DIYbanter - View Single Post

writes:

Hmm... I like it. Now to figure out why the special v-blocks and parallels
work... I suppose since they have narrow slices of magnetic material
sandwiched between non-magnetic, then the flux has to continue up and do its
looping over the top of the vee block. So I suppose if this is all correct
that they would work the best when the iron/brass strips were lined up with
the strips in the chuck.

That makes sense. If the iron strips in the V-block are at right angle
to the iron strips in the chuck, the V-block would provide a magnetic
circuit connecting the alternating N and S poles in the chuck. When the
V-block is oriented the same way as the chuck surface, the magnetic
field has to go all the way up to the workpiece to make a "complete
circuit". And for the strongest field, the iron in the V-block should
be directly over the iron in the chuck, if both have the same spacing.

Dave