Z axis zeroing/tool setting

Z axis zeroing/tool setting

Postby Edmeaux » Wed Apr 23, 2014 5:52 pm

I've been using the archaic method of stepping down the Z-axis/bit until it causes drag on a piece of paper. Its been faily accurate, but I feel I can do better. I've looked at the tool setters with the little light and that looks like it could be a tad more accurate than what I'm doing. But what about a contact plate? Could I potentially hook a contact plate to the leads going to my Limit switch in the Z-axis and to the bit and then step down until the "circuit" is closed? Then add the thickness of the plate to get my true zero?

Can I do this through a Z-axis homing script? Or would it damage the tip of the bit upon contact with the plate? Or are these things so accurate where once 1st contact is made the movement stops immediately... I know electricity travels fast and all, but I don't want to drive my fine tip bits into a copper plate and damage the cutting tip. I'm just looking for a quicker and more accurate way to zero the Z-axis.
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Re: Z axis zeroing/tool setting

Postby ssflyer » Wed Apr 23, 2014 5:56 pm

Pretty standard way to do it, actually. What control software do you use? Most have the functionality built in.
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Re: Z axis zeroing/tool setting

Postby Edmeaux » Wed Apr 23, 2014 6:28 pm

DeskCNC. It has a standard homing script, and I know I can home an axis individually. I just might have to modify the Z-axis script for this purpose. I assume a soft metal like copper would be the best choice for contact to sensitive bit tips?

Note. I am pretty mechanically inclined. But a complete novice in software and CNC stuff. I know the basics and thats about it. I've been slowly learning over the past year or so. I'm looking for some guideance. Thanks.
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Re: Z axis zeroing/tool setting

Postby FixitMike » Wed Apr 23, 2014 6:44 pm

I believe all of the automatic zeroing methods check for contact between each very small z movement, probably on the order of .0005", before making the next move.
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Re: Z axis zeroing/tool setting

Postby Adrian » Wed Apr 23, 2014 9:04 pm

Been asked a lot lately. See this thread for example and other links - viewtopic.php?f=35&t=19656

One of my touch plates is ali the other is steel. The approach speeds when setting Z are very slow so there's no real risk of damage. Even my sharpest v-bits are fine.
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Re: Z axis zeroing/tool setting

Postby Edmeaux » Wed Apr 23, 2014 9:18 pm

fantastic. Thank you!
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