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IndustryArena Forum > MetalWorking Machines > Cincinnati CNC > Encoder feedback on TC30 spindle
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  1. #1
    Join Date
    Dec 2005
    Posts
    29

    Encoder feedback on TC30 spindle

    A machine operator crashed Z axis on a horizontal boring mill for the second time in less than a month. The original motor is still at the repair shop, The mechanical Repairman is off since last Friday for gall bladder surgery.The 32 HP spindle motor has a Heidenhain ROD -323.007 encoder with 1024 pulses per revolution. When we removed the first one,(motor) we damaged the motor gearbox coupling so with a 13 week replacement date, no spare is in house.Therefore, we ordered a replacement encoder,and plan to replace it on the machine without removing the motor. We hope this is possible without a Mitchell Electronics black box. This is an attempt to avoid laying off 25 employees right before Christmas.Thanks in advance.

  2. #2
    Join Date
    Sep 2010
    Posts
    1765

    Re: Encoder feedback on TC30 spindle

    1 machine supports 25 employees? Wow.

    Enc on spindles do not require phasing. So no Mitchell needed.

    Never had a machine down case where we could not get a coupling to our customer in a couple days.

    Seems like something needs tweaking on your machine to stop allowing such destructive crashes.

    Hoping for good luck for you!

    Sent from my SM-G900V using Tapatalk

  3. #3
    Join Date
    Dec 2005
    Posts
    29

    Re: Encoder feedback on TC30 spindle

    Thank you for confirming what I suspected. Due to the fact that it is an induction motor and not true servo motor.Crash #1 sheared off both drive dogs and jammed the tool in the cat 50 taper. Cutting through forged steel and concrete with a 10 inch sawblade with carbide inserts. To remove the tool I had to jumper out the release solenoid, Jog the blade back into the kerf and jog the z axis at 10 percent. It pulled the part it was processing 2 inches before the tool came out of the taper. The part weighed 9000 pounds!

  4. #4
    Join Date
    Dec 2006
    Posts
    584

    Re: Encoder feedback on TC30 spindle

    What spindle drive and spindle motor do you have on this machine??? Should be a SIEMENS 650 I am guessing. How did the crash happen???

    MIKE CNC Machine Services INC | Cincinnati Milacron MachinesCNC Machine Services

  5. #5
    Join Date
    Dec 2005
    Posts
    29

    Re: Encoder feedback on TC30 spindle

    The motor has no tag on it (No BS) flag number 1. The Heindenhein connector was mounted in the peckerhead alongside the 380 volts UVW leads. The two removable plates that accommodate the encoder amphenol connector were never used. This motor is an emergency replacement from a local servo motor rebuilder. The machine has a 650 simodrive and 610 servo amps. We spin high pressure cylinders and this machine processes the necks. (TC30 s/n 3129B0192-0002) The dual chain toolchanger has custom dual cartridge tooling , some which weigh 95 to 110 pounds. I believe the max tool weight is set at 65 pounds by the factory. Changing tools the big ones sag and the arm shifts as the tool rides up into the spindle.The thing that does the most damage is when our favorite operator uses the 10 inch saw blade to rough cut the necks. He has no concept of feedrate override, refuses to change inserts, and is known to cut off oversize pieces which tend to pinch the blade as the scrap falls clear of the neck. They have a new machine due to be delivered in February. We were jogging this beast a tenth of a thousand today. The new machine (German manufacturer, Heindenhain controls telescoping ram, production robbing light curtains,etc,will be destroyed inside of six months.

  6. #6
    Join Date
    Dec 2005
    Posts
    29

    Re: Encoder feedback on TC30 spindle

    It looks like someone screwed up the fault mapping. The true fault should of been C axis encoder disconnect. Through trial and error found the parameters to complete a mechalign. Y axis 2.89, Z axis 49.435, C axis 7 degrees (3861 counts) Ran spindle 50 RPM (49.8) then 200 RPM (199.7) after 5 minutes we got a Y axis encoder disconnect fault with no axis movement other than the spindle. Performed another axis align then mechalign. Ran spindle at 1000 RPM jogging XYand Z axis for 10 minutes without incident. Then started using spindle overide to go above and below 1000 rpm, then the spindle stopped on a dime, DC buss Overvoltage spindle is locked up. Looks like a 50 thousand dollar spindle rebuild is in our future.

  7. #7
    Join Date
    Sep 2010
    Posts
    1765

    Re: Encoder feedback on TC30 spindle

    Quote Originally Posted by damelman View Post
    ...then the spindle stopped on a dime, DC buss Overvoltage spindle is locked up. Looks like a 50 thousand dollar spindle rebuild is in our future.

    sorry to hear your problems! But just know thaht overvoltge and stop on a dime due to lock up do not go together. Now blowing the drive and getting overCURRENT could go along with that, but NOT overvolts. So if indeed you got OV you may want to remove the spindle motor from the spindle assembly first and see which is really locked up. Your repair may not be so bad; when bearngs go in our old spindle motors, our repair cost is typically only a few tho.

  8. #8
    Join Date
    Dec 2005
    Posts
    29

    Re: Encoder feedback on TC30 spindle

    Mike could you please tell me Saturday's lottery numbers. You know your stuff. A Cincinnati tech arrived yesterday to assist with the spindle rebuild. We removed the gear cover. he then used a pry bar to take it out of gear and the spindle spun freely. WE then pryed it back into gear noticed the gear movement stopped at the pinion heading to the spindle motor. Spindle motor locked up. Tried to turn drive to access set screws in zero max coupling with a 8 ft 2 by 4 with no results. I put a halt to that maddness and stated a coupling is a lot cheaper than a damaged gear train. Unbolted the motor and sacrificed the fiberglass inserts in the coupling. Ordered a coupling from FIVES and had our original motor expedited from the repair shop. Machine is back online as of Noon today. Thanks to all for your input!

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