It was when I made a steel vice that I was alerted to the problem.
I needed the base flat and parallel with the bottom, and the jaws flat and parallel at 90 degrees at the same time
The tiny amount of vibration from milling was also fatal for a good finish, you can see the shaper finish
on the left and the milling marks on the right

The other big advantage I found was that I could skim off the teeniest weeniest amounts of metal when required, removing a ding or error only down to its minimum depth
I was quite impressed with the accuracy I could achieve, even as a noob, but shapers are specifically designed for this kind of job and make it relatively easy
Setting up a parallel job is also quite easy, because a shaper can scribe a very very light mark along the full length of a good edge on one side, then you can track across and do whatever needs doing on the other side or wherever
Edited By Ady1 on 17/06/2012 01:21:48