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IndustryArena Forum > MetalWorking Machines > Okuma > please, i have 2 questions
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  1. #1
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    please, i have 2 questions

    hello to improve concentricity, when driling with M axis, is good to also spin the spindle; please, is there a recomandation for main spindle rpm, in relation to live tool, or something that is good to know ?



    if you switch from auto or mdi to manual, the machine resets ( rpm stops, tool offset is gone ); but why doesn't it reset if i switch between auto to mdi, or viceversa ?
    ... in auto mode, i can press mdi and program will continue; however, i can't input anything in mdi as long as main program runs in background
    ... in mdi mode, i can switch to auto, but i can't select a program, until i press reset, otherwise it will throw an error

    please, is there something about switching between auto - mdi ? or is it possible to activate mdi during auto mode/mid-auto, so to test a random code while the machine runs the main program ? kindly
    Ladyhawke - My Delirium, https://www.youtube.com/watch?v=X_bFO1SNRZg

  2. #2
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    Re: please, i have 2 questions

    You must press cycle stop button before auto to mdi switch, i think you can enter mdi commands because auto program is interrupted.
    "Imagination is more important than knowledge."

  3. #3
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    Re: please, i have 2 questions

    You need to run at an RPM that is not an exact multiple of what the main is running or else you are basically doing polygon turning and can get some weird patterns. Pick something like a 1:3 ratio so that this will not happen.

    Auto and MDI are both basically auto and able to run code. Since Manual is not able to run code, the control is reset when switching modes. It is not possible to insert random code in the middle of an auto cycle due to the obvious safety concerns of injecting something unproven into the middle of running proven code.

    Now of course it's possible to start something in MDI and then switch to Mid-Auto Manual to accomplish something like boring jaws with the spindle running and the offset called up. As always, when sequence restart is pressed, it will return (shortest path) to the point where Mid-Auto Manual was pressed.
    Experience is what you get just after you needed it.

  4. #4
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    Re: please, i have 2 questions

    hello sorry for the late reply, i was busy with some deliveries ...

    You must press cycle stop button before auto to mdi switch, i think you can enter mdi commands because auto program is interrupted.
    hy kurmay
    ... i stoped from slide hold / feed hold / that red button
    ... then swithced to MDI, input M05, enter, cycle start : only that this did not stoped the spindle, but made the program go-on

    but i am not sure if, before going to MDI, if manual intervention was on or off ? i think i will try again

    Auto and MDI are both basically auto and able to run code. Since Manual is not able to run code, the control is reset when switching modes
    hy mr wizard like that, it makes more sense

    It is not possible to insert random code in the middle of an auto cycle due to the obvious safety concerns of injecting something unproven into the middle of running proven code.
    i don't know, this is what i try to find out, thus to activate random codes inside an autocycle

    during automatic, if you activate mid-auto manual then move axis, stop/start spindles, etc, it won't be possible to continue the interrupeted program, unless sequence restart will perform; i don't reffer to restarting the program, but to that button that, when pushed after intervention is done, will bring the turret back to position before interpution started; thus that button, runs some check to see if it is ok to bring back the turret ( for example if turret index is as before, if rpms are as before, etc )

    thus the sequence restart makes sure that machine status is as before, otherwise it won't execute

    so sequence restart snaps the machine state before intervention, and compares it to the moment when being pushed, and if those 2 match, then it will allow to continue work; in between those 2 moments, the operator moved the machine from the buttons, but what if he just inputed some codes in MDI ?

    thus why should sequence restart care if the modifications where done from control panel buttons, or from MDI g-codes ? i am not sure, but maybe the difference is that manual intervention is 'clean', while MDI g-code alters the buffer ? so, is easier to restore the axis to their previous position, but maybe is hard to undo the buffer ?

    boring jaws
    as a side note, about boring jaws for od work, i have a custom part that the master base jaws clamp on ( requires to remove the inner sleeve ), always at same position, somewhere close to hydraulic travel / 2, and at that position i machine ( turn/grind ) the soft/heat treated/replaceable jaws; i don't mdi it, because most of the times i need to control the taper

    it works to clamp on it, also to machine the jaws for id clamping, but it does not work as well on chucks that are no longer new / good condition, because they have different play inside them, when clamping od or id

    so lately, i started thinking about a similar solution, but for id work ... thus a big ring, for the master base jaws

    You need to run at an RPM that is not an exact multiple of what the main is running or else you are basically doing polygon turning and can get some weird patterns.
    you are right around january, this year, i roughed a part with small conical inside, and i used a tiny live tool; i got a piramid inside, with many faces ( by the way, it looked interesting ), and after i read your reply, i checked the program : S200 M2000 so, it was 1:10 .... yes, like you said, it was polygon turning; thank you mr wizard !

    Pick something like a 1:3 ratio so that this will not happen.
    please, have a bit more patience ... actually, this is the answer i was searching for

    i know you told me something similar a few years ago, but i couldn't understand it back than, also i couldb't find it any more, and i can't understand it even now

    for example if 1:10 is bad, then why 1:3 will work ? ain't it an exact multiple ? i thought to try and draw those flat turn / loci shapes, maybe i will spot something

    a few days ago, it hit me : you mean something like phasing ? for example, if to make an analogy to gears :
    ... if ratios is 1:1, then each tooth will always pair with the same tooth on the opposite wheel
    ... if ratios is 1:2, then contact will occur at 0 and 180*?
    ... if ratiso is 1:3, then contact will occur at 0 120 240 ? but ain't this means a piramid with 3 faces ?

    thus if ratio is 1:2 3 4 5 ... the result won't be polygonal turning ?

    is tricky ... i also delayed my answer because i tried to understand it

    writing this, i just imagined that to solve it, then is needed to avoid feed on z axis, thus to keep the live tool in contact with the part at fix position, just like gears, then try to control the contact phase :
    ... if result has to be a gear ( thus live tool is a hob ), then phasing has to be identical, so to generate straigth teeth ( for simplification, lets avoid tilted teeth )
    ... if result has not to be a gear, like when drilling, then is needed to avoid identical phasing, or at least achieve some pattern, but twisted enough to be considered 'random'

    i think that the answer is a ratio of 1:?.x, or 1:?.xx, thus 1 to something that is not an integer, like, for example, an analogy of replacing gears transmision with belt transmision

    i also believe that 1:3 that you suggested may fail if feed is too low, while it may deliver in most aplications, simply because normal cuttings spec deliver high enough feed ... so you still get a piramid, but it is twisted, and it simply repeats it's phasing position after 3 tool revolutions, but it does not matter, simply because the drill is deeper inside the part; kind of when running on a twisted roller coaster

    this just crosed my mind : what about 1:3.142 ( 1 : pi ) ? it is similar to 7:22 ... thus, for 1:3, original phasing will repeat after 3 revolutions, while for 1:3.14 it will repeat after 7 revolutions; and this makes sense, as belts transmisions, or 1:<>1, will eventually repeat it's phasing, sooner or later ... hmm ...

    let's take it next step :
    ... 1:3 repeats in 3 revos
    ... 1:3.142 repeats in 7 revos
    ... is it possible to use 1:3.xyz, so to repeat in 15 revos ? i need to dig this a bit futher



    when i opened this discusion, i just started a long setup, and somehow, i solved this by mistake : s rpm is not constant, but under m695, so it continuosly changes ratio; i did not activate m695 for the drilling operation, but for a previous operation, then i simply left it active ...

    thank you mr wizard of your time and patience / kindly
    Ladyhawke - My Delirium, https://www.youtube.com/watch?v=X_bFO1SNRZg

  5. #5
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    Re: please, i have 2 questions

    You must press cycle stop button before auto to mdi switch, i think you can enter mdi commands because auto program is interrupted.
    hey kurmay, it worked cycle stop, switch to MDI then input whatever, then press cycle start 2-3 times, and only after that the actual comand inputed in MDI will be executed

    i think that is needed to empty the buffer, so pressing 2-3 times empties the read-ahead, than it will execute whatever is inputed in MDI

    also, is possible to switch back to auto, and continue from wherever you are; off course, is up to you to restore initial axis position and rpm, etc, since sequence-restart does not work; i wonder if i can make it work / kindly
    Ladyhawke - My Delirium, https://www.youtube.com/watch?v=X_bFO1SNRZg

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