What should I expect with CNC

I am getting closer to getting my CNC Sherline working. I have the
longbed Sherline Mill with the 2amp Camtronics driver board, and the
96oz steppers.

The last time I posted, I was having problem getting the current to the
steppers. I have now built a power supply that is providing 35 v at
idle, to 29 v when all 3 steppers are moving. I am using a 10,000 mfd
cap. I am thinking this is enough. ??

However, I am still having problems with loosing steps when I run the
machine in my "stress test" G-code. This G-code exercises each axis,
from one extreme to the other, several times. ( No Cutting ) It then
repeats a couple loops using all axis at the same time. I seem to loose
steps in both parts of the test. My observation is that while at the
extreme of each axis, I have notice an increase in resistance. Using
Jog, on the X axis, I can not exceed much more then 25 mm and 215 mm,
by the scale on the machine. On the Y axis, I am limited to 0 to
120mm. At the 0 side, I can usually jog the machine to this machine
without any problems, but I have noticed an increase in resistance by
hand. The Z axis, oddly enough, doesn't seem to loose any steps. It
works from 0 - 160 mm. The only limitation is at 160 mm, is my own as I
am afraid of running the slide off of the lead screw. More on this
later.

My question. Is this normal for the Sherline ? Or should I need to
adjust something ? Or, should I work around the stiffness by allowing
less working area in the G-code. Did I get the right size (oz)
steppers ?

Any suggestion would be greatly appreciated, and I would like to thank
all of you for the information provided here. I have learn much, but I
just need to keep learning more.

Thanks
Bruce