Re: [CAD_CAM_EDM_DRO] Thumb Calibration

You don'[t say what dia the cutter is, or how many flutes. A practical
starting point for endmills is 100 ft/min for HSS tools. Also, limit
chip load to .0002" to .0008" per flute (smaller chiploads on smaller
dia's). 400 RPM at .9 in/min is a chipload of .001125 on a 2-flute
cutter. 400 RPM at 0.9 in/min is a good rpm for a 7/8" to 1" dia
cutter. If you were using a 3/8" cutter, I'd recommend going to about
1000 RPM's.

RayHex

reed_irion wrote:

>
> I am trying to get an idea of rules of thumb for speed and feeds
> that work.
>
> This weekend I was milling my first few parts with EMC and I noticed
> that the cutters dont fare quite as well as they did when I was
> doing it by hand.
>
> I made a .1" deep cut in hot rolled mild steel at .9 ipm for about
> 30 inches. The HSS tool died quite suddenly from overheating, with
> no gradual degradation. It was working fine with little smoke from
> the cutting oil then- poof, blue chips burned cutter... The machine
> has a 2 HP motor and was running about 400 rpm.
>
> Should I switch to carbide ? I never liked them because I chip them
> easily, but the EMC is much more patient than me so maybe this wont
> be a problem. How much improvement will I get from carbide ? Will
> the flood coolant system make a big difference ?
>
> What are other users experiences with speed/feeds in various
> materials ?