Two Questions

[JimN]

I know everyone answer is proably correct, but for a sherline mill setting on my desk, changing speed and feed while trying to cut a 1/16 slot in 1/8 brass that is 3/16 long is not going to happen. Its easy enough to change the speed of the bit, but the amount of feed is much harder. As it is I almost have my safety glasses touching the spindle so I can see how much further to cut on a pass. I guess with time, I will be able to judge better the feed rate and be able to change that but for now will go with the 2 flute cheap end mills.

But on the other hand everyone's answer brings new learning to this hobby, so thank you all. If I never make a good machinist, that is still ok, doing this for fun and that is something I am having alot of. The engine that I made in another thread runs great, I keep hooking it up to air to watch it run. Already working on another one, and I marvel at the work most of you do here, its amazing.

JimN

 

[kendo]

Hi JimN

The three jawed self centering chuck is much quicker.I tend to use the four
jaw after using the three jaw when i need to machine the rest of the bar
to keep it concentric to the previous machining, as this is a much more
accurately way of doing it,and worth spending a little time on.

As for using end mills for producing slots, Well i tend to use slot drills as
these are what they are designed for, end mills strictly speaking are for
machining side faces/small shoulders and profiling to achieve a good surface
finish. Although you can use end mills but is not good practice.
Hope this helps
Ken