SCHLAGE HIGH SECURITY: Upgrading Primus to Primus XP

READING THE FINGER PINS

To convert a Primus lock cylinder to a Primus XP lock cylinder, the sidebar and one or more finger pins must be changed to match the new side milling of the replacement Primus XP keys.

Before recombinating the finger pins, we will discuss reading the finger pins by determining the depth and the angle. To determine the angle, the finger pin should be held using a pair of tweezers by the gate. The gate is the cut-out in the finger pin onto which slides the notch in the side bar. The position of the extension determines the angle. Hold the tweezers horizontal with the finger pin extension on the bottom. If the extension points towards the right of the tweezers, the finger pin is right. If the extension points away from the tweezers, the finger pin is center. If the extension is towards the left of the tweezers, the finger pin is left.

Once the angle has been determined, the next step is to determine the depth. There are actually three depths of cut. The deep cuts, left finger pin number 2 and right finger pin number 6, have the gate closest to the top of the pin. The center finger pin number 4 is the one-half increment lower, but is still a deep cut.

The center finger pin (number 3) has the gate closest to the bottom, making this finger a shallow depth. The three remaining finger pins are shallow cuts; left finger pin number 1 and right finger pin number 5 have their gates one half increment higher than the number three finger pin. The right finger pin number 7 has its gate one-half increment higher than the number 1 and number 5 finger pins. This additional height of the key milling requires a new key blank in order to create a side milling having a number 7 finger pin.

KEYING A PRIMUS CYLINDER

Keying a Primus lock cylinder for most standard applications does not require changes to the finger pins or sidebar. However, to simplify the keying procedure and eliminate problems that can occur with a sidebar, springs and finger pins mishap, I strongly recommend obtaining and using a Schlage 40-066 Plug Holder when rekeying Primus or Primus/Everest lock cylinders. This Plug Holder has grooves at 3 and 9 o'clock in order to accommodate operating the plug using a Primus key, loading finger pins or pin tumblers and generally keeping all of the components together.

When loading an empty Primus plug, begin by making sure the five finger pins agree with the five depths of cut in the side milling of the key. Once the five finger pins have been determined:

Step 1. With no key and no bottom pins in the plug, insert one spring into each end of the side bar slot in the plug.

Step 2. Place the sidebar against the two sidebar springs in the body of the plug and keep these pieces in place. The sidebar must press into the body of the plug in order to enter the Plug Holder.

Step 3. Beginning with the rear, slide the plug completely into the Plug Holder with the keyway upside down and the side bar sliding into the 9 o'clock groove.

Step 4. Insert one finger pin spring into each of the five finger pin chambers.

Step 5. Choose the five finger pins that will accommodate the milling positions in the side of the key.

Step 6. Beginning at the bow of the plug, insert the first finger pin into the into the pin chamber. Use your finger to keep the first finger pin within the plug.

Step 7. Insert the Primus set-up key into the plug just far enough for the side bitting to keep the first finger pin in place. The tip side milling does not have to be the same depth and angle of the finger pin.

Step 8. Insert the next finger pin into the plug and slide the set-up key in one cut further in order to keep the finger pin in place.

Step 9. Repeat this three more times until all five of the finger pins are installed and the set-up key is completely in the keyway.