High Performance Machining or HSM

[Scott_bob]

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...

[hardmill]

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

[Gunner]

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.

[Scott_bob]

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...

[cadman]

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.

[Scott_bob]

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...

[Gunner]

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.

[JIMMY]

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.

[Scott_bob]

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?

[camminc]

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.

[Gunner]

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).

[Scott_bob]

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...