Previous in Forum: How to Setter Welding Porosity After Sand Blasting   Next in Forum: Manufacturing Job Tickets
Close
Close
Close
26 comments
Anonymous Poster #1

How to Calculate Exact CNC Turning Time From Drawing

01/19/2016 3:25 AM

Dear All,

I need some help in calculating cnc turning time from drawing ,we have engineering standard in which we have used mean dia for all calculations with rpm constant, while cnc machine works on fix Vc(cutting speed) & variable rpm & feed to improve tool life & tool wera & quality of job.Is there Any method to calculate cycle time just like cnc machine works?with constant vc(cutting speed) .

Thanks,

Reply
Interested in this topic? By joining CR4 you can "subscribe" to
this discussion and receive notification when new comments are added.

Comments rated to be "almost" Good Answers:

Check out these comments that don't yet have enough votes to be "official" good answers and, if you agree with them, rate them!
Guru
Technical Fields - Technical Writing - New Member Engineering Fields - Piping Design Engineering - New Member

Join Date: May 2009
Location: Richland, WA, USA
Posts: 21022
Good Answers: 795
#1

Re: how to calculate exact cnc turniung time from drawing

01/19/2016 3:32 AM

Arithmetic is usually taught in elementary school. Find a local one and sign up.

__________________
In vino veritas; in cervisia carmen; in aqua E. coli.
Reply Off Topic (Score 5)
Guru
United Kingdom - Member - Indeterminate Engineering Fields - Control Engineering - New Member

Join Date: Jan 2007
Location: In the bothy, 7 chains down the line from Dodman's Lane level crossing, in the nation formerly known as Great Britain. Kettle's on.
Posts: 32119
Good Answers: 838
#2

Re: how to calculate exact cnc turniung time from drawing

01/19/2016 3:53 AM

Take the time at the beginning of the operation. Take the time at the end of the operation. Simply subtract the earlier time from the later time.

__________________
"Did you get my e-mail?" - "The biggest problem in communication is the illusion that it has taken place" - George Bernard Shaw, 1856
Reply
Guru

Join Date: Oct 2008
Posts: 42376
Good Answers: 1692
#13
In reply to #2

Re: how to calculate exact cnc turniung time from drawing

01/19/2016 4:15 PM

Say I start at 4:00PM on Monday and finish at 4:00PM on Tuesday.

4:00PM-4:00PM=0

Reply
Guru
United Kingdom - Member - Indeterminate Engineering Fields - Control Engineering - New Member

Join Date: Jan 2007
Location: In the bothy, 7 chains down the line from Dodman's Lane level crossing, in the nation formerly known as Great Britain. Kettle's on.
Posts: 32119
Good Answers: 838
#14
In reply to #13

Re: how to calculate exact cnc turniung time from drawing

01/19/2016 5:15 PM

<...The supply of fools will always outstrip the demand.....>

Quite.

__________________
"Did you get my e-mail?" - "The biggest problem in communication is the illusion that it has taken place" - George Bernard Shaw, 1856
Reply Off Topic (Score 5)
Guru
Popular Science - Biology - New Member Hobbies - Musician - New Member APIX Pilot Plant Design Project - Member - New Member Hobbies - CNC - New Member Fans of Old Computers - ZX-81 - New Member

Join Date: Jan 2007
Location: Centurion, South Africa
Posts: 3921
Good Answers: 97
#3

Re: how to calculate exact cnc turniung time from drawing

01/19/2016 4:22 AM

You can make s decent estimate if you know the Vstart , Vend , Vmax , Acceleration , Deceleration and length for each vector of the tool path.

If you are really pressed for performance you can optimize the tool path by re-sequencing the cuts and keep moves time to a minimum.

__________________
Never do today what you can put of until tomorrow - Student motto
Reply Score 1 for Good Answer
Guru
Technical Fields - Technical Writing - New Member Engineering Fields - Piping Design Engineering - New Member

Join Date: May 2009
Location: Richland, WA, USA
Posts: 21022
Good Answers: 795
#4
In reply to #3

Re: how to calculate exact cnc turniung time from drawing

01/19/2016 5:14 AM

Ooh, that's too hard. It entails arithmetic, as suggested by that meanie in post 1.

__________________
In vino veritas; in cervisia carmen; in aqua E. coli.
Reply Off Topic (Score 5)
Guru
United Kingdom - Member - Indeterminate Engineering Fields - Control Engineering - New Member

Join Date: Jan 2007
Location: In the bothy, 7 chains down the line from Dodman's Lane level crossing, in the nation formerly known as Great Britain. Kettle's on.
Posts: 32119
Good Answers: 838
#5
In reply to #4

Re: how to calculate exact cnc turniung time from drawing

01/19/2016 5:20 AM

What <...meanie...>?

__________________
"Did you get my e-mail?" - "The biggest problem in communication is the illusion that it has taken place" - George Bernard Shaw, 1856
Reply
Guru
Popular Science - Biology - New Member Hobbies - Musician - New Member APIX Pilot Plant Design Project - Member - New Member Hobbies - CNC - New Member Fans of Old Computers - ZX-81 - New Member

Join Date: Jan 2007
Location: Centurion, South Africa
Posts: 3921
Good Answers: 97
#6

Re: how to calculate exact cnc turniung time from drawing

01/19/2016 6:22 AM

Not so complicated - To do any calculation you need coordinates.

What file format are your tool path / output of your drawing in ? (NCI, NC . . . . )

__________________
Never do today what you can put of until tomorrow - Student motto
Reply
Guru

Join Date: Oct 2008
Posts: 42376
Good Answers: 1692
#7

Re: How To Calculate Exact CNC Turniung Time From Drawing

01/19/2016 8:47 AM

Get a stop watch and a stool and park your butt by a machine and time some cuts.

You can develop your own formulae, maybe.

Cutting speed has many variables. I'll give you two to start you on the road to knowledge. The rest you can ask a machinist about, if you actually have any machinists on staff.

Ready?

1. Type of material.

2. Cutter diameter.

Milling Speed and Feed Calculator - CustomPart.Net

Calculation for Cutting Speed, Spindle Speed and Feed ...

Reply
Guru
Technical Fields - Project Managers & Project Engineers - New Member

Join Date: Aug 2006
Location: Midwestern United States
Posts: 843
Good Answers: 76
#9
In reply to #7

Re: How To Calculate Exact CNC Turniung Time From Drawing

01/19/2016 11:34 AM

And add tooling to the list of variables. If you're looking at high volume production, you can make custom inserts that have a significant impact to cutting time... well, depending on what you're cutting.

Example, CNC cutting of premium and semi-premium threaded connections on OCTG utilize custom-designed inserts... 1) because of the proprietary profiles, and 2) to reduce cutting time.

__________________
Reuters - Investigators found that the recent thread derailment in CR4 was caused by over-weight creatures of lore and request that membership DON'T FEED THE TROLLS.
Reply Score 1 for Good Answer
Guru
United Kingdom - Member - Indeterminate Engineering Fields - Control Engineering - New Member

Join Date: Jan 2007
Location: In the bothy, 7 chains down the line from Dodman's Lane level crossing, in the nation formerly known as Great Britain. Kettle's on.
Posts: 32119
Good Answers: 838
#11
In reply to #9

Re: How To Calculate Exact CNC Turniung Time From Drawing

01/19/2016 1:04 PM

It's going to be one hell of an equation!

__________________
"Did you get my e-mail?" - "The biggest problem in communication is the illusion that it has taken place" - George Bernard Shaw, 1856
Reply
Guru
Hobbies - CNC - New Member Hobbies - DIY Welding - New Member Engineering Fields - Electromechanical Engineering - New Member

Join Date: Aug 2007
Posts: 23578
Good Answers: 419
#12
In reply to #9

Re: How To Calculate Exact CNC Turniung Time From Drawing

01/19/2016 1:08 PM

If they're looking for 'Exact" results, my opinion is that this company's (profit) margins are way too tight.

__________________
“ When people get what they want, they are often surprised when they get what they deserve " - James Wood
Reply Score 1 for Good Answer
Guru
Technical Fields - Technical Writing - New Member Engineering Fields - Piping Design Engineering - New Member

Join Date: May 2009
Location: Richland, WA, USA
Posts: 21022
Good Answers: 795
#17
In reply to #12

Re: How To Calculate Exact CNC Turniung Time From Drawing

01/20/2016 1:04 AM

Indeed. The word "exact" in the post title is a dead giveaway that the person in question does not know such concepts as error bands.

__________________
In vino veritas; in cervisia carmen; in aqua E. coli.
Reply Off Topic (Score 5)
Guru
Hobbies - CNC - New Member Hobbies - DIY Welding - New Member Engineering Fields - Electromechanical Engineering - New Member

Join Date: Aug 2007
Posts: 23578
Good Answers: 419
#19
In reply to #17

Re: How To Calculate Exact CNC Turniung Time From Drawing

01/20/2016 7:13 AM

What's error bands?

ohh,.. and an off topic remark, too..... That's good right?

__________________
“ When people get what they want, they are often surprised when they get what they deserve " - James Wood
Reply Off Topic (Score 9)
Anonymous Poster #1
#23
In reply to #7

Re: How To Calculate Exact CNC Turniung Time From Drawing

01/30/2016 11:50 PM

pl send me any method for turning from drawing

Reply
Guru
United Kingdom - Member - Indeterminate Engineering Fields - Control Engineering - New Member

Join Date: Jan 2007
Location: In the bothy, 7 chains down the line from Dodman's Lane level crossing, in the nation formerly known as Great Britain. Kettle's on.
Posts: 32119
Good Answers: 838
#24
In reply to #23

Re: How To Calculate Exact CNC Turniung Time From Drawing

04/28/2020 7:18 AM

Invitation declined.

__________________
"Did you get my e-mail?" - "The biggest problem in communication is the illusion that it has taken place" - George Bernard Shaw, 1856
Reply
Guru
Hobbies - DIY Welding - Wannabeabettawelda

Join Date: May 2007
Location: Annapolis, Maryland
Posts: 7873
Good Answers: 452
#8

Re: How to Calculate Exact CNC Turniung Time From Drawing

01/19/2016 10:44 AM

I'd be surprised if the software that operates the CNC machine couldn't tell you that when you enter the STEP file and the type and size of the raw material along with the specified feed rates for the various tools, RPM, and so on. Or use a stop watch for the first one.

Reply
Anonymous Poster #1
#22
In reply to #8

Re: How to Calculate Exact CNC Turning Time From Drawing

01/30/2016 11:47 PM

Sir,

I am working in engineering ,we are receiving lot of drawing every day for time study,so we have never made job before,to confirm the order marketing ask us for time estimation for quotation.exact or accurate estimation can help organization making profit other wise loss.

Reply
Guru
United Kingdom - Member - Indeterminate Engineering Fields - Control Engineering - New Member

Join Date: Jan 2007
Location: In the bothy, 7 chains down the line from Dodman's Lane level crossing, in the nation formerly known as Great Britain. Kettle's on.
Posts: 32119
Good Answers: 838
#25
In reply to #22

Re: How to Calculate Exact CNC Turning Time From Drawing

04/28/2020 7:24 AM

<...estimation...>

Oh! So it's a guess?

In the absence of any useful information, any old guess will do.

<...marketing...>

Ah! So there are other people at the facility. Good. These people have access to data on previous production runs that is commercially-sensitive. Use it, for there is none here.

<...making profit other wise loss...>

Is it fair to burden a global anonymous internet Engineering website with that in the absence of a reward for doing so?

__________________
"Did you get my e-mail?" - "The biggest problem in communication is the illusion that it has taken place" - George Bernard Shaw, 1856
Reply Off Topic (Score 5)
Guru
Hobbies - CNC - New Member Hobbies - DIY Welding - New Member Engineering Fields - Electromechanical Engineering - New Member

Join Date: Aug 2007
Posts: 23578
Good Answers: 419
#10

Re: How to Calculate Exact CNC Turning Time From Drawing

01/19/2016 12:57 PM

Experience helps,

actually running the geometry through CAM programming software is better (after the operation variables in the software have been put in)

__________________
“ When people get what they want, they are often surprised when they get what they deserve " - James Wood
Reply
Guru

Join Date: Jun 2009
Location: South of Minot North Dakota
Posts: 8376
Good Answers: 775
#15

Re: How to Calculate Exact CNC Turning Time From Drawing

01/19/2016 7:02 PM

Just show your drawing and time requirement to the experienced machinist who will be making the part.

When you need a precision part made you have two options.

One you can have it done in a specific time constraint or two you can have it done correctly.

As for who an experienced machinists going to see your drawing and time numbers to him its just a sheet of paper with some suggestions on it.

Reply
Guru

Join Date: Mar 2007
Location: by the beach in Florida
Posts: 33315
Good Answers: 1810
#16

Re: How to Calculate Exact CNC Turning Time From Drawing

01/19/2016 10:40 PM

You can take the weight of the finished product and subtract it from the weight of the starting block...then figure the weight of swarf produced per minute by calculating the chip load for the bit and speed you will be using....

"Chip load - The distance a bit moves forward as a single flute cuts into a material. The amount that each flute cuts during a single revolution of a cutting tool. The formula for chip load is CL = (feed rate / no. flutes) / RPM. The TOTAL chip load is defined as the distance a bit moves forward during a single revolution (TCL = feedrate / RPM) and is given in inches (or millimeters) per revolution."

chip load calculator...

http://zero-divide.net/index.php?page=fswizard

The final figure may need some tweaking...

__________________
All living things seek to control their own destiny....this is the purpose of life
Reply Score 1 for Good Answer
Anonymous Poster #1
#18
In reply to #16

Re: How to Calculate Exact CNC Turning Time From Drawing

01/20/2016 4:59 AM

Dear Sir,

Thanks for your support,in case of turning & facing is this software can work ?

Thanks

Reply Off Topic (Score 5)
Associate

Join Date: Apr 2014
Location: Erie, PA
Posts: 44
Good Answers: 1
#21
In reply to #18

Re: How to Calculate Exact CNC Turning Time From Drawing

01/20/2016 8:05 AM

No, not from just a drawing. If you write a program for it, there is software that will estimate the turning time.

Reply Off Topic (Score 5)
Guru

Join Date: Oct 2008
Posts: 42376
Good Answers: 1692
#20

Re: How to Calculate Exact CNC Turning Time From Drawing

01/20/2016 7:51 AM

<Don't feed the trolls>

<Ban Anonymous Posters!>

Reply Score 1 for Good Answer
Commentator

Join Date: Jul 2019
Posts: 83
#26

Re: How to Calculate Exact CNC Turning Time From Drawing

07/24/2020 8:14 AM

Exactly lyn.

Reply
Reply to Forum Thread 26 comments
Interested in this topic? By joining CR4 you can "subscribe" to
this discussion and receive notification when new comments are added.

Comments rated to be "almost" Good Answers:

Check out these comments that don't yet have enough votes to be "official" good answers and, if you agree with them, rate them!
Copy to Clipboard

Users who posted comments:

Anonymous Poster (3); Brave Sir Robin (1); DeputyDawg (1); Hendrik (2); JavaHead (1); lyn (3); msbettyhunt (1); phoenix911 (3); PWSlack (6); SolarEagle (1); tcmtech (1); Tornado (3)

Previous in Forum: How to Setter Welding Porosity After Sand Blasting   Next in Forum: Manufacturing Job Tickets

Advertisement