[Scott_bob]

Jimmy,

Post#8
I would have to say the tool is the most important factor because without the right tool the other factors might not come into play.

Post#20
I agree with you camminc, I didn't think about it like that. Thank You. I am so used to using top performance machines that I worry about the cutters most of the time. Thank you for the info.

Look, some things should be obvious. In a discussion about high performance machining or HSM, no one should consider trying this technique with cheap cutting tools or a bad holder. Come on, if you're going to do CNC on the cutting edge, or as this poll has posed the question as to what "MOST AFFECTS" high performance milling, (sorry lathe guys, but HSM is not really part of turning, let's not get side tracked).
The "High Performance Cutting Tools and Holders" option refers to high cost cutters and say shrink fit or hydraulic collet chucks...

Choose the "One" Factor that affects High Performance Machining the most:
Remember that this forum is for average CNC users out there.
Most CNC users in the USA own commodity type, low cost vertical machines...

You're entitled to your opinion but, try to be more objective, less subjective (considering only your own perspective)...

Instead let me ask: Put the following list in your order of priority...

High Performance Cutting Tools and Holders
Active Dynamic Speed & Feed Control
Programmed Tool Path
CNC Machine "Control"

Having eliminated the 2 options:
High Speed Spindle
High Speed G-Codes
(They didn't get much consideration in this poll)...

[Zipdrive]

Scott_bob

What system did you use to upgrade the 4020? What was the cost of the hardware?

Thanks.

Tom.

[Scott_bob]

Tom,

Check out the other posts that I've made and you'll get a better summary...
Use the "search" button, this will save me from having to go into detail again.

What is your interest level?
Do you have a CNC machine that you'd like to upgrade?
Do you know about Fadal CNC's?

[Scott_bob]

Today 6-15-04

Rubicon (Numeryx) CNC Control retrofit on a 1996 Fadal 4020 Pallet CNC.
Machining variables:

6061-t6 aluminum sheet stock. Clamping excellent. Solid End Mill Holder. Pallet Changer (Fadal not so rigid). Good coolant volume and 150 PSI.

Shallow pocket geometry with ribs between, Z depth = Z-.150
RPM= S13,500
Roughing at F500. (five hundred) inches per minute Z-.130 Smooth acceleration and deceleration at all corners and inside radii feeds are dynamically compensated by the control.
Finishing at F240. for better surface finish on pocket floors Z-.150

It's awesome to see the chips flying and the machined part more accurate than we used to make with the old control at 1/6th the feed rates...

No exaggeration, we have already saved enough time on cycle times to have paid for the control retrofit after just 30 jobs or 60 days...

Sincerely,

[Scott_bob]

Here we are coming up on 1,000 views on this poll.

And we have 73 votes.
Well that is just 7.3%
I wonder just how many individuals read this forum... We know only 73 voted.
I was hoping for better participation. Maybe if you're reading this now, and you have not voted, you'll be next to chime in.

What do you say? Don't just sit there on the sidelines, be a player!
Don't be afraid of commitment, take a stand.

Blah blah blah,

[Scott_bob]

Here is an example of excellent flood coolant on a VMC...

http://www.cnczone.com/forums/showth...1013#post41013

We are also filtering with a bag style filter (25 micron).

[Gunner]

Scott_Bob,
I just attended a seminar on high speed machining at a company called "Tech Solve". They were previously named "IAMS" for the " Institute of Advanced
Manufacturing Science". They describe high speed machining as a "SYSTEM". All parts of the system are of equal importance because if one portion is weak, the rest will not perform to expectations. The six catagories they list are as follows:
1. Machine Tool - rigidity, power, repeatability, capacity
2. Machining Parameters - speed, feed, depth of cut
3. Machining accessories - fixturing, tool sensors, high pressure coolant
4. Cutting Tool - type, grade, coating, geometry, tool holders
5. Work Material - type, grade, micro structure, mechanical properties
6. Cutting Fluid - type, flow, temperature

Their definition of high speed machining is the manipulation of speed, feed, and depth of cut to develope increased metal removal rates with lower cutting force. This process, in turn, reduces or eliminates secondary work for an overall increase in productivity.

They also discussed other aspects which relate to the "SYSTEM" such as tool balancing, drive systems (linear vs ball screw), acceleration - deceleration (control), static and structural stiffness, and the frequency response funtion (which is camminc's claim to fame). All of these have an equal place in the high speed machining "SYSTEM". After attending the seminar I think I should retract my vote of the machine controller and vote for all of the above and more! High speed machining is really quite complex until you obtain all the pieces of the puzzle. It requires information from the machine builder, spindle builder, and tool developers. It also requires frequency analysis equipment and a thorough understanding of your machine controller and its abilities. Once these pieces are obtained you can start to put your formulas to work to find the highest performance areas for your machining application. The beauty is, it does work! It just takes commitment and a cultural change to implement.

[Scott_bob]

Gunner,

I agree that near extremes of the spectrum of HSM, the process variables will contribute more equally. All of the variables are indeed important contributors to the success of high speed machining.

But, it would not be correct to suggest that one variable contributes equally to success. Surely one variable rises to the top of the pile in your experience. And this changes depending on the quality of the "control on your CNC (since you mentioned your vote).

For us, we have decreased cycle times by 50% average, and improved quality by just replacing the CNC control. For us, it is completely impossible that any other process variable could contribute this much influence.

Regards,

[Gunner]

Hello Scott_Bob,
I think your 50% decrease in cycle time is fantastic, but is it all you can get? I'm not an expert in HSM but the one factor I did like from the seminar was you could find your maximum operating ranges and depth of cut. From there you back off a hair for optimization. No more guess work. You know for sure that you can't get anymore! At this point I'm limited because of the long barfeeds on the lathes and because I don't have the ability to change coolants. We have cleaning problems on our parts further down the process. You seem to have free reign to try some things. Because of your interest and ability I strongly suggest the seminar at Tech Solve (www.techsolve.org and no, I'm not affiliated with it in any way). From what you've written about HSM on "The Zone" I think the rest of the system would put you at the top of the HSM food chain. Great Job so far, I've thoroughly enjoyed this topic.

[Scott_bob]

Gunner,

Our current average cycle time reduction is actually 65%.
There are have been three improvements to the CNC.
1) Retrofit Rubicon Control with Delta Tau motion control cards
2) New digital encoders (800x the resolution of the old DC analog resolvers)
3) 150 psi Higher pressure coolant pump (Not High Pressure Coolant)

This is by no means as fast as we can go but...
There was no point spending a nickel on the other products before fixing what was the root cause of accuracy and speed problems.

We have tried all the higher logic standard control commands, better cutters, different coolants, shrink fit holders, better clamping...
The only thing we did not try is the dynamic feed compensation technology or the holder / cutter assy analysis technology. I don't consider these variables worth considering for us until we can get accurate high speed motion, 1st.

Making progress though, we have scheduled the 2nd CNC retrofit.
Believe me, this is significant cause you would not believe the paradigm shift that has occurred to take this next step...

Sincerely,

[bradleycnc]

With so much improvement to cycle times, how come I have not heard of this control before?

Bradley

[Scott_bob]

Bradley,

True, I also had not heard of the Rubicon aka Numeryx formally Numatix control.
I have had opportunity to use many other controls though. I could list them but what would the point of that be? I have never used a better CNC control in the most important characteristic: performance... People who see the transformation of their CNC machine from before, to afterward wonder if more than just the control has been replaced. Questions like: Is that a new spindle, or did you replace the servos?

Tell you what, I'll post here some test cuts that we have been doing, and show you what I mean...

[Scott_bob]

I need to mention that the 2 parts laying on top of one another have both been machined on Fanuc controlled CNC machines. I did not keep the test cut part we ran on our Rubicon / Numeryx retrofitted Fadal VMC.
It was more accurate than the better part above, within +/-.001 on both the width and length of the slots and corner radius. The feed rates on the slots when using a .125 diameter 3 flute carbide end mill was 150 IPM. Because of the accuracy loop back in the system, and acceleration limitations of the servos and drives feeds did not get above 70 IPM in the small inside corners. Programmed feedrate for the .375 diameter 3-flute carbide end mill used on the R.462 and along the edges of this test cut part was 400 IPM. Accuracy on these features: +/-.002

We have determined that doing a test cut is the only way to prove performance claims. It is like using the scientific method for testing new brands of CNC machines under consideration. At the same time we are going back on our existing CNC machines and testing them to be able to calculate time savings for when control retrofit dollars are available.

There is a lot of work yet to be done, but at least there is hope...

[camminc]

We can’t leave out Impact testing - Dynamic Process Optimization. This is some thing, which needs to be addressed here also. It is a key factor to use of any machine, for HSM or conventional. Impact Testing and Audio Chatter Recognition can open up avenues of machining not usually known - for any kind of machine tool to improve cycle time, part finish, etc. Milling or turning. I would certainly go with Gunner on things he says. He states he is not an expert in HSM, yet by going to the Tech Solve seminar and having an open mind, he has been given the right tools to certainly be one. It is wonderful that he shares this information with us all.

On the other hand, I have also run across Scott_Bob many times on this forum and he refuses to believe in using Impact Testing, (Dynamics) which uses selected RPM's from a stability lobe diagram to point out stable and unstable cutting area's of machining. He seems consumed with controllers instead of looking at the big picture, even goes so far as to degrade Impact Testing, but yet has never actually seen it or used it.

By all means, do not discount any machine tool you are looking at by what he says. Impact Testing can make a machine tool shine in many instances. Test cutting is not the best way to test a machine unless you know it’s dynamic’s first. In most cases an incorrect RPM is used causing the machine to not perform it's full potential. Test cutting is not accurate by any means without first using Impact Testing prior and examining the frequency response function (FRF) and stability lobe diagrams produced by it for maximum depth of cut, enabling maximum use of power by proper selection of RPM. I know it may sound like what many call “The Magic Pill” joke in the industry, but as Gunner states, it all works, by way of what he learned at Tech Solve. One must not think in antiquated ways, go beyond there comfort zone to reach technology that is out there today and use it.

I know about Impact Testing because I have been using Impact Testing and Audio Chatter Recognition for years, along with Boeing, Sikorski, Northrop, Airbus, University of Florida, North Carolina State, Tech Solve and many others. UF and NCS teach Impact Testing methods to there student. In 1997 I gave my first presentation for the SME High Speed Machining Clinic at IAMS, now Tech Solve as Gunner has stated, called "Pieces of the Puzzle in High Speed Machining". Shrink fit, tool holder balancing and Tooth Pass Frequency (Impact Testing). I am an expert in these three fields and highly recommend Impact Testing to any one wanting to improve there machining process. I have also attended many other HSM seminars as an attendee and presenter across the country, represented Ingersoll Cutting Tools at IMTS demonstrating “The Harmonizer” (Audio Chatter Recognition) and other machine tool manufactures at IMTS in demonstration of “CRAC” (Chatter Recognition and Control). The are both related closely to “Impact Testing”. You can read more about Impact Testing - Frequency Response - Dynamic Process Optimization at:

http://highspeedmachining.mae.ufl.edu/htmlsite/faq.html

I hope this helps and opens up some doors that were not there before.

[camminc]

Seminar: Dynamics
April 8, 2005
Time(s)
One Day
Contact Tomi Williams at 513.948.2076 (local) or 1.800.345.4482 (toll free).

Location
TechSolve Cincinnati Facility

Course Description
Dynamics of High Performance/High Speed Machining (HPM/HSM) is an introduction to the importance of machine, tool and work-piece dynamics in HPM/HSM. The course includes classroom instruction as well as live demonstrations of high speed machining on TechSolve’s HyperMach. The HyperMach is a prototype 5-Axis horizontal machining center that is capable of achieving 40,000+ RPM. Attendees will learn:

Dynamic Characteristics of Machine Tools
Types of Vibration
Critical Parameters for Each Type of Vibration
Methods of Control for Each Vibration
Dynamic Cutting Errors
Plant Managers, Method, Process, and Quality Engineers, Senior Level Machinists and NC Programmers will all benefit from attending this course.

[Scott_bob]

Gommer,

You are so hopeless!

[cadcam]

camminc the small stab you try and take at Scott_Bob is not called for in this post.

There are allot of ideas on how HSM works and I have heard allot of them including yours. I heard and have seen the idea of Harmonics years back.

As of right now I am keeping my opinion with me.
But I do feel there is logic in all the comments made in this thread.

Please guys to try and keep it as civil as possible this contains good info and like always there are opinions flying to.

[Scott_bob]

High speed G-codes only got 1 vote. Maybe this person knew something about the high performance limitations of the industries most common control; Fanuc.
You cannot get "what I call" high performance CNC motion without these codes activated. All motion with feed rates above 100 ipm will benefit from Ai Nano or HPCC contouring control. Basically: "feed rate and feed back loop enhancement" set by a variable. This "option" from Fanuc is just that, it costs extra. We can feed accurately more than 2 times faster with these codes activated...

Well worth it though, what do you think?

[camminc]

Choose the "One" Factor that affects High Performance Machining the most. There is one thing missing from this selection, it is dynamics. Seems to be many on this forum that do not believe in it and give high resistance to using it. Possibly to put it in better perspective, I feel there is a misunderstanding about limiting factors, such as the tool “Dynamics” and controller being pitted against each other on this tread. They are two different things entirely each having their own benefits. Maybe what is misunderstood is that not all tools are the limiting factor of a machining operation therefore not needing dynamic's taken. Take for instance a 5 or 6 inch face mill. It is dynamically stiff enough so that it is not the weakest point of the operation, therefore chatter is not a problem. The question is? "Which tool is or isn't the limiting factor" by which dynamics can or cannot make a difference to improve MRR. A 1/2 inch carbide end mill by 3" long would certainly benefit from dynamics, some 30%-60% of tools used in a shop can benefit from dynamics no matter what controller you are using. The most efficient way to determine this is by impact testing, to create a stability lobe for study of possible best rpm's to allow highest mrr for that cutting tool assembly, called a "Stackup". Stability lobes are very easy to read and very easy to produce by way of impact testing. Possibly it is not understood that an impact test takes into consideration material being machined "Specific power - torque and horsepower required to machine that type of material by mrr and torque / horsepower ratings of that machine being impacted, max rpm of spindle and number of teeth. Impact testing also measures movement of the tool at it's tip in relation to the force of the impact hammer to calculate deflection, flexibility, for stable depth of cut and natural frequency of the tool at it's tool tip to calculate best rpm's, which may result in several sweet spots of spindle speed while also showing many unstable rpm's that the cutter should not be run at. We are talking about many materials being machined also, not just aluminum. Cast iron, titanium and a variety of others can be improved with a stability lobe diagram. You can view example stability lobes in different materials at www.cammhsm.com to understand more. I am sure it is very important to use specific controller, g-code but they do not have any influence on the dynamics of the machine, they only control of movement of the machine "Not it's dynamics". Impact testing uses the entire machine physical dynamics, which programming and controllers do not use, to give logical, sensible prediction of best rpm and depth of cut. In the end result impact testing gives the programmer a place to begin for rpm and depth of cut instead of making costly and timely test cuts from guesses of rpm and depth of cut. Why not sensibly select a stable rpm and depth of cut from a stability lobe first and then tweak the programming to enhance the operation if need be, instead of working backwards? There are many factors of a stackup that a programmer cannot predict. If a tool is put in a different holder, sticks out differently, number of flutes are changed, or a different brand of tool is used, the dynamics change therefore changing what rpm and depth of cut would be best. Most programmers think, we used this rpm and depth of cut last time and it worked. Possibly they are not aware that if the tool is set up differently it will run differently? Many times they program a cutter on many different types of machines using this line of thought, when these different types of machines may all have different dynamics and frequencies making those parameters chosen to be in very bad, unstable cutting zones resulting in poor mrr. This is why operators spend so much time tweaking rpm’s and depth of cut on operations instead of getting it correct from the programmer in the first place. Don’t get me wrong, programmers are very knowledgeable people, and due respect, but it is impossible for any one to be able to program maximized programs the first time because of so many variables. Impact testing is a tool that they need to consider, it takes out some of the guess work, providing more intelligent programming and efficient presetting. Problem is many have tunnel vision, thinking programming, controllers, servos, etc are the only thing that matters. Many times the part was ran before but this time around it is not running correctly, due to the stackup is not being the same as before. It happens over and over again from company to company all around the USA. The most logical way is to impact some tools, use a database to log these results and then choose the "Stackup's" in this database for parameters such as rpm and depth of cut. It sure made my life easier. For those that do this there is a great financial benefit in reduced cycle time, reduced programming time, reduced preset time, longer tool life, better finish, less damage to spindle bearings - machine axis, maximized MRR. Just so people do not get confused, Audio chatter recognition such as the “Harmoinzer” is for fine-tuning the spindle rpm, not for collecting best suitable rpm and depth of cut stability lobes like impact testing does. The “Harmonizer” is also an excellent tool for determining if a problem on an operation is chatter or forced vibration because the operator tells it the rpm being used so it filters out the spindle speed rpm frequency so it will only pick up any other frequency if it is present, which would most likely be the chatter frequency. If it does not pick up any dominate frequency then the logical solution is that there is no chatter occurring and it is therefore eliminated as the problem. Forced vibration such as feed rate or depth of cut is probably the culprit. This has happened many times, they think it is chatter when it is just an error in programming feedrate. There is also CRAC, which works directly with the controller of a machine tool. It monitors for dominate frequencies occurring using a microphone such as the Harmonizer does, during a cut and if found tells the controller to change the rpm to a calculated speed from this dominate frequency to stabilize. It works directly with the controller while it is running, working together. I can’t tell you how many times I have used the Harmonizer or impact test to improve an operation. No matter how magnificent they speak about their machine, programming, and controller, all the latest gizmos they put on them, million dollar machines. Most all of them have a hard dealing with the idea that such a simple thing like rpm or depth of cut can make it run so much better, maximizing MRR beyond what the controller could do. It is right under there feet all the time. It’s like Harold Cook, the inventor and patent holder of “The Shrinker” once told me, it is usually the simplest thing that we don’t think of that is overlooked, “The Shrinker” being a prime example. It doesn’t stop there either, impact testing can also be used as a machine tool modal analysis tool, preventative maintance and to trouble shoot a machine tool when it is not performing correctly. It can be used for conventional and hsm. It can even be used in turning, to match tool and part frequencies to reduce chatter, dampening, tunable bars, etc. One thing for sure is that as spindle speeds increase, so does chatter conditions and stability charts can be a very useful tool to maximize. To dynamically monitor your machine tool is a very smart thing to do.

[Scott_bob]

Camminc,

Well said... I salute you on your improved temperment!
When I started this thread I included the catagory: "Active Dynamic Speed & Feed Control"
This is the category that I would put the "dynamics" tool. It got 15% of the vote.
I don't consider the results of this poll as being conclusive but it is what it is. Perhaps, the thing you have come to understand is that this is a forum "discussion", we can all disagree, at the same time present our points of view as best we can. I don't know about others here, but how you or I say something will be remembered almost more than "what we say". I know you and I both have had to grow thicker skin to better understand each others point of view. As much as you may disagree with my point of view I hope you understand that my response to you is more the result of how you say it, than what you are talking about. Maybe someday I can get an oportunity to see a better demonstration of "dynamics" here...

What would a complete system cost?