Hello Guest it is July 11, 2020, 04:46:33 PM

Author Topic: Lathe losing steps I think  (Read 3504 times)

0 Members and 1 Guest are viewing this topic.

Lathe losing steps I think
« on: November 08, 2009, 04:08:11 AM »
I have a Boxford TCL125 lathe which uses the standard drivers and steppers .

If I program using feed/rev the machine constantly loses steps and I have to re-home . If I use feed/minute and use a feed of 600mm/min the machine behaves ok and repeatability is great .
Anything over this and either axis may play up . I know 600mm/minute is slow , but at the moment it is what works .

The confusing thing however is that if I jog reasonably quickly the machine behaves . Is Mach3 doing something under program that I am missing or could it be the hardware ? Mechanically the slides and ballscrews have no detectable sticking points that I can notice moving them by hand . Any help would be appreciated .

Offline Hood

*
  •  25,846 25,846
  • Carnoustie, Scotland
    • View Profile
Re: Lathe losing steps I think
« Reply #1 on: November 08, 2009, 04:10:12 AM »
Try increasing the pulse width and Dir Prechange.
Hood
Re: Lathe losing steps I think
« Reply #2 on: November 08, 2009, 04:35:46 AM »
Once again a quick reply . Thanks once again Hood . I shall go and try it now and let you know .
Re: Lathe losing steps I think
« Reply #3 on: November 08, 2009, 06:10:29 AM »
Right . I have tried all combinations of pulse width and dir pulse but to no avail , so I have reset both to the original setting .

After a couple of changes the program and machine ran fine to a predetermined stop in the program . However when I rewound the program , and started the program with the axis at a different start point , the problem arose again . Badly .

Whilst writing this reply I had a thought and I have just checked the original brochure for the machine and have found that at 100% feed , rapid traverse rate is 350mm/min , and programmable feed rates to 300mm/min .

Me thinks I will try again .
Re: Lathe losing steps I think
« Reply #4 on: November 08, 2009, 07:01:49 AM »
Gadzooks!!!!!!!! Me thinks me azzit !!!

Just put the speed to 350mm/min and run everything fine . Very slow but fine . Thanks again hood .

Offline Hood

*
  •  25,846 25,846
  • Carnoustie, Scotland
    • View Profile
Re: Lathe losing steps I think
« Reply #5 on: November 08, 2009, 07:40:29 AM »
You will probably find that the only way to get more would be to get drives such as geckos and probably new motors and possibly another power supply (depending what yours is now)
At least its moving now so you can get some cutting done :)

Hood
Re: Lathe losing steps I think
« Reply #6 on: November 08, 2009, 11:07:14 AM »
Yes i'm afraid I have to agree . The trouble is I know nothing of that sort of thing . Indeed the machine was sorted out with the original Z80 based board removed and a completely new board constructed . It seems a shame to remove it and replace it with new gubbins , but hey , needs must I suppose . The only problem I would have is sorting out the spindle drive etc . But I suppose I could always ask . Funnily enough I thought the problem was with the existing kit , so I am already in the throws of getting things priced . But for now the machine is good to go even if it is a "tad" slow .

Offline Hood

*
  •  25,846 25,846
  • Carnoustie, Scotland
    • View Profile
Re: Lathe losing steps I think
« Reply #7 on: November 08, 2009, 01:47:23 PM »
Probably best just to use it the way it is at the moment, then when you get more experience with that particular machine it might start feeling slow and you can then upgrade.
Hood