How to Replace the Shaft Lock on a Dremel Rotary Tool (Model 3000)

The shaft lock assembly allows you to lock your rotary tool's shaft so you can change the bit. The assembly consists of the lock pin and the retainer. Over time, the pin can wear down, causing it to slip (making it difficult to change bits). Occasionally, the retainer can break. If either occurs, the assembly will need to be replaced.

Let's get started.

REMOVING THE SHAFT LOCK ASSEMBLY   1. Remove the collet and collet nut.

a. Make sure the tool is not plugged in.

b. Depress the shaft-lock button (if possible) and unscrew the collet nut and the collet.

c. Remove the front collar by unscrewing it from the front of the rotary tool.

  2. Open the main housing.

a. Remove the four screws.

b. Use a utility knife slice through the labels on the sides of the tool. (Cut along the line where the two halves of the housing meet.)

c. Pry apart the two halves of the housing.

  3. Remove the shaft lock assembly.

a. Lift the motor and switch assembly out of the housing.

b. Remove the retainer from the front of the housing.

c. Remove the shaft lock pin from the housing.

INSTALLING THE NEW SHAFT LOCK ASSEMBLY

  4. Install the shaft lock assembly.

a. Install the new lock pin into the slot in the front of the housing.

b. Install the new retainer onto the new lock pin.

REASSEMBLING THE UNIT

  5. Reinstall the motor and switch.

a. Align the switch lever with the slot on the motor housing and install the motor and switch assembly into the housing.

b. Verify that the internal components (armature, shaft, motor, switch, bearing) are properly aligned with the mounting tabs in the housing.

  6. Install the side covers.

a. Slide the side covers over the brush caps.

b. Align the grooves on the side covers with the tabs that run along the housing.

  7. Reinstall the top half of the housing.

a. Install the top half of the housing onto the unit.

b. Secure the two halves of the housing with the four screws.

  8. Reinstall the front collar, collet, and collet nut.

a. Thread the collar onto the housing (by hand).

b. Insert the collet into the spindle shaft.

c. Secure the collet by fastening the collet nut onto the spindle shaft.