Feed and Speed Resource

Not sure if this has been referenced elsewhere, but I found an interesting article which does an excellent job of explaining Speed and Feed for our class of CNC Router.

Speeds and Feeds Basic

There are also links to a basic spreadsheet to calculate feed. (I would have attached but cannot upload .xls) With my limited knowledge of this topic the spreadsheet appears to fit better than others I have seen. Just started experimenting with the info generated but the feeds calculated seem to make my cuts much quieter.

I hope this helps someone struggling with this area, like me.


Thanks for posting that article. Its a simple explanation with some real numbers I can start off with for a newbie like me!
Happy carving

Everything I have read said a noisy bit is a hungry bit - reduce RPM on router or speed up feed. I originally thought it was noisy because I was feeding too fast. Seems backwords to me. After I read this article it started to make sense.

I have to run my downcut endmill at 12000 RPM and 60 in/min. (.002 chipload) There was no way I was going to hit the chipload I saw in other articles.

Glad this helped.

Interesting read, what is your depth of cut? I have been using lots of maple running 1/4" end mill, 18000rpm @ 100in/min with depth set at .65, makes me wonder if i’m set correctly, if I should be going slower and deeper,

I am pretty new with the bigger longmill CNC, I have been very conservative on my depth of cut and speed / feeds in general. Since reading this article, I increased my cutouts to 12000RPM, 60in/min, 6 passes at 0.125" or 3 at 0.25" (0.25 DC endmill), mostly pine. I am slowly working up to faster feeds.

0.65" seems like a pretty deep cut, to me, unless you mean .065".

When time allows, I will give your settings a try. Stay tuned. Thanks.

I got some time to test out cutting with different speeds and feeds. I used a piece of 1" thick pine (0.755") to cut out circles and rectangles, 1 each at each setting. Used Whiteside RD2100 0.25" endmill.

12000 RPM, 60 in/min, 20 in/min plunge, 0.125 and 0.25 pass depth (4 cuts)
17000 RPM, 85 in/min, 25 in/min plunge, 0.125 and 0.25 pass depth (4 cuts)
22000 RPM, 100 in/min, 30 in/min plunge, 0.125 and 0.25 pass depth (4 cuts)

The quietest and cleanest cut was at 12000 RPM, 60 in/min, 20 in/min plunge, 0.125 pass depth (from the article basic spreadsheet - .0025 chipload). At 85 in/min the bit was noisy (slight squel). 100 in/min scared me but was about the same noise as at 85. It felt like things could go out of control fast at 100 in/min.

All in all I am very happy with the results of the 12000 RPM, 60 in/min, 20 in/min plunge, 0.125 pass depth. Very quiet and nice clean cut. I am not sure if I will revisit this later and be a little more adventurous.

Hope this helps.

yes .065" depth of cut, Thanks for the feed back I will be try your method of cutting later today, Thank you, Happy New Years