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Tech Support - FAQ - C1900 - 20

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C1900 FAQ


    Why is my chart plate gears slipping everytime I change pens?
    Can I get the parts and replace the gears myself?

    Answer: This is one of those situations that "progress" has created. This problem is not evident in original (MKI) chart plates, only newer (MKII) chart plates. If your chart plate tends to slip while changing pen arms or pens, then care MUST be taken to insure the pen yoke is not moved while changing these items.

    The original (MKI) chart plate used a fixed (screwed in place) black round gear that can withstand some abuse when changing pens. The new (MKII) chart plate however, uses a moon shaped gear that relies on spring tension to keep the gear properly lined up and the teeth engaged. If this spring tension is removed, then the gear may disengage from the mating gear.


This video illustrates just how easily the
MKII Pen Yoke assembly disengages.


Original MKI Pen Yoke Assembly
Yoke gear is black and round

Newer MKII Pen Yoke Assembly
Yoke gear is white and moon shaped



    Answer: Individual gears are not available for purchase from ABB, only complete chart plate assemblies. However, we do stock these gears and the parts necessary to convert the MKII pen yoke assembly to the much preferred MKI pen yoke assembly.  

    Gear replacement should not be performed in the field unless it is done at a workbench. The reason is because there are many small parts that are easily lost when the chart plate is disassembled. The Commander 1900 uses a few different gears and they are listed below.

Photo Part No. Description


MKI Pen Yoke Gear
Qty: 4 per chart plate


MKII Pen Yoke Gear
Qty: 4 per chart plate


Round Gear with Stop
Qty: 5 per chart plate


Round Gear without Stop
Qty: 4 per chart plate

    * These are not factory part numbers, they are internal DIS numbers assigned to the part.


This illustration identifies which white
round gear is used at that location.

ABB, ABB Kent-Taylor, Kent, Taylor and Bailey-Fisher and Porter, are registered trademarks of ABB, Inc.


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1/12/2011 5:10:33 AM

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