Assuming that work holding is not a factor, (material is clamped down well)...

What is the most significant 'limiting' factor in High Performance Machining, or HSM (High Speed Machining) on any CNC machine?

Or, Choose from the above list, what affects high performance machining the most...

You can only choose one, so we going to identify 1st place...

Balanced tools, Rpm, and ability to take in code to the control fast enough. Lets not forget the
cutting tool itself. Very important!!. All these will weigh into the harmonics the Caminc was speaking
of and you need to decide which is of more importance. Get the jobs off the machine a little quicker
or possibly sacrifice some fretting of the tool holder and surface finish.


PEACE:D

I believe in a production environment it is matching the work to the machine and its capabilities. From your list above it's a tough decision since they all work hand in hand. You can have the proper tools but if you don't have the spindle speed or control they won't work properly and vice-versa.

Gunner,

Would you say the "machine" is the control? Not entirely, of course...

For instance, if i replaced the old control on a CNC say a Fadal, with say a Fanuc control, or a PC based control, would we still refer to that old original CNC as a Fadal?

I wouldn't... And, depending on the control I choose, the CNC would be sooo much faster, accurate, reliable...

Can't vote in this poll. HSM (as developed by the major aerospace firms) is the sum of all the processes listed in the poll, plus another important part that people overlook: machine dynamics. Removing one or more of these processes is kind of like letting the air out of your tires, it will still roll but not very well.

It is true, that to suggest that "one of" the above Poll options would suddenly solve the problems that prevent high performance machining. This would be another one of the many myths that are common today.

IMO, one technology cannot promise (and deliver) all the solutions...

But, on the other hand, I wonder if those professionals who vote in this Poll will end up identifying the option "Most" responsible for the lack of performance...

If I may, ask yourself the question:
Rank the options, then vote on the one that is at the top of your list...
This exersize is somewhat relative because, to some of us with crappy CNC controls for instance, our option may be more obvious than the option to a guy with a good control...

Scott_Bob,
I guess I'm going to take the machine control. A good control will be equiped and allow you to have the ability for HSM. I'd rather have that first. I can always upgrade the spindle and tooling. This is taking into consideration that the machine isn't 25 years old and worn.

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

Jimmy,

If I put the finest cutting tool available in the best possible holder, run this fantastic tool on a poor quality cnc machine that has a crappy control, do you think I can get high performance out of this set up?

The most problematic limiting factor of High Performance Machining is Chatter. Otherwise, it would be forced vibration due to improper programming, unbalance, etc. Just so you know, unbalance is a forced vibration condition and has nothing to do with chatter. The frequency of unbalance and chatter occur at different frequencies, which can be determined. If you see MoldMaking Technology Magazine in June you can read about this

Controllers, cpu, motions of a machine tool are excellent to have, but they do not control the cutter at the tool tip during the cut. Dynamics at the tool tip of the cutter are the determining factor of the machining operation, period. Hardmill is very much correct about machine tools and their capabilities as far as controllers, cpu, etc, yet it all comes down to the tool tip after that. The machine is the platform, the cutter assembly is the end result of that platform. It all has to do with dynamics, the entire machine tool.

We run CNC Lathes here in a high production environment. We don't usually run into chatter problems unless we are dealing in long parts using a small diameter stock or deep bores that have a boring bar out past its recommended effective length ratio. This part mix is minimal for us. I think the dynamics plays a bigger role when you have a stationary part and rotating tooling (such as milling) vs stationary tooling and a rotating part (like a lathe).

Let me ask the Fanuc users out there these questions:

Can you get high performance machining or HSM without using your Fanuc high speed codes?
How much faster can you go when you activate these codes?

Ref.
On our Fadal control, by using these special codes, you get 2 to 3 times the feed rates...
G8 (FEED RAMPING OFF) *THIS IS THE LEAST ACCURATE,
BUT FASTEST ESPECIALLY WHEN GOING THRU A LOT OF POINTS

G9 (FEED RAMPING ON) *THIS IS THE MOST ACCURATE, CNC SLOWS
AFTER EVERY BLOCK, THEN RAMPS BACK TO PROGRAMMED FEEDS
G51 R0+0.5
G51 R0-0.5 (FADALS FEED RAMPING TIME CONTROL, .5 TO 2. RANGE
1. BEING DEFAULT, .5 WOULD BE 1/2 TIME, 2. WOULD BE DOUBLE)
---------------------------------------------------------------
FROM HERE DOWN, A LOT OF DETAIL MUST BE INCLUDED,
RECOMMENDED FOR ADVANCED USE ONLY, MUST UNDERSTAND THE MANUAL...
---------------------------------------------------------------

M94 (ONLY FOR HIGH SPEED LINEAR CONTOURING 'POINT TO POINT')
M95 (CANCELS M94)

M94.1 (LINEAR ONLY, 'POINT TO POINT' FEED FORWARD BY FEED MODIFICATION)
EXAMPLE:
M94.1 P179 Q33. R0+90. R1+0.1 R2+20
M95.1 (FEED FORWARD CANCEL)

It is interesting that not 1 person so far has voted on these High Speed G Codes...

To Gunner: That is a good point about turning. Your are very correct in saying "I think dynamics plays a bigger role when you have a stationary part and rotating tooling (such as milling) vs stationary tooling and a rotating part (like a lathe).

I have not talked that much about turning. I have to say, I am not an expert in turning, I can only recommend this from what I have seen, used and shown.

From my experience natural frequency of the cutter / holder / called Stackup assembly is the same with milling as with turning. You can measure the frequency of a lathe tool and flexibility of it the same as with a milling cutter to determine proper RPM and depth of cut. Yet you can also determine dampening characteristics for turning. In most cases it is not required but with longer cutter parameters special devices can be incorporated into a lathe tool body to further enhance length of cut, so called stick out, such as a set of springs with a carbide plug or heavy metal, to dampen any cutting vibration frequency. Spring pressure, length and weight of carbide mass can be measured with the proper equipment to maximize. Just turn a screw to maximize once a reading is taken. Increase spring pressure or decrease. It is a simple thing to do as with performing an impact test of a milling machine Stackup, not complicated as every one thinks.

By doing so, you can further maximize a turning tool, giving much higher lengths of cut. In milling, one cannot work with dampening characteristics as much because the assembly is in rotation. Dampening of a such method in milling cutter would cause massive unbalance due to rotation force as spindle speed increases of that assembly creating problems, creating forced vibration. As in turning the cutter does not rotate giving it an advantage as not to rotate - thus enabling it to dampen into the structure / holding device, etc. This is Dynamics.

Where would coolant fit into the equation....flood through spindle. granted they aren't specific to HSM but still somethign that should be brought into the equation as it is a definite facilitator

avsfan733, to a point it helps but one of the thoughts of HSM is to remove the chip fast and take the heat with the chip.

So some time this may be done dry with some inserted tooling.

Camminc,

I've never heard of using springs as a dampening method. Is there a link or documentation describing a recommended procedure or setup diagram? We are always looking for a better, faster way. Thanks.

Avsfan 733,

Coolant or the ability to keep the cutting edge cool is definetly a factor as is all the other components we've discussed from above. It doesn't make any sense to "crank" speeds and feeds to get one part out quickly and then incur downtime to change all your tooling. I think the ideal situation would be to reduce the part cycle time and extend tool life. After all, in the high production environment we're all after more good completed parts at the end of the day, hopefully not causing undue stress or problems for the machine operator . We've discussed some of the pro and cons of high pressure coolant systems in other posts. I believe it was in the high speed machining thread.

The HSM CNC control retrofit is installed and is running!
The results I'm sure, will be worth the the time it took. If there is one thing that I've learned through this process it's this.

If a project is worth doing, make sure it's done right or don't start it at all.

It's early still, but by replacing the CNC control we are seeing feed rates 3x faster with better quality parts. Profile tolerances of +/-.001 at programmed feed rates of over F150. At 1st we were trying to see just how fast could we go, but surface finish tolerances force us to slow down. Also, we have to use 3 fluted end mills in aluminum as having 50% more flutes per revolution we get better finishes. Sloting is almost as good as a 2 flute end mill and with the increased coolant pressure and volume we get good chip removal...

At programmed feed rates of F300. the control is not moving this fast all the time of course, when small radii are coming up or a sharp corner the feed rate is reduced as needed, automatically. This is extremely helpful in optomizing a program as the feeds are compensated based on the geometry detected by the look ahead and by the limitations of the acc and dec of the servos.
You've gotta see this thing to believe it.

In summary:

We have a 1996 Fadal 4020 VMC with a 2 pallet changer, box way model, with DC drive servos, and 15,000 spindle, 30 tool changer. Easy to use PC based, extremely high speed control (None faster). Huge file size capable, incredibly smooth motion control able to dynamically control motion up to this machines rapid traverse rate of 700 inches per minute.

Investment?

Less than some shrink fit systems and holders...

Scott_Bob,
Just wondering how the control retrofit is going now that you've had a few weeks play?

Awsome...

I can't even tell you how much better the CNC performs cause I start to sound like a fanatic.
Just as an example:

4-19-04 We are cutting oval .250 wide slots by .375 long and .37 deep.
Using a .187 3 flute carbide stub end mill, 3 passes .13 each...
(we do drill the start point with a .23 diameter drill)
At 14,000 Rpm this tool has just one feed rate of F70. that's 70 inches per minute!

The slot measures .250 wide x .375 long +/-.0005
The Control is not always trying to do tiny radius motion at F70. it slows the feed depending on the geometry ahead (thru 5 axis motion look ahead), we only do 3 axis...

Far better accuracy, basically we don't have accuracy problems on the machine any more...

Today 4-20-04 We are circular interpolating a 1.375 Dia bore to within +/-.001 feeding at F110. The bore is round within .001
We used to have to ream this bore and it was a hastle with that big a reamer... The 3 flute 3/8 carbide end mill using G03 programmed at F162. also made an excellent round bore, but needed a better finish so we slowed to F110. (should have used a 4 flute).

Last night, 4-23-04 We were roughing 1/8" thick 6061-T6 Aluminum sheet at F366. (That's three HUNDRED sixty six) inches per minute with a 1" diameter 2 fluted Sandvick Insert end mill, then finished a highly contoured profile with a 3/8" 3 fluted carbide end mill F216. (two HUNDRED sixteen) inches per minute. Profile tolerance? Within +/-.003, inside radii vary from R.188 R.500 R1.250 up to R4.750 an interesting pattern...
By the time I got in to work in the morning, all 60 parts were done, and the next job was being set up...

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.

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)...

Scott_bob

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

Thanks.

Tom.

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?

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,

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,

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

http://www.cnczone.com/forums/showthread.php?postid=41013#post41013

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

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.

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,

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.

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,

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

Bradley

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...

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...

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.

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.

Gommer,

You are so hopeless!

(member.php?u=2118) camminc the small stab you try and take at Scott_Bob is not called for in this post. (member.php?u=2118)

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.

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?

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.

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?

Thanks for the good word. To be honest the reason I lashed out prior was because that is what it took to get attention, of the subject. You and a few others on this forum have certainly put up with alot of my crap. I picked you and hard mill because you were the most verbal on your ways. Sometimes one must challenge us to drive to the next step and you have certainly done that. The PhD’s and Professors that have developed and teach this technology to their customers and students would never concede what I do in my writings on this forum, actually they frown upon it and let me know as they monitor my big mouth, yet they also know me and understand I speak from the heart. My goal from the beginning was to let others know what I have learned and to give that information back. I found a few quotes when I first started this thing of HSM, that impressed me, so I put it in my presentations. I didn't realize just how true they were. The quotes were "Challenge Antiquated Ways" and "Go out of your Comfort Zone" and "Venture beyond familiar Boundaries". I have the utmost respect for programmers, engineers, managers, CEO's and such, because they did their homework, studied, gave up many things to learn to get those positions. I do not disagree with you Scott Bob, you know everything I don't know about controllers, motions, etc. I on the other hand, challenge you and all others that do not venture those three quotes - to understand that controllers, programming and motions are not what makes machining. I simply present alternative methods to enhance the machine, by way of the tool tip when it is the defining factor. I will be at IMTS and certainly would love to meet anyone on this forum to discuss machining. Of course I will not talk much I will let my associates do the talking for me - Professor Scott Smith of the University of North Carolina and Dr. Tom Delio of MLI would certainly be willing to discuss Dynamics with you if we can set up a meeting place. Of course we all love to eat to discuss things. The fine foods of Chicago are one of a kind. Possibly I can get Harold Cook "Shrinker" and some tool balance people to attend from American Hoffman. Anyone that wants to attend from this forum can email me at rharper@cammhsm.com. Any suggestions to met with spindle makers, machine tool, cutting tool or otherwise, we can try and get them to come also.

So now that we all know you have had something to sell all along, what does it cost?

Just so you understand me, there continues to be so much of what you say that I disagree with. You and the rest of your group... But, I am not going to debate it here, or anywhere else. Good Luck...

Scott_bob. When I was taught dynamics in 1997 I developed a software program to collect that data. I have an education of database development started from 1986. I also developed many types of shrink fit devices and balancing methods. In 1998 came two patent applications in balancing, trips to Boeing, demonstrations at machine shows of the Harmonizer, presenting at HSM conferences for the SME of shrink fit, balancing, tooth pass frequency. I even learned of cutting inconnel at 2,000 sfm at Boeing which BF Goodrich took off with from my telling them. All that time, I was on the floor in a machine shop capacity of tool and cutter grinder, etc, making it happen. I am still on the floor at my day job. On my website I sell only my experience of HSM of contacts. If I get consulting or sell a balance machine or software product along the way from this forum then that would be different. I have not sold any product or service due to this forum. I believe in the products on my site and they believe in me. I promised myself along time ago, to give back what I learned, I stick to it no matter how you try to make it. Scott_Bob, it seems you try to make profit the issue for me being on this forum? Have we not discussed "Antiquated ways" "Going out of your comfort Zone". I assure you I have made no money from this forum what so ever. If I have then let them tell you so. It is your choice to use companies on my website. Again, it is my right to express my ideas on this forum, just as it is yours. As far as the price of the MetalMax System I promote, I have no idea. I don't know nor do I care, it matters to me none. You will have to contact them. It varies of course for what you want. For all readers of this forum, I would suggest to call and discuss. Instead of diving into a full blown impact testing package it might be better to have them come in and do it for you, at a very much lesser amount and tell you what they come up with. Like a trial try. They could impact some tools and give you a detailed result. To tell you the truth, if your going to IMTS, then sign up and we will met with you and discuss it all. It won’t cost you but about $100 a person to come and hear it from the experts. That is just an estimate. I can get a lot of experts to come to this event in many fields if I get enough people to attend, otherwise it won’t happen. You need to let me know what you want. Go to my website and let me know who and what you want to discuss at the meeting, so I can have time to make it happen. The only thing you have to loose is a good meal and meeting everyone on this forum.

Possible companies to attend: Ingersoll, Fischer Spindle, Boeing, Shrinker, American Hoffman, Kennametal, Iscar, etc. Tell you supplier, make a date. I need to know in advance.

Go to cammhsm.com and sign in and give your idea’s at “Please sign in our quest book”

Scott_Bob Said:

Just so you understand me, there continues to be so much of what you say that I disagree with. You and the rest of your group

From Camminc:

I give you the opportunity - If you want to really know, talk to the rest of the group as you speak of. In another words "Talk to the experts and not me" to really find out the truth.

I challange you to put an effort to your statement or stop knocking what you do not know:)-

it all begins with the machine and machine controller lots of older controllers cannot output fast enough to keep the program running at high speeds , which causes unwanted dwells because the controller cant process the information being pumped through it fast enough, next is good cutting tools and a good program to match , simple er or tg holders are satisfactory on speeds below 15000 rpm shink fit is over rated , and you need a heavy oddball tool to need balancing , next is fixturing which typically included as tooling , rigid and quick loading , what good is high speed to save production , when it takes forever to load your parts
this is my personal experience in high speed machining in a company where we had our own product , we came to the point that we could no longer refine the process ,speeds and feeds on steels that made seasoned machinists shake
make me run any part for any period of time and this is what i do continuously CRANK ER UP ,LETS SEE WHAT SHE LL DO
this is what i love about cnc , high end parts at an unbeleavably fast rate , not to mention safe , this is where good programming comes in

what it truely takes is guts ,should be a catagory for that

any one heared of creative evolutions cnc controler?? its supost to be the fastest??

I agree. I will tell you, to crank er up is not a bad idea. To many crank her down when they need to go up. Use it or loose it :)-

machines are better , tools are better , programming is getting better


why by a street racer if you aren t going to press the gas pedal down

any one heard of creative evolutions cnc controller?? its supost to be the fastest??

http://www.creat.com/profile.shtml
One of the fastest for sure... It takes a great deal of commitment to turn down this road of CNC control replacement / retrofit / evolution. You might call it "guts". For those of us who focus on the resulting machined part, this element of the game is critical. Todd Schuette (Creative Evolution) used to work with Gil Hagiz (Numeryx) at Sharnoa, so they benefited from that work. There are others that have pioneered advances in this field. If a person is informed these days as to the performance of today’s machining, it should not take long to realize the gap that exists between your own production levels or accuracy, and what the industry is doing. The good news of the above solutions is you don't "have to" buy new machines to get the results that are possible. We do have to fix what is wrong though, make no mistake about it.

I like to think of it this way:
If a technology exists that could double you cars gas mileage, and increase power for a 1/10 the cost of a new car, would you consider it? I would, on the other hand a lot of people only consider new. That is their prerogative.

In the area of CNC machine controls, your machine can make better quality parts & get 2 to 3x the production (depending on what kind of machining), at 1/10 the cost of a new CNC. It's your choice...

BTW, the creative evolution control is not windows based either...

good quality parts and high speed can be done simply on a fanuc controller , or similar controllers that offer high speed options , im sure some controllers can beat these in processing speeds , but the cutting tools will still have to catch up , thermal break down is always and will always be a factor

retro fit is only as good as the old machine is is put on

It has been my experience that with todays good cutting tools in good holders, the weak link in the high performance chain is the accuracy of the CNC. Even the tool life of those quality cutting tools are dramically reduced due to the weak link in the high performance chain, the jerky, poor acceleration and deceleration of the control.

Remember trying to climb mill on a manual milling machine? Remember when the axis your feeding wants to get out of your control when the cutter is engaged in the material? If you let an end mill grab and pull that axis out of your control, do you think those same forces are not at work in the CNC when it's cutting? They are... and at the expense of that tools life and resulting accuracy results. Like Camminc says: a tool will perform best when the ideal conditions for that assembly are present. The better that assy, the better the results.
We have been running a brand new high end VMC with a Fanuc 18i control and as good as it is, the Fanuc motion control algorithms for Acc/Dec are just about what I expected. Either too loose in accuracy in favor of high feed rates, or too slow in motion control for best accuracy. This of course is with Ai Nano activated because without it, the programmed feeds would be less than 1/2 of where they are with it on...

All your high performance machine tool builders know this, so they offer you the Ai Nano or the HPCC as options that you have to pay extra for. They are worth it... As you cannot get high performance without them. Don't even think the builder is gonna offer you some snake oil that does not really work. On a Fanuc, if you want decent motion control, you have to buy these upgrades. Ai Nano = 5k HPCC = 10k (roughly)

so your telling me that i should tell to co to retrofit all our brand new machines that are 500,000 + each

who do you think your kidding?
i work in extreme accuracies that most other companies won t touch

i was looking at the videos on the website you posted , tools are impressive to handle cutting that type of material dry , but those speeds and feeds aren t impressive in this day and age , most controllers can do that , what ever type of material it may be , and have smooth finish
sorry dont mean to slam the system , but it sure isnt the be all and end all

dertsap,

I am not sure who you're talking about telling you that a 500k machine needs a new control. I would not suggest retrofitting a machine that new and expensive. Many of my comments suggesting a control retrofit are aimed at the lower end machine tool owner. Now personally, If I were buying a CNC, I would not buy a Fanuc because I have seen better controls, thats all.

I did however say that if you have a Fanuc control, and you have not purchased the high speed options, then the machine cannot feed accurately compared to what it can with the advanced high speed codes and systems activated. I'll bet your machines offered these options, did your company purchase them?
Also, I don't know what videos you're refering too? Dry?

my appology ,i miss understood you about the idea of the retrofit
http://www.creat.com/profile.shtml , i checked out those videos here , hard machining is the one i was talking about , runnig the ballnose on the 60 hrc , looks to me that it is running dry , or are they misting that?
either way that is a tough material , that is why i thought the tool was more impressive than anything else ,
seeing the video brough back a memory of a trade show i went to , i was watching a demonstration on a small mori that had a 25 horse spindle , they buried a 3" facemill into (obviously ) mild steel , full engagement , and had it hauling thru the material , ya it was nice that the mori didnt stall or show any sing of weakness ,
but i was interested in the tool they were using and the inserts that they were using , that was a nice cutter ,a lot of machines have that kind of horse power and more ,
my point is that in order to show how fast that controller can push a tool ,they should have taken simple aluminum ran that at 16000 rpm @500 + in/min and acomplish a good finish and smooth corners ,that shows that the controller is processing the info like we want , most times it is easier to accomplish a nicer finish on hard material than soft

i totally agree with the fact high speed is the way to go , but i firmly believe that we are still limited by the tooling , thermal break down is a huge factor , chip removal is another one ,
but personally i have a hard time believing that it is worth retrofiting an older machine to accomplish high speed machining , because the control will be limited by the machine it is put onto
and yes any high speed options is most always an extra cost, but that is the price you pay for better

http://www.datrondynamics.com/videozone.htm

this is pretty quick

AS I'm new on this forum, I give you my answer. I've listened that HPC is the opposite or HSM or HPC = HSM.

I consider high performance machining like a roughing operation with low cutting speed and heavy axial and radial depht of cut (high "chip removal flow" [mm^3/min])
For this operation, you need special tool. If you take standard end mill, which is not designed for this operation, it breaks immediatly.
An other point is the spindle. Be careful concerning the cutting torque. If you lock the spindle, it's a big problem for the tool life duration of spindle.

Now the High speed machining. For me, it's machining with very high cutting speed and low axial and radial depth of cut. The most of heat generated by the cutting is evacuated by the chip.
For HSM everything is important.
The principal problem is the chatter. If the spindle speed is closed to the natural frequency of the tool-tool holder-spindle unit you can machine with high radial depth of cut. Else chatter happen very often.
When you use HSM for aluminium or material easy to cut, you can take heavy axial and radial depth of cut with high cutting speed, the power asked is very high.
With material difficult to cut, the chatter happen more rarely than material easy to cut. You can not machine with heavy axial and radial depth of cut else the tool breaks immediatly. The tool is more problematic. You need a tool especially designed for the HSM of material difficult to cut in order to have acceptable tool life duration.

Concerning the roughness, it's better if you use nurbs curve. If the tool path is described by point, the tool accelerate, deccelerate and after machining the roughness.
With nurbs curve, the decceleration and accerlation are less important and the roughness is better.
The CNC software is too important. If the tool path don't take a axial/radial depth of cut constant, it'll be bad for the tool and the roughness.