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If the rollers do not operate at all, check the following:
- Wiring and connections.
- SSR umbilical cable -- is it properly connected to the SCU or MCU?
- Motor -- is it burnt out or are the brushes worn out?
- Circuit breaker -- it may have tripped from excessive current.
If the rollers are turning in opposite direction, unplug the motor and reconnect to the supplied port with the polarity reversed. If the rollers are making a rubbing or grinding noise, check the following:
- Placement of the wheels with respect to the shield slots. The wheels should be roughly centered. If they aren't, the roller or roller shield is damaged or out of specification.
- Alignment of the roller surface to the roller shaft. The roller's curved surface should be roughly concentric to the roller shaft.
Open the roller assembly and carefully press on the shield between each wheel to see if the noise lessens. If so, manually reshape the shield in that position using a rubber hammer and a chunk of wood. Continue until the sound is completely gone.
- Preload screw. The preload setscrew should be no more than 1.5 turns in. With the roller turning, turn the screw in till the roller begins to deflect, which is easy to see. Then turn the screw 1.25 to 1.5 turns further to set the correct preload. If the rollers are still chattering, then the shield is not to specifications or the bearings at each end are somehow misaligned.
If the rollers do not load the paper in the precompression cavity, check the following:
- Paper may have jammed up around the 'batwing', impeding the paper from entering the precompression cavity. Remove the paper, then see if the slipsheet unit is suspended too low relative to the picker or plenum. If the picker height is incorrect relative to the plenum, check the position of the mounting rails for the SSR. If the height is correct relative to the plenum, check the picker height.
Also watch for any bending in the 'batwing', which may also result in this error.
- Rollers may not be giving equal traction. With the SSR suspended in the machine and the batwing temporarily removed, close the rollers and leave them stationary (not turning). Manually turn each of the independent rollers (on the moving backbone) by hand to get a feel for the traction and torque required to make the wheels slip. There will be some variation, but if there is an obvious reduction in traction from one end to the other, the chassis mounting rails on the machine may not be parallel, causing a twist in the SSR chassis. The twist results in high traction at one end and in some cases, no traction whatsoever at the other end. If there is a weak or excessively strong point in the center, the preload may be adjusted incorrectly.
Also look for a twist in the moving backbone or SSR chassis. The chassis may twist if the mounting rail on the base machine or MCU isn't parallel, or the chassis could have been manufactured out of specification.
- 'Obstruction above rollers' sensor. Clear any paper from the roller assembly. Place a piece of paper in front of the sensor to verify that it is functioning correctly. The light on the back of the sensor should be 'on' when the sensor can see itself in the reflector, and 'off' when the light path is blocked.
- Batwing. Move the batwing up and down to verify that it is not breaking the sensor's path. If the wing is breaking the path, verify that the two windows on the sensor are side-to-side and not top-to-bottom. Look for obvious bends in the batwing that would cause it to interrupt the sensor.
- Cabling and connectors
- Slipsheet obstruction reflector. Check the position of the reflector in case it is out of adjustment.
- Vertical face on chassis. Check that the sensor mounting surface and the reflector mounting surface are vertical.
- Rollers may be worn out, so that their diameter is reduced. The resulting gap would cause ~0 traction at that wheel location. Increase the preload if the wear is centrally located, and decrease it if the wear is located at the front/rear of SSR. Arrange to replace the rollers at a future visit.
- Compactor. The compactor can handle 2 VLF-sized sheets, but occasional jams may occur. Clear the paper and check the plate stack for double slipsheets.
- Adjust the airflow from the plenum. The adjustment is located at the blower in the back of the MCU.
- Observe the slipsheets as they drop between the rollers. The default release position is 150mm, this can be adjusted by changing val psrp from 150mm to 120mm.
If the rollers fail to open/close, check the following:
- Wires/hoses. Test that the open and closed functions of the wires and hoses are not reversed somewhere in the circuit, both in the SSR and in the SCU or MCU.
- Sensor. Verify that 'Rollers Open' and 'Rollers Closed' sensors are working properly and the wiring is correct.
- Path of backbone travel. Look for a physical interruption that is hindering the path of the backbone travel. For example, the bin covers on the end of the slipsheet chassis may be obstructing the path.
- Solenoid valve. The valve may be damaged or plugged by debris.
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