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IndustryArena Forum > MetalWorking Machines > Okuma > G85 LAP CYCLE - Doesnt like my U value
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  1. #1
    Join Date
    May 2009
    Posts
    41

    G85 LAP CYCLE - Doesnt like my U value

    Hi Guys,

    I am wondering if any of you can help me with my LAP cycles.

    OSP7000 lathe.

    I frequently get error 2380 - LAP U(W) illegal order- Infeeding direction is reversed by finish allowance.

    An example program is below that brings up the error.

    I start the tool in a clearance plane. i.e for this program X66

    Largest diameter on finish contour is 63mm and I want finish allowance of 1mm.

    63mm finished + 1mm finishing cut = 64mm. This leaves me 2mm to rough off in the roughing cycle so I designate D2 as this is of course ok in one cut.


    Why doesnt this work. I play around with the numbers and it doesnt work unless I start out in the high 70's or reduce U to 0.5,

    Thanks for your help guys.

    Iain.


    G00 X400 Z200
    T010101

    (FACE ROUGH)
    G00 X68 Z60.5 M08
    G96 G01 X35 M03 S100 F0.25

    (ROUGH Ext. CYC)
    G00 X66 Z63 M08
    N0103 G85 NAT01 D2.0 F0.25 U1.0 W0.5

    M09

    (FACE FINISH)
    G00 X500 Z200
    T020202
    G00 X68 Z60 M08
    G96 M03 S150
    G01 X35 F0.1
    G00 X67 Z65 M09

    (FINISH Ext. CYC)
    N0202 G96 M03 S200 T020202 M08
    G00 X67 Z63 M08
    N0203 G87 NAT01
    M09

    (EXT CONTOUR)
    NAT01 G81
    G42
    N0000 G00 X61 Z61
    N0001 G01 X61 Z60 F0.1
    N0002 G03 X63 Z59 K-1
    N0003 G01 X63 Z-4.5
    G40
    G80

    N2222

  2. #2
    Join Date
    Jun 2015
    Posts
    4131

    Re: G85 LAP CYCLE - Doesnt like my U value

    pls share tool nose radius, and compquad ( P )

    also, pls do a quick test, with nose radius = 0; if it works, then the problem may be a too big radius, and/or too short clearance / kindly
    Ladyhawke - My Delirium, https://www.youtube.com/watch?v=X_bFO1SNRZg

  3. #3
    Join Date
    May 2009
    Posts
    41
    Thanks for your reply, nice to hear from you :-)

    0.8mm TNR and P value 3

    Im at home for the night so cant try 0 TNR sorry atm.

  4. #4
    Join Date
    May 2009
    Posts
    41
    Hi.

    I tried with TNR = 0 and it made no difference.

    However, when I turn off TNR comp in the contour definition, it does work.

    What am I missing?


    Iain.

  5. #5
    Join Date
    Jun 2015
    Posts
    4131

    Re: G85 LAP CYCLE - Doesnt like my U value

    hi, try this :

    Code:
    (EXT CONTOUR)
    NAT01 G81
    N0000 G00 X61 Z61
    N0001 G01 X61 Z60 F0.1 G42
    N0002 G03 X63 Z59 K-1
    N0003 G01 X63 Z-4.5
    G40
    G80
    why there is no N*** in front of your G42 ? kindly
    Ladyhawke - My Delirium, https://www.youtube.com/watch?v=X_bFO1SNRZg

  6. #6
    Join Date
    Apr 2009
    Posts
    1262

    Re: G85 LAP CYCLE - Doesnt like my U value

    Mathematically your code doesn’t work. Your DOC of 2mm and your finish stock of 1mm adds up to equal your reference point diameter of 66. You must start higher than that in order to work. You also have no imaginary next vector on N0003 which will get you when adding in comp.

    Best regards,

  7. #7
    Join Date
    May 2009
    Posts
    41

    Re: G85 LAP CYCLE - Doesnt like my U value

    Okuma Wiz - thankyou for sharing your invaluable knowledge in this forum and with me. I assumed mathematically my code was 'spot-on'. Because it all adds up nicely. The reason I did/do this is because I only have a small roughing cut on this, and if I start further out at lets say X67 or greater, then I am cutting air etc or making 2 cuts where 1 would be fine.


    Regarding the no 'next vector', does this only mean the tool wont stop at X-4.5 'face' per se,. This is all clearance to part off so hasn't been an issue. Is that what you are referring to?


    Lastly, my code didn't work at all (Same error) until I had the tool starting position out at X79 or something like that - a few mm extra above X66 didn't help - I must be missing something further re the call of G42 as the main problem with my original code.


    Thanks deadly Kitten ,always a great help. - I always leave 2x nose rad. after calling G41/G42 which is 2(0.8) in this case. No N**** because Ive been lazy in editing to try and get this working. Sorry.

  8. #8
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    Jun 2015
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    4131

    Re: G85 LAP CYCLE - Doesnt like my U value

    Quote Originally Posted by OkumaWiz View Post
    Mathematically your code doesn’t work. Your DOC of 2mm and your finish stock of 1mm adds up to equal your reference point diameter of 66. You must start higher than that in order to work.
    hy mr wizard next code performs just fine :
    Code:
    NAT01
    N0100 G97 S2000 M42 M03 M08
    N0101 G00 X21.5 Z2.5 T010101
    N0102 G96 S150
    N0103 G85 N0104 D2 F0.25 U1
    N0104 G81
    N0105 G00 X20
    N0106 G01 Z0 G42 E0.25
    N0107 Z-10
    N0108 G40
    N0109 G80
    N0110 G97 S2000 M05 M09
    N0111 G00 X500 Z250 T0100
    maybe clearance has to be above U, not above U+D just saying, who knows ?

    if i wish to make a roughing cycle, to behave like a finish cycle, i simply use a big value for D, so to force it to deliver 1 single cut

    however, i don't like roughing cycles, because they don't deliver well when the difference between diameters is not a multiply of D; for long setups, i don't use cycles

    You must start higher than that in order to work.
    i also believed that

    Quote Originally Posted by gibsoni View Post
    Okuma Wiz - thankyou for sharing your invaluable knowledge in this forum and with me
    hey mr wizard, you know about that event-horizon ? like of you still continue to expand your knowledge, you won't be able to share it anymore ?

    The reason I did/do this is because I only have a small roughing cut on this, and if I start further out at lets say X67 or greater, then I am cutting air etc or making 2 cuts where 1 would be fine.
    did you tried to reduce the number of passes by lowering the clearance ? so to make the roughing deliver a single-shot ? if so, avoid editing the clearance, by using a copy-cycle, or a finish cycle with U>0, or increasing the doc of the rough cycle

    Lastly, my code didn't work at all (Same error) until I had the tool starting position out at X79 or something like that - a few mm extra above X66 didn't help
    tricky tricky, whatever to make the code work

    I always leave 2x nose rad. after calling G41/G42 which is 2(0.8) in this case
    where do you leave 2 x 0.8 ? i don't understand what are you refering to ...



    at post 5, i shared a code for you : try it / kindly

    ps : do you believe i really wonder why you don't use N*** in front of your G42 ? it was a tricky question
    Ladyhawke - My Delirium, https://www.youtube.com/watch?v=X_bFO1SNRZg

  9. #9
    Join Date
    Apr 2009
    Posts
    1262

    Re: G85 LAP CYCLE - Doesnt like my U value

    On N0003 try putting K-1. It would be an imaginary next vector for that line and should stop it from using the next rapid move for nose comp calculations. If that doesn’t work put it on the G40 line to test.

    The control will read up to 4 lines ahead in order to search for the next vector so the rapid move is what it will see next.

    Have you tried using single block to more accurately find which line is causing you trouble? It may not help inside the LAP cycle because internal calculations are happening but can often point more closely to where the error is occurring.

    Best regards,
    Experience is what you get just after you needed it.

  10. #10
    Join Date
    Jun 2015
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    4131

    Re: G85 LAP CYCLE - Doesnt like my U value

    On N0003 try putting K-1. It would be an imaginary next vector for that line and should stop it from using the next rapid move for nose comp calculations. If that doesn’t work put it on the G40 line to test.
    hi mr wizard, a comp code should work on it's own, regardless if also imaginary vectors are being used ... imaginary vectors only control the start & end-point, so to eliminate some auxiliary movements, to keep some clearances constant regardless of radius values, etc .... you know that

    one problem with that code is that compensation is started too soon : normaly there should be "rapid + feed comp", but that code has "rapid + rapid comp + feed", and in this moment 2 things appear :
    ... 1st compensation movement, thus the lead-in movement, is a control specific : it may be executed at current position, or when moving to next position
    ... knowing how the controller behaves when entering, it can be seen, as in attached image, that the segment [23] won't be compensated, because the toolpath is too ' crowded '; there is no space, because compensation is started too soon : this is causing the compensation toolpath to execute a segment with "zero length" or with "reversed direction"

    another problem is the syntax of the code; that is not an original, not a vanila code is edited ... as a result, G42 is not where it should be, and the cycle can no longer perform as it shoud; normally, the cycle should go like this : " positioning + comp-in + cutting + comp-out + repositioning, and so on "; that code is forcing the cycle to always reposition during compensation

    if G42 is put back in place, as shown at post 5, the code will work; there is no example inside manuals & igf, that uses G42 one line after G81, but only using a positioning/rapid movement in between; there is no problem with U, or with initial clearance position; the problem is a 'faulty' code edit, or a faulty post-processor ? kindly

    ps : gibsoni, please try to wrk with Z0 in front of the part ...
    Ladyhawke - My Delirium, https://www.youtube.com/watch?v=X_bFO1SNRZg

  11. #11
    Join Date
    Jul 2010
    Posts
    287

    Re: G85 LAP CYCLE - Doesnt like my U value

    It's upset because it's a bit lost.
    It doesn't like having the G42 as it's first "move".
    Make this:
    NAT01 G81
    G42
    N0000 G00 X61 Z61
    N0001 G01 X61 Z60 F0.1
    N0002 G03 X63 Z59 K-1
    N0003 G01 X63 Z-4.5
    G40
    G80

    Read this:
    NAT01 G81
    G0 G42 X61 Z61
    G1 X61 Z60 F0.1
    G3 X63 Z59 K-1
    G1 X63 Z-4.5
    G40
    G80

    And it will run.

    Drop all the extra N lines to save yourself 24 characters on the old girl.
    Drop preceding 0's to save 4 more for 28 total characters or about 33% of the total characters in the code.
    Or don't. Whatever.

  12. #12
    Join Date
    Jun 2015
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    4131

    Re: G85 LAP CYCLE - Doesnt like my U value

    And it will run.
    yes, will run, but will it deliver ? should g42 be in the block with the rapid ( code-a ), or with the feed ( code-b ) ? let's compare :
    ... image 1 : code-a ( left side ), won't move under X61
    ... image 2 : code-a toolpath is yellow, and code-b toolpath is blue; it can be seen that code-b has more movements, and it delivers the radius, while code-a won't deliver the arc marked with green

    code-b, as a type, is osp default

    Drop all the extra N lines to save yourself 24 characters on the old girl.
    Drop preceding 0's to save 4 more for 28 total characters or about 33% of the total characters in the code.
    did you worked a lot of time on machines with limited memory ? just asking ...

    let's continue the trend : also spaces may be removed :

    Code:
    NAT01 G81
    G0X61Z61G42
    G1X61Z60F0.1
    G3X63Z59K-1
    G1X63Z-4.5
    G40
    G80
    also duplicate coords :

    Code:
    NAT01 G81
    G0X61Z61G42
    G1Z60F0.1
    G3X63Z59K-1
    G1Z-4.5
    G40
    G80
    now, let's boost the compiling speed, so to reduce execution time, by removing lines without chars, and lines with comments to keep the comments, without reducing the execution time, then they can be written like below :

    Code:
    NAT01 G81 ( EXT CONTOUR )
    G0X61Z61G42
    G1Z60F0.1
    G3X63Z59K-1
    G1Z-4.5
    G40
    G80
    
    or like this, but it will be a few ms slower
    
    NOEX ( EXT CONTOUR )
    NAT01 G81 
    G0X61Z61G42
    G1Z60F0.1
    G3X63Z59K-1
    G1Z-4.5
    G40
    G80
    
    and this is only the begining i won't develop futher

    Or don't. Whatever
    yeah, me too / kindly
    Ladyhawke - My Delirium, https://www.youtube.com/watch?v=X_bFO1SNRZg

  13. #13
    Join Date
    Jul 2010
    Posts
    287

    Re: G85 LAP CYCLE - Doesnt like my U value

    I can't in good conscience recommend doing something that won't work 100% of the time. You can always drop N lines not being referenced. You can always drop preceding zeroes. You cannot always omit spaces.
    Case in point: G85NLAP1 D2U.5W.1F.25 works
    G85NLAP1D2U.5W.1F.25 doesn't

    Changing:
    G0 G42 X61 Z61
    to:
    G0 X61 Z61 G42
    or:
    G1 G42 X61 Z61

    makes no positional difference. Out of morbid curiosity, I tested the code and took pictures of all the positions for each sequence to verify because today I have time and a machine.

    Lastly, the OP's question has been answered with a fix that solved the issue.
    Debating programming format should be done elsewhere to prevent topics being inundated with information outside of the original question or purview of the OP's question.

  14. #14
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    Jun 2015
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    4131

    Re: G85 LAP CYCLE - Doesnt like my U value

    Changing:
    G0 G42 X61 Z61
    to:
    G0 X61 Z61 G42
    or:
    G1 G42 X61 Z61

    makes no positional difference
    hi teahole, i am not talking about that, but about this :
    Code:
    NAT01 G81
    G0 X61 Z61 G42
    G1 X61 Z60 F0.1
    G3 X63 Z59 K-1
    G1 X63 Z-4.5
    G40
    G80
    
    NAT01 G81
    G0 X61 Z61
    G1 X61 Z60 F0.1 G42
    G3 X63 Z59 K-1
    G1 X63 Z-4.5
    G40
    G80
    a difference can be spotted

    to analize what's happening, i have removed uw : "N0103 G85 NAT01 D2.0 F0.25 ( U1.0 W0.5 )"

    this is what i have / kindly

    Code:
    G0 X61 Z61 G42 X Z G1 X61 Z60 F0.1 G42 X Z
    u1.0 w0.5 66 63 u1.0 w0.5 66 63
    64 61.85 64 62.25
    64 58.7 64 58.7
    64 -4.8 64 -4.8
    64.1 -4.7 64.1 -4.7
    66.1 -4.7 66.1 -4.7
    66.1 61.85 66.1 62.25
    64 61.85 64 62.25
    62 60.7 62 61.5
    62 60.312 62 60.312
    64 58.7 64 58.7
    64.1 58.8 64.1 58.8
    66 63 64.1 61.5
    62 61.5
    60.4 60.5
    62 60.312
    62.1 60.412
    66 63
    u0 w0 66 63 u0 w0 66 63
    64 61.88 64 62.2
    64 -5.3 64 -5.3
    64.1 -5.2 64.1 -5.2
    64.1 61.88 64.1 62.2
    64 61.88 64 62.2
    62 60.76 62 61.4
    62 59.444 62 59.444
    63 58.2 63 58.2
    63 -5.3 63 -5.3
    63.1 -5.2 63.1 -5.2
    64.1 -5.2 64.1 -5.2
    64.1 60.76 64.1 61.4
    62 60.76 62 61.4
    61 60.2 61 61
    61 59.812 60 60.375
    62 59.444 60 59.974
    62.1 59.544 62 59.444
    66 63 62.1 59.544
    62.1 60.375
    60 60.375
    59.4 60
    60 59.974
    60.1 60.074
    66 63
    Ladyhawke - My Delirium, https://www.youtube.com/watch?v=X_bFO1SNRZg

  15. #15
    Join Date
    Aug 2011
    Posts
    418

    Re: G85 LAP CYCLE - Doesnt like my U value


    Changing:
    G0 G42 X61 Z61
    to:
    G0 X61 Z61 G42
    or:
    G1 G42 X61 Z61

    makes no positional difference.
    OSP convert your part program to FCC codes.
    it compile and run FCC codes when cycle start pressed.
    You can't view these codes.
    OSP generates these codes by ordering them with a certain logic.
    "Imagination is more important than knowledge."

  16. #16
    Join Date
    Jun 2015
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    4131

    Re: G85 LAP CYCLE - Doesnt like my U value

    hei kurmay, what is fcc ? however, even if you can not see the logic, you may observe the output coordinates; futher more, based on those coordinates, you may figure what the logic is, and be able to predict, at least simple operations / kindly
    Ladyhawke - My Delirium, https://www.youtube.com/watch?v=X_bFO1SNRZg

  17. #17
    Join Date
    Aug 2011
    Posts
    418

    Re: G85 LAP CYCLE - Doesnt like my U value

    Factory Classification Codes
    The FCC codes are written on the last pages of the Alarm&Error List book.
    "Imagination is more important than knowledge."

  18. #18
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    Aug 2011
    Posts
    418
    Although the G85 macro seems simple, it has a rather complex structure.
    "Imagination is more important than knowledge."

  19. #19
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    4131

    Re: G85 LAP CYCLE - Doesnt like my U value

    yup, it's a flow of paralel lines, intersecting a toolpath made of segments & arches + some offset function, so to handle U W <> 0

    mmm, just saying
    Ladyhawke - My Delirium, https://www.youtube.com/watch?v=X_bFO1SNRZg

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