Recommendations

Gentlemen,
First my position - I have the basics+ of ac/dc/electronics knowledge. I am
a self-taught machinist. I am retired so have limited resources.

My problem - I purchased a Sherline 2000 which I ran by hand for a while
then retrofitted with a Maxnc retrofit kit 145oz steppers and w/4th axis as
I knew not of this list at that time. I use BobCad/Cam to draw parts and as
I learn more it seems to handle my needs OK. In looking at software I got a
demo copy of Flashcut which I now use to verify tool paths and edit cnc
programs created with BobCad. I have never been able to get reliable cuts
from the system. I loose or gain(?) steps randomly. Example; while
engraving a letter 'A' the horizontal bar was displaced to the right by
aprox 1/5 the bar length ( as a way to express the displacment as it varies
with size). This has also happened on the y and z axis at times as well. I
have tried all the mechanical remedies I know and have seen here on the
list. Do I need more powerful steppers, should I change to servos and how
much of my present system would be usable in that case? I also seem to be
at a crossroad where the Sherline MIGHT be too small/frail and I should look
at a bigger machine?
While I am willing to learn I do not wish to become an expert in
steppers/servos, more I would like to produce useful parts for my various
hobby projects
PJH