should be the next thing to focus on once you have sufficient power and can either:
a) produce sufficient RF and use a good magnetostatic to convert that to RotaryCraft
or
b) make a CVT (requires you can mine bedrock which can be done relatively easily with 4 hydrokentic engines) then you can do it easily with 4 steam engines.
or
c) use a few gasoline engines
It's better to use a gearbox instead of a CVT because the CVT is always bugging out when you leave the chunks it's in, even when it is chunkloaded. As for the magnetostatic, in the version of Rotary craft in Monster, you need roughly 800 RF/t to be able to run an extractor at all stages.