It should be possible to edit in the file directly
Well, in any text editor that I know, one just places the prompt where he wants to edit and has a keybord (physical or virtual) handy to make any edit.
What is the "KUKA way" ? I just find it so frustrating that straightforward stuff like that are made complicated.
Thanks for the Varcor advice, I get the ".N" thing.
It works, except this variable is write-protected 
How do I un-protect it ?
In fact, you should be able to change them through the VarCor, as long as you're logged in as Expert or higher.
VarCor ?
I followed "DISPLAY / VARIABLE /SINGLE" and found that the value has an extra string of characteres "FRA:" compared to the one in the $Machine.dat file.
Is that important ?
But anyways why can't I just edit the values in the file directly ?
Is it just not possible ?
Sorry : KRC4 - KR210 R3100 - KS V8.3.422
I don't use WorkVisual.
When I select the $Machine.dat file and press "Edit", I get a buch of options (cut, copy, paste,...), but I just can't go ahead and edit a value.
I have the wrong gear ratio on my 7th axis, and I found the line in $machine.dat where I can change it ($RAT_MOT_AX[7]=...), but although I'm logged in as expert, and have stopped the submit interpreter, I am unable to change the value : no virtual keyboard as one could expect.
What other hoops must I jump to change a value in there ?
Should I exit to windows and change the values in a text editor ?
First results show that the scan allowed me to define my best XYZ / ABC values yet.
Rotation around tool TCP still shows unwanted displacements, but much less than what I obtained with the "4 directions" and "ABC world" methods.
I give up trying to get a proper measurements done by the robot itself.
This thing seems un-capable of consistency, and errors, play, backlash, etc... keeps adding up to give a shitty result.
I decided to make a 3D scan of the wrist with the spindle and reverse-engineer my way to get the XYZ and ABC values of the center of the tool's collet chuck.
As an added bonus, I can model the cable management system to take it into account in my simulations.
I'll report back my results based on these values.
The small movements also give a small accuracy in the internal calculations but when you check the tcp like you did, you find a big deviation.
So in my opinion and experience best practice is a movement round about 40 degrees.
I think I have to agree with you on that one.
OK then, back to calibratin'
so can you please show what you are doing and ... how? which tool and coordinate system is selected? post full screenshot of the HMI
Have you zoomed in enough ?
I can see it clearly on all the HMI captures.
It goes back to my one of the first posts in this thread.
As I rotate around tool "A" (tool "Z" ) axis, the pointy end shifts in an un-expected direction.
Consider the "real" point in space described by my current tool XYZ.
As I rotate around tool "A", the pointy end should move in a plane normal to the "A" ("Z") axis, but certainly not ALONG that axis.
It's just geometry basics.
The fact it moves the way it does is what makes me call it "Nonsensical".
I can't even use this deviation to correct my values because it is not "false" , it is just awkward.
earlier in your first post you reported that rotating about this tool Z axis using jog keys (A+/A-), tool was not really rotating as expected but rather moving along the tool Z axis.
The rotation is exactly as expected. What is strange is the translation of the dummy tool point ALONG the tool "A" axis.
Anyways, it is evident that the XYZ are completely wrong.
I just don't understand how it can be THAT bad.
Here is the shabby result of my tool check.
the question is do you still see robot moving in wrong direction when trying to rotate about tcp.
Ugh... Yeah, it's just aweful. Worse than before.
Let me gather some photos
so occasional kick in the tenders to reorient them and help them focus may be needed
I agree. Actually, your nit-picking reminded me of Werner's video that I "though" I had watched carefully.
In fact, (what I had overlooked) he insists on not changing the angles too much between measurements.
After the first measurement is done, he rotates axis 4 slightly more than 7° and moves the dummy tool tip back to the ref. point in carthesian.
He does the same with axis 5 for the third measurement, and again with axis 6 for the 4th. measurement.
I followed his advice and also, each time took close-up pictures of my tip, then zooming on the picture to finely adjust X, Y and Z.
Guess what ? I got an error of just 0.115 !!!
Here's for steps 1 and 2.
I looked for how to display $FLANGE but could find this nowhere accross my documentation.
If I search for $FLANGE + KUKA with google, I get the price of a KUKA flange (quite pricey by the way).
No, it says: move, so that the origin point has a negative coordinate in the xy plane.
Nope. Sorry to be a stickler here, but that's not what it says.
It says "Move the tool so that the reference point in the XY plane has a negative Y
value."
Holy cow... I had it wrong from the beginning.
I SHOULD HAVE BEEN USING A FORK !!!
OK, I see what you mean. You want to check if I'm a total idiot, and you are right.
So back to fiddling the pointy thing around...
Reply to Hermann :
Well I'm standing on the X axis of the robot, so when I rotate tool A +90, the tool is on my right, and when I rotate -90, it's on my left. Get it ?
Forget the numeric data if you don't need it.
I'd just like to understand how it is even POSSIBLE that the point of my tool shifts in that direction.
I used my old ABC values and rotated the TCP around tool A.
Attached are the documented results.
To me, it makes no sense...Even if my XYZ is off, I don't expect the TCP to move along the tool's "A" axis of rotation.
It looks like it's breaking the laws of the universe.
You can try to move to the 4 calibration positions a few times within the calibration screen (on the newer robots it is possible to move to the stored positions), and make them better, until the result is better.
I noticed this on the interface, indeed.
Great advice, thanks !
Next step will be to calibrate my ABC, and this time, I'm going to try the 2 points method.
But isn't there a mistake in the manual ?
It SAYS move to a negative Y and SHOWS a positive Y ...
