Low Feed-speed???

i agree you'll be fine until your comfortable with higher speed/feed, the adverse affects are not to your machine, but your tooling, stainless is the one material that may really be an issue to both the tool and the material, because you can work harden SS by taking too light a cut, then the next cut has to be deep enough to get below the hardened surface. forget all the speed feed crap, focus on chip load, chip load is what is gonna keep your milling cutters sharp, with a slow rpm but the right feed to keep the chip load optimal will prolong tool life until your comfortable with bringing rpm up as well as the feed to match and keep the correct chip load.

keeping the correct chip load is what is going to take the heat outta the work piece with the chip, and therefore keeps the tool cooler....
 
New to milling here but have gained confidence and have tried different speeds and feeds. I try to get my lathes and mill running "as smoothly" as possible then finish the job at those settings. Tool sharpness is critical and shape is also important. Someone here I think, stated the DOCs and Feed rates were primarily for industrial applications and that hobbyists may not always achieve these recommendations due to home-shop conditions- I believe it. Just a note from operating heavy equipment; speed will come with experience and smoothness with constantly concentrating on the operation of the machine.
Have a good day!
Ray
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surface feet and feeds may be unattainable by hobbyist, most of us don't have 10k rpm spindles, and most are hand cranking and cant feed at 50ipm by hand, you can use a drill tho, I used to do that before I had cnc on the mill.
my fav alum end mill, Ferocious 2 flute from CGS Tool, has a starting rpm for a half inch at 8k with a .006 chip load, that's 96ipm feed, I use it at 4k rpm, at about .005 chip load, 40ipm, and have great results, I can run that at 1 inch DOC, at .100 radial. you have to remember to figure HP for big cuts, if you start bogging the spindle down then you need to decrease feed or increase speed(rpm) CGS says that too much feed with too little speed can cause the tool to shatter.

I think everyone running a machine for hobby needs to smarten up, learn how to optimize tool life, and optimize work flow, learn your chip loads and how to calculate how to use it right. the best way to run a tools stepover is either 30% or 70% of diameter but not 50%, those two reduce radial chip thinning IIRC, radial chip thinning I believe leads to rubbing, and dull tools, Sandvik has a video about those percentages and why to run the tools at them. find it on youtube or their website
 
slow is better until you get used to what you're doing, then you can start increasing speed'n'feed until you start breaking things or get crazy chatter. Then you can slow down a bit :)
 
To reinforce what others have said. if you're using carbide, either cemented or inserts, It is expecting to go fast, I've always thought that carbide anneals the steel because of the heat, letting it cut better. I've been told this isn't the case, but that's how I remember it. If you are using High Speed Steel, (HSS) assume that the fastest you can go, is about 80 or 90 surface feet of work going past the tool per minute. MAX. There is one type of steel (with .03% alloy of lead) that is comfortable at 300 SFM, but that's a lesson for another day. A piece of steel, 3.8 inches in diameter should not turn faster than 80 RPM with a HSS cutter. 3.8 inches times Pi equals 12, (one foot), and that's how you figure SFM.

After years of experience, the sound the tool makes will tell you if you're too fast or not. With HSS there's no such thing as too slow.
 
What Tom said, but more blatant, don't use carbide until your ready to go fast, otherwise your wasting good tools, it needs the speed, same goes with some coatings, it needs the speed to work right, otherwise, again your wasting money on fancy coated tools...

Standard carbide is 350sfm, some coatings allow an increase of 50%, over 500sfm, not just allow, but perform better, and don't care about the heat, they like it
 
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