Need Help! Syil X7 X AXIS help when not remembering position


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    Unhappy Syil X7 X AXIS help when not remembering position

    Syil X7 X AXIS help when not remembering position

    Hi, I am new to this CNC Zone - Forum.

    I have a X7 Syil Mill. Bought it new. And even though I have had it for 4 yrs, and not used it, now I come to use it it is causing me grief.
    It will not return to a set position on the X AXIS. Yes it moves ok. But when repeating a job, it losses reference point and starts somewhere else even though the controller being a ADT - CNC4240 thinks its at that point. These are stepper motors I believe on this mill.

    I DO NEED HELP as jobs need to go out the door.
    Thanks Jon.

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    Glider,

    It sounds like it is loosing steps. Are you running code and taking aggressive cuts? Does the axis loose position when cutting air? Any description of what you are doing when it looses position will help with identifying the cause. These things are not able to take aggressive cuts like a real VMC.


    gb



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    TY Chevalier, ty for this reply.

    I pulled the stepper motor apart last night as it had been making a ticking noise like a micro switch does. Blew it out as could not find anything wrong inside. Clean and dry. No swarf etc. Tested it in machine. Yes, running G-code from Cam software. No, not making machine work hard at all eg: 0.2 cuts in 6061 Al...Question: Can the MPG hand controller be the culprit given if I wind too fast it lags and catches up after I have stopped winding the hand wheel.
    I had guessed it would know where it was. Could it be this. No signs as yet on actual cutting paths jumping around losing it reference as yet. I don't want to even think about that factor. Yes, I know only to well they are a toy.
    What do you think please?



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    Glider,

    I am not an expert on steppers but suspect you may have done more harm than good by disassembling the stepper. There are 2 schools of thought on disassembling steppers, some say its not a problem whilst others say you loose torque by disturbing the magnetic field. In any case, its done now. At the end of this reply are some Googled responses to stepper disassembly.

    The "overtravel" you describe with the MPG sounds to me like the "acceleration" and "max speed" parameters may need to be adjusted in the controller. My ADtech controller has the following:-
    General parameter (p1)
    parameter 009 (X-axis fast speed) set to 3000mm/min (I have set this value to 5000mm/min and run a stress test program with no lost steps)
    parameter 017 (X-axis accel) set to 1000 kpps.
    The above parameters allow my MPG to control the table movement without noticable overrun. BTW its not actually over-run but the stepper is simply moving the number of pulses you rotate the handwheel. If the acceleration rates are set low then the motor ramps down gradually. This gives the opertator the feeling the table is overrunning.

    From Anaheim Automation:
    "Q: Is there any damage caused by a stepper motor that is disassembled?
    A: Yes! Up to 60% magnetizing loss can be the result if the rotor is pulled apart. If all parts are replaced properly, the motor can be remagnetized at the factory, but the charge is substantial. If you have a motor failure, or are concerned about the performance, contact Anaheim Automation. Please note that the warranty period is 12 months from the date of invoice. "
    From ServoRepair.com:
    "First, any time a motor is disassembled, there is a high probability that the magnets will be discharged to a point where the torque will be diminished. The results vary and may or may not initially be noticeable. With some motors, the results will be immediate. In fact, disassembly of a stepper motor will typically demagnetize the magnets to a point that the motor is useless until it has been properly remagnetized."

    From Lin Engineering:

    "Do not disassemble motors; a significant reduction in motor performance will occur."

    From a post by Mariis Freimaniss, of Gecko, who knows as much about stepper motors as anyone in the world:

    "This topic came up in another group. The stator acts as a magnetic "keeper" for the rotor.

    Nothing like running an experiment to know if something is true or not.

    I had a motor I didn't care for (MO62-FD04), so I ran dyno tests on it that showed 112 in-oz low-speed torque. I removed the rotor for 5 seconds, then replaced it and re-ran the dyno test.

    The low-speed torque now was 70 in-oz, or only 62% of what it was before disassemby.

    You may not notice the loss in torque but it is real and it is there.
    Mariss"

    Disassembly of a stepper motor WILL damage it! Guaranteed!"



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    Chevalier,
    It was a very grateful inquiry reply to my thread. Assured, you HAVE BEEN OF very significant HELP. THANK YOU!
    I am in debted to be on the receiving end of your knowledge and advice. A certain agent / supplier on the Central Coast which we will not mention, currently has not assisted in ANY of my situation and naturally we all seek for a resolution in our learned paths.
    Again, ever grateful. Syil have replied to notify me that they are looking at the issue. Time never stands still for any one.



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    Default Re: Syil X7 X AXIS help when not remembering position

    Hello:
    Maybe the frequency at which the CNC4620 sends out pulses is to high. There's an axis parameter which sets the max acceleration rate for axis servos. Maybe by lowering it you could see some improvement.

    By the way, I'm looking for information about the axis reset signals on the CNC46XX controllers but can't find it. Do you use these signals? If so, how do you connect them to your servo drives?

    Greetings



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    Default Re: Syil X7 X AXIS help when not remembering position

    You are saying that when you zero the x axis, then say "G00 X5" and then "G00 X0", it does not return to the zero point, correct?

    Some easy things to check:
    1. Often, one of the causes of lost steps is the coupling between the stepper motor and the ball screw gets loose. It is attached usually by 2 allen headed screws. Check to make sure they are tight. Clicking noise could easily be a symptom of this.

    2. If you didn't have linear rails on your x-axis, I would say check to make sure the bed was adequately lubricated. Are your linear rails supposed to be oiled or greased?

    Tim
    Tormach 1100-3 mill, Grizzly G0709 lathe, PM935 mill, SolidWorks, HSMWorks.


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Syil X7 X AXIS help when not remembering position

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