Keeping Puller Performance on Track

When your puller is performing at its peak, it significantly boosts overall productivity and profile quality—reducing scrap, improving line efficiency, and delivering even, twist-free profiles. Those returns can diminish, though, if preventive maintenance is neglected.

Here, we look at a few of the key ways to combat the impact of normal wear and tear and keep your puller running smoothly.

Maintaining Proper Pulling Power

To maintain accurate, consistent pulling tension, the friction offset should be adjusted monthly, or whenever any part of the drive or carriage has been changed. Using a biasing scheme to cancel out frictional losses ensures that the pulling tension the operator specifies is the pulling tension actually received.

Give the puller a command to move, then incrementally increase the motor torque until the head begins to move. This will indicate that the torque setting is sufficient to overcome frictional losses. The data can then be stored and applied to future operating cycles to keep pulling tensions consistent and repeatable.

Keeping It Clean

Debris in the runout area can interfere with profile quality. To maintain a clean environment, clear debris from the chip trough and puller rail on a daily basis. Every six months, check the puller jaw teeth for build up and ensure the jaws can move freely; clean and lubricate as needed.

Running at the Right Height

Maintaining proper running heights for puller heads is critical to smooth operation—particularly for double pullers. Large differentials between the running heights of puller #1 and puller #2 can cause marking during handovers and extra wear and tear on the puller heads.

Puller head running heights should be checked weekly. A good general guideline for double pullers is to adjust head #2 so the lower jaw rides 1/4" above the highest point on the runout conveyor. Once the height of the head #2 jaw has been adjusted, adjust head #1 so the lower jaw rides 3/8" higher than that of head #2. This allows the extrusion to easily pass from head #1 to head #2, while limiting jaw height differential that can result in excessive extrusion movement during the handover.

Keeping Communication On Course

Communication between the control system and puller heads can become erratic if debris accumulates on the conductor rail or the sliding shoes become worn. Regular inspection and cleaning will help maintain the integrity of the electrical connection.

Sliding shoes should be inspected weekly. Inspect the shoes for uneven wear on the sides and sliding surface; replace as necessary.

Over time, airborne contaminants in the plant and dust produced as the sliding shoes wear down can accumulate on the conductor rail, degrading communication. To keep communication flowing smoothly, clean the conductor rail monthly, or more often as needed.

For additional information on puller maintenance, consult your Granco Clark service manual. Always disconnect and lockout the external power source, following established lockout procedures, prior to performing maintenance or service on any equipment.