Homing backoff

Results 1 to 8 of 8

Thread: Homing backoff

  1. #1
    Registered
    Join Date
    Apr 2014
    Posts
    9
    Downloads
    0
    Uploads
    0

    Default Homing backoff

    Hi all!

    Not sure what to call it, but i think in Mach3 it was homing backoff. In otherwords, when the machines homes, after it hits the limit switch, it would back off a configurable amount. ( I had my machine at .5 inches).

    Now with UCCNC, when it homes, it seems to stay just off the switch bounce, but occasionally, i get a false trigger.

    How to configure UCCNC to back off the limit switch by X amount?

    Similar Threads:


  2. #2
    Member ger21's Avatar
    Join Date
    Mar 2003
    Location
    Shelby Township
    Posts
    35538
    Downloads
    1
    Uploads
    0

    Default Re: Homing backoff

    There is no built in function to back off of the switch. Mach3 does not have one either, btw.

    This post should shed some light on how to create a homing macro that does back off.

    forum.cncdrive.com ? View topic - Slaved gantry offset macro

    Gerry

    UCCNC 2017 Screenset
    [URL]http://www.thecncwoodworker.com/2017.html[/URL]

    Mach3 2010 Screenset
    [URL]http://www.thecncwoodworker.com/2010.html[/URL]

    JointCAM - CNC Dovetails & Box Joints
    [URL]http://www.g-forcecnc.com/jointcam.html[/URL]

    (Note: The opinions expressed in this post are my own and are not necessarily those of CNCzone and its management)


  3. #3
    Member
    Join Date
    Apr 2014
    Posts
    59
    Downloads
    0
    Uploads
    0

    Default Re: Homing backoff

    Hi,

    Now there is no parameter for this, but maybe sometimes... You have to write your own homing macro to do it.



  4. #4
    Registered
    Join Date
    Apr 2014
    Posts
    9
    Downloads
    0
    Uploads
    0

    Default Re: Homing backoff

    Ger21,
    Thanks for a point in the right direction. Looks like I need to write a macro, create a custom button where the home all button was and implement the macro. I think if i give the new button a high number like 21000, then the M21000 macro will automatically run.

    As an aside, and BTW, here is a screen shot of the Mach3 home config dialog, where the backoff value can be seen. This caused my macine to hit the limit, then backaway the designated amount.




    Quote Originally Posted by ger21 View Post
    There is no built in function to back off of the switch. Mach3 does not have one either, btw.

    This post should shed some light on how to create a homing macro that does back off.

    forum.cncdrive.com ? View topic - Slaved gantry offset macro


    Attached Thumbnails Attached Thumbnails Homing backoff-2017-09-12-jpg  


  5. #5
    Member ger21's Avatar
    Join Date
    Mar 2003
    Location
    Shelby Township
    Posts
    35538
    Downloads
    1
    Uploads
    0

    Default Re: Homing backoff

    The Home Off. value in Mach3 is not a backoff amount. It's the position the DRO's are set to when the machine hits the home switch. Mine is set to 45 inches, and it does not back off after homing.
    I think that some Mach3 motion controller plugins may back off after homing, but it is not a standard Mach3 function.

    Gerry

    UCCNC 2017 Screenset
    [URL]http://www.thecncwoodworker.com/2017.html[/URL]

    Mach3 2010 Screenset
    [URL]http://www.thecncwoodworker.com/2010.html[/URL]

    JointCAM - CNC Dovetails & Box Joints
    [URL]http://www.g-forcecnc.com/jointcam.html[/URL]

    (Note: The opinions expressed in this post are my own and are not necessarily those of CNCzone and its management)


  6. #6
    Member
    Join Date
    Apr 2014
    Posts
    59
    Downloads
    0
    Uploads
    0

    Default Re: Homing backoff



  7. #7
    Member handlewanker's Avatar
    Join Date
    Sep 2006
    Location
    Australia
    Posts
    6463
    Downloads
    0
    Uploads
    0

    Default Re: Homing backoff

    Hi....am I doing things wrong then......at the end of the job.....held in a vice..... I have a Z 50 to firstly raise the spindle to be above the work piece and then X-50 Y50 to move the table to the right a bit and towards me so the cutter is behind and out of the way of the workpiece .....G54 being the corner of the vice etc.

    When the next work piece is started the spindle only has to move a short distance to be at the starting point.

    The home positio0n puts the head all the way to the top and the table all the way to the right and right back to the column.........I don't want the cutter to be right at the front of the job when it's finished.

    Is it just a convenience to have a single command in the program to move the table to the home position or is that so that a CAM program would do it without having to hit anything otherwise.

    Would I be right in thinking that calling up a home position at the end of a program is a universal way to park a spindle safely to suit all Cam programs?

    I do realise that if you have a G code sequence generated with CAM the spindle will be up and parked out of the way automatically as part of the final move before stopping......hand written code can be as you want it for convenience.
    Ian.



  8. #8
    Registered
    Join Date
    Apr 2014
    Posts
    9
    Downloads
    0
    Uploads
    0

    Default Re: Homing backoff

    Thanks, that proved very helpful.
    When I get a chance this weekend, I will post a video of my machine which has been re-wired and re-tooled to use UCCNC. While I was confused at first, its all coming together nicely.



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

Homing backoff

Homing backoff