Modification of Office Chair to Swivel Chair

The core method for converting an ordinary office chair into a movable swivel chair is to install suitable casters. The specific steps are as follows:

Material Preparation and Compatibility Check

• Caster Selection: Prioritize purchasing universal casters with self-tapping screws (such as silent rubber casters). Ensure that each caster has a load-bearing capacity of ≥40kg (the theoretical load-bearing capacity of four casters is 160kg, which can cover regular office needs). If the chair legs are made of metal, prepare additional matching screws; if they are made of wood or plastic, the self-tapping screws can be directly fixed.
• Tool Preparation: In addition to the caster set, prepare a screwdriver (cross-head or flat-head, depending on the type of self-tapping screw) and a tape measure (used to measure the distance between the chair legs to ensure symmetric caster installation).

Removal of Original Components

• Invert the Chair: Turn the chair upside down so that the chair legs face upwards. The operating surface should be stable (you can place a soft cloth underneath to prevent scratches).
• Remove the Original Plastic Pads: The original plastic pads are usually fixed to the bottom of the chair legs with self-tapping screws. Use a screwdriver to rotate counterclockwise and remove the self-tapping screws. Keep the screws for later use (if the casters come with their own screws, this step can be skipped).

Caster Installation

• Locate the Installation Points: Use a tape measure to measure the four corners at the bottom of the chair legs and mark the center positions of the casters. Ensure that the four casters are arranged in a rectangular pattern to avoid offset and chair wobbling.
• Fix the Casters: Align the center hole of the caster with the marked point. Insert the self-tapping screw vertically and rotate it clockwise until the caster base is tightly attached to the chair leg. If the chair leg material is hard (such as metal), drill a hole at the marked point (with a diameter slightly smaller than the screw) before inserting the screw for fixation; if the material is soft (such as wood), the self-tapping screw can directly penetrate.
• Check the Firmness: After installation, gently shake the casters by hand to confirm that there is no looseness or wobbling. Tighten all the fixing screws.

Testing and Adjustment

• No-load Test: Stand the chair upright and gently push it to observe whether the movement is smooth and whether the casters rotate flexibly.
• Load Test: Sit on the chair and move slowly to check the load-bearing stability. If there is stuttering or abnormal noise, re-tighten the screws or replace the casters.
• Fine-tune the Position: If the chair moves in a skewed direction, adjust the installation angle of the casters (such as slightly rotating the caster base) or replace the casters with more evenly load-bearing ones to solve the problem.

Precautions: After the modification, avoid using the chair on uneven or slippery surfaces to prevent caster jamming or slipping. Regularly check the wear of the casters and replace aging components in a timely manner. If the office chair originally had casters but needs to be replaced, first lay the chair down, pull out the old casters against the direction of the force core, and insert the new casters by applying force in the direction of the hole position.