How to make sure if I have eked out the last bit of life from my cutting tool ie inse

Acejunker · Sep 24, 2014

Usually I replace change the cutting edge if I have to repeatedly change offsets on my machine.
2. When the cutting edge is chipped off

I am told that if we run the recommended parameters given by cutting tool provider, the wear out rate is higher. (True or false.)

Tonytn36 · Sep 25, 2014

In short, the answer is: It depends.

It depends on what material you are cutting.
It depends on what machine you are using.
It depends on what type of set-up you have for fixturing.
It depends on what condition the material is in (heat treat, scale, etc)
It depends on what type of cooling medium you are using.
It depends on what type of cutting paths you are using.
It depends on what type of cutting parameters.

Lots of "It depends" factor into cutting tool life....

Thomas Paine · Sep 25, 2014

usually i'll go till about 30 seconds before the insert blows and wrecks the pocket. It depends.

WILLEO6709 · Sep 25, 2014

Thomas Paine said:
usually i'll go till about 30 seconds before the insert blows and wrecks the pocket. It depends.

do you use the way way back time machine to go back in time to do this or is this a feely thing you have an incredible knack for?

I like my inserts to run for a full day if possible.... or at least hours instead of minutes. But it depends... sometimes you just can't get that.....

DMF_TomB · Sep 25, 2014

Acejunker said:
Usually I replace change the cutting edge if I have to repeatedly change offsets on my machine.
2. When the cutting edge is chipped off

I am told that if we run the recommended parameters given by cutting tool provider, the wear out rate is higher. (True or false.)

.
usually maximum recommended parameters are given by tool provider. most back off sfpm and feed if depth of cut is higher. for example is sfpm is 200-450 i take that to mean at low depth of cut 450 is possible but at heavy depth of cut 200 is usually used. some people do not adjust settings depending on depth of cut are in for the most surprises.

Orange Vise · Sep 25, 2014

Tonytn36 said:
In short, the answer is: It depends.

It depends on what material you are cutting.
It depends on what machine you are using.
It depends on what type of set-up you have for fixturing.
It depends on what condition the material is in (heat treat, scale, etc)
It depends on what type of cooling medium you are using.
It depends on what type of cutting paths you are using.
It depends on what type of cutting parameters.

Lots of "It depends" factor into cutting tool life....

Unfortunately for the OP, it seems as though his homework is multiple choice and T/F.

rlockwood · Sep 25, 2014

Thomas Paine said:
usually i'll go till about 30 seconds before the insert blows and wrecks the pocket. It depends.

Yeah, and if not, I either change it before that point, or after.

Jashley73 · Sep 25, 2014

Acejunker said:
I am told that if we run the recommended parameters given by cutting tool provider, the wear out rate is higher. (True or false.)

Answer: Maybe. Obviously the carbide salesman wants you to buy more carbide. (From Him...) But what he may be trying to prove to you, is that by increasing your speeds/feeds and sacrificing tool life, you may be able to cut LOTS more material, and make more money in the same amount of time.

The only way to know is to humor him a little, and try increasing speeds & feeds, and see what your machine/tools/process is capable of. You may be surprised.

In short, a GOOD tool guy doesn't just want to sell you more carbide. He wants to help you be more productive, so that you make more money and grow. And when you need to grow, and buy more carbide, he wants you to remember how much he helped you before, so you'll let him help you again, and buy EVEN MORE carbide from him the next time...

Bobw · Sep 25, 2014

Already been said.... It depends... On a lot of things.

I have no problem swapping or turning an insert after 10 minutes... If I need to. If I'm trying to make time..

There is no point in running through inserts like water to drop the cycle time if you are busy doing other stuff and
won't get back to machine for a bit....

If I'm trying to make time, I'll sacrifice roughers... and then run my finishers conservative. I figure the small amount of time
saved on a finish pass isn't worth scrapping material and taking the time to dial it back in on tight stuff.

If you are running something long enough, you'll learn when you should just change inserts... Most machines can be
set to alarm out at a certain # of parts or a certain amount of cutting time.

It really all depends..

CarbideBob · Sep 25, 2014

I do not understand the question.
Chipped is of course too late. Usually bad/rework parts costs more than a tool corner.

On the last end, maybe. Going slower increases tool life until you fall off the bottom of the curve at which point there is no gain.
It also reduces the money you make in a day.
"recommended parameters" are a guess to put you in the middle of the curve but can not understand your particular operation which is why you see a wide range.
There are no industry wide "right" numbers.

Production part tool changes are set to stay 20% or so inside of the safe point.
Small run stuff may run up to or over the edge of no longer cutting.
Making 2-3 parts or 500,000? Production or job shop? High or low scrap cost and machine rate?
The answer is never nice and neat.
Bob

Acejunker · Sep 26, 2014

Tonytn36 said:
In short, the answer is: It depends.

It depends on what material you are cutting.
It depends on what machine you are using.
It depends on what type of set-up you have for fixturing.
It depends on what condition the material is in (heat treat, scale, etc)
It depends on what type of cooling medium you are using.
It depends on what type of cutting paths you are using.
It depends on what type of cutting parameters.

Lots of "It depends" factor into cutting tool life....

Accepted. How to arrive at optimum parameters for best results.

Cutting paths?
Please elaborate

Do theoretical formulas work practically ?

machtool · Sep 26, 2014

Acejunker said:
Cutting paths?
Please elaborate

Do theoretical formulas work practically ?

You could help if you declared your level of interest.. Are you a student? Intern? Process Engineer?

Tony is the most forthcomming prick here. 10% of what he post's here, he shoudn't.

If you can lay out which part of the education / experiance chain you are in, then you will get a better answer.
If we mentioned Toroidal, would the do your head in?

Regards Phil

Guest · Sep 26, 2014

I run them until the finish on the part goes out of tolerance or they start leaving too nasty of a burr.

PixMan · Sep 26, 2014

Getting maximum life out of the insert is false economy. If you get a $3 edge of a $12 insert to last 8 hours, how much more money would have made if you ran it 30% harder? Suppose you speeded it up and went through 4 edges in 8 hours instead of one. Your tooling cost is 4x, now $12 instead of $3. It took you 8 minutes to index inserts instead of two, yet you got 20% or more work out that's billed at $75 or more an hour.

If you are going to nitpick about the cost of expendable inserts instead of maximizing productivity you are missing an opportunity and your competitors will be blowing right by you.

chainfeed · Sep 26, 2014

just put two inserts on top of each other so when one blows up theres a new one under it.

Jashley73 · Sep 26, 2014

chainfeed said:
just put two inserts on top of each other so when one blows up theres a new one under it.

I was doing some insert testing once with the MFR' rep right beside me. We noticed that the machine (turning center) sounded kinda funny during the cut, and stopped the machine after the tool was done to check it out. It turns out, while carrying on a conversation and changing inserts, I got distracted, left the insert out of the toolholder, and started the machine. It made it through the entire cut with just the seat, and no real damage.

It was at that point, we kicked the tool-salesman out, and made the company-wide decision to quit buying inserts - we would just cut all the parts using the shim-seats...

chainfeed · Sep 26, 2014

Jashley73 said:
I was doing some insert testing once with the MFR' rep right beside me. We noticed that the machine (turning center) sounded kinda funny during the cut, and stopped the machine after the tool was done to check it out. It turns out, while carrying on a conversation and changing inserts, I got distracted, left the insert out of the toolholder, and started the machine. It made it through the entire cut with just the seat, and no real damage.

It was at that point, we kicked the tool-salesman out, and made the company-wide decision to quit buying inserts - we would just cut all the parts using the shim-seats...

lol that is excellent!

NAST555 · Sep 26, 2014

In theory 45 min of cutting time while hitting the sweet spot is acceptable... but then again
Theory is where you know everything but nothing works.
Practice is where everything works but nobody knows why.

Metalcutter · Sep 26, 2014

T

NAST555 said:
Theory is where you know everything but nothing works.
Practice is where everything works but nobody knows why.

Now, I really like this, a LOT.

Interesting.... It had to come all the way from Gauteng, South Africa
Thank you Nast555.

Regards,

Stan-

Tonytn36 · Sep 26, 2014

Acejunker said:
Accepted. How to arrive at optimum parameters for best results.

Cutting paths?
Please elaborate

Do theoretical formulas work practically ?

Formulas will get you started. It's all about your unique process and testing after that. No two machines are identical, no two holders are identical, no two tools are identical. It's about eliminating variables that have no influence in order to detect and manage those that do - because the variable field is too big. You have to do it via process of elimination.

If you will give this group of grouchy old machinists some details on what you are trying to do, they will help you eliminate a lot of variables right off the bat and point you toward some that matter. Details matter when it comes to cutting tools, which is why I posted that first response. You asked a question with 10,000,000+ possible answers. Give details on what you are trying to do, what you are cutting, what machine, what type of holder, cutting tools, current feeds/speeds and the detail on results you want to achieve. These guys can get you there (or a lot closer than you are now).

Believe it or not, cutting paths do influence tool life. Things like how you enter the material with the cutter, what your step-over % is, the method of corner machining, etc all can play a significant role in tool life.

You can post here about some off-the-wall-never-heard-of-it-before material and someone here has cut it before and will have tools, speeds and feeds to recommend. It's an amazing knowledge base if you use it properly.

How to make sure if I have eked out the last bit of life from my cutting tool ie inse

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