# Z axis set up - how to?



## Chipper5783 (May 8, 2019)

New CNC guy here - having lots of fun with it.  I went the route of getting a 20 year old industrial machine and, so far, it has been a positive experience.  It is a Bridgeport VMC 1000/22 - it really just needed cleaning, power , fixed a few small computer glitches and away it went.  To date I have been entering my part programs through the MDI (manual data input) - one line at a time, proving each step is doing what I want/expect.  Obviously my part programs are pretty short and pretty simple.

*Is there sort of a typical approach to setting up the Z-axis parameters?*  I'm not thinking of the specific steps for this particular machine or its' G-code dialect (it is DX-32).

Right now I describe a Z-position that puts the tool well up out of the way, then step through the program in block mode - which gives me the chance to measure the Z gap.  Then I edit the code to bring the tool to where I want it.  When I do a tool change, I go through about the same steps (keeping track on a note pad for the desired Z positions).

That works, but obviously it is not what was intended.  I assume that when setting up a program there is some sequence of defining the the part Z-axis zero, a Z-axis clearance point, tool length offsets, and . . . .  ?  The menu selections for doing all those things are pretty straight forward - just wondering what approach to take on defining all those terms.

All my stopping, measuring, "air cutting", editing etc.  is goofy.

Regards, David


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## T Bredehoft (May 8, 2019)

I'm 19 years after my last MDI episode, (The only way the machines I ran could be operated). but do you have tool offsets and can you not call up the  tool offset then GO Z plus (or minus) 4 or some such?

If I remember, I allways kept a center drill, the shortest too. as tool zero, that way I was forced to input tool offsets to keep the tool away from the work.


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## jumps4 (May 8, 2019)

hello chipper
z zero is normally the top of the material you have prepared to machine.
part zero is the top of the lower left corner x0 y0 z0
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years ago I made a few training videos that may help. they leave a bit to be desireed at first but the quality gets better.








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## RJSakowski (May 8, 2019)

I use the Tormach TTS tool system so tool offsets can be set off the machine.  I use a digital dial indicator to set my z axis zero when the indicator zeros.  The indicator is tool 00 and all my other tool offsets are referenced to it.  For most tools, the offsets are negative so neglecting to failing to enter an offset would result in a safe situation.

When I start a new program, I will double check tool offsets by moving to work zero up by 1.000", 2.000", etc. and running through the tools.  The tool hieghts at Z = 0 for that tool should be exactly 1.000", 2.000", etc. above the work zero.  When finished checking, I drop down the 1.000", 2.000", etc. and reset my zero.


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## JimDawson (May 8, 2019)

On the VMC when we set up for a job, we set the Z zero to the top of the work.  We use a tool setter like this https://littlemachineshop.com/products/product_view.php?ProductID=5447 

Then just enter the offsets for each tool into the offset screen, which I assume exists on your machine.  To run air cuts, we do as RJ suggests above.


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## Boswell (May 8, 2019)

I am not near so sophisticated and I reset Z-Zero to the top of the part (or where ever I selected when I did the CAM work) each time I change tools. It only takes about 2 min or so to change the tool and set Z-Zero. Some day I may work out my tool offsets but until then. this has worked very well. Of course if your change tools and forget to set the Z Zero, it can get exciting fast.


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## Karl_T (May 8, 2019)

Find yourself a programming manual. I did a search and found this thread:





						Need Help! 1999 Bridgeport VMC 1000/22 Manuals
					

I just purchased a used 1999 Bridgeport VMC 1000/22 Milling machine with a DX-32 controller on it but did not receive any manuals for this machine! Can



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						Bridgeport Vmc 1000 22 Operator Manual PDF Book - Network Media Sharing
					

Download  EPub PDF Ebooks.




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Yep, Z0 is generally the part top surface (part zero).  then you use tool length offsets for the different tools. it is done slightly differently on different controls - that's why the manual.


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## Chipper5783 (May 8, 2019)

Thank you to all for the quick responses.  I have the manuals (both the VMC1000 manual and the BP DX-32 Programmer's Manual).  The "How to" is pretty straight forward (read the book, do what it says).  There seem to be a number of approaches to setting up the machine (depending on the project, the machine, what tooling is available, personal preference,  . . . ) - and the manuals do not talk about that aspect.


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