Quiz / Quote this job

I intend to take the results of this quiz further on to explain some of the newer cutters on the market so we can all understand the
concept of why they work so effectively, making you more competitive, saving you money and possibly your business. So have some fun with this one. If you like this stuff I can keep them rolling in here.
There is nothing intended to be tricky or hidden, simply doing the math properly to ensure the tooling is cutting properly.
Start of Quiz: You have a job come across your desk to quote. It is 1018 steel, not difficult to machine. The part is 3” wide, 1” thick and 12” long. There are 2 features to machine in it.
Feature # 1 is a .750” wide, Flat Bottom Channel that is .0215” deep and it runs the complete length (12”) of the part. A Standard Flat Ended Endmill is to be used.
Feature # 2 is a Full Radius Channel, designated as a 3/8” radius, it also is .0215” deep and runs the complete length (12”) of the part. A Standard Ballnose Endmill is to be used.
Both of the Endmills you have available for this job are 4 Flute, Carbide, Stub Flute Length, Coated tools.
The Tool Manufacturer for both of the Endmills you are using suggests you use 500 SFM for this material and a chipload of .002 Feed Per Tooth.
What would be the total Time In The Cut (not including rapid positioning moves) for both of these tools combined to machine both of these features in the part?
Multiple Choice Answers: A.    Less than 35 Seconds B.    Between 35 and 44 Seconds C.    Between 45 and 50 Seconds D.    More than 51 seconds but Less Than 1 Minute E.    More than 1 Minute
If you want to explain your math behind the answer feel free to do so.
Again, have fun with this.
JR
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I intend to take the results of this quiz further on to explain some of the newer cutters on the market so we can all understand the concept of why they work so effectively, making you more competitive, saving you money and possibly your business. So have some fun with this one. If you like this stuff I can keep them rolling in here.
There is nothing intended to be tricky or hidden, simply doing the math properly to ensure the tooling is cutting properly.
Start of Quiz: You have a job come across your desk to quote. It is 1018 steel, not difficult to machine. The part is 3” wide, 1” thick and 12” long. There are 2 features to machine in it.
Feature # 1 is a .750” wide, Flat Bottom Channel that is .0215” deep and it runs the complete length (12”) of the part. A Standard Flat Ended Endmill is to be used.
Feature # 2 is a Full Radius Channel, designated as a 3/8” radius, it also is .0215” deep and runs the complete length (12”) of the part. A Standard Ballnose Endmill is to be used.
Both of the Endmills you have available for this job are 4 Flute, Carbide, Stub Flute Length, Coated tools.
The Tool Manufacturer for both of the Endmills you are using suggests you use 500 SFM for this material and a chipload of .002 Feed Per Tooth.
What would be the total Time In The Cut (not including rapid positioning moves) for both of these tools combined to machine both of these features in the part?
Multiple Choice Answers: A. Less than 35 Seconds B. Between 35 and 44 Seconds C. Between 45 and 50 Seconds D. More than 51 seconds but Less Than 1 Minute E. More than 1 Minute
If you want to explain your math behind the answer feel free to do so.
Again, have fun with this.
JR
you said in the subject line to quote this job. 3hrs setup...20 mins a piece run.
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JRWheels wrote:

    I just sent my answer to Jim.
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So, what, you never let people copy off you in grade school???? Sheesh........
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Proctologically Violatedฎฉ wrote:

PV:
    Ahhh, but when you copy from someone else you're never really sure if who you're copying from is correct or not.
    Since Jim has posted the answer and explanation, here was what I sent him:
=================================================================Jim:
Well, tool #1 RPM = 3.82 X 500 SF / .750 or 2546 RPM
IPM = .002 X 4 teeth X 2546 RPM or 20.4 IPM
So adding .5 on each end of the bar to clear the 3/8" radius of the end mill should give a 13" length. 13" / 20.4 IPM = .64 min. or 38.4 sec.
Tool #2 Would be .750 ball end mill. But being that the dept. is only .0215 the width of cut would be c = 2 X square root of h(2r-h) or .2503. So RPM = 7640 IPM = 61.12 Starting off and finishing off the bar by .250 on either side, the length would be 12.5 / 61.12 IPM or .205 min. or 12.3 sec.
So adding 38.4 sec. and 12.3 sec I get 50.7 sec. So my answer would be "D".
Now IF the tool centerlines were started ON the 12" bar length the times would be: 12"/20.4 = .588 min. or 35.28 sec. And 12"/61.12 .196 min. or 11.76 sec. 35.28 + 11.75 = 47.03 sec. or "C". ================================================================    After sending that to Jim, I looking at his list of multiple choice answers more closely and a saw I had made an error. So I sent the following addendum:
=================================================================BottleBob wrote: >
> So adding 38.4 sec. and 12.3 sec I get 50.7 sec. So my answer would be "D".
Opps, 50.7 seconds is less than 51 seconds, so BOTH of my answers would be "C". ================================================================    After sending that addendum, I looked at his multiple choice answers AGAIN and saw that there was STILL an error. So I sent the following (I've just now added a copy of his original multiple choice list).
=================================================================Jim:
There's an anomaly in your answer list. My first answer of 50.7 is MORE than "C" and LESS than "D". LOL
Multiple Choice Answers: A. Less than 35 Seconds B. Between 35 and 44 Seconds C. Between 45 and 50 Seconds D. More than 51 seconds but Less Than 1 Minute E. More than 1 Minute ================================================================    You see how convoluted things can get? And YOU want to copy from ME? LOL
    Also, you can see how handy saving E-mails and posts to an accessible "SENT" folder can be now, right? <g>
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You ARE scary!! And we're not even getting meteephysical or exeestential!!!
Well, mebbe Jim will give you a make-up quiz.
One thing is for sure: Vinny either has the most profitable shop in the USA, or has no bidniss at all!! :)
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Mr. P.V.'d (formerly Droll Troll), Yonkers, NY
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=========================================> Jim:

=========================================>
Bob & PV,
I couldn't have planned that if I tried to, leaving a gap between the (50 second) max of one answer and the (51 second) beginning of the next. I surely didn't plan on that but makes you aware of how things can get twisted around. Of Course Bob fits an answer right in there for me to stumble and bumble on. hahahaha
The whole premise behind the quiz was to simply get everyone that is interested to realize these tools run differently even though they show up on the same page in some tooling catalogs calling them 3/4" endmills and refer to a certain page for Tech Help.
Then to show the theory of calculating the True Diameter that is cutting is how it leads into the High Feed Cutter Designs that look scary as hell to see them run. These tools are money makers when running properly. However, let me repeat this, HOWEVER since they are traveling so fast and shooting chips all over the place, if and when something may turn ugly, its REAL ugly. You don't want to walk away from the control when these things are ripping material off of blocks.
The other thing a shop recently justified while running these cutters on several machines was a Clean-up Kid. The Operators had to keep stopping the machines and clean out chips and dump chip hoppers so often, at which time the machine sat idle, they actually justified the additional cost of a Clean-Up Kid to speed things up. If you measure Milling Effectiveness by the amount of chips coming from a machine, these tools will win you over.
JR
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Revolutions to complete cut == 12/0.008 (4 flute, 0.002 per flute) == 1500 Revolutions required per cut
Assuming a 0.625 EM to cut the 0.75 slot 500 SFM = 3055 RPM / 60 sec = 50.916 rev/sec Assuming a 0.75 EM to cut the 0.75 slot 500 SFM = 2546 RPM / 60 sec = 42.43 rev/sec
Ball EM = 0.17437 actual cut dia 500 SFM = 10953 RPM / 60 sec = 182.55 rev/sec
So, for the 0.625 EM, 1500/50.916 = 29.46 seconds x 2 == 58.92 sec for flat slot For the 0.75 EM, 1500/42.43 == 35.35 sec for flat slot For the radius EM, 1500/182.55 = 8.21 sec
So, depending on whether you use a 0.625 em or a 0.75 EM for the flat spot:
0.625 EM + Ball em = 67.13 sec 0.75 EM + Ball Em = 43.56 sec
--
Anthony

You can't 'idiot proof' anything....every time you try, they just make
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Anthony wrote:

Anthony:
    To use a 5/8 end mill you'd have to make more than one pass.

    .17437 is the chord length for a diameter of 3/8" not a radius of 3/8".
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Yes, I knew that and thought I took that into consideration with the cycle time calculation, did I not? (Can't see my post.)

You are correct. I flubbed that one.
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Anthony

You can't 'idiot proof' anything....every time you try, they just make
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Anthony wrote:

Anthony:
    Yes. You absolutely did. I missed it first time around.
===========================================================Anthony wrote:
So, for the 0.625 EM, 1500/50.916 = 29.46 seconds x 2 == 58.92 sec for flat slot ==========================================================>>> Ball EM = 0.17437 actual cut dia>> .17437 is the chord length for a diameter of 3/8" not a radius of

    Why can't you see your post?
    I have all my outgoing E-mails and posts copied to a "SENT" folder, so I can review them at a future date if necessary.
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It got marked read, so disappeared. I could have reconstructed the thread to get it back, but I was pretty sure I included the double pass. Other than this upper respiratory infection affecting my brain similar to what it has my sense of balance, I cannot explain the 3/8 R vs 3/8 Dia error though. This infection has had some bad side effects......I'm having to hold onto walls just to get to the crapper and back...fluid behind the eardrums is making me dizzy as hell when I move around.
--
Anthony

You can't 'idiot proof' anything....every time you try, they just make
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Anthony wrote:

That's terrible. I hope you get over this in a hurry.
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John R. Carroll
www.machiningsolution.com
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Anthony wrote:

Anthony:
    Cripes! I sure hope you get over it fast. I HATE being sick, the worst part is using up your sick days actually being SICK! <g>
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I hear DAT!!!
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Mr. P.V.'d (formerly Droll Troll), Yonkers, NY
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Plain and simple
Get well soon.
Chers:
http://images.google.com/images?gbv=2&hl=en&safe=off&q=Cher&btnG=Search+Imag es
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Which IS a little scary.... :)
But then, with the likes of jb running around, you gotta do whatchoo gotta do....
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Proctologically Violatedฎฉ wrote:

PV:
    Why would that be scary? Isn't that what the "SENT" folder is for?          You're not scared by Google's archiving process, are you? LOL
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Quote:
JRWheels wrote:

2 hours setup, 5 min/pc. run time, plus 1 (one) end mill per, say 200 pcs. ( 5 axis is nice. <G>)
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