535,633 active members*
4,008 visitors online*
Register for free
Login
Results 1 to 18 of 18
  1. #1
    Registered
    Join Date
    Dec 2013
    Posts
    120

    Photoelectric encoder with mach3 turning

    Attachment 455094
    I have got a 3 pin Photoelectric encoder like this
    and i was wondering if it is possible to use it to encode my lathe spindle with mach3
    but how the start of the single point threading will be detected?
    thanks

  2. #2
    Community Moderator ger21's Avatar
    Join Date
    Mar 2003
    Posts
    35291

    Re: Photoelectric encoder with mach3 turning

    Mach3 only needs 1 pulse per rev for threading. It can't use an encoder.
    Gerry

    UCCNC 2017 Screenset
    http://www.thecncwoodworker.com/2017.html

    Mach3 2010 Screenset
    http://www.thecncwoodworker.com/2010.html

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

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

  3. #3
    Registered
    Join Date
    Dec 2013
    Posts
    120

    Re: Photoelectric encoder with mach3 turning

    Quote Originally Posted by ger21 View Post
    Mach3 only needs 1 pulse per rev for threading. It can't use an encoder.
    great, is that accurate enough?
    thank you so much

  4. #4
    Member
    Join Date
    Aug 2009
    Posts
    827

    Re: Photoelectric encoder with mach3 turning

    ...is it Rigid Tapping you're thinking about?
    https://www.cnczone.com/forums/novak...witch-bob.html

  5. #5
    Registered
    Join Date
    Dec 2013
    Posts
    120

    Re: Photoelectric encoder with mach3 turning

    Quote Originally Posted by machinehop5 View Post
    ...is it Rigid Tapping you're thinking about?
    https://www.cnczone.com/forums/novak...witch-bob.html
    as mentioned single point threading
    but to be honest rigid tapping can be another extra question, i am assuming it will be much more challenging , you think it can work with a single pulse / rev?

  6. #6
    Member
    Join Date
    Jan 2005
    Posts
    11929

    Re: Photoelectric encoder with mach3 turning

    Quote Originally Posted by Graphicman View Post
    as mentioned single point threading
    but to be honest rigid tapping can be another extra question, i am assuming it will be much more challenging , you think it can work with a single pulse / rev?
    A single pulse works fine for threading or rigid tapping, it is just used to synchronize the spindle with the axis, you can just make a disc with a single slot or up to 4 slots which must be machined precise if you do more than ( 1 slot ) Mach3 can use more that ( 1 ) slot, but this can slow it down the more slots it has, In the real-world of Encoder use it is called an ( index pulse or Z pulse ) which all Encoders have for all cnc machines, and for other Encoder use as well, machine homing is all done with a single index Pulse, so this is nothing new to use a single pulse for positioning or synchronizing ( 2 ) axis

    So you could mount a cheap Encoder that has an Index Pulse and you have nothing to make, you can see in this encoder disc the single slot Z Pulse marker
    Attached Thumbnails Attached Thumbnails Index Slot.PNG  
    Mactec54

  7. #7
    Registered
    Join Date
    Dec 2013
    Posts
    120

    Re: Photoelectric encoder with mach3 turning

    Quote Originally Posted by mactec54 View Post
    A single pulse works fine for threading or rigid tapping, it is just used to synchronize the spindle with the axis, you can just make a disc with a single slot or up to 4 slots which must be machined precise if you do more than ( 1 slot ) Mach3 can use more that ( 1 ) slot, but this can slow it down the more slots it has, In the real-world of Encoder use it is called an ( index pulse or Z pulse ) which all Encoders have for all cnc machines, and for other Encoder use as well, machine homing is all done with a single index Pulse, so this is nothing new to use a single pulse for positioning or synchronizing ( 2 ) axis

    So you could mount a cheap Encoder that has an Index Pulse and you have nothing to make, you can see in this encoder disc the single slot Z Pulse marker
    I think more than one slot will be needed for rigid tapping to sync the rotation with the feed, but if I used this setup how the single point threading will work as well? how mach will know the start of every pass?

  8. #8
    Community Moderator Al_The_Man's Avatar
    Join Date
    Dec 2003
    Posts
    23574

    Re: Photoelectric encoder with mach3 turning

    Quote Originally Posted by Graphicman View Post
    I have got a 3 pin Photoelectric encoder and i was wondering if it is possible to use it to encode my lathe spindle with mach3
    but how the start of the single point threading will be detected?
    thanks
    You could either make another single slot disc up for the Opto you have or block/cover them all except one.
    To simulate true synchronized threading, you require a controller that can use electronic gearing, where the Z axis etc, is electronically geared off of a spindle incremental encoder.
    For DIY, Galil Motion does this, as does Dynomotion shown in the forum here.
    Al.
    CNC, Mechatronics Integration and Custom Machine Design

    “Logic will get you from A to B. Imagination will take you everywhere.”
    Albert E.

  9. #9
    Registered
    Join Date
    Dec 2013
    Posts
    120

    Re: Photoelectric encoder with mach3 turning

    Thanks
    is it possible to single point thread manually on mach3?

  10. #10
    Member
    Join Date
    Jan 2005
    Posts
    11929

    Re: Photoelectric encoder with mach3 turning

    Quote Originally Posted by Graphicman View Post
    I think more than one slot will be needed for rigid tapping to sync the rotation with the feed, but if I used this setup how the single point threading will work as well? how mach will know the start of every pass?
    If you think it is not going to work for, but has for hundreds of users before, you then could change your control and get the Acorn control which can use an encoder for threading and rigid tapping

    Eding CNC control are working on a full encoder connection they to have a single pulse for threading and rigid tapping

    Acorn is the easiest to connect encoder threading and rigid tapping for a lathe control

    Here is a Mach3 video using a single pulse with a sensor he made and sells, but any single pulse method will work

    https://www.youtube.com/watch?v=Y8NCtrCytDQ
    Mactec54

  11. #11
    Member
    Join Date
    Jan 2005
    Posts
    11929

    Re: Photoelectric encoder with mach3 turning

    Quote Originally Posted by Graphicman View Post
    Thanks
    is it possible to single point thread manually on mach3?
    What would be the point Mach3 would not be doing anything if you where doing it in manual operation
    Mactec54

  12. #12
    Member
    Join Date
    Dec 2020
    Posts
    1

    Re: Photoelectric encoder with mach3 turning

    You may be interested in ultrasonic sensor like HC-SR04. You can use it with Arduino in easy way. Here is a good example.

  13. #13
    Registered
    Join Date
    Dec 2013
    Posts
    120

    Re: Photoelectric encoder with mach3 turning

    Quote Originally Posted by mactec54 View Post
    If you think it is not going to work for, but has for hundreds of users before, you then could change your control and get the Acorn control which can use an encoder for threading and rigid tapping

    Eding CNC control are working on a full encoder connection they to have a single pulse for threading and rigid tapping

    Acorn is the easiest to connect encoder threading and rigid tapping for a lathe control

    Here is a Mach3 video using a single pulse with a sensor he made and sells, but any single pulse method will work

    https://www.youtube.com/watch?v=Y8NCtrCytDQ
    sure, i have seen all these videos it works, but if the spindle is not capable enough or the tap is big enough there will be issues with only 1 pusle/rev for rigid tapping correct?

    I dont see any reason for mach3 not to do its job in manual mode, all that is needed is to gear axis electronically (feed/rev and start), it will just makes things much faster and easier for single projects

  14. #14
    Registered
    Join Date
    Feb 2008
    Posts
    629

    Re: Photoelectric encoder with mach3 turning

    Quote Originally Posted by Graphicman View Post
    sure, i have seen all these videos it works, but if the spindle is not capable enough or the tap is big enough there will be issues with only 1 pusle/rev for rigid tapping correct?

    I dont see any reason for mach3 not to do its job in manual mode, all that is needed is to gear axis electronically (feed/rev and start), it will just makes things much faster and easier for single projects
    Yes, with only one pulse per turn, the controller would have to estimate the spindle angle, this would get worse with larger taps
    and larger load changes generating speed variations that the controller cannot "see". Even guessing the reversal point is going to be pretty
    iffy with 1 pulse per turn

  15. #15
    Registered
    Join Date
    Dec 2013
    Posts
    120

    Re: Photoelectric encoder with mach3 turning

    Quote Originally Posted by PCW_MESA View Post
    Yes, with only one pulse per turn, the controller would have to estimate the spindle angle, this would get worse with larger taps
    and larger load changes generating speed variations that the controller cannot "see". Even guessing the reversal point is going to be pretty
    iffy with 1 pulse per turn
    exactly that is what i am trying to say

  16. #16
    Member
    Join Date
    Aug 2009
    Posts
    827

    Re: Photoelectric encoder with mach3 turning

    ...or do it old school
    https://www.google.com/search?client...=threading+die

    acorned
    https://www.ebay.com/sch/i.html?_fro...n+die&_sacat=0


    works great in a power failure..or 911 doesnot work too

  17. #17
    Member
    Join Date
    Jan 2005
    Posts
    11929

    Re: Photoelectric encoder with mach3 turning

    Quote Originally Posted by Graphicman View Post
    exactly that is what i am trying to say
    Let us know how this works out for you, ( manual mode, all that is needed is to gear axis electronically ( feed/rev and start )

    That is why I said you have choices Acorn control you can use a regular Encoder spec's below
    Attached Thumbnails Attached Thumbnails Encoder Specs.PNG  
    Mactec54

  18. #18
    Registered
    Join Date
    Dec 2013
    Posts
    120

    Re: Photoelectric encoder with mach3 turning

    Quote Originally Posted by mactec54 View Post
    Let us know how this works out for you, ( manual mode, all that is needed is to gear axis electronically ( feed/rev and start )

    That is why I said you have choices Acorn control you can use a regular Encoder spec's below
    I am not intending to change my controller
    if you know a way to let mach3 lock feed/rev plz let me know, otherwise I will not bother to try

    thanks

Similar Threads

  1. photoelectric sensor
    By iancraggs in forum DNC Problems and Solutions
    Replies: 0
    Last Post: 03-06-2019, 11:11 PM
  2. newbie! need help with photoelectric sensor
    By iancraggs in forum General CNC Machine Related Electronics
    Replies: 0
    Last Post: 03-06-2019, 10:51 PM
  3. Replies: 0
    Last Post: 09-02-2014, 10:50 PM
  4. photoelectric switch circuit
    By Malph in forum General CNC Machine Related Electronics
    Replies: 8
    Last Post: 05-19-2009, 05:06 AM

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
  •