Andy - Beta MIRACO Showcases of Bones, Shells, Art, Design, Modifications

Using Miraco to design a part that fits to a complex object

Problem
The controller for my drone (DJI Mini 4 Pro) only has mounts for a neck-strap at the rear.

This means it flops forward when not supported. I would like a way to hold it at it’s center of mass.

image

There are trays that mount to the controller but they increase it’s bulk quite considerably. Ideally I want something that mounts a strap here:

Scanning
In order to create the part, we first need to create a scan of the DJI RC2 controller. It doesn’t need to be mega-detailed but we might as well show off Miraco while we’re doing it:

Getting it in to CAD
There are several ways we can get this model in to CAD. We could re-draw it from section sketches like I’ve shown before but for this project, we’ll use a different way.

Triangles to quads
I want to create a T-spline model of the controller in Fusion360. Unfortunately, the mesh to T-spline converter can only deal with quad meshes and the output of Revoscan (and all other scanning tools really) is triangles. We can covert the model to quads using a nice, free tool called Instant Meshes: GitHub - wjakob/instant-meshes: Interactive field-aligned mesh generator

Let’s load up our scan; click Open Mesh:

Our mesh is loaded and ready for conversion:

At the moment, our target vertex count is way too high at 100k. Fusion360 will have a fit. We want that around the 10k mark ideally. Move the slider to 10k:

Screenshot 2023-10-17 at 22.05.02

Screenshot 2023-10-17 at 22.05.18

Next, hit Solve under Orientation Field

Screenshot 2023-10-17 at 22.05.23

Our mesh will have lots of pretty colours on it now.

Then, hit Solve under Position Field
Screenshot 2023-10-17 at 22.05.43

And now our mesh is all squares:

Hit Export and choose Pure quad mesh (this will ensure that all the facets are quads and that no triangles remain.

Screenshot 2023-10-17 at 22.05.59

Screenshot 2023-10-17 at 22.06.10

Finally, Extract Mesh

Screenshot 2023-10-17 at 22.06.16

And Save

Screenshot 2023-10-17 at 22.06.37

Now, over the Fusion360:
Create a new project, import your quad-mesh and orientate it so that it’s aligned with X, Y, and Z.

Next, under the surface tab, select New Form

Then hit Convert

We want Quad-mesh to T-Spline

Hit OK, and Fusion will chew on it for a while, then hit Finish Form

We now have a defined solid in Fusion that we can do all sorts of things with:

As you can see, we can cut it up just like a normal solid

OK, back together we want to make a copy of it

The new object, we want to scale it to make it bigger. I want something that will fit around the controller but follow the controllers lines. Let’s make it 1.1x bigger. Make sure to scale from the origin rather than a corner.

Screenshot 2023-10-17 at 21.19.27

Now, let’s cut it up and make the rough model that we want:

Now we have our rough model, let’s put it over the 1.0 scaled original model and then use that model as a tool to cut out from our new part:

We end up with this, ready for an attachment to be added:

A quick bit of CAD and we have our part:

This is what it looks like rendered in Fusion:

Let’s print it and see how it fits:

Like a glove:

10 Likes