cnc router, project, Casting

Sagrada Familia Knight


I recently went to Barcelona and visited the Sagrada Familia there. It's an awesome building and if you have the chance I recommend a visit. The pictures really do not do it justice.

There are hundreds of statues, but one of the cool ones that caught my eye was this one of a knight


Whilst the Sagrada Familia is a Antoni Gaudi design, much of the construction has occured since his death based on his ideas and designs. The Passion Facade was actually designed by Josep Maria Subirachs who was working from what he thought Gaudi's intention had been.

His original sketch for this knight is sold in various forms in the gift shop, I bought a t-shirt with it on. The sketch looks like this:


So I decided to make my own min version of the statue, by starting from the sketch and sticking with a fairly cubist design.

I used Fusion360 to first draw out the lines and arcs from the sketch that I wanted, then connecting them to create discrete panels that could be extruded to different heights and angles to create my own model

This STL is available in our shop

This STL is available in our shop

Once I had the model, I created a few CAM paths to cnc it out from some high density model board. Which takes detail really well and it quite easy to machine. I wound up doing a face operation to flatten the stock, then a 3d adaptive clear with 1mm clearance from the model to remove the bulk of the material. Then a parallel pass with 0.3mm stepover using a 3mm ballnose bit. And finally with a 1.5mm flat bit I did another parallel operation but with rest machinging switched on, so it only cut in places that the previous 3mm bit could not reach. This helped pull out some of the finer details and sharp internal corners.


The above is what it looked like after the machining. There was still quite a bit to do with the file to clean up the edges, I sanded all the faces to try to remove any tooling marks, and filled all the details in.

Once I was happy with this master, I cast it in silicone. Basically I stuck it down to a sheet of mdf, then built some little walls around it to form a shape, then poured on the silicone rubber and left it to set.

Once that had cured I was left with this chunky mold


Now that I have a mold I can easily produce many copies of the model. My first attempt I used a concrete mix. However that did not work well. The agregate in the mix was too large, I didn't really mix it right, the whole thing just was note well suited to something at this scale.

Instead I bought some Jesmonite. This stuff is pretty amazing. it comes as a powder and fluid, it mixes up fairly fluid and pours in the mold quite nicely. It sets up in about 30-40 minutes, but continues to harden over a few days I believe. By default it comes out quite white and stone like which is really nice. It can also be coloured with pigments.

Again I needed to file some to clean up anywhere it spilled over the mold, but generally the castings came out great. The only issue I had was with the sword/lance type thing the Knight has, it's quite a thin section and it was very prone to snapping whilst I tried to de-mold.

To resolve this I found some heavy gauge copper wire from some house electrical wire (the kind that is actually quite stiff used to wire up plug sockets). a length of this stipped of it's inuslation dropped into the length of the sword and overlapping into the head of the horse seemed to work perfectly to provide a little extra support here, and I've not broken a single one that I did this way.

Lastly I made up a quick oak mount to put the model on. My idea was that this would work well as a book-end on a shelf in my study. So I made up a simple bracket for that, and shaped a piece of oak to form a 'terrain' beneath the horses hooves. Which you can see at the top.

If you'd like to make your own knight model, the STL is available for sale here

As always I also made a video of my build


I actually made two videos, the first one I made was a lot longer and I spent more time talking about the steps, that longer version is here: