CNC Milled License Plate Frame

I created a License plate frame on the CNC Mill using Fusion 360 for the design. I included a custom design on the bottom of the frame from a vector I translated in inkscape. The frame was made using a 7x12 inch piece of .25 inch thick aluminum plating.

1. Fusion 360: Used for the design process of the project.
2. CNC Mill: Used for the actual manufacturing of the frame.
3. Vertical Band Saw: Used to cut the stock down to size and to remove the external tabs off of the frame once the Milling was complete
4. Die Grinder: Used to remove the internal tabs off of the frame. (What I found to be the easiest and most efficient way)

The making of this prototype came from my brainstorm sketch which I mostly kept the same. It was to see if the dimensions I had researched and found would actually fit with the car. I would highly recommend this step because you don't what to have the finished piece and have it not fit.

The first step of the project was to design the Frame in Fusion 360. To find the dimensions for the frame I researched the standard size of license plate frames and went from there. The engraving pattern on the bottom was also added in this step, I would highly recommend simplifying your DXF file in inkscape before putting it into fusion, it caused my computer to crash because there were to many points.

After the design was complete I created the CAM software In Fusion and uploaded it to a USB drive. The first operation in my CAM was facing the part then i engraved the design and then I did the contouring in 3 separate operations, first the inside then the outside.

The speed for both the engraving and the contouring was 8000 RPM. For engraving I used a 1/4" spot drill. For the contouring I used an 1/8" Flat end mill. The cutting dept I used was the same as the high of the stock, .25".

This is an interactable version of the CAD model for the design:

The second step of the process was mounting the stock in to the CNC Mill. This was by far the most difficult as each method we tried posed issues. We decided on the setup that is pictured above.

The reason for the custom mounting blocks is that we cut the stock too small to be able to comfortably machine the piece without knowing we wouldn't hit the blocks. I would recommend to cut the stock into 8x12 that way you have more material to work with.

The custom blocks were created by by drilling a hole using a drill press into a piece of scrap metal, then we bolted them down in the machine like normal strap clamps.

This part went smoothly, except for when we broke the endmill. To avoid this I would recommend adding a ramp feature into your Fusion 360 design, The Ramp toolpath is designed for machining areas with steep angles or vertical walls. Instead of cutting at a constant Z, the Ramp strategy ramps down the walls, ensuring the tool remains engaged throughout the cut and dose not break from too much stress. This can be seen in the Fusion 360 design process above.

During machining we first did the engraving on the frame because it would be easier for the machine. We then cut the main frame out. An issue that occurred during this part was that the stock got moved over before machining started so the sides of the frame were uneven. My best guess as to why this happened was that after we had probed the stock in the machine it was moved over slightly. To fix this I went back to Fusion 360 and edited the design so that the sides would be an even size.

After machining there were tabs left connecting it to the left over stock, these were so the piece wouldn't fly away in the machine. To remove these tabs I used the horizontal band saw to remove the one on the exterior. The internal tabs were a little more of a challenge. At first I tried using a hacksaw to remove them but they were too thick, so I decided to use a Die Grinder. I clamped the piece to a work table and went along the edge of the part to cut the tabs. This worked very well, unfortunately it is very easy to damage the part like I did so make sure to be careful.

After removing the tabs I used a belt grinder to sand down the final imperfections, and then I tested it out on my car. It worked perfectly and this was a very fun project to do. My only area of improvement to note is finding a better way mount the stock in the machine. I'm sure it could be achieved in a much easier and more reliable fashion than what I did.