[gar]

060519-0953 EST USA

SGP:

What is your latest information?

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[little bubba]

So before I make any kind of decisions in keeping it or selling it, I want to get some inputs from HAAS users (or even non HAAS users).

Non-Haas user. We picked up a '98 Mazak QT20 in 2004. As the literature that came with it said, .0003 diameter from cold to hot on fast moving bar feed jobs. Very predictable, and no thermal compensation that I've ever come across.. Of course for just a few more dollars in 2004 we could have had a new Haas, but I'll stick with this lathe, $416 dollars in total repairs in the 23 months we've had it, and it gets up and goes every day.

I could live with a thou for a bargain, but .012 or even .004. I'd drag it out to the parking lot. Definitely something wrong.

[miljnor]

I have 9 haas machines and out of the 9, 2 of them have never needed any maintenec related repairs i have had one crash and take the turret out of tram and one the crash that took a tool prob and tail stock casting out. But other than the dimwitts that were working for me, no repairs. And both machines are over 4years old.

but I have to agree most other Higher end machines have alot less maintenence on them.

I know a shop that is getting rid of all thier haas machines for this very problem. and going to Okumas. They say the Okumas don't break! Personally I know they have had one of theirs break 2 time and I think their memory is just mucky.

The one thing you also have to think about when purchasing is down time from the breakage. How soon can a tech get out to fix it and how soon after that can they have a new part to fix it. None of my Haas machines is ever down for more than 3 days usually 1 day. The last time they had a down Okuma it was down for 2weeks waiting for a part.

[brucifer33]

I just recently purchased a new HAAS SL20 and its giving me about 0.012 inch part dimensional increase from morning start up till machine warmed up.

Does anyone have experienced this?

Acatually, I have some experience with a sl 40 and its just grreat, ive been in job training for over 3months in the cnc lathes. I love this job and im making it my career now. im looking for some good info on learning how to program.

[bebe_boom8]

hi!

I have the same problem but that is default from parameter dealer... dealer must be updated for you a new revision of parameter...

[GAS]

The best I can tell the SL-20 with the thermal growth problem does not exist. If it did it would have been fixed. I have made every effort to contact this indavudal and solve his problem. For thoes of you who do not know it is a simple paramater adjustment. We have had our dealears search the southern California area for this troubling machine and no one can find it.
I have asked this indavidual to contact me so that I could get his machine adjusted, but he has not responded. It would seam to me if he has a complaint or problem that he would like to have it fixed. Maybe the whole thing is a fake, posted to see what type of responces could be generated.

[gar]

060619-1025 EST USA

GAS:

Do you work for HAAS or an HFO?

As far as I know none of our HAAS machines have any temperature compensation, except for HAAS warm-up compensation. We do not use the warm-up compensation, and therefore as far as I know we have no compensation. If this is our case and others are the same, then how could any parameter adjustment influence temperature drift. Yet there seems to be a lot of talk on this thread about parameter changes influencing variations with run time.

Also if you are with HAAS please explain any possible way you might get this excessive amount of thermal drift, 0.012". The maximum we ever normally see is 0.001" to 0.002". However, we do not run our machines at high load.

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[GAS]

Most machines have the ability to compensate for thermal growth. All of the Haas machines I have run were capeable of holding .0005, day in and day out. If they could not then we adjusted them so that they could. It is possable that the parameters were set incorectly and a simple adjustment could have fixed the problem. It would usualy take a couple of days to chart the growth and compensate for it with the paramaters. If the machine has no other mechanical problems then it should be achievable. If you wanted to compensate for thermal growth the first thing you would need to do is measure the tempature of the ball screws. As the tempature increases the screw grows, and this growth can be measured. If we chart the measured data using SPC then we can compensate for the growth. What I discoverd was that while running a production run of 500 parts with a bore tollarance of +.0005 -.0000, was all I needed to do was warm up the spindle for 30 min and make parts. If you leave the spindle run when you go to lunch then you will have to make an adjustment because the rest of the machine cooled off. The next day I went to lunch and let the machine set and the bore was right where I left it. We used our VF-2's to hold .001 true possition tollerances on the aircraft parts we manufactured and our SL-20 could hold .0003 on the spherical balls we machined on it. We have other brands of machines as well but for the money it was the best value for what we had to spend. Besides when you are trying to ship 2.2 mil who has time to waite for your machine to get fixed. I wanted to help that person with the thermal growth problem because I felt that the level of Customer Service he had reported was not up to the Haas Standard.

[Haas_Apps]

It is very unfortunate that SPG has this thermal growth issue. I generally work with mills and have little to do with lathes. However I think the same principals apply to them when it comes to thermal growth. I have done quite a bit of testing in this area a couple of years ago. In the control it maintains a mathematical model of the heating and cooling of the ball screws and adjust the commanded position accordingly. The test I have done have show that if the parameters for the model are set correctly, you can expect no more than about .0002 of positional deviation over time. For many this is acceptable. Some have mentioned ambient temperature as a main cause of the problem. This does not hold water as the part is most likely at the same ambient temperature as well as everything else on the machine. Changes in ambient temperature have very little to do with thermal compensation as the rate at which the ball screw heats and cools are the same.

I would very much like to help resolve this issue with SPG. If he could please call the Haas service department at 800-331-6746 I believe we can resolve this matter in a few days if not hours.

[Geof]

Haas Apps; Your post implies all machines have this thermal compensation model. I have two SL10 and depending on the job, small parts from bar stock, they will change by up to 0.003" on the X. Our parts are not such fine tolerance that we have ever noticed any Z change. I was under the impression that for automatic thermal compensation I needed temperature sensors installed. Your post suggests that just by adjusting parameters I should be able to reduce the change to what we would consider negligible.

[Haas_Apps]

Geof,
Well, as I said before I do not really work with our lathes. However, if you check your parameters you might see parameter 272. If this has a value in it then you are using thermal compensation. Also, you may have setting 158. This setting will allow you to adjust the thermal comp. by up to +/-30% if you have it. If you want to adjust this setting it may take some time to adjust it correctly.

[Geof]

Thank you, there is a value in Param 272 but no values in the Setting. Some day I might play with it if we need to make something critical.

[scappini]

we just purchased a SL20 lathe today. Our SL30 has negligable size variations first up in the morning, maybe .008mm. Our temperature variation is about 24 C to 33C. Have not warrented using the temp. warm up settings, but if I did it is always predictable.

[htishop]

I had the same .012 creep problem and had to change some parameters . Now long run +/-.002 is no problem, but I really have to watch on .0005 dia. the thermal comp jumps that much.