I hope this will be my last question with the "gosh that's so stupid" tone to it.
I'm looking at stepper motors for my home design. I just figured out that NEMA is more of a size for mounting than any other indicator of motor parameters. Although, I guess the larger the number, maybe the more powerful motor, but not always.
OK, to the real question. I'm fairly certain that torque requirements are related to any individual machine. Since mine will be unique to the world, and I've never owned one of these things, can someone give me an idea of what the minimums might be for a non-optimized-designed CNC PCB 3 axis mill? I've been all over the place trying to see what commercial machines use just for reference, and it looks as though something in the 300+ oz-in range would be a starting point. I'm going to design a moving gantry machine (stationary table) and the spindle will more than likely start out as a Dremel or tile routing machine. So I'm guessing the gantry will need the most torque, followed by the Y axis Dremel holder, and then the Z axis Dremel height. The motor will more than likely be connected directly to an Acme screw type drive, but I find a few Ebay motors with a gear already mounted, so should those be a consideration and what are the limits of gear ratio if I should purchase one of those? I'm guessing that the torque drops or rises based on the gear ratio at the expense of speed.
And lastly, is holding torque the parameter that I should be considering as the main criteria. I've been trying to get a handle on all those torque and inertia definitions, but have to admit, I've not put the time into "study hall" as much as I should have.
Again, any help and patience would be greatly appreciated as I plow through this learning curve.