Cam As The Master Program

Hi I am from the uk and now live in the Philippines so it was great to find this forum
I bought my first cnc machine a Bostomatic 300 and a cam system in 1977 the cam was Olliveti GTL3 on mini-computor (PC's were not around them), so I went on a GTL3 programming course before the Bosto arrived. the biggest attraction after the course was all the calculations it could perform and I did not have to understand G-codes. The course told me that the CAM program must always be the master.
My question is why did this practice disapear when cam went from command language to solid modeling
I asked recently to most of the leading cam producers for a system as follows
CAM source program to always be the master programs
No editing on machine tool control
No editing on cnc control program
No need to read G-codes
Bearing in mind I had run the above for 20 years on Visi-Mill 4.8
None of them came back
Also some of our spares work had 6 A0 sheets, I do not want to or are not capable to have to re-draw in cad
Also is there a up to date cam system that still has a command type system on board
Jigborejeff

Jeff,

Not quite sure what you are asking? What practice are we talking about and what do you see as having changed? It is up to each shop to determine the practice that best suits them. I make sure that and edits I do at the machine make it back to the cam program. My cam is always the most current running program of any job I do.

Is this what you are talking about?

Smallshop,
I think its where you open your mind and become one with the cnc, but because no one has to use their imagination anymore, the machine cannot see what you're thinking because your mind is blank

I learned the same way you did many years ago when programming with CII. The G-code file was treated like a disposable tool, throw it away when you are done with it. We did not wory about the tape, and if an edit was made on the shop floor, the CAM program had to be changed to reflect the floor edit, and a least one part ran off with the new tape file. Then came Fanuc with their G71, and G72 roughing and finishing cycles, now the shop floor could edit the finish profile, and the roughing updated for free, family of parts, yada, yada, yada. Seemed to be a faster method to upper management, but what do they know. I still don't buy into it, and good luck getting ISO certified using the g-code as the source, and not the solid model and CAM system.

Well, to post something to the contrary, I run small to medium production stuff with roughly 90% return.
In every one of those cases the program is the boss and the CAM file is only a rough original to be used if there is a major change in the part.
Sure, if the edit is obvious and is easily done in CAM I do make the change there, but more often than not the edits I make are for speed or tool/part requisite, and some of those changes just plain cannot be done in CAM.
Well, actually they can but the edits take more time in there AND more often than not they are "unruled" toolpath edits, so they will not be associative to the part anyway.

The nice thing about the program being the boss is that the job traveler and setup sheet can define each and every step, including the not so obvious stuff without discrepancy. There is never a question about the program. It ran the last time, it will run this time and will run again tomorrow just as it dit the last time.

My $.02

smallshop said:

Jeff,

Not quite sure what you are asking? What practice are we talking about and what do you see as having changed? It is up to each shop to determine the practice that best suits them. I make sure that and edits I do at the machine make it back to the cam program. My cam is always the most current running program of any job I do.

Is this what you are talking about?

Click to expand...

The practice is the cam source program is always the master
As soon as you make an edit on the machine the cam program goes out the window, if you have 20 machines with 10 different controls I found it easier and so much safer to edit the source program and post process a new cnc program, a few seconds to process plus the edit time
When you edit the cam you do it once safely, when you edit the machine you still have to edit the cam thats two edits, say you edit the cam incorrectly, you won't know till you run the part again maybe months later and maybe have scrap, believing it to be perfect

SnakeD0ct0r said:

I learned the same way you did many years ago when programming with CII. The G-code file was treated like a disposable tool, throw it away when you are done with it. We did not wory about the tape, and if an edit was made on the shop floor, the CAM program had to be changed to reflect the floor edit, and a least one part ran off with the new tape file. Then came Fanuc with their G71, and G72 roughing and finishing cycles, now the shop floor could edit the finish profile, and the roughing updated for free, family of parts, yada, yada, yada. Seemed to be a faster method to upper management, but what do they know. I still don't buy into it, and good luck getting ISO certified using the g-code as the source, and not the solid model and CAM system.

Click to expand...

Yes it looks good to senior management but as you say what do they know perhaps not the difference between a end mill and a windmill
In the UK companies including aerospace suppliers get ISO certified using G-code no questions asked about Cam. I think it is weird

SeymourDumore said:

Well, to post something to the contrary, I run small to medium production stuff with roughly 90% return.
In every one of those cases the program is the boss and the CAM file is only a rough original to be used if there is a major change in the part.
Sure, if the edit is obvious and is easily done in CAM I do make the change there, but more often than not the edits I make are for speed or tool/part requisite, and some of those changes just plain cannot be done in CAM.
Well, actually they can but the edits take more time in there AND more often than not they are "unruled" toolpath edits, so they will not be associative to the part anyway.

The nice thing about the program being the boss is that the job traveler and setup sheet can define each and every step, including the not so obvious stuff without discrepancy. There is never a question about the program. It ran the last time, it will run this time and will run again tomorrow just as it dit the last time.

My $.02

Click to expand...

I found any edits easy to perform in Visi-Mill but this a command language Cam
Not certain what tool/part requisite is
The nice thing about Cam being the Boss is that the commands you give are like a complex planning sheet and it is in English
The great thing also if you have different machines and different controls you can move it to any machine with no editing whatsoever
You do require all of your PP's to be completely de-bugged
And when you purchase more new machines it will work on them
I am trying to say maybe that latest CAM systems are not robust enough to handle being the master easily
All the shops I have visited recently produce cam program pp it and dump it onto the guy on the machine first thing he has to do is the edits for the pp which has never been de-bugged correctly then proceed to edit the cnc program and then it becomes the master it feels risky and uncertain to me
I appreciate all shops are totally different and follow different paths and disciplines and we all think we are doing right thing
Give 10 guys a complex part they will all do it different whether on a manual mill or programing a cnc machine even if they come from the same company spread it to 10 companies and it gets worse, one guy will be No 1 and one will be last at No 10
We must all try to make our companies however small to be No1
Machines are very dumb so they need smart programmers and the best of tooling to jump about at their best

Machines for show......Tools for dough
Your darkest hour is only 60 minutes long ( for cnc programmers)

Sorry to go on a bit but this is my only engineering chat for 2 years
Regards
Jigborejeff

HuFlungDung said:

Smallshop,
I think its where you open your mind and become one with the cnc, but because no one has to use their imagination anymore, the machine cannot see what you're thinking because your mind is blank

Click to expand...

Machines are dumb, controls are dumb, get your mind into a coated carbide end mill or a balanced boring head tools do all the work and make all the money, driving these the best way possible is better than sex (well nearly as good), but they are very expensive so you have to concentrate so you don't break them
Use your imagination with innovation and you will end up with a great finished component with everyone in the batch a good one

Jeff

The tool/part requisite are things that are not so obvious during programming.
For example you make a thin feature an the rougher pushes the material out.... slowing it down for that segment only however resolves the issue.
CAM doesn/can't know that, but you also don't want to sacrifice the other cuts just for this.
Ditto for "voids" in the part. Example you have a part with a large hole in the middle. the path takes the tool through this hole, where there is no material whatsoever. Let's assume that the tool spends 5-10 seconds through this area with no material.
You can:
A: Leave it be, it's only 10 seconds.
B: reprogram the features in CAM by breaking it into segments
C: Edit the toolpath by hand and increase the feed to say 200IPM for that segment

A is wasteful for production,
B will create a whole bunch of approach/depart/ramp-on/ramp-off movements, liklely not saving any time at all.
C is easy and quick.

D. Create a false program to take the 'hole' out using a rest machining feature and then delete it before generating G-code. Bingo

Here is the big thing to remember! if you start with the CAM, you modify the CAM. if someone changes the GCode on the machine and then someone reposted the program without doing the changes you are back to square one!

now you have more than one type of machine and the GCode and MCodes are different you can now post to them and your CAM file will be correct for all of them.

Another big thing about CAM is the type of industry you are in. If you do production you tend to modify at the machine, if you are a Prototype shop you modify at the computer , just in case of having to cut more than one or you make a booboo and if you are a mold shop you modify the the CAM as you may have to cut mutible cavities and electrodes or have to make repair later on to the molds.

If you modify the CAM you always have a back up to the verification to run the parts again 1,2,6 months to 1 to 2 yrs later.

CAM is just an extension to your hand skills, its just like a big video game, the more you play, the better you get and you can make it fly like a F18!

Well, I am still new at this, And I have been programming for a tad over 20 years now.

But the more you know, The more you realize you don't know shit.

Currently I have 67 different machines with over 25 families of controls.

Plus I now hold 40,938 C-Code programs for these machines,
( I just checked )

I also work with 5 different Cad-Cam Packages and two Cad packages.

That's not counting the 1,656 programs I have on the Trumpf Punch written with yet another program.

With this amount of files, I have to state that Hands Down the G-Code is Master.

It's what the machine reads and what it will read tomorrow.

I do however strive to make all changes in my Cad-Cam to keep the Cad-Cam as current as I can. But I have found over the years there are certain things that you just can't do in the Cad-Cam and you do still spend a lot of time tricking the Cam to get the results you need.

And I like you guys fell into the belief that if your Cad-Cam program is perfect as to Feeds and Speeds, You can with a simple click through this part onto another machine.

I have yet to see that work as well as you would think.

And your Post and Tool Cribs better be as good as you can make them too for you to have any success with that simple click.

I have within the last year or so, Set aside Genesis, Virtual Gibbs, DP Esprit, and Master Cam to focus on FeatureCAM.

Mainly due to the ease of being able to edit the posts to get exactly the results I want.

I do have some programs that do run straight from the Cad-Cam with NO Hand Edits at all, AND I am proud of them.

I am also trying to get as many machines as I can that will work like that. But it is a hard uphill battle.

But in the long Run, G-Code is MASTER and will be for some time still.

Good Luck

Mohawk

PhillipM said:

D. Create a false program to take the 'hole' out using a rest machining feature and then delete it before generating G-code. Bingo

Click to expand...

How's that gonna not break my feature into segments and high-feed over it???

As far as multiple machines, I thik Mohawk summed it up.
Yes, a simple repost will take a program from a Haas to a Fanuc.
The problem is that the control don't mean shiit. If that Fanuc is sitting on a Matsuura, do you want to cripple it with the speeds/feeds of the Haas?
Or do you make each program with copied operations unique for each machine, and whenever you make a change in one you make it on the other for the sake of keeping it current????

Remember, I am only talking about production parts here and not protos or short runs. I know folks who don't even care what order his holes are done making the machine jump all over the place to where CAM thought is the easiest for it.
I OTOH usually even go to the extent of making a spot operation separate from the drill just to have even more control over it AND to have all spots ordered regardless of finished holesize.
I cringe whenever the tool rapids to the rapid plane between cuts.
I hate when the tool moves to a clearance plane after finishing one feature just so it can move back down to start the other.
If you're plunging into air when cutting an outside profile, who says you can't comp on and off in one fell swoop without Z-rapid -> Z-clear -> Z-depth -> Comp-on -> Path-on.... Path-off -> ramp-off -> Z-clear -> Z-rapid...... I just Z-rapid -> XYZ path-on with comp in one shot.
And no, the "It only takes 2 seconds to move there" doesn't wash when you make 200 parts with 5 features... That's 2000 seconds (1/2 hour) wasted when the manual change takes 2 minutes and will last a lifetime.

SeymourDumore said:

How's that gonna not break my feature into segments and high-feed over it???

As far as multiple machines, I thik Mohawk summed it up.
Yes, a simple repost will take a program from a Haas to a Fanuc.
The problem is that the control don't mean shiit. If that Fanuc is sitting on a Matsuura, do you want to cripple it with the speeds/feeds of the Haas?
Or do you make each program with copied operations unique for each machine, and whenever you make a change in one you make it on the other for the sake of keeping it current????

Remember, I am only talking about production parts here and not protos or short runs. I know folks who don't even care what order his holes are done making the machine jump all over the place to where CAM thought is the easiest for it.
I OTOH usually even go to the extent of making a spot operation separate from the drill just to have even more control over it AND to have all spots ordered regardless of finished holesize.
I cringe whenever the tool rapids to the rapid plane between cuts.
I hate when the tool moves to a clearance plane after finishing one feature just so it can move back down to start the other.
If you're plunging into air when cutting an outside profile, who says you can't comp on and off in one fell swoop without Z-rapid -> Z-clear -> Z-depth -> Comp-on -> Path-on.... Path-off -> ramp-off -> Z-clear -> Z-rapid...... I just Z-rapid -> XYZ path-on with comp in one shot.
And no, the "It only takes 2 seconds to move there" doesn't wash when you make 200 parts with 5 features... That's 2000 seconds (1/2 hour) wasted when the manual change takes 2 minutes and will last a lifetime.

Click to expand...

Yes we had a different cam program for different machines when feeds and speeds had to changed to suit a machine capabilities, but it was rare as we would not try and put a part for a Mori Seiki on a little Bostomatic
The things relating to rapid and clearance planes all were possible staying down staying up whatever I asked for, there was one exception when I had to drill a long hole say 3/16 dia 5 inches deep and to a 0.004" positional tolerance at the bottom, I would spot first then drill 0.75 and then peck with the 5" drill dropping into the bottom of the .75 depth I could never get it to return to ch to remove all the chips using Cam so I had to use the dreaded G-code and incorparate into the Cam program.
It seems you a funny Cam system doing those weird things, I used manual technolgy on my system so I controlled all the moves as opposed to the automatic part of the cam choosing for me
You are right all those seconds add up to hours at the end of the year
But it is my experience that when a part is up and running it never gets changed ever unless it starts to scrap or is losing money
Jeff

jeffrey atkinson said:

But it is my experience that when a part is up and running it never gets changed ever unless it starts to scrap or is losing money
Jeff

Click to expand...

In that case does it really matter if the G-code file matches the CAM or not???

SeymourDumore said:

Jeff

The tool/part requisite are things that are not so obvious during programming.
For example you make a thin feature an the rougher pushes the material out.... slowing it down for that segment only however resolves the issue.
CAM doesn/can't know that, but you also don't want to sacrifice the other cuts just for this.
Ditto for "voids" in the part. Example you have a part with a large hole in the middle. the path takes the tool through this hole, where there is no material whatsoever. Let's assume that the tool spends 5-10 seconds through this area with no material.
You can:
A: Leave it be, it's only 10 seconds.
B: reprogram the features in CAM by breaking it into segments
C: Edit the toolpath by hand and increase the feed to say 200IPM for that segment

A is wasteful for production,
B will create a whole bunch of approach/depart/ramp-on/ramp-off movements, liklely not saving any time at all.
C is easy and quick.

Click to expand...

In my old cad I would turn it into 2 or more cutter profiles and just rapid between them.
MILL,PF1
GOTO,PF2,RAP
MILL,PF2
Should not the cam and its PP do whatever you can do in G-codes
If not add the mods in g-code into cam and you can pp it everywhere
Jeff

SeymourDumore said:

In that case does it really matter if the G-code file matches the CAM or not???

Click to expand...

It was just an observation, it maybe a great program and of course needs no change or a crap program written by someone lacking experience
To change it of course needs to be worth all the effort

It does matter if you want to move it to another machine or new machine in CAM just 30 seconds to PP and away you go and not a single edit

There is a saying
There is never enough time to do it right first time, but always plenty of time to do it again

A lot of companies I have visited 75 CNC machines downstairs, upstairs in the engineering dept one old boy capable of handling the complex parts with 50 tools or over, 1 young guy doing the 3D work lots of operators downstairs doing the editing

Looks a bit like a Jig Boring dept today 6 machines and one grey haired operator

Only my observations

Jeff

jeffrey atkinson said:

Hi I am from the uk and now live in the Philippines so it was great to find this forum
I bought my first cnc machine a Bostomatic 300 and a cam system in 1977 the cam was Olliveti GTL3 on mini-computor (PC's were not around them), so I went on a GTL3 programming course before the Bosto arrived. the biggest attraction after the course was all the calculations it could perform and I did not have to understand G-codes. The course told me that the CAM program must always be the master.
My question is why did this practice disapear when cam went from command language to solid modeling
I asked recently to most of the leading cam producers for a system as follows
CAM source program to always be the master programs
No editing on machine tool control
No editing on cnc control program
No need to read G-codes
Bearing in mind I had run the above for 20 years on Visi-Mill 4.8
None of them came back
Also some of our spares work had 6 A0 sheets, I do not want to or are not capable to have to re-draw in cad
Also is there a up to date cam system that still has a command type system on board
Jigborejeff

Click to expand...

Hi Guys
Many thanks for your replies
My conclusion is that modern Cam systems are ideal for moulds and 3D milling but for 2 1/2D seem to be more difficult to edit than my old command system and G-code
General Engineering London (now sadly gone). Machined large aluminum 5 Axis components for Airbus on big 4 axis horizontals and 6 axis Boko's using NCL 5axis Cam (very clever guys)
They also machined very large magnesium auxilary gearboxes very accurate and complex parts lots of op's, tools and many boring heads, I asked how NCL coped the reply was we programmed them manually in G-code

PLEASE IS THERE A MODERN CAM SYSTEM SUPPORTING A COMMAND TYPE LANGUAGE OUT THERE

Regards
Jeff

PLEASE IS THERE A MODERN CAM SYSTEM SUPPORTING A COMMAND TYPE LANGUAGE OUT THERE

Click to expand...

You don't have to shout (really). But I agree, it is what I would like to find too. Open source would be good, perhaps a functional programming language that generates GCode, is user-extensible, etc. I hope you get some answers...