cutter RPM

3000 rpm

edit to add:

it can depend on the condition of the steel, the quality of the carbide, any coatings on the carbide, and the rigidity of your setup.

That said, something between 2000-6000 will probably work.
 
Last edited:
You will probably want to use a fairly light depth of cut per pass. I wouldn't push it to more than .050" (a little under 1/16") per pass if plowing.

Remember, don't dwell in your cut or you will work harden the steel. Try to maintain a nice steady feed rate. Your feed rate is dependent on RPM and cutter diameter and number of flutes (and material being cut and depth of cut and length of cutter and cutter grind and cutter sharpness and cutting fluid and mill condition and spindle bearings and is it monday and how long has it been since you mowed your grass and are you facing magnetic north and...) . That cutter at 3000 RPM should be fed around 10 inches per minute if it is a 4 flute, half that for a two flute.


...coffee...
 
I also have a HF type clone round column mill. (not sure that is what you have jr).
That being said I would never take 50 thou off per pass. 10-15 is the most I feel comfortable with with smaller end mills. But of course it has surely more to do with my lack of knowledge and experience than with the mill itself.
 
I don't know Pat, you know your mill better than I do. I honestly don't know much about using the small machines. I assume their limitations only become pronounced with larger cutters. On the one hand, I can't imagine there being a problem with a .050 X.188 slot - but on the other hand I've never actually tried it on a miniature mill. It should become very evident in use and a simple adjustment to make.

John,
I use two flutes for deep slots and sometimes for cutting plastics and aluminum that tend to weld up. Four flute produces a better finish and will usually cut more material at a higher pace than a two flute. But a four flute doesn't clear chips as well. The use of high pressure flood coolant allows four flute cutters to be used in applications that would otherwise cause problems.

Two flute plunges better.

I use a lot of three flute cutters in production in plastic and aluminum where traditionally a two flute would be used, allowing for 50% greater feed rate and cutter life compared to a two flute without the clogging problems of a four flute.

That said, I generally rough and finish with four flute cutters if I can. I even use five flute cutters quite a bit down to 1/2". They've come a long way with flute geometry and can fit a lot of chip clearance in a five flute cutter.



An application for two flutes:

Last week I was running a production job in ABS plastic on an CNC router (a dry machine with no practical limits to speed or feed, 24,000 RPM and 4,000 IPM max feed, lord). I settled on a 1/4" two flute at 16,000 RPM feeding at 250 IPM. I used a two flute instead of a four flute because heat and rewelding would have been a greater limiting factor than the number of cuts available per rotation. The free cutting action of the two flute allowed for much higher SFM and a larger chip load per tooth, which in turn allowed for a faster feed rate - which is what it is all about...
 
Pat the mill you got is about the same as i got and i have taken .250 cut with 1/4 end mill it is all about speed and feed.
I have run bridgeport mills so i push my HF mill hard and it seems to take it well but big cutters chatter 5/8 and up. JRH
 
Sorry, I was mostly thinking about smaller cutters. I've had some trouble with 1/8 cutters. Not cause the mill couldn't take it but because I was snapping the little buggers like there's no tomorrow. :( I is better now that I pre-drill as you guys suggested.
But even with larger ones I don't do production work so I never push things too hard. When I do I usually get a little too much chatter for my taste. I know it has to do with speed and feed (and setup rigidity) but it is just too complicated for me to figure out.
 
You must log in or register to reply here.
Back
Top