This project shows you how to turn scraps of wood into wooden building bricks. These wooden building bricks are LEGO compatible, so they can be used in LEGO builds and showcase their beautiful wood grain.

This CNC milling project covers using the Bantam Tools PCB milling machine and Fusion 360. 

Learn how to CNC a two-side part using an alignment bracket and LEGO base plate as a holding jig. 

This guide covers setting up wooden stock material, facing and milling operations for the top and bottom side of a 2x4 lego compatible brick.

The techniques and process used in this CNC project can be adapted to create unique bricks and maybe even those rare types that are hard to come by.

Parts

1 x BantamTools Desktop CNC
PCB Milling Machine
1 x 1/8in Flat End Mill
Achieve a nice finish on both the top and bottom of material
1 x 1/16in Flat End Mill
Fish Tail, Downcut Spiral Bit
1 x PCB Alignment Bracket
Bantam Tools Desktop PCB Milling Machine Tool Set
1 x Double Sided Nitto Tape
1in wide x 36 yrds roll
1 x Hard Wood Material
1/2in Thick Wood Material

Fusion 360

The bricks were designed in Autodesk Fusion 360 and features parametric timeline and sketches for modifying.

Use the link below to download the source file.

User Parameters

In the Design workspace inside Fusion 360, click on Change Parameters under the Modify dropdown menu.

These user parameters allow quick modifications to the various features such as brick length, width and height.

Pattern Driven

The studs are driven with a rectangular pattern. Double click on the rectangular pattern feature in the parametric timeline modify the quantity for scaling up the top side of the brick.

CNC Tool Paths

The GCode files are also included for reference using the Bantam Tools PCB mill.

The tool paths are optimized for milling the top and bottom sides of the bricks separately.

The file names indicate tool size, operation and the top or bottom side of the brick.

Choose Material

Decide what type of material you'd like to use. Consider the size of your CNC machines spoil board when deciding the size of your stock.

The BantamTools Desktop PCB Milling machine has a maximum build area of 5.5" x 4.5" x 1.6" (139mm x 114mm x 40mm). Your stock should be smaller to accommodate for probing alignment brackets and installing a tool.

Measure & Cut Material

Measure the length and width of your desired material, followed by the thickness.

Cut your material down to size to fit within the working volume using a power tool or hand tool, such as a hand saw, miter saw or similar.

If you're using the PCB milling machine from Bantam Tools, we suggest keeping the length of your stock ~130mm (5in) and width ~100mm (4in).

Top & Bottom Facing

If your material is slightly warped, you'll want to face both the top and bottom surfaces of the stock material.

If your material is 13mm thick, you will need to get it down to 11.5mm thick. This means you'll need to remove 0.75mm of material from the top and bottom of the stock.

Download Tool Library for Fusion 360

If you haven't already, download and install the Bantam Tools library for Fusion 360. Click on the link below for a walkthrough of installing the library.

Model Stock

In Fusion 360, create a new design and make a new sketch on the floor plane.

Enter the length and width of your material using the sketch dimension tool.

Use the extrude feature to extrude the sketch profile and enter the materials thickness. This example rounds off the value to 13mm.

Stock Setup

In the manufacturing workspace, create a new stock setup.

Click on the bottom left, upper stock point of the stock model.

Select the stock tab and enter 0 for the stock side offset and stock top offset.

Click OK when finished.

Face Operation

Select the face operation under the 2D dropdown menu. 

Under tool, click the select button. Search for the 1/8in Flat End Mill in the Bantam Tools Fusion 360 Tool Library and click Select.

Face Speeds and Feeds

Update the values in the Feed & Speed tab, spindle speed, cutting feed rate and the plunge feed rate.

Under the Heights tab, update the offset value under the Bottom Height section.

Under the Passes tab, enable Multiple Depths and enter 1mm into the Maximum Step down text field.

Click OK when finished.

Simulate Face Operation

Click on the simulate icon in the actions dropdown menu.

Use the playback controls to simulate the face operation.

Post GCode

Right-click on the face operation under the setup in the Browser panel.

Select Post Process. Under Post, select Bantam Tools.

Enter a file name under the name/number text field. For example, 1-8-face-100x130mm.

Click the folder icon under the Output folder and choose a desired location to save the gcode file.

Click Post when complete.

Material Setup in Bantam Tools

In the Bantam Tools software, click on the material setup icon in the menu.

Enter the stock dimensions under the material size section.

Under material placement, enter 0.3mm in the material offset z text field.

Initial Setup in Bantam Tools

Click on the Initial Setup icon and then click Open File.

Browse and locate the gcode file from earlier and click Open.

Under the T1 section, click and select the 1/8in flat end mill tool from the dropdown menu.

The next page walks through prepping your stock onto the spoil board.

Install Tool for Facing

In the Bantam Tools Software, click on the JOG icon in the menu on the lower left. Then, click Install Tool.

Use the wrenches to loosen the collet from the spindle and remove the current tool (if there is one already installed).

Insert and install the 1/8in flat end mill into the collet. Tighten the collect using the wrenches.

In the software, select the empty dropdown and choose the 1/8in flat end mill tool from the menu.

Click NEXT and then START. Watch the machine probe the 1/8in flat end mill tool by touching off the spoil board.

Secure Stock to Spoil Board

Wipe down the surfaces of the stock material using a paper towel. Remove any stickers or packaging material from the wood stock.

Apply strips of double-sided nitto tape to one of the surfaces of the stock.

Use several strips of tape to gain the most coverage possible across the surface of the stock. Ensure none of the strips are overlapping.

Peel and remove the protective backing from the strips of tape when ready to secure the stock to the spoil board.

Align the stock material with the lower left corner of the spoil board. Place the stock down onto the spoil board with the edges being as square as possible.

Firmly press down and apply pressure to secure the stock to the spoil board.

Mill Single File

Click on the Plan Setup icon on the left menu. If you see a collision warning, you can add a 1mm value to the X text field under the plan offset section.

Click on Summary Run Job icon on the left menu. Click Mill Single File when ready to begin milling.

Remove Stock from Spoil Board

When the milling job is complete, remove the stock from the spoil board.

Drops of alcohol can be used to loosen the tapes adhesive. Be careful removing the stock from the spoil board.

Flip and Continue to Face Material

Update the material thickness in the Material Setup tab.

Change the Z 13mm value to 12.25mm (because we removed 0.75mm from the surface of the stock).

Apply new strips of double-sided nitto tape to the surface that was just milled. Secure the stock back onto the spoil board.

When ready, click Mill Single File to begin facing the other side of the stock.

After the milling is complete, leave the stock on the spoil board. Proceed to the next page to continue milling a batch of 2x4 building bricks.

Bottom Brick Body

In the design workspace, hide the top brick body from the Browser panel.

Click on the eye icon to show/hide bodies in the Browser panel.

We'll begin milling the bottom side of the 2x4 bricks first.

Setup Stock for Bottom Side

In the manufacturing workspace, create a new stock setup.

Click on the bottom left, upper stock point of the bottom brick model.

Select the stock tab and enter 0 for the stock side offset and stock top offset.

Click OK when finished.

Bottom Contour Settings

Click on the 2D contour icon in the 2D Milling Menu.

Select the 1/8in flat end mill under the tool section.

Update the values in the spindle speed, cutting feed rate and plunge feed rate.

Select the Geometry tab and select the bottom outline of the of the 2x4 brick, it should be highlighted in blue.

Under the Passes tab, enable Multiple Depths and enter 1mm into the Maximum Roughing Step down text field.

Click OK when finished.

Bottom Pocket Settings

Click on the 2D Pocket icon in the 2D milling menu.

Select the 1/16in flat end mill under the tool section.

Update the values in the spindle speed, cutting feed rate and plunge feed rate.

Select the Geometry tab and select the surface on the 2x4 brick highlighted in blue.

Under the Passes tab, disable Stock to Leave and enable Multiple Depths.

Update the value in the Maximum Roughing Step down text field.

Under the Linking tab, update the ramp clearance height text field.

Click OK when finished.

Contour Pattern

In the Browser panel, right-click on the 2D contour and select Add to New Pattern.

Under the Direction 1 section, select the X axis or a line edge on the bottom brick body.

Update the Spacing for Direction 1 and the Number of Instances 1.

Enable Additional Direction.

Under the Direction 2 section, select the Y axis or a line edge on the bottom brick body.

Update the Spacing for Direction 2 and the Number of instances 2.

Click OK when finished.

Post Pattern GCode

In the Browser panel, right-click on the Pattern of the contour operation and select Post Process.

Select Bantam Tools in the Post section.

Enter a file name in the name/number text field under the Program section.

Click on the folder icon under the Output folder section and choose a desired location to save the file. 

Click Post when finished.

Repeat this process for the Pattern of the pocket operation.

Pocket Pattern

In the Browser panel, right-click on the 2D pocket and select Add to New Pattern.

Under the Direction 1 section, select the X axis or a line edge on the bottom brick body.

Update the Spacing for Direction 1 and the Number of Instances 1.

Enable Additional Direction.

Under the Direction 2 section, select the Y axis or a line edge on the bottom brick body.

Update the Spacing for Direction 2 and the Number of instances 2.

Click OK when finished.

 

Bantam Tools Plan Setup

In the Bantam Tools software, click on the initial setup icon.

Click Open File and select the contour pattern gcode file for the bottom brick.

Select the 1/8in flat end mill from the T1 dropdown menu in the milling tool section.

Click on the plan setup icon. Under the gcode file, add a 1mm value to the X and Y text fields in the Plan Offset section.

Repeat this process for the pocket pattern gcode file.

Be sure to select the 1/16in flat end mill when setting up the milling tool section.

Milling Bottom Bricks

The 1/8in flat end mill should already be installed. Your stock material should be 11.5mm thick and secured to the spoil board.

When ready, click on Mill Single File for the contour pattern gcode file.

When the milling job is complete, run through the Clean-Up Wizard process.

After cleaning, proceed to install the 1/16in flat end mill.

Proceed to click on Mill Single File for the pocket pattern gcode file.

When the milling is complete, run through the Clean-Up Wizard once again.

Proceed to remove the bricks from the spoil board.

Finish Bottom Bricks

Use sand paper to remove any rough edges and burs.

Test Fit Bottom Bricks

The bottom bricks should fit onto standard LEGO base plates and bricks.

In the next page, a LEGO base plate is used as a jig holder to mill the top side of the bricks.

LEGO Base Plate Jig Holder

Use a 4 x 12 stud LEGO base plate as the jig holder for milling the top sides of the bricks.

Top Model Update

In the Fusion 360 Design workspace, hide the bottom brick body and show the top brick body.

Click the eye icon to Show the "studs" sketch and double click the length and width dimensions to edit them.

Enter 31.8mm for the width and 95.8mm for the length.

Double click on the R-Pattern icon in the timeline to edit the pattern.

Update the quantity values in the rectangular pattern panel.

Click OK when finished.

Top Side Stock Setup

In the Fusion 360 manufacturing workspace, click on the Setup icon.

In the setup panel, click on the Stock tab and choose Relative size box from the dropdown menu.

Under the stock section, enter 0 into the stock side and stock top offset text fields.

Click on the Setup tab and then click on the bottom left, upper stock point of the top brick model.

Click OK when finished.

Top Side Pocket

Click on the 2D pocket under the 2D menu.

Select the 1/16in flat end mill under the tool section.

Update the values in the spindle speed, cutting feed rate and plunge feed rate.

Click on the Geometry tab and select the surface highlighted in blue.

Click on the Passes tab. Disable Stock to Leave and enable Multiple Depths. Update the value in the Maximum Roughing Step Down.

Click on the Linking Tab. Under the ramp section, update the value in the Maximum Ramp Step Down text field.

Click OK when finished.

Top Side Post

In the Browser panel, right-click on the top side pocket operation and select Post Process.

Select Bantam Tools in the Post section.

Enter a file name in the name/number text field under the Program section.

Click on the folder icon under the Output folder section and choose a desired location to save the file. 

Click Post when finished.

Top Side Material Setup

In the Bantam Tools Software, update the dimensions of the material under the material setup tab.

 

New Material Thickness

The material thickness is updated to 14.8mm to accommodate for the LEGO base plate.

The material offset is set to 0.3mm to accommodate for the thickness of the Nitto tape.

Top Side Gcode Setup

Under the Initial Setup tab, Click Open File and select the top side gcode file.

Select the 1/16in flat end mill under the T1 milling tools section.

Install Probe Tool

Click on the JOG icon and select Install Tool in the panel.

Select the 1/8in Diameter Probe tool from the dropdown list.

Use the wrenches to remove the currently installed 1/16in tool.

Install the 1/8in flat end mill upside down, with the blunt end facing the spoil board.

Click Next and watch the machine probe the 1/8in tool.

Install Alignment Bracket

Under the initial setup tab, expand the brackets and accessories dropdown.

Click on the Locate button under the PCB Bracket section.

Proceed to attach the bracket and securely tight the included screws.

Click on Next and watch the machine probe the edges of the alignment bracket using the 1/8in tool.

Install and Secure LEGO plate

Apply a strip of tape to the bottom of a 4x12 LEGO base plate.

Secure the LEGO base plate to the lower left corner of the alignment bracket.

Secure Bottom Bricks

Proceed to press fit 6x bottom bricks onto the 4x12 LEGO base plate.

Apply firm pressure to ensure the bricks are fully seated onto the base plate.

Mill Top Side

Click on the JOG icon and select the 1/16in flat end mill.

Proceed to install the 1/16in flat end mill.

Click on the summary Run Job icon and then click on Mill Single File when ready.

Finished Milling Job

Once the milling job is complete, proceed to run through the clean-up wizard.

Remove Bricks

Once finished, remove the bricks by pulling them off the LEGO base plate with a fair amount of force.

The top side didn’t require any additional sanding, so they're ready to go straight off the jig.

Test Fit Bricks

Begin test fitting the bricks by snapping two bricks together.

Try stacking all six bricks to get a feel of the tight tolerances.

Create a block by stacking three sets of bricks together by alternating the orientation of the bricks.

Make More Bricks!

Congratulations on CNC milling your first batch of wooden building bricks! 

You can repeat the process to create more bricks and continue to get familiar with this workflow.

This guide was first published on Jun 15, 2022. It was last updated on Jun 15, 2022.