How to Make 2-Piece MDF Doors in Mozaik

To make a 2-piece MDF door in Mozaik, build the door as a separate MDF frame plus an inset panel that drops into the frame from the back, then set up dedicated CNC tool groups (an edge tool group and a panel tool group) so the whole door cuts from one side. Done right, this gives you a clean two-piece MDF door with no flip-side operations on the machine, and you can bore your hinges on the CNC at the same time.

This guide follows Mozaik's official walkthrough. Watch the original on Mozaik's channel:

What "2-piece" means here

A 2-piece MDF door is built in two parts: an MDF frame (the outer rails and stiles) and a separate panel that sits inside that frame. In Mozaik you cut a Glass Door Cutout into the back of the door so the panel can be inset from behind. The payoff is avoiding flip-side operations on the machine, which keeps the run simpler and more predictable.

Step 1 — Build the edge tool group

Open the optimizer and create the tooling you'll use to cut the door's outside edge.

1. Open the Optimizer.
2. In the optimizer, open the CNC Tooling library.
3. Add a new tool group and name it something clear like "two-piece edge" so you know it's the cutout for the two-piece door.

The green line in this view represents the edge of the door. Add your edge bit (in the demo, a 3/8" compression bit) to the group with the plus sign. With the bit on that edge line:

• Enable Flip Side so the tool cuts from the bottom (back) side of the door.
• Enable cut through (through cut) so the bit cuts fully through the material and into the spoil board, based on the through-cut settings you have for that bit.

Step 2 — Build the panel tool group

Back in your tool sets, set up a second group for the panel.

• Add a new tool group and name it "two-piece panel."
• Bring in a down-shear bit (the demo uses a 3/8" down shear), select it, and enable Flip Side so it cuts from the back.

Here the green line divides the part: everything to the left of the line is the stile and rail (frame), and everything to the right is the panel. Keep the tool centered on that line so the panel cuts through cleanly.

• Set the cut depth for the panel pass to about 5/16" — that gives a little leeway over quarter-inch panel material.
• Add your compression bit to the same group, enable Flip Side, offset the tool by the bit's diameter, and enable cut through so this pass cuts away the surrounding stock and releases the panel.
• Optionally add a smaller down-shear bit (the demo starts with a 1/8" down shear, then matches it to a 1/4" so the bits are equal) with Flip Side at the same ~5/16" depth and a small negative offset to sharpen up the inside corners and tighten them.

When the edge and panel tool groups are both set, click OK and close the optimizer.

Step 3 — Create the quarter-inch panel material

The thin panel needs its own material entry.

1. Open the Materials library.
2. Highlight your half-inch MDF, copy it, and paste a new entry.
3. Rename the copy (for example, "1/4 MDF") and set it as the panel material.
4. It has no grain, is two-sided, and the demo sets the width and length trim to 1/4".

Step 4 — Set up a material template for the door

Now bundle the frame and panel materials into a template.

1. Open the Material Templates library.
2. Add a new template and name it something like "two-piece MDF door."
3. Set the frame to 3/4" MDF.
4. Set the door panel and drawer panel to the 1/4" MDF you just created.
5. Bring this material template into the room of the job.

Step 5 — Create the two-piece door in the door library

1. Open the Doors library.
2. Add a routed door (select router), and name it "two-piece door."
3. Select the panel on the door and set the panel type to Separate Panel — this is the panel type Mozaik uses for 2-piece doors, and it's what lets the panel inset from the back.
4. Set the panel radius (the demo uses 1/16", relying on the small down-shear bit to tighten the corners).
5. Set the inset all the way around (the demo uses 5/16", leaving about a sixteenth of play as a joint for the door).

Then assign the tools in your routed door profile settings:

• Set the pocketing tool to none (no pocketing on this door).
• Set the routed door tool to the tool group you built for the Separate Panel door type (the "two-piece panel" group from Step 2).
• Critical: set the Glass Door Cutout tool to none. If any tool is left in that slot, you'll get a flip-side operation even though you never selected it.
• Set the edge tool group to your "two-piece edge" group, then click OK.

Step 6 — Check the door in 3D

Open the 3D viewer to inspect the door. You'll see the separate panel and the inset.

One visual quirk: the separate panel won't appear flush to the inside of the cut — it shows to the inside of the profile instead. Don't take the 3D look at face value. When you place a product, double-check the cut list to confirm the panel is the correct size for the values you entered.

Step 7 — Apply the door to your cabinets

• Go to your doors and drawers settings, select the base door, and pick your "two-piece door."
• Choose use defaults so it pulls in the door's defaults (the two-piece edge for the outside edge, the two-piece panel for the routed door tools, and no pocketing tool).

Step 8 — Optimize and cut from the back

• Draw a quick room, place the two-piece-door cabinet, and open the cut list.
• Optimize only the 1/4" MDF and the 3/4" MDF, then click OK to send it to the optimizer.
• In the optimizer, open the Optimize tab, confirm the correct tool set is selected, and optimize the panels.

The doors will show up green, which represents a flip-side operation. Use flip parts to flip those parts over. Right-click a door, choose edit shape, and open the 3D viewer to confirm the finished two-piece door before you process and cut.

The key thing to remember: doors are always sent to the optimizer face up. If your edge tool group and panel tool group are set up correctly and the Glass Door Cutout tool is removed, you can simply flip the parts in the optimizer and cut everything from the back side — no flip-side operations needed on the machine.

Get it done-for-you

You can set this up yourself using the steps above. If you'd rather skip the setup, PAC's Mozaik training and done-for-you services can help — phillanton.com.

Full disclosure: this guide is published by Phill Anton Consulting.

FAQ

Why do I have to set the Glass Door Cutout tool to "none"?

Because leaving any tool in the Glass Door Cutout slot forces a flip-side operation on the door — even if you never select that tool. Setting it to none is what keeps the two-piece door free of flip-side cuts.

Can I drill my hinges on the CNC for a two-piece MDF door?

Yes. Per Mozaik's walkthrough, you can drill your hinges on the CNC machine while making the two-piece MDF door, alongside cutting the frame and panel.

Why does the door look wrong in the 3D viewer?

The separate panel shows to the inside of the profile rather than flush to the inside of the cut, so the 3D preview can look off. Verify the actual panel size in the cut list instead of trusting the 3D appearance.

Why are my door parts showing green in the optimizer?

Green indicates a flip-side operation. For a two-piece door that's expected — use flip parts to flip them, then cut from the back side. That's the whole point of the setup: everything cuts from one (back) side.