Re: [CAD_CAM_EDM_DRO] Re: Speeds and Feeds and Torque and Power

Frank wrote:

>
> Depth was 1mm, width was full width. I was profiling a shape. I've
> broken cutters on Aluminium chequer plate, and on a cast aluminium
> electronics enclosure - I don't know the exact alloy. The enclosure
> was well held. The chequer plate was held at the corners, so there
> was no X/Y movement, but possibly some lift in the Z.
>

Well, that sounds good. A little cutting oil helps, rigidity is
a GREAT help. If the spindle is at all wobbly (either the
bearings are not rigid or the way the spindle is mounted to the
gantry isn't) then the cutter can be grabbed into the workpiece,
and no tweaking of feeds and speeds will keep cutters from breaking.

> What is "cheap" for carbide cutters? My local tool shop here is
> Australia sell them for about $A40 each ($A70 for coated cutters),
> $A20 for HSS. $A1 = $US0.90

I recently bought some 1/8" solid carbide end mills for about $4
each. I don't think the coatings add much benefit for this type
of work. Look on eBay, both auctions and stores.

Jon