# Z-Axis DRO for Column Mill?



## neer724 (Feb 16, 2022)

Hello,

So far enjoying the new King Mill!   Nice little machine!

So I want to install a DRO on this machine and was looking at the myriad of youtube videos of DRO installs on the G0704 and the PM-25v and cant figure out why people are mounting a z-axis scale on the column and head?  You don't really do any precision machining by lowering the head?  I would tend to use the spindle\fine feed for that.  Am I missing something?

Since the King mill already has a z-axis DRO on the spindle (although it is mediocre at best) I was thinking of mounting a scale on the side of the head and connecting to the spindle so the z-axis displays on the main DRO.

Alternatively, I could just go with a 2 axis DRO and use the built in z-axis dro.

Your thoughts...

Thanks,
Steve


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## YYCHM (Feb 16, 2022)

Which mill do you have?  Some DROs take 4 scale inputs where two can be combined.  This is more common to knee mills.  What you are suggesting is exactly what I did on my mini-mill and RF30clone.


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## neer724 (Feb 16, 2022)

YYCHM said:


> Which mill do you have?  Some DROs take 4 scale inputs where two can be combined.  This is more common to knee mills.  What you are suggesting is exactly what I did on my mini-mill and RF30clone.



I have the King KC-20VS-2.  Basically the same thing as the Grizzly G0704 or BB CX601\CX600.


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## whydontu (Feb 16, 2022)

I have a BB CT129, with an x & y axis DRO, a separate iGaging DRO on the head, and the factory quill DRO. In general, the iGaging head DRO is useless. It’s cute to see the numbers change when the head moves, and I suppose it <could> be possible to get within a few thou, but I’ve never had a milling operation that couldn’t be done using the quill DRO and  1-2-3 blocks to re-locate a reference point if I needed to move the head up or down.


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## neer724 (Feb 16, 2022)

whydontu said:


> I have a BB CT129, with an x & y axis DRO, a separate iGaging DRO on the head, and the factory quill DRO. In general, the iGaging head DRO is useless. It’s cute to see the numbers change when the head moves, and I suppose it <could> be possible to get within a few thou, but I’ve never had a milling operation that couldn’t be done using the quill DRO and  1-2-3 blocks to re-locate a reference point if I needed to move the head up or down.


Agree....

I was thinking of getting a 3 axis LCD DRO similar to this one:









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either from Aliexpress, eBay, or even banggood....


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## LenVW (Feb 16, 2022)

Steve,
I have a KING mill, but a smaller version.

The purpose of the DRO is to display accurate position from a reference surface.

Choose your cutter and take a skim cut ‘Or‘ use a strip of tracing paper so you don’t mark the workpiece. When the cutter tears the tracing paper you are within a few 0.001”.
Set your DRO to ‘0’ position, the display will be measurements from that surface.

Measurements are always related to a reference plane or surface.


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