[cabnet636]

here it is

jim

[kiwisoundguy]

Hi Jim,

Thanks for this. What units are the feed rate in?

Cheers, Ben

[cabnet636]

i used it this week and it is in inches

[cabnet636]

here is another calculator near the bottom of the page just download "cnc toolkit" and go to tools

Josh Glenn’s Blog » DIY-CNC Tutorials

[kiwisoundguy]

Hi Guys,

Thanks very much for all the info. Its great. Would any of you know of a speed / feed calculator that is metric?

Cheers, Ben

[CNC Lurker]

I entered some numbers in the XLS file

Enter desired chipload: .035 (for natural wood)
Enter RPM: 10000
Enter # of flutes: 2
Feed rate = 500

Is the 500 "inches per minute"? I don't even think my DIY can do 500 ipm rapids, much less cut at that speed. And that's on the low end, my Porter Cable 690 variable speed does 10,000-27,000 rpm.

[ger21]

.035 is a very high chipload, much too high for solid wood. So yes, 500 would be ipm.

However, with most 1/4" tools, cutting hardwoods, a chip load of .003-.007 would be more common.

Chiploads over .015 are probably more than most handheld routers are capable of, or are nearing the limit.

[CNC Lurker]

.035 is a very high chipload, much too high for solid wood. So yes, 500 would be ipm.

However, with most 1/4" tools, cutting hardwoods, a chip load of .003-.007 would be more common.

Chiploads over .015 are probably more than most handheld routers are capable of, or are nearing the limit.

Thanks, I was looking at the recomended chip loads for hard and soft wood on the Onsrud site for Ø1/4" bits. The maximum chip load is .017 on some bits, but most of them are .009 or under.

Onsrud chip load charts

Some other useful tips on there:

To increase your chipload you can:
Increase the feedrate
Decrease the RPM
Use less flutes

To decrease your chipload you can:
Decrease the feedrate
Increase the RPM
Use more flute