Sync motor(s)

["acmnovak" <acmnovak-at-msn-dot-com> (by way of Terry Fritz <twftesla-at-uswest-dot-net>)]

Hello All,
I'm thinking of converting a small motor of mine to synchronous. However, when
I looked inside to determine the size of the flat, I found it to be *really*
tiny. Look at the diagram at 
<http://members.xoom-dot-com/mpn54601/motors_2.gif>http://members.xoom-dot-com/mpn5
4601/motors_2.gif
There is only one dead pole per side... This is kind of strange because the
flats required would only be about 1.5cms across! That's tiny. The motor I
would like to use is only 1/15 hp, but that should be good enough.
Another motor I was planning to covert to sync is 1/4hp at 3450 rpm. Some quick
questions about this:
Do the flats have to be perfect? You can do this with a simple angle grinder
right? How could you remove enough material? 
I'll be making 4 flats for 3600rpm sync right?
Would a bench grinder work to mill the flats?
 
Any help would be much appreciated,
Thanks
-Michael