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.

This page (Milling Top Sides) was last updated on Jun 14, 2022.

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