Preset Table is a mess

Hi I am Nirosh, new to CNC machining and milling. My company purchased a CNC machine from Sahos Br+L 6015 and iTNC 530 from Heidenhain installed. The problem is someone changed the 0 line in the Datum Preset table and this line is protected from editing. I would like to get help from you to reset the line 0 to all value 0 (now it is like z=135 x=-2530 etc..).
I think this explanation is enough to solve the problem. Thanks.

That preset is never used for any part datum and can't be called from a program. Fro my experience, it is used for setup purposes. At least that is how I used it. To zero it out, move the machine to home position. Activate datum zero, then set datum zero using the set datum function. Should be easy to do. This is off the top of my head. We moved our Heidenhain machine last week and it is not up and running yet. But anyway, you need to be on machine zero to set that datum to zero. There is no harm leaving that datum with a number in it. It won't do anything crazy.

Paul

Dear Paul, Thanks for the reply. But what is datum function. Is it so easy as you say here but it raises me a question because this line 0 is protected, can't be edited??

Another thing is the tool measurement program not touching the probe. I think the problem is 0 is not 0.

I run the 640 control.. Forget the datum table exists, use the preset table, it's much easier.

No you cannot outright edit datum 0. But datum 0 can be set just like any other datum. 5 Axis Fidia Guy is correct. You do not have to do anything to it if you don't want to. It's rather meaningless. But, you can zero it out if you want. Learn how to set a datum manually and you will learn how to zero out Datum 0. It's not rocket science. By the way, I use a TNC640 also, but no different than a 530 when it comes to datums.

Paul

5 axis Fidia guy said:

I run the 640 control.. Forget the datum table exists, use the preset table, it's much easier.

Click to expand...

I think he is talking about the preset table. I have never bothered with the Datum Table myself either.

Paul

The probe not touching sounds like the probe (and perhaps tool setter) need to be calibrated.

Preset line 0 is just where the "no particular preset in use" values from a built-in probe op, or pressing the orange X Y Z etc buttons, gets put. Having it set to 0 just means programs using whatever random preset (bad practice) or Q247=0, will use the machine base origin for program origin - which will almost never be correct.

ALSO - the preset lines contain the distance from the machine origin home to wherever that preset is supposed to be - and this is almost NEVER ZERO. Note that the home position for tool changes and the out-of-the-way position set by M92 need not be zero either. (They're different and neither anywhere near zero on my iTNC530 machine.)

some cnc 1st tool if you change length or dia comp it effects all other tools. it is like a grid shift or calibration thing or using a solid test bar tool to set stuff. for example known tool with known tool length and length comp active set 4.0000 off table top and see if actually measures 4.0000 gap
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if tool 1 is adjusted -.005 it can effect all other tool comps. it is like a common offset effecting all work offsets G54, G55, etc but its a common tool offset
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i have had where probe tip changed to new tip and the probe values were not in sync with tool offsets. for example probe set work zero and try to mill .001 but nothing is removed. sometimes probe length comp is adjusted like any tool would be adjusted
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grid shift checking or any parameter change some times PWE or parameter write enable needs to be turned on in mdi mode. i would read your machine manuals. same as editing 8000 and 9000 series programs requires a parameter change to turn write protection off. write protection designed to prevent unintentional changes

Ok thanks for everyone who replied me with details. But my question leads me forward than before bcos I've forgot to say at begining, that in the manual operation we can move the -x axis out of the range that machine is defined to move(out of the table) we can move it over the fence that Heidenhain has setup. The machine is literally out of moveable range. As i am new to CNC and milling, this is rocket science to me.

If your machine over traveled you should be able to just jog the other way to get back "over the fence". If, on the other hand, you have traveled into no man's land where only the probe is allowed to go, then there is an M code to turn that off temporarily. It really sounds like you need some training. That was not a put down. Heidenhains are very powerful controls and very user friendly once you learn them. If you are new to CNC or just new to Heidenhain, let's just say they are very different. If you are used to Fanuc, well...........

I was nervous getting on the HH for the first time, even after training. Now? I would actually prefer the HH control. And I am the laughing stock of the Fanuc guys. Well, the jokes on them.

Paul