How to Fix Matrix KI Stacking Chairs (Patent D246813)
A Complete Guide to Replacing the Broken Stacking / Ganging Connector
Matrix KI stacking chairs are extremely common in churches, schools, auditoriums, and event spaces. They're durable and lightweight — but one small plastic part consistently fails: the stacking/ganging connector located under the seat.
And because KI no longer manufactures this part, finding a replacement online is almost impossible.
This guide will help you:
- Identify your exact Matrix KI chair model
- Understand why the connector breaks
- See what the part looks like
- Learn how to replace it
- Get access to a custom-manufactured replacement part
How to Identify a Matrix KI Chair (Patent D246813)
Flip your chair over and look for molded markings or a sticker label that includes:
- The Matrix KI branding
- A patent marking: D246813
- A molded plastic shell with welded wire frame
If your chair looks like this, this article and the replacement part below are exactly what you need.
Matrix KI chair underside showing seat labels, patent number D246813, and mounting position for the stacking / ganging connector that commonly breaks.
Original 1978 design patent (D246813) for the Matrix KI stacking chair manufactured in Green Bay, Wisconsin.
Why the Matrix KI Stacking / Ganging Connector Breaks
The small connector under the seat is responsible for:
- Stabilizing stacked chairs
- Helping chairs align when nested
- Keeping tall stacks from shifting
- Connecting (“ganging”) chairs into a row
But after years of use, the original connector often:
- Cracks at the screw holes
- Breaks completely off
- Becomes brittle
- Falls off during stacking
- Causes chairs to lean or collapse when stacked
Unfortunately, KI no longer sells this part, and there is no OEM replacement.
Broken Matrix KI stacking / ganging connector showing common failure under the seat—this is the part most often needing replacement on Patent D246813 chairs.
The Solution: A Custom 3D-Printed Replacement Connector
To help facilities avoid throwing away an entire inventory of chairs, we engineered a precision 3D-printed replacement connector that fits all Matrix KI chairs under Patent D246813.
This upgraded connector:
- Matches OEM dimensions
- Uses the original screw holes
- Fits securely on the frame
- Is printed with durable engineering-grade materials
- Is stronger than the original plastic part
These are manufactured in the USA and available in single units or multi-packs.
Are you lookig to order in Bulk? Contact us for our Bulk Price.
A custom 3D-printed replacement stacking connector designed for Matrix KI chairs (Patent D246,813). This part restores proper stacking alignment and replaces the original connector that commonly cracks or breaks over time.
How to Install the Replacement Connector
You only need a screwdriver. Installation takes about 2 minutes.
Step 1 – Flip the chair over
Place it on a table or clean floor.
Step 2 – Remove the three screws
These hold the old connector in place.
Underside of a Matrix KI chair (Patent D246813) showing the original connector location and the screws that must be removed to replace the broken part.
Step 3 – Position the new connector
The replacement part aligns exactly with the original footprint.
Step 4 – Reattach the screws
Tighten firmly but do not overtighten.
Step 5 – Test the stack
Stack multiple chairs to ensure even spacing and stability.
Matrix KI chairs stacked on their storage cart—the repeated stacking pressure is what causes the original ganging connector to crack or break.
Does This Fit My Chair?
This replacement stacking/ganging connector is compatible with:
- Matrix KI chairs
- KI Matrix branded chairs
- Chairs manufactured under U.S. Patent D246813
- Models with two-piece molded shell + welded wire frame
If your chair looks similar to the images, you have the correct part.
Matrix KI stacking chair in use—this style is commonly found in churches, schools, and auditoriums and often requires connector replacement after years of stacking.
Where to Buy the Replacement Connector
You can purchase the replacement stacking/ganging connector here:
👉 Click here to buy the Matrix KI Chair Replacement Connector
Available individually or in multi-packs for facilities with large inventories.
Why We Created This Replacement Part
We originally engineered this connector because our own facility had dozens of chairs with broken connectors. After contacting KI, searching online, and checking resellers, we discovered:
- The part is no longer made
- No third-party replacements exist
- No repair kits are available
So we reverse-engineered the original design and produced a stronger, more durable replacement that fully restores the stacking capability of Matrix KI chairs.
Now, through ReplacementPieceFinder™ by Crazy Amazing Designs, we make these parts available nationwide.
Need a Custom Replacement Part?
If you have a broken or missing part from furniture, equipment, staging, rigging, or anything that needs repair, we can design and manufacture a replacement.
We offer:
- Custom 3D modeling
- 3D printing with engineering plastics
- CNC machining for metal, wood, and composites
- One-off or multi-part production
👉 Contact us to start a custom part project
This guide explains how to repair Matrix KI stacking chairs (Patent D246813) by replacing the broken stacking/ganging connector using a custom 3D-printed replacement part. Includes identification photos, installation steps, failure examples, and where to buy the replacement connector.
