High Speed Machine Demo Questions

[Smit]

Hi folks,

9/27 some people from my company are flying to Dallas to watch a demo of a Mori Seiki high speed machine running parts we've supplied to them. This will be our first high speed machine purchase so I'm not real knowledgeable about the systems. Can anybody suggest questions that are important to ask and things that we should watch out for when comparing high speed machinery? In October we are planning a trip to California to watch a Haas machine perform. Thanks in advance for any replies,

Larry

[ 09-20-2001: Message edited by: Larry Smith ]

[cadcam]

Some of my thoughts how many read ahead blocks does the machine follow.

Is there a built in excel rate & decelerate for corners and Z's.

JM2C

Now Larry smith when your company comes out here to haas if you are coming let me knows on the forum.

If you might then I will crab my visitor badge for Haas out of the car and come and say hi.

[ChrisD]

We use all Matsuura high speed machining centers. One thing that you may want to ask is what options that the machines come with.

The problem that we are having right now is with surfacing- not big problems- but we notice that when the ballnose tools come into a small outside corner, the machine tends to slow down ( the machine is thrown into G107 look ahead) What we didn't realize is that there is a package addon for multisurfacing.

Maybe you want to ask about what is involved or included in their HSM package---nurbs interpolation, multisurface HSM etc.

I'm not sure if the machines you will be looking at have boxways or linear guideways.

Our Matsuuras have linear guideways and that makes it a little harder to cut harder steels. I have to be a little more careful when I am programming .

But I'm pretty sure the philosophy is all the same --- lighter cuts at much faster feedrates.

Hope this helps

Chris

[ 09-20-2001: Message edited by: ChrisD ]

[Allan Brown]

Mastercam has a high speed multimedia presentation at mmsonline.com that may be of interest:

Mastercam High Speed Machining on mmsonline.com

[Turf Toes]

Larry,

I went thru the same things that your going thru about 2.5 years ago. We looked at all the major players, Mori-Seiki, Makino, Haas, Okuma, some other non-brand names. We looked extinsively in the look-ahead features that would control the cornering, the accel/decell of each, the top end spindle speeds, feed rates, networking capabilities, memory, etc. In the end, we decidied on the Mori SV-500B. It clearly outperformed all the others, except Makino, but was cheaper by about 25%, which is really what your bean counters are going to be concerned with too! Now, since then, we purchased a Fidia out of Italy, which does everything that all the others are claiming with some additions. It has a bi-directional indexable spindle head on it, plus it has a Windows based controller on it. It can't do continuios 5 axis movements, but it gets us going in that direction. BTW, I do die-cast molds with some being very deep. Now this machine can keep my tools at a short length and still get to the depths I need to completely hard machine the cavities with no need for all the EDM'ing and polishing. Anyway, back to your topic, I believe if you choose the Mori, you'll be more than satisfied with your decision, the Fanuc control has all the options you need to really take advantage of most high-speed machining needs!!

[ 09-20-2001: Message edited by: Loyd Harris ]

[ 09-20-2001: Message edited by: Loyd Harris ]

[Guest CNC Apps Guy 1]

Make sure they show yout the features of the Machine Tool. Comparing a Haas to a Mori is like comparing a Ford to a Cadillac. Defnintely not even in the same class. Have them push a 2 Inch Drill in steel with their lowest end machine(Only 7-10 HP!!!). Mori can do it, and end up with a bored finish, day in day out, year in year out. Haas, throw it away in a couple of years. Mori = Investment, Haas = disposable.

If you're getting a High Speed Machining Demo, from Dan, tell him James Meyette said "Hello".

JMHO

[Guest CNC Apps Guy 1]

Ask other machine tool builders if they scrape the beds of their Linear Way machines or if they shim them. Shimming is bad because it does not offer the most rigidity possible in a linear way configured machine. Also ask about if they have direct drive spindles. Or if they make their own spindles for that matter. Direct Drive is better for high speed applications because there are less moving parts, and you're not spending as much horsepower keeping the spindle going. In case you were wondering, it takes about 1HP to run every 1000 RPM of spindle speed. So if you're machine is say 10,000 RMP and you've got 10 HP, you're not going to have much left for the cut. If you're looking at Mori, you're probably looking at 30-50 HP depending on the model. If your machine has a 20,000 RPM, you should have at least 30 HP to give you enough head room for heavy cuts. Ask about HP on the axis drive motors. The higher the HP the faster it is capable of accelerating/decelerating.

[ 09-21-2001: Message edited by: James Meyette ]

[mcrae_andrew]

As soon as James is finished trashing Haas, I suggest that you purchase the following book from Modern Machine Shop Publications -

High Performance Machining

Miles Arnone - Author

There are several things he points out in looking for and evaluating new machine tools to do just what you are asking. Other considerations to remember are to budget for some premium tool holders and hydraulic chucks etc. The investment now will save in consumables then!

Andrew

[Guest CNC Apps Guy 1]

I was not trashing them per se. It's just that generally people who are considering a Mori/Kitamura/Makino/Yasda/, etc... won't even look at the throw away class of machine tool, and likewise people who are considering a machine tool in that class won't even look at Mori/Kitamura/Makino/Yasda/, etc... As Andrew said, there are numerous factors to consider when making Machine Tool purchases. Budget should not be the first consideration! Why not? Because for one, if you are asking something of a machine that it is not capable of doing (holding and repeating true position of ±.0005 or better all day every day in a non-climate controlled facility, you will not be able to achieve that on a lesser class machine tool. Maybe for the first year or so (depending what you are cutting), but not for the long haul. A buddy of mine works in a shop that has an old Mori Seiki SL-6, it's about 20 years old or so, that thing still holds ±.0002 on diameters! Try that with a lesser machine tool. NOT going to happen. So if budget is your primary concern and you need the above specs, the point is moot. NOT going to happen.

[Lucky]

The main features needed for successful HSM are:

Spindle - you need 30k+ rpm. Beware of high rpm/low HP spindles; however, high rpm/high HP = money! HSM spindles live hard lives. Check out the spindle warranty and replacement cost before buying anything. Some mfgs. have a spindle replacement program.

Acceleration - usually expressed in g's. Above 0.5 g's is good. Top of the line machines are 1 to 2 g's. This is a measure of a machine's ability to rapidly slow down entering a corner and rapidly speed up exiting the corner. High G machines spend more time at programmed feedrate rusulting in shorter cycle times. High G machines tend to be fairly massive with heavy stationary components and lightweight moving components.

Control - Look-ahead buffer and block processing speed are important. Automatic Accel/Decel based on a contour tolerance simplifies programming.

We use a Mikron with 42,000 rpm 18 hp spindle and 1 g acceleration. We cut graphite, steels up to 60 Rc, aluminum, and copper-tungsten.

[mcrae_andrew]

Sorry James - I am used to working with a higher calss of machine tool and I am sure that Mazak, Haas, Fadal, and Hitachi all offer great value for certain types of work. As well, Toyoda, Mori, Enshu, Makino, Toshiba offer great value for the precision stuff that has to be right -first time, everytime-. Also remember that "Conversations" are something people have on a telephone and not on a machine tool!

[Guest CNC Apps Guy 1]

quote:

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......Also remember that "Conversations" are something people have on a telephone and not on a machine tool!

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Andrew my friend...... I could not have put that better myself.

Have a nice week ahead.