I need a small slot in my sundial bases. Usually I pre-drill the hole
(either 3/16" or 1/4") and then extend by 0.075" (1/4" hole) or 0.50" (3/16"
hole) the material is 3/8" key stock, galvanized, made in USA. The mill is a
generic X2, the mill bits are Chinese box set.

I have been using the side of the mill doing the full thickness all at once.
The slots have been coming out skewed which was visually obvious even at
these short distances. The wise was checked and is fine (0.001" over 4"
parallel).

Today I decided to experiment. First I did this:

http://www.flickr.com/photos/2768312...n/photostream/

then I progressed to this:

http://www.flickr.com/photos/2768312...n/photostream/

and this:

http://www.flickr.com/photos/2768312...n/photostream/

with the final event documented he

http://www.flickr.com/photos/2768312...n/photostream/


I interpret this that doing the full thickness slot is a bad thing,
presumably the mill is conventionally milling one side of the slot and climb
milling the other with resulting sideways movement. I have not seen this
documented elsewhere so my question is: Do those with the Big Beasts see the
same thing? Is this a reflection on poor rigidity of my mini or is this a
universally bad procedure to do the full thickness at once?

The other question is the mill bit: I think I milled less than 10 slots with
this particular one. Am I unreasonable expecting it to last longer? Was it
my technique or the provenance of the bit? Are there manufacturers I should
look to preferentially for replacement?

Thanks,

--
Michael Koblic
Campbell River, BC