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  1. #121
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    [QUOTE=alskdjfhg;3203606

    I'm kinda confused, I disconnected the motor and encoder from the machine.

    Then I did the test like ox and alphonso said, manually turning the ballscrew, and seeing if the encoder senses the position change. I did that and the numbers moved, but how is the encoder talking to the control when I disconnected the encoder?

    [/QUOTE]



    That is very confusing that the Z AXIS position reading changes when the cables are disconnected. Yes, the motor you are fucking with is the Z AXIS motor. The X AXIS motor is the other motor you pointed out. While you have stuff disconnected, turn the ballscrew so that the carriage moves closer to the chuck to make sure it clears the travel stops.

    On your Z axis drive, there is a device to the right of the LED stack that I don't recognize. What is the part number of the board? (A paper label at the bottom of the back board, behind and underneath the circuit breaker.) Something along the line of A06B-6058-H025/7000.

    The 424 error that you had before. The first thing the trouble shooter asks is to check parameters 8X04 (X being 1, 2). Mine are both set at 8X04.3 and .4=1 (00011000).

    Since you have motor wires disconnected, disconnect the other end of the wires in the cable at the U,V, W G terminals on the drive board. These terminals are at the bottom right of the board, three black wires(don't mix them up) and a green/yellow wire.

    Check for continuity between each motor wire and the ground wire.

    Then check for continuity between each of the U, V, W wires. i.e. U to V, U to W, V to W. Anything other than open means there is a problem with the cable.

    If cable checks okay, hook it back up to the motor and repeat the checks. If resistance is essentially the same(need ohmmeter than can check .001 ohms) between all the pairs, the motor is probably good.

    The manual says to check the transistor module, but gives no instruction on how to do that.

  2. #122
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    Quote Originally Posted by Mud View Post
    Any chance there's an encoder on the other end of the screw?
    Socket wrench was on the other end. (video)


    -----------------

    Think Snow Eh!
    Ox

  3. #123
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    Mr. Houston - you may want to pull the Z axis way covers back and see what's yonder...


    -------------------

    Think Snow Eh!
    Ox

  4. #124
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    [QUOTE=
    Check for continuity between each motor wire and the ground wire.
    Then check for continuity between each of the U, V, W wires. i.e. U to V, U to W, V to W. Anything other than open means there is a problem with the cable.
    [/QUOTE]

    When the cable is being checked for continuity remember to bend it in different directions during the test. A broken wire can reconnect when the cable is laid out flat on a table.

    Robert

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  6. #125
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    Quote Originally Posted by alphonso View Post
    If cable checks okay, hook it back up to the motor and repeat the checks. If resistance is essentially the same(need ohmmeter than can check .001 ohms) between all the pairs, the motor is probably good.
    Emphasis on "probably". Important to note that an ohmmeter will only tell you if there is a actual (or very close to actual) short. You need a megger to reliably test the motor / cable.

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  8. #126
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    Quote Originally Posted by alphonso View Post
    Glass scales: Not to my knowledge.
    If no scales, how else can the machine be reading position with encoder unplugged? Does your do that too?

    Quote Originally Posted by Ox View Post
    Can you absolutely verify that the screw that you turned is 100% the other end of that motor that you have unhooked?

    Did you by chance verify that the indicator and the DRO agreed in terms of distance? (could be skewed by indicator angle)
    I can double verify, but I'm pretty sure I was turning the Z axis ballscrew, can't see what else it would be.

    I wanted to try and verify with an indicator, but the holder I was using wouldn't let me get the indicator in anyway that didn't a indicator angle.

    But I want to check that.

    Quote Originally Posted by alphonso View Post
    That is very confusing that the Z AXIS position reading changes when the cables are disconnected. Yes, the motor you are fucking with is the Z AXIS motor. The X AXIS motor is the other motor you pointed out. While you have stuff disconnected, turn the ballscrew so that the carriage moves closer to the chuck to make sure it clears the travel stops.

    On your Z axis drive, there is a device to the right of the LED stack that I don't recognize. What is the part number of the board? (A paper label at the bottom of the back board, behind and underneath the circuit breaker.) Something along the line of A06B-6058-H025/7000.

    The 424 error that you had before. The first thing the trouble shooter asks is to check parameters 8X04 (X being 1, 2). Mine are both set at 8X04.3 and .4=1 (00011000).

    Since you have motor wires disconnected, disconnect the other end of the wires in the cable at the U,V, W G terminals on the drive board. These terminals are at the bottom right of the board, three black wires(don't mix them up) and a green/yellow wire.

    Check for continuity between each motor wire and the ground wire.

    Then check for continuity between each of the U, V, W wires. i.e. U to V, U to W, V to W. Anything other than open means there is a problem with the cable.

    If cable checks okay, hook it back up to the motor and repeat the checks. If resistance is essentially the same(need ohmmeter than can check .001 ohms) between all the pairs, the motor is probably good.

    The manual says to check the transistor module, but gives no instruction on how to do that.
    Thanks for the pointers, I just downloaded the manuals you sent, thanks a bunch.

    I'll definitely give those check you wrote out a try.

    Quote Originally Posted by Ox View Post
    Mr. Houston - you may want to pull the Z axis way covers back and see what's
    Yeah that's next. What I can see of the X axis ways, it doesn't look like the machine is in too bad a shape.

  9. #127
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    You are looking for something that looks like a DRO scale along the Z axis ways.


    edit:

    There is some value in an X axis scale, but not exactly seeing the value in one on Z.



    --------------------

    Think Snow Eh!
    Ox
    Last edited by Ox; 07-12-2018 at 02:47 PM. Reason: added

  10. #128
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    Quote Originally Posted by Ox View Post
    You are looking for something that looks like a DRO scale along the Z axis ways.


    edit:

    There is some value in an X axis scale, but not exactly seeing the value in one on Z.



    --------------------

    Think Snow Eh!
    Ox
    From what I can see from his pictures and videos there does not appear to be a DRO scale on the machine. Let me look at all his pictures and videos again.

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    Quote Originally Posted by alphonso View Post
    From what I can see from his pictures and videos there does not appear to be a DRO scale on the machine. Let me look at all his pictures and videos again.
    I hear a scrap yard calling.
    Sorry to be the party pooper but it is what it is.
    It is JULY the original post so old anyone only working on this thing be out of business.

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    This is a part time hobby. Could go on for years. Like that machinist's vice you worked on in your apprentice ship.

    Tom

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  14. #131
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    Quote Originally Posted by TDegenhart View Post
    This is a part time hobby. Could go on for years. Like that machinist's vice you worked on in your apprentice ship.
    Yes, but:

    Quote Originally Posted by Kaszub View Post
    I hear a scrap yard calling.
    Sorry to be the party pooper but it is what it is.
    It is JULY the original post so old anyone only working on this thing be out of business.
    Who cares how long it takes him? It doesn't seem like he does, or he would have paid someone to actually fix it by now. The first tech he took in seemingly wasn't interested, or was not on the clock long enough to be interested.

    The lathe is practically running. It might (or might not) need some parts, but a competent person could have that ready to make chips in a couple of hours.

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    Think of this as a teaching laboratory. Houston has little knowledge of electrical components. Good way to get an understanding of the electrical and controls part of a machine without fear of shutting down production or damaging an expensive machine. Say he screws something up that result in machine destruction. Ya, lost a potential useful machine, but gained a lot of knowledge. Remember he is college getting his stripes as an engineer. This is something that will useful for many years.

    Tom

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  18. #133
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    Quote Originally Posted by alphonso View Post
    From what I can see from his pictures and videos there does not appear to be a DRO scale on the machine. Let me look at all his pictures and videos again.
    All right. Silver capped device below the servo motor is a "pulse coder" attached to the end of the Z axis ball screw. and of course there is a "pulse coder" in the servo motor. Same setup on the X axis. So, while it isn't a (glass)scale, there does appear to be two devices measuring axis movement. Don't have a clue as to how this works.


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  20. #134
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    That's why I asked if there was an encoder on the other end of the screw, I thought the servo was coupled right on the end of the screw. So the servo is driving the screw via belt? Is the belt in place and OK? Or is the encoder driven by belt off the screw?

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    Quote Originally Posted by Mud View Post
    That's why I asked if there was an encoder on the other end of the screw, I thought the servo was coupled right on the end of the screw. So the servo is driving the screw via belt? Is the belt in place and OK? Or is the encoder driven by belt off the screw?
    The servo is driving the ball screw via a belt. The encoder("pulse coder") is attached to the end of the ball screw. I'm guessing that the belt is present and intact.

  22. #136
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    This picture is of X axis motor and is not oriented correctly; needs to rotate ninety degrees. It does show the Z axis home/stop dogs (beneath the red cap) and it appears the carriage is at or very nearly at the travel. Suggest that you move the carriage in several inches. Coolant hoses are blocking the view of the screw mounted X axis "pulse coder"/ encoder.


  23. #137
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    Quote Originally Posted by alphonso View Post
    So, while it isn't a (glass)scale, there does appear to be two devices measuring axis movement. Don't have a clue as to how this works.
    The lead screw driven encoder is needed on a belt driven design to avoid having to time the servo motor to the lead screw. Otherwise the home position would change depending on how the timing belt was installed. This is true for a zero return that uses the encoder home position mark. Another benefit is that a high resolution encoder can be installed on the lead screw. The servo encoder may not have the resolution needed for the X and Z axes.

    The servo mounted encoder is used for the commutation of the AC motor and the velocity feedback loop. Somewhere in the parameter list there is a gear ratio specified for the X and Z axes. .

    The same design is used for belt driven milling spindles. The home position is determined by a magnet/ Hall effect sensor on the spindle rather than the encoder home position on the servo. The stretch of the timing belt may be another consideration.

    Robert
    Last edited by Robert R; 07-13-2018 at 10:37 PM.


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