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pascual (Mechanical) (OP)
13 Jul 04 7:38
My company is looking for a new vertical machinig center. One of the candidates is a HAAS machine. But I've read about some people having problems with them, a lot of repairs, not able to work 24 hours at day, etc. I'd like to read more opinions prior to take a decision.
Helpful Member!  EdDanzer (Mechanical)
13 Jul 04 12:07
We will be getting rid of our first and hopefully last Haas VMC in September. This machine is so limp in the axis and spindle you can only use about 2 hp when cutting. We had a Fadal until the end of 2000. Went through a restructuring and leased a Haas for 36 month. I call it my $36,000.00 mistake. After delivery of a new machine I tried running a program that was run in the Fadal, destroyed some tooling and scraped some parts. Had to reprogram to run a 1 ¼” face mill instead of 2”. Got no help from Haas, so I built a tool to compare spindle stiffness of several machines. http://www.danzcoinc.com/html/machining_center_stiffness_tes.html Will connect you to our web site information.
This Haas VF2 with less than 100 hours of use had over twice the deflection of any other machine tested, with .0005 movement with 50 lbs of tangential load in any direction. This translates into .001 out of roundness on any circular interpolation with more than 2hp or 50 lbs force when cutting.
jbel (Mechanical)
13 Jul 04 12:53
Ed,

That looks like a pretty ingenous way of testing the spindle stiffiness. Did you speak with Haas factory about the results?

I have also heard many not so kind things about Haas spindles. Remarks to the effect that they are disposable items.

It may be worthwhile to steer clear.......
EdDanzer (Mechanical)
13 Jul 04 16:27
I offered to take the tool their plant, and test other machines so they could see how poor their machine is. All they had to do was pay travel and lodging expenses if their machine was limper than others.
Neither, Haas or the dealer Selway showed any interest in fixing the problem, so I wrote the machine, the manufacture and the dealer off as people to avoid if at all possible for other machines.
Tmoose (Mechanical)
17 Jul 04 10:40
Very clever tool EdDanzer.  For the last 7 years I worked as an engineer at a US precision spindle manufacturer, so I have a few questions and "concerns" about your test. It sounds like you limited the radial load to 50 lbs, and maybe even the results were compared between "good" and "bad" machines, so some of my imagined concerns might be completely imaginary.

Applying a load several inches from the face of the spindle also tests the tooling and interface stiffness as well as the spindle stiffness.  Overhang built into the spindle (with the bearings moved back from the spindle face) clobbers the stiffness.  Tool overhang can clobber the stiffness even faster.

Your test rig looks to be testing the combined system stiffness of the entire machine.  If it has a rubber lead screw that large deflection will be added right in.  Not that system stiffness isn't real important.  A grounded reference to the spindle housing helps isolate the spindle shaft/bearing stiffness, when that is the desired information.

I was just thinking that real Uniform radial or tangential stiffness would show up as diameter variation, not out-of-round.  I would expect the spindle shaft/bearing radial stiffness to be fairly uniform, but the housing/column/table/?? stiffness to be hugely different X/Y/Z.
EdDanzer (Mechanical)
17 Jul 04 12:32
Tmoose,
This tools design is to compare one machine to another, in what would simulate a difficult cutting condition. The part that clamps to the bed is tall, and the cutter long to amplify weakness.
We can apply and measure loads to 500 lbs.
There are several things to change if a person is going to use the tool for actual measurements of individual elements of a machine.
1. The dial indicator should be replaced with a scale to connect to a data collection system.
2. A 3 dimensional laser measuring system would be connected to a separate target on the part of the machine in question to see the direction of movement as different loads are applied.
3. The pillow block bearing and the main pivot bearings replaced with precision angular contact bearings.
4. All parts precision ground square and flat.
5. A circular interpolation done at each load to observe deflection differences as directions of axis drives change. I personally think this would surprise most people, electric drives have poor stiffness when a load is applied to the ball screw.

As to the tool interface stiffness, the only testing done has been with quick change tooling. There is more information on Thread281-80549
Rleu (Industrial)
18 Jul 04 13:39
It sounds like you should be looking for a higher end machine Mazak is my personal choice ( I used to be field service for them) The product support is very good, I've been working with them for over ten years as an employee then a customer. The Mazaks have an excellent spindle the FJV series and MTV series are very good machines. Haas maches a in expensive machine but more times than not you get what you pay for

Richard Leu
Cascade engineering and Service
Richard_Leu@hotmail.com

surfdog (Mechanical)
21 Jul 04 13:24
Check out a Matsuura....well worth the $...I wish the US would make a machine this good.  Methods Machine Tools is the only US distributor....good luck....let us kow what you buy.  We have a bunch of "Mats" here and love 'em all...(wouldn't buy anything else)....Check out Nakamura Lathes if you need a lathe....Methods sells those too
pascual (Mechanical) (OP)
21 Jul 04 13:54
thanks to all. Finally we won't buy a Haas. The impression I have it's that it's not a bad machine, but it fails in spindle. The final decision will be after vacances.
timbarnett (Industrial)
23 Jul 04 6:58
We have 7 Haas machines and 1 Chiron. I'm part of the manufacturing engineering team here and have been involved in CNC machining for over 20 years. Pryor to working here I was a CNC service Engineer for a major machine tool company. I have programmed, run and repaired most every CNC machine and control there is. It is my opinion (which don't always mean anything)is that for the money you can't beat the HAAS. We run 24\7 and for the most part the problems I see are normal under these conditions. Parts are much cheaper than parts for the German and Jap machines.
EdDanzer (Mechanical)
23 Jul 04 9:56
Tim,
I did not say you can not use a Haas, we have been running 1 for 3 years. If you are running plastic, or other soft materials, or are doing low power requirement machining they may well be a cost effective machine to operate. We do small lot quantity (1 to 10 pc.), in some cases the amount of material removed is more than is left. When doing low volume parts we can not spend a lot of time playing with tooling and programming 2 or 3 time as many cuts to do the part, it doesn’t pay.
If you are running 24/7 these are high volume parts and you can spend the time to optimize the process, but it might pay to look at a good make of HMC. Some times the through put of one machine and 1 operator may be less than several machines and several operators.
mrainey (Industrial)
25 Jul 04 8:54
Here's a thread with comments from a number of Hass owners:


http://www.practicalmachinist.com/ubb/Forum13/HTML/000551.html

Manufacturing Freeware and Shareware
http://mrainey.freeservers.com

mrainey (Industrial)
25 Jul 04 9:00
And another Haas thread (this time I spelled it correctly)


http://www.practicalmachinist.com/ubb/Forum13/HTML/000574.html

Manufacturing Freeware and Shareware
http://mrainey.freeservers.com

timbarnett (Industrial)
4 Aug 04 12:29
Ed,
 I guess my point is that these machines are 20hp 40 taper machines. They are also as simple to program as it gets. I also prefer a Mazak but don't knock the HAAS. Just because we run 24\7 doesn't mean that we never do set-up's or write programs. We do! These machines are not table routers for machining plastic. They do get the job done. This of course is my opinion. You have the right to have your own. Have a nice day.
billehling (Mechanical)
5 Aug 04 10:24
pascual,

    Our company has 6 Haas VMCs.  We run everthing from plastic to titanium, but mostly high strength steels.  I won't tell you it's the best machine out there, but I can tell you we rip up a lot of metal and (with the right end mills) we can hold some tight tolerances.

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