How do you Figure out the Feed Rate on Manual Mills?

Calculating chip load and IPM is for CNC machines. I never saw a manual machinist try to calculate it or care to. Dial the power feed down low and engage. Gradually increase the feed until it feels/sounds about right, stopping just shy of breaking the endmill. For all of the science in machining, it's still an art.
 
My free Niagara speed and feed slide rule, arrived at the shop, last week.
 
MrWhoopee said:
Calculating chip load and IPM is for CNC machines. I never saw a manual machinist try to calculate it or care to. Dial the power feed down low and engage. Gradually increase the feed until it feels/sounds about right, stopping just shy of breaking the endmill. For all of the science in machining, it's still an art.
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That’s absolutely true, you need to be a good artist to be able to translate what the sound of you machine is telling you when machining.

Nicolas
 
P. Waller said:
There are no "tricks", if the device that you are using has no defined feed rate you would simply measure it and make note of the actual speed at an indicated speed setting, you are a machinist after all.
Measure, do a bit of math and have at it, you will not be terribly far from what you require this way.
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Sadly, owning a small machine shop in my garage hasn't magically made me a machinist. I'm working hard at it, but there us no substitute for experience. The slide rule has made me comfortable taking bigger bites than I was previously. I'd swap my little slide rule for one if you all to fly out and show me the ropes, but until then, this stuff is a bit intimidating to us noobs!
 
benmychree said:
Tha

That is a good plan, I've used these speed/feed calculators for over 50 years, they take the guess work out of (especially) milling, good for drilling and lathe work as well.
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I bought a super beautiful one from 1941....I'll have to post some pictures...vintage wash machine green plastic(?) Bakelite (?)
 
GunsOfNavarone said:
Sadly, owning a small machine shop in my garage hasn't magically made me a machinist. I'm working hard at it, but there us no substitute for experience. The slide rule has made me comfortable taking bigger bites than I was previously. I'd swap my little slide rule for one if you all to fly out and show me the ropes, but until then, this stuff is a bit intimidating to us noobs!
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That’s the true! Owning a mill / lathe does not make me a machinist but I try to be by learning and it will take time. Right now I don’t even know how to use accurately enough any measuring tool, lol
 
T Bredehoft said:
You'll either get to know the feel of a good cut, or break a lot of end mills.
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This,

Once you develop a bit of feel, you can hear, feel, and often smell; when the speeds and feeds are in the right ball park.
 
Mitch Alsup said:
This,

Once you develop a bit of feel, you can hear, feel, and often smell; when the speeds and feeds are in the right ball park.
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I for sure won't break any end mills, but I'll take forever to machine something. I'm super careful and light with the feeds. I'm sure there are negatives to cutting too light, but i feel better too light than too heavy. Working up to the ideal chips, but it is a bit daunting. I would love to have someone with some serious skills show me the ropes...not a lot of machinists in the neighborhood. So what does a quality chip look like from say hot rolled 1018 mild steel? I know my chips are why too small.
 
If you take too light a cut and too small a feed you run the risk of rubbing instead of cutting. Rubbing is a fast way to dull an end mill. Newbies are usually cautious which is good, but too light a cut just plain wears out your tools. Nothing wrong with breaking a few smaller endmills in the pursuit of learning what your machine and you can and can not do.
 
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