234: Friday 13th July 2012

Today I got my motor rotor back. I had a look at it when it was in the lathe and it needed some more skimmed off. In total 1.6mm had to come off to get past the pitting where the brushes had burnt. This picture shows the rotor when I had just started to re-cut the grooves in the commutator. You can see how the cooper is overlapping.
In this photo you can see the junior hacksaw blade I was using to re-cut the grooves between the commutator segments. I have re-cut one groove here. About 50-60 more to go (I haven't counted them).
I started just using the hacksaw blade, but it was taking forever to get the slot right and to start with I was slipping quite often and scratching the copper. For me, the best way was to tap a palette knife (thin paint scraper) along the groove to lift the excess copper out, then use a Stanley knife to trim the edges and finally the hacksaw blade to finish up. The hacksaw blade gets a good size, slot nice and uniform. The knife was good for hooking the copper out at the end of the slot. Hopefully I won't have too many segments still electrically linked when I test them.

No comments:

Post a Comment