I, J, K Error

[NickErmis]

Hello,

I am having an error with I,J and K commands in our Okuma controller.  The specific error that comes in is "Error between the radius which is calculated from I and K commands and the distance between the end point and the center is greater than tolerance.  

Here is my post -  The red text is the violating text

(2D POCKET1)
G138
G0 X25. Z50.
M146
G94 G19 M110
M147
N1 T040404
M8
SB=4584 M13
M146
G0 C295.
M147
G0 Z-3.7754
X1.795 Y0.
Y-0.4164
X1.4214
G1 X1.008 F57.296
Y-0.19
Y-0.1161 F45.837
Y-0.1151 Z-3.7752
Y-0.1143 Z-3.7745
Y-0.1139 Z-3.7735
Z-3.7725
G2 Y-0.1412 Z-3.6028 J0.5173 K0.17
G1 Y-0.1414 Z-3.6015
Y-0.1421 Z-3.6005
Y-0.1431 Z-3.5998
Y-0.1443 Z-3.5996
Y-0.19
G3 Y-0.2087 Z-3.6183 K-0.0187
G1 Y-0.2088 Z-3.8757
G3 Y-0.2033 Z-3.8889 J0.0187
Y-0.19 Z-3.8944 J0.0133 K0.0133

Thanks,

Nick

[Anonymous]

Your code plots without any issues, if you subtract start Z value from one in arc move you get .0178 so that's not the problem.

It shouldn't mater, but just to eliminate the potential, have you tried adding J0 to problem arc move and K0 to following one?

My guess is you have something in machine control raising false flag.

[NickErmis]

With looking at what has worked in the past, I think you may have nailed it.  The only thing is the machine errored out at the line below the green highlighted line.  Do you think that a control would really require a K0 with a J movement? 

That seems a little silly.

Thanks 

[Anonymous]

Like I sad.... "it shouldn't matter"  (and it doesn't) because when any value of IJK is zero it plays no role, but some controls can be weird.

The entire code you posted plots just fine, I stopped on "offending" arc just to show that there is nothing wrong with it, line highlighted in green would be strait line leading up to last arc move in code. 

[Anonymous]

---

@NickErmis wrote:

With looking at what has worked in the past, I think you may have nailed it.  The only thing is the machine errored out at the line below the green highlighted line.  Do you think that a control would really require a K0 with a J movement? 

That seems a little silly.

Thanks 

---

In your first post you marked K value in previous arc move as the reason for error,............ bottom line is you either have bad code or you have some parameter conflict in machine,........ plotting shows no broken links in your code but.....

I had cases where .0001 deviation in IJK accuracy can produce error at the machine.

So if you add J.0133 square and K.0133 square then take square root of result you get .0188 which I suspect is the real reason for error, likely result of rounding to 4 decimals.

If you change that J and K into R.0188 it will go thru because R function allows for such error and result will be the same.

[nick.narzinski]

Okumas are known for this.  There is code in the prototrak post to ensure the circular endpoint lies exactly on center.  you can implement this to your post or contact your reseller to help you out  https://cam.autodesk.com/hsmposts?p=prototrak 

[NickErmis]

Yep, you guys are right, it is a rounding issue.  We tried simply adding a J0 or K0 to lines without any success, was really hoping that would be the silver bullet, but that would have been to easy.  Went into the controls and changed the circular tolerance from 20um to 200um, that didn't seem to help.  We are going to reach out to Okuma to see if they can help us on the control sides.  

I downloaded the protrak post and am going through it right now, not exactly sure what I am looking for.  Any additional help on the programming side would be greatly appreciated. 

Thank you both so much for the feedback and suggestions!!!  I really appreciate this forum and the community support.

[Anonymous]

Have you tried using "R.0188" on last arc moves ?, as I pointed out in previous post, values of J and K are off by some amount that results in error, using R function should not produce error because R allows for more error that .0001

[NickErmis]

I am going to give it a shot this morning hopefully.  I made code manually to get through this part, working on the transfer from main to sub right now, which is a whole other issue .... ugg.  Was hoping to figure this out in the post so we can dump it in the machine and move on, we are doing a lot of milling in this machine.

I will let you know how it turns out.

Thanks again.

[NickErmis]

This worked.  Man my mind is confused right now.  I switched to the exact code you had, only changed the "R" to a "L" which is radius in Okuma logic?? and then the rest of the program ran just fine, with all the J's and K's!!!  I have attached the full code for your reference. 

I am more confused now than when I started, like how can I repeat this in the future without having to review and edit every program for interpolations.  I am sure there is something in the post i am missing.

Either way, thanks a ton for the help with this.

[NickErmis]

O1001
G140
(T040404 D=0.375 CR=0. - FLAT END MILL)
G90 G80

(2D POCKET1)
G138
G0 X25. Z50.
M146
G94 G19 M110
M147
N1 T040404
M8
SB=4584 M13
M146
G0 C295.
M147
G0 Z-3.7764
X1.795 Y0.
Y-0.4164
X1.4214
G1 X1.008 F57.296
Y-0.1899
Y-0.1147 F45.837
Y-0.1137 Z-3.7762
Y-0.1129 Z-3.7755
Y-0.1125 Z-3.7745
Y-0.1126 Z-3.7735
G2 Y-0.1402 Z-3.6018 J0.516 K0.171
G1 Y-0.1404 Z-3.6005
Y-0.1411 Z-3.5995
Y-0.1421 Z-3.5988
Y-0.1433 Z-3.5986
Y-0.1899
G3 Y-0.2086 Z-3.6173 K-0.0187
G1 Y-0.2087 Z-3.8767

(G3 Y-0.2032 Z-3.8899 J0.0188)
(Y-0.1899 Z-3.8954 J0.0133 K0.0133)

G3 Y-0.2032 Z-3.8899 L0.0188
Y-0.1899 Z-3.8954 L.0188
G1 Y0.0926
Y0.0935 Z-3.8952
Y0.094 Z-3.8945
Y0.0941 Z-3.8937
Y0.0937 Z-3.8929
G2 Y-0.0216 Z-3.6025 J0.3109 K0.2915
G1 Y-0.0212 Z-3.4827
Y-0.0214 Z-3.4815
Y-0.0221 Z-3.4805
Y-0.0231 Z-3.4798
Y-0.0243 Z-3.4796
Y-0.1899
G3 Y-0.2086 Z-3.4983 K-0.0187
G1 Y-0.2087 Z-3.9957
G3 Y-0.2032 Z-4.009 J0.0188
Y-0.19 Z-4.0145 J0.0133 K0.0133
G1 Y0.8891
G3 Y0.9078 Z-3.9957 K0.0187
G1 Y0.9079 Z-3.9271
G3 Y0.9024 Z-3.9139 J-0.0187
Y0.8891 Z-3.9084 J-0.0133 K-0.0133
G1 Y0.4034 Z-3.9085
G2 Y0.0974 Z-3.6025 K0.306
G1 Z-3.4375
G2 Y0.0999 Z-3.4002 J0.2785
Y0.1069 Z-3.3635 J0.3359 K-0.0454
G1 Y0.107 Z-3.3625
Y0.1065 Z-3.3615
Y0.1057 Z-3.3608
Y0.1046 Z-3.3606
Y-0.1899
G3 Y-0.2086 Z-3.3793 K-0.0187
G1 Y-0.2087 Z-4.1137
G3 Y-0.2032 Z-4.127 J0.0187
Y-0.1899 Z-4.1325 J0.0133 K0.0133
G1 Y0.8891
G3 Y0.9023 Z-4.127 K0.0187
Y0.9078 Z-4.1137 J-0.0133 K0.0133
G1 Z-3.8087
G3 Y0.8891 Z-3.79 J-0.0187
G1 Y0.4034
G2 Y0.2159 Z-3.6025 K0.1875
G1 Z-3.4375
G2 Y0.4034 Z-3.25 J0.1875
G1 Y0.7026
Y0.8891
Y0.8905 Z-3.2497
Y0.8917 Z-3.2489
Y0.8926 Z-3.2477
Y0.8928 Z-3.2462
Y0.8926 Z-3.2448
Y0.8917 Z-3.2436
Y0.8905 Z-3.2428
Y0.8891 Z-3.2425
Y-0.19
G3 Y-0.2087 Z-3.2612 K-0.0187
G1 Y-0.2102 Z-3.7576
G3 Y-0.2047 Z-3.7709 J0.0187 K-0.0001
Y-0.1914 Z-3.7764 J0.0133 K0.0132
G1 X0.8949 F57.296
Y-0.1899
Y-0.1147 F45.837
Y-0.1137 Z-3.7762
Y-0.1129 Z-3.7755
Y-0.1125 Z-3.7745
Y-0.1126 Z-3.7735
G2 Y-0.1402 Z-3.6018 J0.516 K0.171
G1 Y-0.1404 Z-3.6005
Y-0.1411 Z-3.5995
Y-0.1421 Z-3.5988
Y-0.1433 Z-3.5986
Y-0.1899
G3 Y-0.2086 Z-3.6173 K-0.0187
G1 Y-0.2087 Z-3.8767
G3 Y-0.2032 Z-3.8899 J0.0188
Y-0.1899 Z-3.8954 J0.0133 K0.0133
G1 Y0.0926
Y0.0935 Z-3.8952
Y0.094 Z-3.8945
Y0.0941 Z-3.8937
Y0.0937 Z-3.8929
G2 Y-0.0216 Z-3.6025 J0.3109 K0.2915
G1 Y-0.0212 Z-3.4827
Y-0.0214 Z-3.4815
Y-0.0221 Z-3.4805
Y-0.0231 Z-3.4798
Y-0.0243 Z-3.4796
Y-0.1899
G3 Y-0.2086 Z-3.4983 K-0.0187
G1 Y-0.2087 Z-3.9957
G3 Y-0.2032 Z-4.009 J0.0188
Y-0.19 Z-4.0145 J0.0133 K0.0133
G1 Y0.8891
G3 Y0.9078 Z-3.9957 K0.0187
G1 Y0.9079 Z-3.9271
G3 Y0.9024 Z-3.9139 J-0.0187
Y0.8891 Z-3.9084 J-0.0133 K-0.0133
G1 Y0.4034 Z-3.9085
G2 Y0.0974 Z-3.6025 K0.306
G1 Z-3.4375
G2 Y0.0999 Z-3.4002 J0.2785
Y0.1069 Z-3.3635 J0.3359 K-0.0454
G1 Y0.107 Z-3.3625
Y0.1065 Z-3.3615
Y0.1057 Z-3.3608
Y0.1046 Z-3.3606
Y-0.1899
G3 Y-0.2086 Z-3.3793 K-0.0187
G1 Y-0.2087 Z-4.1137
G3 Y-0.2032 Z-4.127 J0.0187
Y-0.1899 Z-4.1325 J0.0133 K0.0133
G1 Y0.8891
G3 Y0.9023 Z-4.127 K0.0187
Y0.9078 Z-4.1137 J-0.0133 K0.0133
G1 Z-3.8087
G3 Y0.8891 Z-3.79 J-0.0187
G1 Y0.4034
G2 Y0.2159 Z-3.6025 K0.1875
G1 Z-3.4375
G2 Y0.4034 Z-3.25 J0.1875
G1 Y0.7026
Y0.8891
Y0.8905 Z-3.2497
Y0.8917 Z-3.2489
Y0.8926 Z-3.2477
Y0.8928 Z-3.2462
Y0.8926 Z-3.2448
Y0.8917 Z-3.2436
Y0.8905 Z-3.2428
Y0.8891 Z-3.2425
Y-0.19
Y-0.1939 Z-3.2427 F57.296
Y-0.1978 Z-3.2431
Y-0.383 Z-3.2724
G0 X1.795
Y0.
G136
M12
M9

G0 X50.
Z50.
G270

M30

[Anonymous · Accepted solution]

I and K are sides of a right angle triangle and R is hypotenuse, whenever you have 2 variables of IJK in arc move and you get error, add square of each value and then take square root of sum, the result is R or L in your case.

R in Fanuc can be off by more then .001 arc will still get generated but arc having IJK will not budge if there is .0001 error, commonly result of rounding off numbers by post processor.

BTW, plotters don't detect things on that level so you have to know what to look for.

Cool