CNC for Architectural Models

Our client wanted to show 3 models for the Commission of Fine Arts presentation. One would be the existing site, and the two options.

I thought using CNC’s I could mill out the site from MDF. At the scale I wanted to show them, I’d need 1.5″ of travel in the Z direction. The typical MDF thickness is 3/4″ so I could glue two of them together, but you’d see that glue seam in the model and that would be very distracting. I was able to find a 4×8 sheet of 1.5″ thick MDF at a specialty cabinet shop. It cost about 250$, and was very heavy.

I cut the MDF down to size and started experimenting with the CNC’s. This was my first time using these Shopbots, and the software I was using was no where near as precise as RhinoCam. These CNC’s were not a vacuum bed, so I ran screws through the MDF to hold it in place.

I went through a few tests on these. With new software you always have to figure out the work arounds to get the machine to do what you want it to. The first 2 tests I did came out pretty bad.

Luckily I had the 4×8 sheet, so I could make a handful of mistakes.

I set up 3 different bit passes. This one is the rough out. It just takes out a bunch of material quickly.

After thats done I switch it over to a 1/4 ball to get some detail

Then at the end switch to a 1/8″ flat to carve out the stairs and stuff

These photos are a mix of the three different models.

When they were all milled out, I cut the extra MDF off on the table saw, and built wooden frames for them. I laser etched the project name on the frames. I thought it was a nice detail.

Each model took 6.5 hours to mill out.

Turned out pretty nice.


On the topic of CNC’s.

I was also working on another site for a job we were pursuing.

I ordered some really expensive tooling foam for this one. It was 4″ thick and 20#pf. This stuff is awesome. I have since purchased a 4’x8’x4″ and 4’x8’x2″ sheet of this stuff. together those sheets weight 450 lbs.

I altered the file to so that you could  count the stepped topography. This also gave it a really cool look. I only used a 1/2″ flat mill on this one. One pass only, 3.5 hours.

So I set up the Canon.

Of course I filmed a time lapse.


Here is the final output.

Fun Stuff!




  1. Thats awesome. It would be great to have full time access to a CNC for random cool stuff. All the models turned out really nice, the tooling foam one is super sharp!. also I really like all the laser cut details. The videos are fun!

    • I bought the MDF from this East Coast based company
      It is pretty hard to find MDF that think, but if you call around enough, you’ll be able to find it. It usually comes in a 5’x9′ sheet for some reason. A little pricey as well, I think I spent $280 on the sheet. Try large cabinet shops. Good luck.

Submit a comment