High Performance Machining or HSM

[Scott_bob]

Originally Posted by chrisw765 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...

[dertsap]

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

[Scott_bob]

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)

[dertsap]

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

[dertsap]

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

[Scott_bob]

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?

[dertsap]

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

[dertsap]

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

this is pretty quick

[kalmah]

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.