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  1. #11
    iv been using a video edge finder with some success (a modified webcam 5) needs a bit more tuning, its off to one side so its really easy to use with the tool still in
    i just nick the surface in the z and back off a couple of steps
    ill use a rizzler if im feeling fussy

  2. #12
    thanks Phil that helped me

    Quote Originally Posted by M250cnc View Post
    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

  3. #13
    Traditional tool makers used a sticky pin. This is a dressmaking pin held in a bit of plastacine (blue tac or chewing gum works but not as good) put on the cutter or drill. With spindle running, you press on side of tip of pin till it runs true. This could be done with a lolly stick or something like. You now have a fine point that is true with centre of cutter and can be lined up with edges, scribed lines and centre dots/pops.
    A wobbler set is a sophisticated version but although I use a set on lathes and mill I have always found a "Sticky Pin" most useful and quick. Wobblers are useful for edge finding but you do need height.

  4. The Following User Says Thank You to Phil Gravett For This Useful Post:


  5. #14
    fanatic idea thanks for sharing :)

    Quote Originally Posted by Phil Gravett View Post
    Traditional tool makers used a sticky pin. This is a dressmaking pin held in a bit of plastacine (blue tac or chewing gum works but not as good) put on the cutter or drill. With spindle running, you press on side of tip of pin till it runs true. This could be done with a lolly stick or something like. You now have a fine point that is true with centre of cutter and can be lined up with edges, scribed lines and centre dots/pops.
    A wobbler set is a sophisticated version but although I use a set on lathes and mill I have always found a "Sticky Pin" most useful and quick. Wobblers are useful for edge finding but you do need height.

  6. #15
    There are some other choices as well:



    and also



    Below is one i made earlier :lol:

    Name:  m3tap_01.jpg
Views: 148
Size:  133.7 KB
    .Me

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