Newbie PCNC 1100 Info - Page 2


Page 2 of 2 FirstFirst 12
Results 21 to 29 of 29

Thread: PCNC 1100 Info

  1. #21
    Member AUSTINMACHINING's Avatar
    Join Date
    Mar 2011
    Location
    usa
    Posts
    480
    Downloads
    0
    Uploads
    0

    Default

    Quote Originally Posted by widget_maker View Post
    You probably have one machine in a hundred! Mine is about 1.5 thou.
    +1,
    If your getting tenths on a hobby mill, I wouldn't touch a thing !.



  2. #22
    Member BMC_Dave's Avatar
    Join Date
    Jun 2019
    Posts
    14
    Downloads
    0
    Uploads
    0

    Default Re: PCNC 1100 Info

    After truing up my dial gauge and oiling everything I can't measure any backlash in X or Y anymore, Z looks like it could be 5-7 tenths. Think it was just sticking a bit after sitting unused for 9 months.



  3. #23
    Member
    Join Date
    Mar 2008
    Location
    USA
    Posts
    216
    Downloads
    0
    Uploads
    0

    Default Re: PCNC 1100 Info

    If your Z axis has backlash the gibes are too tight! The head and motor provide about 300 pounds of constant down force.



  4. #24
    Member Snecx's Avatar
    Join Date
    Jul 2018
    Posts
    38
    Downloads
    0
    Uploads
    0

    Default Re: PCNC 1100 Info

    Could the machine have been compensated for backlash? Without software compensation, there will always be quite a bit of "backlash"--or more accurately, lost motion--with the dovetail ways design of the Tormach.

    When the gibs are set loose, there won't be any backlash if there isn't any wear to the ball screw and ball nut. Tighten the gibs properly and there will be lost motion introduced, even if it's really tiny (0.01mm / 0.0004" or more).

    It sounded like the gibs could be loose, but I hope it's not that.



  5. #25
    Member
    Join Date
    Jan 2014
    Posts
    126
    Downloads
    0
    Uploads
    0

    Default Re: PCNC 1100 Info

    What a steal. Nice job



  6. #26
    Member
    Join Date
    Jan 2017
    Location
    United States
    Posts
    8
    Downloads
    0
    Uploads
    0

    Default Re: PCNC 1100 Info

    Quote Originally Posted by Snecx View Post
    Could the machine have been compensated for backlash? Without software compensation, there will always be quite a bit of "backlash"--or more accurately, lost motion--with the dovetail ways design of the Tormach.

    When the gibs are set loose, there won't be any backlash if there isn't any wear to the ball screw and ball nut. Tighten the gibs properly and there will be lost motion introduced, even if it's really tiny (0.01mm / 0.0004" or more).

    It sounded like the gibs could be loose, but I hope it's not that.
    Newbie here - could you explain this a little for me? I (with very little experience) thought that my gibs needed to be as tight as possible while still allowing free movement - but your comment seems counter-intuitive to me?



  7. #27
    Member Snecx's Avatar
    Join Date
    Jul 2018
    Posts
    38
    Downloads
    0
    Uploads
    0

    Default Re: PCNC 1100 Info

    Quote Originally Posted by t3kboi View Post
    Newbie here - could you explain this a little for me? I (with very little experience) thought that my gibs needed to be as tight as possible while still allowing free movement - but your comment seems counter-intuitive to me?
    Yes you need it tight, but not too tight. My comment is merely saying the same, you need the gibs as tight as possible while allowing "free movement". But that free movement is not with zero backlash. Tormach's recommendation is to check the lost motion while tightening the gibs and stop when the lost motion suddenly become excessive. However it does not start with zero lost motion.

    If you have done enough tuning on the machine, you'll find that even on a brand new machine with carefully cleaned, flushed and lubricated ways, by the time you tighten the gibs a little bit, there will be very slight lost motion introduced (0.01mm/0.0004"). That's not even with the gibs anywhere near tight.

    It will normally increase to about (0.02mm/0.0008") by the time the gibs are about right. If the leveling is done right so the base is not twisted, the gibs are not squeezed too tight, and all the careful prep work are done, you can reduce it to ~0.01mm/0.0004" with some luck. However the more commonly achievable lost motion is about ~0.03mm/0.0012" given how most of these machines are setup by new owners without extensive experience with machine tools installation.

    On linear ways, there would be almost no lost motion, but it will not be as rigid as the dovetail ways. Dovetail ways will always have a bit of lost motion. So this is one big reason why Tormach gets some bad rep.

    I personally like the dovetail ways.



  8. #28
    Member R.DesJardin's Avatar
    Join Date
    Aug 2008
    Location
    United States
    Posts
    421
    Downloads
    0
    Uploads
    0

    Default Re: PCNC 1100 Info

    Looks like a great deal, don't forget the spindle door latch upgrade.

    RAD. Yes those are my initials. Idea, design, build, use. It never ends.
    PCNC1100 Series II, w/S3 upgrade, PDB, ATC & 4th's, PCNC1100 Series II, ATC, 4th


  9. #29
    Member BMC_Dave's Avatar
    Join Date
    Jun 2019
    Posts
    14
    Downloads
    0
    Uploads
    0

    Default Re: PCNC 1100 Info

    Yeah it was, thanks! Just finished VFD and stepper upgrades and they're quite the improvement. Funny thing is work is asking if I can cut them parts now, on the machine they just sold to me... Could pay for itself with the first job if it comes through haha.



Page 2 of 2 FirstFirst 12

Tags for this Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  


About CNCzone.com

    We are the largest and most active discussion forum for manufacturing industry. The site is 100% free to join and use, so join today!

Follow us on


Our Brands

PCNC 1100 Info

PCNC 1100 Info