Hello everyone! This is my first time posting here and I hope I can make a good first impression, and I apologize for the lack of links because of this being my first post. Currently I am working on a project for my grandfather's engineering business, and part of this project is designing a generator that will be built inside of an air tool that will power an Arduino as well as other electronic components. I have been working on it for maybe 2-3 months now and have learned a lot. I am looking for some guidance in doing the calculations for this generator that I am building. I must let you know that I consider myself under-qualified for this job as I lack the mathematics required so far, so please be patient. So far I have designed a general idea in SolidWorks that I believe will be sufficient for what we need. Rotor: Using 4 x .5" Neodymium Magnets ~14,500 Gauss [Also have some SmCo magnets (unsure on rating for these)] The pieces between the magnets are made of Cast Iron. The rest of the assembly is Alum. img585.imageshack.us/img585/8581/rotor.png Stator: The stator is going to be made of an 0.007" thick Electrical Steel whose relative permeability [μ/μ0] we will assume is 4,000-8,000 [Not 100% sure what the actual Perm. is]. img526.imageshack.us/img526/3769/stator.png First here are my main variables: The air-tool will be spinning at 5,000-7,000 RPM Our wire is 22GA Enameled Copper Wire. Core Material Relative Permeability 4,000-8,000. The cross section of the core is .150" x .750" I'd expect to be able to get 200+ winds per coil. It's going to be in three phase. The rotor has 4 poles We will assume that the is 1 tesla at the stators surface. The stator has 12 coils There is a gap between the stator and rotor of about .030" So what I'd like to know is with the above set-up what kind of output am I looking at? I have looked closely at Maxwell's equations [I'm not even 100% sure if I am on the right track]. But after much effort I have still failed to grasp how I am to apply these laws and equations to my situation. We need around 15v @ 2A, 35W would be ideal. Please let me know if I am forgetting anything. I hope I organized things well enough that all of this is easily understood.