Water based touchoff?

All,
I've had been trying very hard to determine a non-destructive manner to perform z-axis touchoffs with minature end-mills on a CNC vertical mill. I
just had a flash of inspiration, in that it seems that using the cutter to complete a low-voltage circuit in a small vessel of water mounted at a known height and filled to a known height, would give me a highly accurate Z reading without the cutter making contact with metal and then getting broken.
Question is this: would the surface tension of the water grabbing the cutter throw off the accuracy significantly?
Just curious,
The Eternal Squire
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I've been using the gage pin method that someone suggested here a while back. Lay a gage pin down on a known surface then bring the end mill down below the diameter of the pin. Gently hold the pin against the end mill the use the MPG to raise the end mill. When the pin slides under the end mill you know where you are.
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Dan

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Question should be how you exactly get the water to the height you want. And next what resolution you expect.
Why not use a height feeler that is made exactly for that purpose. Place it under the mill and feed until die dial shows zero. Add the 50mm (or what) height of the feeler.
Nick
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The Eternal Squire wrote:

I would be curious to find out how fast the water evaporates on any given day.
Just how small is "miniature"?
Later,
Charlie
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Don't know Charlie, never checked the toilet <G>. But then he should use a thin piece of paper.
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Piece of paper or a cellophane from a cigarette pack works for me, on a rough dial-in. Indicator for getting exact.
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Anthony

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The Eternal Squire wrote:

Get close with a piece of paper. Turn the spindle on and run the end mill down until it scratches the surface. You may need a magnifying glass. Do it in a place that will be cut away later if finish is important. Randy
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Squire,
I've set endmills as small as .005 diameter by rolling a pin under them. With mills this small I use a small dowel pin, .062-.094. It takes a light touch, (don't drink the nignt before)
Mark

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The Eternal Squire wrote:

yes
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What size end mills and what method are you using now?
I have been using a Z Axis Setter for a quite a few years now on all tools down to 1/64" diameter mills and sharp point engraving tools and have never had a problem.
http://www.jlindustrial.com/catalog/product.jsp?origin=VIRTUAL:VIRTUAL_CAT&id=PCO-00015K&partnerURL=http://catalogs.shoplocal.com/jlindustrial/index.aspx%3fpagename=shopmain%26pagenumber 98%26jsessionid=4ov42rxi33n1flaubiwsfevmcqfcyiv0%26mode=%26epcode Tom
The Eternal Squire wrote:

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