What's High Speed for a Top-Quality CNC?

What kind of RPM and feed speed represents top-flight performance for modern CNC equipment? February 20, 2011

Question
I was talking to a German fellow the other day who has spent many years running CNC's. He is currently working for a company which has a Weeke CNC, and he was telling me that he runs a triple flute compression bit at 24000 rpm with a travel speed of 25 meters/min. He said it cuts like butter. I was thinking of giving it a try, but was wondering what others thought or how many are doing this.

Forum Responses
(CNC Forum)
From contributor I:
25 meters per minutes translates to about 985 inches per minute. It might be possible depending on the tool geometry. There are tooling vendors out there that have claimed even higher possible cutting rates. When evaluating a claim of cutting speeds, one has to determine if the speed being referred to is programmed speed or actual achieved speed.

Depending on the part sizes and the acceleration/deceleration rates of the machine, the programmed speed may be rarely or never actually achieved. A couple of sheets of nested drawer box parts may cut fine, whereas a couple of pantry gables could burn your tool out.



From contributor K:
I have cut on a Homag machine at 40 meters per min. It is amazing what quality machines and tooling can do.


From contributor F:
On my Thermwood I have cut 3/4" plywood at 1200 IPM with a 3/8" two flute compression bit turning 18000 rpm. It actually cut quite well, however you are going to get more tool deflection. This was for large curved framing parts so the machine easily got to the 1200 ipm.



From contributor M:
Speed is a funny thing. I have cut over 2000 IPM, but standard feeds for me are between 175 IPM and 1200 IPM. Why the big difference? It depends on the tooling capability and material being cut. The other consideration is the acceleration and deceleration of the machine. It takes space to attain speed and slow for corners, or direction change. Unless you have a long arc, or straight line, top speeds never happen on most machines. Everybody likes to see how fast we can go, but going flat out, day in and day out just doesn't happen very much, if at all.


From contributor Y:
I am new to CNC and have owned our Weeke (Homag) for about two months. At first I was running 15m/min. The good folks here at WOODWEB have helped me with chip load and feeds and rpm. I am currently running with great success a 1/2" compression two flute at 21-22 m/min at18000 rpm in 3/4" material (one pass not stepped).

This is the actual cutting speed achieved. I can watch the feed speed as it is cutting and it drops for a very short period at corners. The ramp up speed (acceleration) on my machine is fast, the tech who installed it actually slowed it down he said I didn't need it so fast. I have a three flute I am waiting to try and will start cutting with it over 30 m/min. It's so fast I needed to hire guys just to keep up with its output. It runs maybe 20% of the day on average.