Thread: Edge Finding For Newbies
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
Last edited by M250cnc; 09-01-2011 at 02:11 PM.
The Following User Says Thank You to M250cnc For This Useful 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.
your all pussies !!!! i use one of my eye lashes.... while its still attached to my face :)
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.
and we can still see, those bionic eyes aren't all they're cracked up to be.
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.
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