Needle Centering

Measurement

  1. Click the Head Up button in the AMAYA OS Maintenance-Head Timing menu and then color change to the “closest needle” as indicated by the one- or two-digit number written in the front right corner of the base casting.

  2. Take the needle to bottom dead center and check the left to right centering of the “closest needle” (in relationship to the rotary hook center line). Replace the needle and check again. If the centering is off, proceed to the Needle Centering Procedure below.

  3. Click on Head Up, color change to Needle 1, then click Bottom Center and check the needle centering.  Needle centering (left to right) cannot be more than +/-0.004” [0.1mm] from the closest needle.

  4. Repeat the above step for the remaining needles.

  5. If the needle centering requires adjustment, adjust it on the “closest needle” using the procedures in the following section.

Needle Centering Procedure

  1. Press the Head Up button in the Head Timing menu and then color change to Needle 9.

    HTIMER.gif
    Figure 1: AMAYA OS Head Timing Menu

  2. Open the Steppers menu and click on the Home button under the Color Change column.

    cm_steppersmenu.jpg
    Figure 2: AMAYA OS Steppers Menu

  3. Switch to the AMAYA OS Maintenance-Head Timing menu and press the Bottom Center command button and check the centering of the needle in the rotary hook center line.

  4. If the needle is off-center left or right to the rotary hook center line, loosen the color change index sensor screw shown in Figure 2 below.  Move the screw right or left (direction opposite of where needle is off center in the needle plate hole) and tighten the screw back to Melco Torque Specifications, then repeat steps 3 and 4 until the needle is centered to the rotary hook.

    cm_needlesensorscrew.jpg
    Figure 3: Needle Index Sensor Screw

  5. If the needle is off center front to back, consult Engineering assistance.  The needlecase or the upper to lower alignment is probably out of adjustment.

  6. Click the Head Up button in the AMAYA OS Head Timing Menu and then color change to needle one.  Press the Bottom Center button and check the needle centering.