Re: [CAD_CAM_EDM_DRO] Dumb question on the drilling of holes

Marv Frankel wrote:

>Tim,
> I'm pretty familiar with reaming holes for proper fit, but the holes
>I'm talking about, are sometimes so misshapen, they almost look triangular.
>They're 1/4" holes, and I've even tried cutting them through with an end
>mill, and that wasn't great either.
>
>

A properly sharpened drill bit will not do this except on very thin
sheet. A dull drill bit can
sure do things like this. End mills generally make VERY round and
smooth holes, even when
plunged. If you are trying to plunge an HSS end mill into tool steel,
however, that could cause
deflection. Are you sure your spindle is solid? A bad spindle bearing
or loose quill could
do this. I hope you aren't holding a 1/4" end mill in a Jacob's chuck.
That really won't work,
and isn't safe, either!

Jon