Amount Of Material Removal On Spring Cut

epanzella said:
The reason I did this in the first place was to test my spindle bearings with the test bar I just got. I had another indicator at the spindle and it wasn't moving at all.
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Think of it like a rifle, if you move the barrel .0001" how much will the point of impact change at 50 feet

My point is even the most minuscule movement in the spindle is amplified the farther you get away from it.
 
kingmt01 said:
I use both. Usually cheap caribide.
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My lathe is only a 12 x 36 and I have no problem with .100 DOC @ 800-1000 rpm with relatively cheap set of carbide insert tools on various steels & stainless steels. The harder I push them the better the finish. Your lathe should be rigid enough to do that and more without breaking a sweat. It seems to me that you're losing rigidity somewhere either in your setup, gibs, or spindle bearings. Maybe those cutters are not sharp or have the wrong relief.
 
joshua43214 said:
lol, I think your just being too easy on the machine.
I was making 0.200" deep cuts in stressproof on my 13x40 the other day, it just hummed into it. Made some really beautiful cobalt blue chips :)
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I gotta try that, see what I can break
 
I've been turning 3/4 rod at around 1200 RPM I think. The carbide is well used & I've never sharpened this piece. I've only honed it when it quits cutting well. I'm turning blue chips at that. It might be more likely I'm not holding the tool at the right angle. I just guess at the most of it & do what seems to me to look good.
 
Deerslayer said:
Are blue chips the goal?
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Not really a goal, but show that the machine/tool can take a good cut/feed rate. Generally when pushing the tool to break a chip, you will get blue chips. A little less blue if running coolant. That is where most of your heat goes, is out through the chips coming off the cut
 
Deerslayer said:
Are blue chips the goal?
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The chip will tell you more about how well you are machining than the finish will.
A blue chip just is an indicator. A lovely blue color with carbide can mean you have hit the sweet spot for taking lots of material off.
In my case I was using HSS, and many will suggest that straw color is as hot as you should get with HSS. HSS will roll up a nice blue chip at the cost of tool life. I'm not a pro, so I am happy to trade some time on the grinder for faster roughing.
The color needs to be taken into account with other indicators such as evenness of finish, temperature of the work, sound, etc.
 
joshua43214 said:
The chip will tell you more about how well you are machining than the finish will.
A blue chip just is an indicator. A lovely blue color with carbide can mean you have hit the sweet spot for taking lots of material off.
In my case I was using HSS, and many will suggest that straw color is as hot as you should get with HSS. HSS will roll up a nice blue chip at the cost of tool life. I'm not a pro, so I am happy to trade some time on the grinder for faster roughing.
The color needs to be taken into account with other indicators such as evenness of finish, temperature of the work, sound, etc.
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That's why I don't remember it from machining class, preservation of tooling was always a key consideration and there was little to no carbide in the classroom environment
 
joshua43214 said:
lol, I think your just being too easy on the machine.
I was making 0.200" deep cuts in stressproof on my 13x40 the other day, it just hummed into it. Made some really beautiful cobalt blue chips :)
Click to expand...

Chip color was one thing our CC instructors spent quite a bit of time with, explaining how it will clue us into how much heat is going into the workpiece, whether or not we could cut faster/slow down feed, etc.
 
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