Re: [CAD_CAM_EDM_DRO] plunging endmill

heroaku wrote:

>Hi,
>
>I am very new to machining as well as to CNC and will like to ask the
>group about the advisability of plunging an endmill vertically into a
>workpiece. I am using the set of 6 endmill purchased from Sherline
>(does these have cutting edges on its bottom)
>
>

You can do this with center-cutting end mills. Some work better than
others at this.
They generally don't, however, work as well as a regular drill bit.

>Initially, I plan to cut only softer materials like wood and plastic.
>Do I need to program the cutter to enter tangentially, or is it
>sufficient to plunge them straight vertically into the workpiece.
>
>

Depending on the material characteristics, you generally can plunge
straight in, with a
center-cutting tool, but on brittle materials, it sometimes takes so
much infeed force
that the material will crack. Plastic tends to melt quickly, and you
have to feed in slowly
to avoid cracking. You may have to take small bites and then come up
for cooling and
chip removal. Anyway, you will find that the plunging in needs to be
done at pretty slow
feed rates, or the tool may fill with chips and make a mess.

Jon