Retracting and releasing stripper pins

 

 

About this topic

This topic describes how to retract and release the tip box stripper pins on a disposable-tip pipette head.

 

CAUTION Do not use the Tips On command while the stripper pins are retracted. The tip box could be picked up by the pipette head, which could result in a crash if the head is accessing a shelf.

Tip box stripper pins described

The disposable-tip pipette heads have four stripper pins that prevent the tip box from raising off the shelf when tips are being applied.

However, you can retract the stripper pins to perform a task where the pins will interfere. For example, you should retract the stripper pins when you teach a tip box shelf.

Figure. Pipette head components

 

The pins are spring-loaded and should retract until the pin head is nearly flush with the surface of the pipette head. The tip of each pin, which is hidden within the pipette head housing, has a semi-circle-shaped locking mechanism that aligns with a dowel inside the pipette head to lock the pin in the retracted position.

Retracting tip box stripper pins

 

CAUTION If you apply too much force when pressing down or rotating the pin to retract it, the locking mechanism at the tip of the pin can bend or break. A damaged pin cannot lock in the retracted position. Use only gentle pressure to push down and rotate the pin to lock it into place.

To retract the tip box stripper pins:

1	Place the pipette head upside down on a stable surface, so that the barrels are facing up and the front of the pipette head is facing you as the following figure shows.

If directional arrows appear on the pins, gently rotate the pins so that the arrows are facing you.

 

2	Insert the end of a 2-mm hex wrench into the head of one of the pins, and very gently push the pin down into the pipette head until you feel the pin stop.

Verify that the pin is properly seated, as the preceding figure shows. If the pin has an arrow, the square end of the arrow should disappear or be barely visible.

 

If the pin hits a stop before it retracts completely, the pin locking mechanism is above instead of below the locking dowel. While removing any downward pressure on the pin head, gently rotate the pin in quarter-turn increments until you feel the pin drop into the seated position.

 

3	When the pin is properly seated, rotate it counterclockwise no more than 180° until it locks.

4	Repeat this procedure for the other pins.

Releasing tip box stripper pins

To release the retracted tip box stripper pins:

1	Insert a 2-mm hex wrench into the pin head.

2	Turn the wrench clockwise to release the pin.

3	Repeat this procedure for the other pins.

 

 

Related topics

 

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Teaching a tipbox shelf	Teaching shelves 7 and 8 for tipboxes
Removing a pipette head	Changing the pipette head
Maintaining the Vertical Pipetting Station	Routine maintenance
Reporting a problem	Reporting problems