What kind of stepper motor should I get? - for 3 axis cnc desktop mill

I am currently working on building my first desktop CNC mill, I plan on it being 3 axis and the spindle being a dremel tool. I am searching for stepper motors that will work for my project and would like some suggestions as to what kind/which ones I should buy.

I have seen ones from 96-200 steps/rev, does this make a large difference which end of the spectrum I use?
I figure the more steps,the more accurate it can be but for my basic machine would 96 step/rev be sufficient?

aka what kind of accuracy can I expect from 96steps/rev?

Should I get bipolar or unipolar?

Does it matter if the controller connects through USB or parallel port? is there even a difference

Thank you for your time

Comments

[ARJOON]

for the controller i strongly recommend using parallel port. it is far much easier. don't forget to use optocouplers. never connect them directly to your pc else you may damage it. for the stepper motor it depends on how much precision you want.

[slayer04]

Thank you, also can you estimate the precision I could expect to achieve with 96 steps/rev motors vs a 200?

[LargeMouthBass]

You don't specify how precise your positioning must be, so its not possible to specify whether 96 steps is sufficient.

The choice of bipolar versus unipolar will impact the drive circuitry and step sequence needed to appropriately energize the motors windings.

There is definitely a difference between the USB and parallel port. I would think that USB would be the more logical choice, as the parallel port interface has long ago stopped being a standard feature on PCs.

[slayer04]

well seeing as how using a dremel will impact my accuracy to begin with, I don't expect to hold tolerances better than plus or minus a 64th of an inch

[steveastrouk]

If you want to use MACH 3 or similar, you'll need a real parallel port.

Steve