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Author Topic: Speeds & Feeds, in CAM Packages and calculators  (Read 10186 times)

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Speeds & Feeds, in CAM Packages and calculators
« on: January 26, 2014, 06:10:09 AM »
I've found that the speeds & feeds in BobCad/Cam are, to say the least, a tad on the optimistic side for all materials and had been spending time with data tables & test cuts to get optimal conditions.
Last week I tried HSM Advisor and it took two minutes to deliver very close results to those yielded by hours of mucking about, so as it promises to make me considerably more productive I bought it.
Other things I particularly like about HSM Advisor are;
It takes into account machine RPM, Hp & Torque, warning of insifficient power or excess tool flex, adjusting cut parameters accordingly
Calculations take into account depth & width of cut when calculating tool flex and required torque.
It's programming allows it to locate a named active window in the CAM package and capture or insert data directly from selected fields.

What do you guys use and what do you particularly like about it?

 - Nick

Offline RICH

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Re: Speeds & Feeds, in CAM Packages and calculators
« Reply #1 on: January 26, 2014, 08:23:55 AM »
Nick,
I just a take quick look at the speed and feed info you will find in link below and use past experience.

http://www.machsupport.com/forum/index.php?action=dlattach;topic=20045.0;attach=28531

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FWIW ........................
There are a number of calculators out there and I am sure they all do a mathematical great job.
Cleveland was leader back in the old days and actualy published their works.
The only real testing over time, and that was for machining different types of steel, was done by SME ( Society of Manufacturing Engineers)
and provided factors to be taken into take account when calculating.  I have noticed that some / many of the insert manufactures use what SME published. 
Out of curiousity I went through a whole bunch of calculations to see what values one should use and will just say that it realy becomes "subjective" since there is no hard guidance on the assumptions one could use when calculating. We designers / engineers tend to be conservative in approach.

So what I elude to is to use any advanced calculator as a guide with consideration taken into account for your systems / tooling capabilities.
In the end nothing beats some basic testing especialy for different materials.

Foot in mouth and off to the side, :)
RICH


Re: Speeds & Feeds, in CAM Packages and calculators
« Reply #2 on: January 28, 2014, 05:42:08 PM »
Hello,
I accidentally stumbled upon this post.
I am Eldar Gerfanov - the maker of above mentioned calculator.
I am a professional CNC Programmer and machinist.
Thank you Nick for getting the word out.

I would like to just say that my calculator is not just looking up material specific cutting speed and chipload, puts it into the old 4x sfm/dia formula and spews out result that has no relation to real world conditions.
Yes it does that too, but in between it estimates deflection of the cutter and torque, checks those numbers against practically found values and warns the user about possible cutter breakage.
It also suggests depth/width of cut in relation to the workpiece material/tool type beimg used.

I beleive it is very much of an approach that an engineer would like to take.
The main advantage of using a calculator is consistency of results.

If some parameters are getting you better tool life than others, you can just save them for future re-use.

Yes doing things experimentally will get you results where your endmills would not break anymore, but how many tools would one have to go through to get the same results?
I personally know many people who have "figured out" their speeds and feeds and have been doing things wrong for the past 20 years.

Opinions?
I just hope this topic generates some feedback. I need to get input from as many people as i possibly can.
Re: Speeds & Feeds, in CAM Packages and calculators
« Reply #3 on: February 13, 2014, 10:30:12 PM »
CNC cookbook offers a feeds and speeds calc. Anyone using it?