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Suggestions for a good feed and speed calculator

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John281

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#1
I'm planning on adding the TouchDRO to my mill using an Android tablet and I thought it would be handy to have a feed and speed calculator on the tablet as well. (That way, I can get oily fingerprints on the tablet instead of the Machinery's Handbook.)
Can you recommend a good machining feed and speed calculator to run on the Android tablet? There seem to be a number of them out there but I'd like to hear what is recommended.
 

Bob Korves

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#4

John281

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Bob Korves

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#6
Feeds and speeds are all over the map depending on machine, and machine age, wear, rigidity, setup, tooling, finish requirements, coolant, and more. Commercial shops that are reaching for the most efficient machining to stay competitive will often try to tweak a job for the very highest speed that does not cause excessive tooling wear, broken tooling, and scrapped work, which is still much more cost, wear, and scrap than hobbyists generally care to allow. Time is not money in my shop, time in my shop is enjoyment. Using calculators is fine, but be prepared to change the speeds and feeds to get the results YOU want, and that can be done with no chart at all, or just a simple one to use as a starting point.

I'm not opposed to paying for a good calculator, especially if it helps extend the tool life.
That is not what most commercial speed and feed charts are trying to best optimize.
 

stioc

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#7
It's only a couple of simple formulas, at least this is all I use.

RPM=(SFM x 4) / tool diameter
Feed = RPM x chip load per tooth x no of flutes

In fact, it wasn't until the CNC that I worried about the feeds and speeds much as long as I was in the ballpark because I could feel through the hand wheels if I was pushing the tool too much or not enough, even with the power feed on the X axis I could make small adjustments.

In my case it's even simpler since I dislike changing belt config I keep my RPM at 1850 which works well for me for alum so I typically just use the second formula and after doing it a few times I know it by heart for my main go-to endmills. If I'm doing something new/different is when I consult the feeds/speeds calcs to double check and believe it or not I usually just go for the one on LittleMachineShop.com since it's pretty simple and on the conservative side which works well for me. I have others too but they're all sorta the same, some are fancier of course and allow for HP reduction etc. Just my 2cents.
 

Boswell

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#8
Even with a fancy paid for Speeds and Feeds calculator that I can use for my CNC work. I find that I typ use the same RPM and so like [stioc] I also have easily memorized the typc numbers for the 4 most comment tools I use covering about 99% of all the work I do in Aluminum.
 
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