I was wondering if these motors would be find for an x2 cnc? I like the dual shaft but since cost is a problem (student budget here) I'm looking at the single shaft motors. I was wondering if anyone has used them without problems on an X2? Here are the specs...

# Step Angle: 1.8 Deg ± 5°
# Insulation Resistant: 500VDC 100M Min.
# Insulation Strength: 50Hz 1Minute 500V Min.
# Ambient Temperature: -20 ~ 50°
# Operating Temperature: 110°C Max.
# Radial Play: 0.02mm Max.
# End Play: 0.1-0.3mm

Check this thread: http://www.cnczone.com/forums/showthread.php?t=63535, you may want a larger one on the Z.

What price? Inductance?

I'm just looking at the electronics since it's been cold to do much else. The one's I was looking at go for under 30 dollars.
They are single shaft:
-Inductance is 2.4 plus/minus 20%mH.
-Resistance 1.2 plus/minus 10%
-Holding torque is 20kg.cm
-Voltage is 3.6
-current 3.0A

I'm trying to get something that is not physically huge, but has plenty of room for whatever I need later. I was reading about the nema 24's which have the same nema 23 mounting, but are supposedly a bit larger inside so you can get more torque or whatever you need I guess. Frankly I have never seen a stepper so this just makes is a bit tougher to plan it. I know the specs are more important, but like someone else has said, there are so many types and prices, it's tough to settle on something. I'm just starting the research, but it can be a bit overwhelming at times. I guess I'm slowly chipping at this. I would like to make them all the same size if possible. I guess I can't rule out the dual shafts just yet.