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Thread: Haas TL-1 Accuracy issues
08-07-2008, 09:42 PM #21
08-08-2008, 07:01 PM #22
CB, you mentioned a 1mm finishing pass, which is 0.039". That strikes me as a pretty big finishing pass if you are aiming for better than 0.001" tolerance, I'd trying knocking the finish pass down to 0.015" or so and see if you get better repeatability.
08-09-2008, 01:59 AM #23
I've had a TL-1 in my shop since 2005 and can tell you that the Aloris tool post just plain sucks for repeatability, you'd be lucky to hold .001" on multiple run parts. I have the Aloris, the Haas turret and I use a gang tool system on the lathe. I have no problem holding .0003" with the turret and the gang tool set-up. I do a lot of 100 to 200 part runs and once dialed in I almost never have to adjust the tool to hold .0003" through that size run. I do use a separate roughing and finishing tools to maintain that accuracy. I only use the Aloris for prototyping. I have looked into The Aloris QCTP that will mount into the Haas turret but haven't bought it yet. That will make it so I don't have to pull the turret off to use the 40+ Aloris holders I have when prototyping .
If you don't want to spend the money for the turret or make a gang tool set-up then I agree with Ross about the Multifix being the most accurate way to go to sollve your problem.
I just got the new servo driven Haas turret but have not installed it on the lathe yet, I don't know if it will have the same repeatability as the original turret.
08-09-2008, 10:44 AM #24
Thank you Mark, that is the response I was looking for. someone who actually has a machine and has tried other options. It was suggested to me by the local Haas rep that the turret wasnt that good. However he also admitted to having never used or sold one so that is not what I would call an informed opinion.
I have never seen the turret, I cant find a photo of one. If you have time later would you post or email me a photo of your turret. Perhaps your gang tool setup would be usefull? I have thought about making one and you are the second person who has mentioned it. I have seen the one that Dorian offers but it doesnt look very rigid to me.
Feel free to PM me if you like and I we can share our TL-1 Additions. I have made several modifications and extras for mine.
08-09-2008, 03:16 PM #25
your machine, your time. it doesn't matter to me what you do. our school has a deal with HAAS, as do many institutions: we get two tool room machines for the price of one as well as huge discounts on their other machines. while product placement plays a part of that, we have a lot of Hardinge machines, and Sodick EDM's, but they aren't giving us two for one deals. i think this is a testament to the type of machine you are getting. in the case of a TL1, a $28,000 lathe. there are lots of tool room lathes that cost that much 20 years ago. the TL1 is not a rigid machine. i tried doing some long 304 pieces using the tailstock and ended up doing the project on a manual lathe. sure, the tool post and switching tools plays a big part in accuracy, but even the machine rep. told you that the positioning is only accurate to "about .0004".
08-09-2008, 03:52 PM #26
08-09-2008, 06:07 PM #27
I have contemplated my answer to both of you very carefully. If you care to read my post carefully you will notice two things. One I was asking for input from other users of the TL-1, not input on Hardinge or other machines.
Second, there was never any doubt that this machine wouldnt hold to a tenth, just that I was surprised that under nearly ideal conditions of work holding and soft material that the accuracy wasnt better. I was curious if this was the norm for this machine or should I look at some other options of how I was doing the work.
Several people gave good advice which I will try next time I have the chance. Some of the ideas though appreciated didnt really pertain to the questions that were asked. However, I am greatful that people took the time to offer their opinion.
To those of you who can only offer critisizm and offer blind insults in an attempt to make yourselves feel superior, I dont really give a damn what you think.
As to the idea of taking .04 finish pass it has to do with the nose radius, land and chipbreaker on the insert that I had on hand. Those of you who know how to tell the difference will know what I mean, to all others read your insert manufacturers handbook and then offer your informed opinion.
This type of forum is the only way we have of really comunicating where we can take the time to read what we say before we say it. And still some people end up with their foot in their mouth.
For anyone who feels the need to know, I bought this machine used from a friend who didnt need in and needed the money. It is four years old but has very few hours on it and so far has done a good job of earning its keep.
There are rare occasions were a greater degree fo f accuracy is important. It would be helpful to me if I can find a way to improve my chances of maintaining a set tolerance every time. I am sure a combination of some of the ideas presented here will be useful.
08-10-2008, 01:28 PM #28
The only criticism I offered was at the .039 finish pass. My opinion of that stands. If the insert you were using dictated that as being the lightest cut you could take, then you were using the wrong insert. You would have been better off hand grinding a HSS or carbide bit for the finish pass. I'm a manufacturing Engineer, I'm more than capable of determining the proper insert for the job. And when you can't afford lots of different inserts, grinding your own bits whether HSS or carbide is often much better than using the wrong insert.
If the tool holder is an issue, and you can't buy a new tool holder, take two finish passes and put a stop in between them so you can check your diameter before going to size, and make adjustments in the tool wear offsets to compensate. Takes more time, but keeps you from making scrap.
08-16-2008, 02:26 AM #29
08-16-2008, 01:52 PM #30
Thank you Mark, I have seen a similar turret before but I think it was on a Prototrac machine. I have a couple of jobs that might be repeat ones in the future and I plan to build a Gang tool accessory. I havnt made up my mind how I will build it just yet. I would like to be able to adjust the tools individually but I think that may be too hard to accomplish with the limited time I have. I will likely just bolt a block of steel onto the machine and use the spindle to drill it out for tool bushings.
Did you buy or make your gang tool setup? If you want to send me a picture of the gang tool setup when you have the time. No hurry, I am too busy right now to do much with it for a while.
For what its worth I have tested the machine and its positioning and repeatability with no load is better than I was getting. Will have to wait until I get another long run to see if any of the ideas that have been presented will help out.
08-16-2008, 09:10 PM #31
This thread had me curious about my TL1. I ran 100 parts today. Turning part was a simple cylinder .480 diameter +/-, 12L14, turned in 1 pass from 1/2" material. Gang tooled, so no problems from a tool post.
First 3 parts measured .4814, .4815, .4814.
5 random from the batch, last decimal 5,6,5,6,7
last 3 .4816, .4819, .4817
.0005 variation max of the pieces I happened to measure. I did not adjust any wear offsets during the run at all as these were all well within spec. I don't have much doubt that I could have kept it tighter if I had been monitoring and tweaking for wear. I'm guessing .0002 might be a little tough to hit, but .0004 wouldn't.
Just my observations.
08-16-2008, 09:43 PM #32
I think I ticked off the op...(sorry Charlie...hehe always wanted to say that)
I wasn't knocking the machine, only his expectation that he could hold .0002,
and remove and replace his tool from his tool post with each part. I just don't see that happening.
08-17-2008, 08:46 AM #33
I think that line is copywriten so you owe Charlie Tuna some money...
There was never any dilusion about being able to hold .0002. I had a total tolerance band of .0004 and I thought the machine might be able to hold within that. However I found that there was a great deal more variation than I had expected. I am only intereseted in consistancy, if the machine will consistantly hold a set tolerance then that is fine with me. However my lathe keep changing in jumps with no clear reason for it.
I would run 4-5 parts within tolerance and then for no known reason the dimention would jump .0006. I would run two parts and get the same size so I would adjust the offset by half only to see the part now running below the set tolerance. This is what I meen by "chaseing the tolerance around". I dont know if this is normal or not but I think I would have been better just to run the parts and not made any adjustments as I finished up right back where I started. I felt the tool post seemed to repeat pretty well when I checked it before but I suspect that it is really the weakest link.
Of course I am open to other ideas but what I wanted was input from TL-1 owners who have real experiance with what thier machine is capable of. Input from non owners or people who only offered generalizations really isnt helpful. Real numbers by people who have already tried several different tool holding methods is the best kind of information.
Thanks to each of you who took the time to offer an opinion. I find it difficult for me to type so much so my first question may not have had all the infromation I should have included. This doesnt excuse those who only offered blind criticism and insults but that is ok too. As it is a new and wonderful day, too bad I am here working instead of injoying it.
08-19-2008, 04:48 PM #34
Have you tried a backlash move? My guess would be you are putting on some kind of corner break, feed out in X +.03 after corner break, rapid Z to position before corner break, feed in to diam. and continue to cut part in Z.
08-20-2008, 07:52 PM #35
machine will do the job. .0004 positioning is one thing but repeatability is a different thing and always much tighter on a cnc. One positioning error shows its .0004 error it will repeat it much closer each part after.
08-20-2008, 08:31 PM #36
08-21-2008, 07:38 AM #37
08-21-2008, 08:00 AM #38
Your mention of a backlash move is interesting...I wouldnt think such a thing would be needed on a modern CNC. Perhaps its a little nieve of me but I would have thought that with the processing speed of todays controls most backlash compensation would be pretty automatic. I may have to try that just for fun but on such a new machine I dont think that would really help but who knows? worth a try anyway and I thank you for the suggestion as I wouldnt have thought of that one myself.
For now I am busy with other work and will soon be making a gang tool setup for the machine. I have several jobs now that are in the 500+ parts. This is not the best machine for such a run but the tolerances are loose and I dont think it will be a problem.
I told myself that I wouldnt ever buy a machine tool that didnt have a tool changer. But as it is when this one came available I jumped on it and now thinking I would prefer something different. Last cnc lathe I operated was a Nakamora Tome, big difference...
08-21-2008, 08:39 AM #39
You wouldn't think so with the new techno, but I never assume. Sometimes old school is the way to go. I use to program for a shop that had some pretty worn out machines and they always insisted on backlash moves, just got into the habit and when I started my own shop just carried thru with it. What works for one doesn't work for all. Programming/job productivity is my fortay and I enjoy seeing chips fly like bullets, not intimidated by much a good tooth grinder is good once in a while.
08-21-2008, 11:25 AM #40
i deal with a couple older mills at work that have between .0005 and .0008 backlash, and we have to be cautious when we start getting into jobs requiring .002 or less tolerances and bored holes with .0002 tolerance.