584,862 active members*
5,349 visitors online*
Register for free
Login
Page 2 of 2 12
Results 21 to 29 of 29
  1. #21
    Join Date
    Mar 2011
    Posts
    480
    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
    Join Date
    Jun 2019
    Posts
    14

    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
    Join Date
    Mar 2008
    Posts
    216

    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
    Join Date
    Jul 2018
    Posts
    38

    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
    Join Date
    Jan 2014
    Posts
    126

    Re: PCNC 1100 Info

    What a steal. Nice job

  6. #26
    Join Date
    Jan 2017
    Posts
    8

    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
    Join Date
    Jul 2018
    Posts
    38

    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

    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, 4th

  9. #29
    Join Date
    Jun 2019
    Posts
    14

    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 12

Similar Threads

  1. PCNC 1100
    By ConveyTrex in forum Tormach Personal CNC Mill
    Replies: 1
    Last Post: 12-14-2016, 01:20 PM
  2. PCNC 1100 vs PCNC 770 (Is the 1100 worth it)
    By thunderdork in forum Tormach Personal CNC Mill
    Replies: 30
    Last Post: 09-21-2016, 08:43 PM
  3. Tormach PCNC 1100 ATC info - want to do it myself.
    By SoCalPlaneDoc in forum Tormach Personal CNC Mill
    Replies: 14
    Last Post: 03-05-2016, 02:04 PM
  4. Info on Using the PCNC 1100 as a Lathe
    By smokediver576 in forum Tormach Personal CNC Mill
    Replies: 23
    Last Post: 01-28-2016, 08:02 AM
  5. WTS: PCNC 1100
    By HLF Ordnance in forum Tormach Personal CNC Mill
    Replies: 2
    Last Post: 07-13-2012, 01:41 PM

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
  •