Hello Guest it is August 20, 2019, 07:24:19 PM

Author Topic: threading success with mach turn today.  (Read 3501 times)

0 Members and 1 Guest are viewing this topic.

threading success with mach turn today.
« on: February 18, 2010, 09:22:56 PM »
i have been trying to eliminate threading  problems for a few months now.probably ran 100 test pieces , from 1/2" to 5", different pitches and depths, different versions of mach, index settings, ramp and acceleration settings,could not stop the double tracking while threading.about 6-8 passes would be fine then would  lose position. today read a post about editing the 1076 macro, changed false to true, and now excellent threads. ;D  more testing with threads , from .625 hot rolled to 5" dia 12 tpi piece and all were good. question is why does the g32 work and the g76 not , for me anyways ? all my test pieces had the code generated by the mach wizards, and with poppabears quick threads wizard.

Offline RICH

*
  • *
  •  7,351 7,351
    • View Profile
Re: threading success with mach turn today.
« Reply #1 on: February 18, 2010, 11:26:43 PM »
Quote
question is why does the g32 work and the g76 not , for me anyways ? all my test pieces had the code generated by the mach wizards, and with poppabears quick threads wizard.

All i  can say is  both the g32 and g76  worked for me during testing. I perfer to use the G32 as it provides more info to monitor during the threading. If one works so should the other. You should not have to run a hundred tests. Just do the tests in the Threading on the Lathe  write up as they willquickly tell you what your "system" is capable of. The scribing can tell you a lot about your machine and 1/2" piece of copper tubing can be scribed numerous times saving you some stock.

As of this date i still recommend version 033 when it comes to threading.

What do you mean by double tracking?

Did you read the writeup?

RICH
Re: threading success with mach turn today.
« Reply #2 on: February 19, 2010, 05:44:01 AM »
i had read your threading on a lathe writeup. the threading tool would not keep a consistant cut.after about 6-10 passes the cutting point would be out a position by a few thou. each successive pass would be out of position again by a few thou. backlash cant be blamed as i can turn parts all day and be on dimension. machine is a hardinge chnc 3.currently using version 27. version 36 during threading would make the x axis behave strange,jittered back and forth a few thou and  the x dro would be changed by mach. only using g32 has worked . i agree that i like the format of the g32, more info .

Offline RICH

*
  • *
  •  7,351 7,351
    • View Profile
Re: threading success with mach turn today.
« Reply #3 on: February 19, 2010, 09:31:59 AM »
 tripleback,
Need to try to narrow down the problem. It could be a number of things and using versions of MACH
 prior to or after .033 may mask the real problem and what it is. To do that i am suggesting you use Mach version .033
as the base line. The problem you describe was fixed in later versions / 033.

There was a problem with fast pc's after version 033, see reply 707/page 71, 716/72 and 720/73 in the thread
 Problems Threading on the Lathe. Additionaly there was discussion on the Yahoo about VFD's and motor speed,
where the VFD was changing the speed and at the same time the threading was compensating for the change in speed ,
 thus both were fighting each other.   

Here is what i suggest you do:
1. post your xml as it currently is
2. go back to version 033 ( may need to clean up the pc to make sure the correct driver is being used)
3. I will assume that your "lathe system is accurate", use the Simple Threading ( lathe ) to generate the gcode
    for the thread with output of G32, generate a code for scribing, post the gcode file OR just use the attached
   threading file ( just 2" of threading  on a 1/2" piece and 26 passes)
4. -do a scribing test, if something goes wrong note the pass number and then post a picture of that threading scribe
   along with a close up at the beginning of the first few threads
    - was the rpm stable?
5.post the xml used for that scribing

Descibe your pc / a few questions.........
A-what windows system are you using:
B-what is the speed of your pc:
C-are you using the PP:
D-are you using a Smoothstepper:
E-do you have any anti virus or other software which could interfere with Mach:
F-When you run the driver test, what is your pulses per second and kernal speed you ran it at:
G-Set your rpm to 200, what is the rpm in the dro, does it change any:

How about item #1 above and reply to questions A to G for now:

RICH 

Re: threading success with mach turn today.
« Reply #4 on: March 05, 2013, 09:53:59 PM »
Tripleback,
What wizard are you using to get the G32 code. I also am getting poor results when threading. Do you have a link to the papabear wizard?
Re: threading success with mach turn today.
« Reply #5 on: March 06, 2013, 04:14:22 AM »
i use 043.022 and i get random jittering at the start of the code on the first pass. I put this down to the vfd so i put a 5 second pause in the first line and this removes the jittering on the first pass, and completes the threading without any problems at all.