Page 1 of 2 12 LastLast
  1. #1
    You draw your part in CAD then create a Gcode file using a CAM program

    The attached pic is drawn in the lower R/H corner this is X Plus Y Minus

    The piece is 100 mm square and you want to put a 20mm hole in the centre

    This assume your machine is perfectly set up, no backlash etc

    You only have simple equipment no edge finders of any type

    You will hold this in a vice clamped to the table with the back edge running perfectly parallel to the X axis

    Have the part stick out say 10mm on the left hand side

    You can use a dowel of 6mm dia or a cutter mounted in your collet upside down

    Bring the dowel up on the left hand side so it is just touching you can use a feeler gauge to do this but you have to add the feeler gauge thickness to the DRO's setting

    Once you have TOUCHED OFF set the DRO to the correct dimension then raise the Z and move the table to Zero it should be obvious if the dowel looks correctly on the centreline

    Then you repeat for the other axis

    Using this method you should be able to be accurate to 0.02mm

    You could also have other holes, recesses shapes in the plate but the edge finding is the same



    HTH
    Phil
    Attached Thumbnails Attached Thumbnails Click image for larger version. 

Name:	Edge Finding.jpg 
Views:	187 
Size:	92.0 KB 
ID:	3586  
    Last edited by M250cnc; 09-01-2011 at 03:11 PM.

  2. The Following User Says Thank You to M250cnc For This Useful Post:


  3. #2
    i2i's Avatar
    Lives in Cardiff, United Kingdom. Last Activity: 23-12-2016 Has been a member for 7-8 years. Has a total post count of 693. Received thanks 30 times, giving thanks to others 0 times.
    I get a piece of paper and hold it between the cutter and the job, then gently move the cutter to the job until the paper is just trapped. You can do this on the edge of the cutter and the face, for x,y, and z.

  4. #3
    Quote Originally Posted by i2i View Post
    I get a piece of paper and hold it between the cutter and the job, then gently move the cutter to the job until the paper is just trapped. You can do this on the edge of the cutter and the face, for x,y, and z.
    Yes i used to use a cigarette paper .001" with the spindle running, the trouble is that is very dangerous and i didn't want anyone to think i was in Jonathan & Blackburn Marks gang. :rofl:

    So this is a non dangerous way of doing the same.:lol:

    Phil

  5. #4
    Quote Originally Posted by i2i View Post
    I get a piece of paper and hold it between the cutter and the job, then gently move the cutter to the job until the paper is just trapped. You can do this on the edge of the cutter and the face, for x,y, and z.
    I do that too, adding 0.1mm for the thickness of the paper. Or get the cutter close, put the spindle on and move it so that you just hear it brushing.

  6. #5
    i2i's Avatar
    Lives in Cardiff, United Kingdom. Last Activity: 23-12-2016 Has been a member for 7-8 years. Has a total post count of 693. Received thanks 30 times, giving thanks to others 0 times.
    Quote Originally Posted by M250cnc View Post
    Yes i used to use a cigarette paper .001" with the spindle running, the trouble is that is very dangerous and i didn't want anyone to think i was in Jonathan & Blackburn Marks gang. :rofl:

    So this is a non dangerous way of doing the same.:lol:

    Phil
    obviously without the spindle running.:lol:

  7. #6
    your all pussies !!!! i use one of my eye lashes.... while its still attached to my face :)

  8. #7
    i2i's Avatar
    Lives in Cardiff, United Kingdom. Last Activity: 23-12-2016 Has been a member for 7-8 years. Has a total post count of 693. Received thanks 30 times, giving thanks to others 0 times.
    i used to wet a piece of paper and nudge the tool onto it but sometimes you get a fine witness mark on the job if you're a bit heavy handed. With a dry piece of paper and the spindle off you can feel the connection.

  9. #8
    Quote Originally Posted by blackburn mark View Post
    your all pussies !!!! i use one of my eye lashes.... while its still attached to my face :)
    True but we are not missing any bodily parts.

    Phil

  10. #9
    i2i's Avatar
    Lives in Cardiff, United Kingdom. Last Activity: 23-12-2016 Has been a member for 7-8 years. Has a total post count of 693. Received thanks 30 times, giving thanks to others 0 times.
    and we can still see, those bionic eyes aren't all they're cracked up to be.

  11. #10
    m_c's Avatar
    Lives in East Lothian, United Kingdom. Last Activity: 10 Hours Ago Has been a member for 9-10 years. Has a total post count of 1,831. Received thanks 192 times, giving thanks to others 5 times.
    Edge finders aren't that expensive - http://www.arceurotrade.co.uk/Catalo...t/Edge-Finders

    However, I've always used an edge finder, then if I need critical height, a bit wet paper, or just wind down/up until the tool just starts to mark the workpiece, depending on what I'm doing.

Page 1 of 2 12 LastLast

Similar Threads

  1. The new probe and finding the center of a hole
    By Ricardoco in forum Probing, Digitizing & Scaning
    Replies: 9
    Last Post: 13-11-2015, 06:43 AM
  2. NEW MEMBER: Hello Matt & John here. Excited CNC Newbies
    By matt83 in forum New Member Introductions
    Replies: 16
    Last Post: 18-10-2012, 07:42 PM
  3. Finding pictures and viewing the albums of a member ?
    By WandrinAndy in forum General Discussion
    Replies: 3
    Last Post: 16-10-2012, 03:29 PM
  4. Finding Cheap Sign Foam Alternatives
    By action-kat in forum General Discussion
    Replies: 0
    Last Post: 17-08-2011, 08:45 PM
  5. Help with mach3 center finding script
    By eddie60 in forum Programmers Corner
    Replies: 7
    Last Post: 20-05-2009, 06:23 PM

Bookmarks

Posting Permissions

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