By da1e11oyd
September 1, 2014, 7:50 pm
Tool Length Versus Feed Speed/Spindle Speed
Just found this wizard and thought I would give it a try, but the results it is giving don't seem to make sense, unless I am reading something wrong. Set for SG Iron I put in a 10mm ball nose end mill with a length out from holder of 130mm on 30% for finishing and checked slot/pocket rpm came out at 5000(my max) feed at 253 I then reduced the length out from holder to 30mm and recalculated. rpm came out at 2276 feed at 115. So what the calculator is saying is I can run the tool faster and at higher feed speeds the longer I have the tool length which from my experience is incorrect. Can anyone shed any light on this. Thanks Dale
Eldar Gerfanov (Admin)
Updated by: Eldar Gerfanov (Admin)September 1, 2014, 8:07 pm
Hi! What you missed is that at higher stickout, you will be suggested LOWER cuttimg depth. And at some point when your depth will be below the radius of the tool, effective cutting diameter will be smaller than the diameter of the tool. With smaller effective cutting diameter, you will get higher RPM while Cutting speed remains the same. Please check out an article on the front page with sketches on how effective cutting diameter affects things: ?page=FrontPage&shell_id=151&article_id=4594
da1e11oyd
Hi Thanks for the quick response. Yes I did indeed miss the lower cutting depth. I will incorporate the recommended depth of cut into my Cam program and give it a try. Dale