Need Help!- Picking up partially cut thread in CNC lathe

[tom tom]

Hi everyone,

Question: is it possible to pick up a thread that has been partially cut, removed from the CNC lathe and placed back in the lathe? We have a Haas TL1 lathe. The thread in question is a 3/4-10 with +/-.003 tolerance.

many thanks and best regards to all,

tom

[Ceramic Man]

Maybe.
I would try this:
Put part back in, and add to your X-offset so tool won't touch the part. Run the thread cycle at a verrrrry slow RPM.. like 10 or less. In the middle of the thread cut hit E-stop-- you want the spindle and feed to both stop immediately. Then release the e-stop and go to hand-jog. Unclamp the part and re-position it so the thread lines up with your tool as you jog the x-axis in against the part (barely). Careful not to turn the spindle at all while doing this as it will mess up the whole process.
This should get the part lined up good enough unless you have a very tight tolerance on your thread, but you might as well try it as its the only way to re-align your piece in the chuck.

[Ceramic Man]

+/- .003.... I don't know if you'll be able to pull that off, but the more time you spend carefully positioning the tool in your existing thread just right, the more likely you'll get it in tol.
Another thing-- Small lathes spindles stop much quicker than big ones, so I would run that thread cycle at 1 rpm if you've got a big lathe to ensure the spindle and z servo stop at exacly the same time.

[Ceramic Man]

I was just reading one of the other threads that says the TL-1 doesn't have a spindle brake? If that is so, I don't think this will work. Even at 1 rpm the spindle might drift with no motor brake to slow it.
I don't know-- I've done this successfully before on one of our GT-20s but it has a 5C collet nose on it which weighs a lot less than a jaw-chuck allowing the spindle to stop quickly.

[AMCTony]

If your TL has the newer software in it it should have the thread repair tab in the intuitive programming. I have this on my TL-2 and used it for the first time last week. I works very well and pretty much walks you thru it. It cuts the thread like it was cutting a new thread and does not take just 1 pass so if you need to lengthen a thread this option would work fine.

[Mark Hockett]

AMCTony is correct if you have the intuative software, which I think most TL-1's came with you should have the thread repair menu.
Here are some screen shots,







Its very simple to use and works well, I have used it many times.

Mark Hockett
Island Tech Enterprises
Clinton, WA
http://www.islandtechent.com/

More chip less lip

[Donkey Hotey]

Yup, this is an 'early/late' software question. Early TLs don't have it. It's one of the later features. I think the way to find out is this: if you have 'soft stops' in the control, then you don't have thread repair.

If you don't have thread repair:
I've been told that you can write a short threading cycle in MDI, then run it and watch the threading tool. Adjust the Z work offset each time until it's tracking closely. Then adjust the X work offset until it starts to go down into the thread.

After running the path a few times, you should be getting the cutter close to the existing thread. You're only playing with one thread-pitch of change in Z and the thread depth in X. Once it's skimming the old threads, you can do a final tweak on Z to get the cutter into contact on the correct face of the thread.

[tom tom]

Hi everyone,

Thanks for the excellent advice in short order! Yes, our TL1 has thread repair on it, I never paid any attention to it before. I also appreciate the information on picking up by the offset method as we have an older SL1 without the thread repair module.

thank you!!!

tomtom

[AMCTony]

That is the tab I was talking about. This sounds like it will do your task.

[Donkey Hotey]

Hey Mark,

Thanks for posting those pictures. That's the third version of IPS software I've seen on a TL-1. I am so glad that I bought a new one vs the original series I almost bought (earlier than yours).

The early TL-1 software is shown in the video at the Haas site. It doesn't use tool or work offsets, doesn't have thread repair and a bunch of other details. We have one at work and while I can get things done, the lack of work & tool offsets really limits their use.

It looks like you got a later version of it with all the right features. I think the difference between yours and mine is the Coldfire processor and larger LCD screen. And when they changed the hardware, they changed the screen layout again. I wonder how many other small differences there are.

I really like the IPS software on the lathe. I briefly did the 'try out' feature for IPS on my VF-2. It doesn't seem nearly as useful on the mill.

Oh well, rambling again. Off to work.

[Mark Hockett]

Greg,
I bought my lathe new in 2005 and it originally had the older version software. I recently updated the software and updated to the new style tailstock.

Mark Hockett

[AMCTony]

I have a TM-1 and a TL-2. The Lathe intutive software is extremely usefull. When it comes to the IPS on the mill I fully agree with donkey. It aint worth ****. The Visual quick code on the mill is ok for drilling holes on simple stuff but that is about where it ends. The way Haas like to sell options it would be nice if they offered for sale a USEFULL IPS for the mill. Even better I would like to see an open source software machine that can have custom software loaded into it. Now that would really give the ability to boost productivity. That is also more than likely just wishfull thinking.