With everyone using Apps for so many things, there must be some out there for lathe speeds and feed rates. Any suggestions or advice?
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With everyone using Apps for so many things, there must be some out there for lathe speeds and feed rates. Any suggestions or advice?
I am old school I don't use machining apps. Been doing it 40 plus years in my head any don't see a need to change. That being said I have heard good things about this one https://fswizard.com/
We had our students tape one of these to the inside lid of their toolbox.
https://live.staticflickr.com/65535/...77cd6836_b.jpgLathe Settings by jakefromclemson, on Flickr
I'm in the same boat................Quote:
Originally Posted by M-Tecs
Machinist handbook.
I bought a speed and feed calculator for about $70 about 15 years ago and hardly use it!
I mainly got it for milling because I was breaking end mills.
I found a chart that my machinist teacher gave us but it has not made it into my tool box yet.
I quit being so aggressive and stopped breaking end mills!
I just use SFM x 4 / diameter.
Quick and easy on the fly.
50-80 SFM for HSS cutters and 150 SFM for carbide on a machine that is not especially rigid will give you results that work every time. Those numbers will for for A2, D2, S7, M4 and M42, H13, 4140 pre heat treated to 28-32 rockwell. Weird stuff like Inconel 100 you look up, machineries handbook is good there. Most things IMHO we do pushing the SFM to the highest optimum level does not gain us any saved time to speak of.
If we were running the same CNC program for 8 hours straight sure we would gain something, but typically we are just drilling say (4) 5/16 holes to tap 3/8-16 or some such thing, again IMHO.
Bill
It would be awful hard to go wrong following willbirds advice .
I don't see where there's much need to pay for an app , if your using inserted tooling the manufacturer's website will have all the info you'll need .
And like mentioned for hss or cemented carbide the machinery handbook will have everything a person could need ... any edition after about 1965 will do .
And everyone who has machine tools should have a copy ... it is a veritable wealth of information.
I have a copy of Machinery Handbook, but I feel like I’m always looking for a needle in a haystack most of the time. I did just order a copy of Machinists Black Book. I’m hoping I’ll be able to find things faster in it. That’s a good idea to check the insert makers website. I haven’t tried that yet.
Check the drill an tool makers web sites they used to have free bees for this a small sliding scales that you lined up size stock type and tool material then read the speed in a little window. Not an app but if they still have them they work and are handy in your tool box
There are several factors in play but a BIG one is that many times we are not using a machine rigid enough to actually run the tool we have full tilt boogey. Our process will either stall the spindle or chatter horribly. My Grizzley G4003 for example running 1000 RPM using a negative rake Trigon insert goes a nice job but at .015 feed I cannot take .05" per side, I run out of HP.Quote:
Originally Posted by GregLaROCHE
https://images.app.goo.gl/A2kMyezSDadcyzMV8
I really like that insert style because you get 6 corners per insert, so I just back the feed down to .008-.01 per rev and it all works out. On a cnc chucker lathe we could take .250 per side with that insert and run .015" per rev feed easily because we have WAY more horsepower and a far more rigid machine :-).
So our worst case is destroying the tool by running it too high RPM. And A2, D2, S7, O1, 1018, H13, 12L14, and pre heat treat 4140 will all run at 80 SFM and be happy with HSS tooling, maybe drop to 50 on the 4140 28-32 rockwell. And then just use 150sfm on carbide and IMHO within the limits of your machine all will be well.
Now there are some types of 2"-2.5" R8 milling cutters for knee mills that are purpose made to run pretty high RPM and a fairly high feed rate cutting .200 to .300 deep, but the mfg typically give you the rpm to run in a knee mill. They are flat out amazing really, typically hold a square insert on a 45 degree angle with a high top rake.
I guess one more addendum, the SFM x 4 / dia is the important part so you KNOW the surface speed of the cutter or part, far more important than the SFM number you pick maybe.
And once you do it a bit it all makes sense because your 1/4" tool or part runs twice the rpm that your 1/2" one does, the 1/8" part or tool runs 4 times more rpm than the 1/2" tool.
IN short what ever speed works for a drill in a given material will work for a Lathe tool as well. Understanding how to "read a tool" is the key to success. That means what kind of noise is it making and does it sound good or bad?
I have some basic numbers that I have used for my 40 years in the chair. 1/2" drill in Mild Steel,,,300 rpms. 1" drill in Mild Steel 150 rpms. Modify speeds for other size drills from there. Any size drill up to 1/2" in Aluminum with WD 40 so it doesn't weld chips to the drill 1200 rpms. Any cutter in brass,,, As fast as the machine will go, but keep in mind, you can ALWAYS go slower with any drill in any material !!!! I look and listen to how the tool is cutting. if it is running at the right speed it will sound good. If it doesn't sound good ,,, It probably isn't. Also if the cutter isn't leaving a nice finish you need to do something else, Change Feed or Speed or both or the Cutter itself. (they do get dull!)
Machinability of every material known to man was established 75-100+ years ago. The Machinery Handbook has all of them. (Look in the index for the location in the book?)...Machinability is given based on a percentage using Mild Steel (1018) as the control point. IE: 100% is mild steel. 120% is Cro Moly ? etc. All things relate to mild steel (1018) So whatever the Percentage your material is to mild steel is how you modify your speeds and feed rates.
Where all this comes into play is Programming CNC machinery where you aren't going to be able to just test your feeds and speeds out manually, and have to have some idea of how fast to run things, because you are telling the machine how fast to go on every single move.
You will develop successful feeds and speeds as your knowledge of the machine and types of cutters and materials you use expands. Once you have successfully Programed 50 or so jobs you should have some idea of what you need to be doing. It is best to gain this knowledge while working for someone else. That way if you crash a machine the worst thing that can happen to you is to get fired! As opposed to paying for the damage on your own machines.
All the answers you seek are in that little black book with about 2000 pages.
Randy
Phillips Machinist app works well for me.
Thanks, Dinny