Foot Insole Modelling

[dannytso]

Hi there,

I am very new to CAD and this community. Thank you to everyone who has contributed to putting together Fusion 360. As a novice, I am having a lot of fun playing around with the functions and making simple designs. I especially enjoy the sculpting tools but I definitely need more practice and more learning.

I would like to learn how to model a custom insole to match the plantar surface of a 3D scanned foot.

My first attempt involved loading the 3D mesh into the workspace and pulling a planar t spline body towards the foot. Although the resut somewhat follows the contours of the foot it still is quite distorted and undesired. Is there a way to achieve a cleaner result? I have also tried decreasing the number of triangles on the 3D mesh using Meshmixer but still no help. Perhaps I should change the shape of my planar t spline before pulling? Thank you in advance!

I have included some images of my first attempt. Please be kind!

[dannytso]

Nevermind! I re-watched your video and figured it out that you were using the intersect command. I'm going to keep going and show you how this turns out now that I have more exact profiles.

[dannytso]

Hey Jesse,

I've attached my latest attempt. Everything went extremely well except for the rail part. This is the best looking one I've done so far in my opinion. Sectional analysis looks pretty cool and I can subjectively see how close the fit is. I'm sure I'll figure out the rail part. I am very grateful for your help please let me know if there is anything I can do to return the favor! I will make sure to subscribe to your Fusion 360 lessons!

[Anonymous]

Wow, I'm really impressed by what you did there!  I was able to create a Tspline loft using your two rails, and all the profiles, except the last one because you didn't draw the right rail spline to it.  So I redid that right rail spline, and it lofted fine, as you can see in the first Tspline body.  Then I made a copy of that (so you could see the original) and did a pull, and although it's looking pretty good, it does some funky stuff including crossing itself in places, it appears because for the profiles you didn't actually snap the spline control points onto the intersection curves, so there is quite a bit of space between them in places, greatly diminishing the quality of the result the pull operation will give.  Also your original imported mesh has quite a low face count, I would up that quite a bit (remember, the face limit for mesh to brep conversion is 10,000 faces if I remember right, whereas of course for mesh to Tspline conversion is far lower limit than that). 

Remember, as tips regarding lofting, you must hit new input for each rail.  Also what I do is select the first and second profiles, then the rails, then start adding the additional profiles, so that will know which subsequent one has a failure of rail intersect with profile, if any.  But you used very good technique since that problem did not arise.

Regarding using the attached .f3d model file, you need to download it to your computer, then open the data panel via that rubric cube like button in the upper left, then you should see the upload button.  Once it's uploaded, you should see the file listed to open. 

You're almost there!

Jesse

[dannytso]

Thanks again for the tips Jesse.

I think the rail technique looks great but I couldn't get it to work. However this is not a problem because what I did as a compromise was just make more sectional profiles for my loft especially around the heel. In fact the profiles worked so well that I realized the pull command would actually cause more problems by being too fitted to the mesh model. In practice the surface of the insole should be relatively uniform and smooth to avoid any sharp edging that may cause discomfort or blisters. 

I really didn't think I would get this far so I can't mention enough times how grateful I am that you have taken me this distance.

If its not too much trouble, could you think of a way for me to turn my insoles into something I can send to a mill? Or is it this more involved then what my current understanding allows?

Im also curious to see if there is any way I can add metatarsal pads, arch fills, and heel posting to the designs. For arch fill, which just means rather than the insole being a sheet of solid like it currently looks, its actually filled in the arch area with material. This design is neccessary if the stock material is an EVA foam. I was thinking of some sort of boolean operation? 

I've included my files for you to look at. Thanks mate!

[Anonymous]

Wow looks really good with enough profiles!  I'm curious what problem exactly you're having with the rails (I know it can be tricky to get the hang of for something like this), but great to hear you've gotten a satisfactory result. 

Regarding the next steps for manufacturing, some more information would be helpful.  So would you have the actual insoles machined, or a "negative" mold of the insoles?  Do you plan on just sending a compatible CAD file of the model to the machine shop (most likely scenario), or would you for some reason want to use the CAM side of Fusion 360 to generate gcode toolpaths for a specific CNC machine?  For these additional features, what exactly needs to be modeled (sketches would help)? 

Very cool to hear that you've made great progress towards an exciting goal!

Jesse

[dannytso]

When I try to select the rail, it says it "The loft will flow in an invalid direction. Try adjusting the continuity settings...".

It gave me this even after selecting the rail after 2 profiles. Does it have anything to do with the curves being perpindicular since the sketch planes are perpindicular? I know for a fact that it intersects. I made sure of it when creating the face curve and snapping to the intersect points. 

I've included images named respective to their examples for your consideration.

For the machining, at first I intend to send to a machine shop and be able to mill the negative and positive images. An example of a negative image would be milling the orthotic device directly. This will also require milling of both the top and bottom of the insole. An example of a positive image would be the opposite and milling only the contour of the orthotic. This one would be used for vacuum forming if I needed to use materials that can't be milled. 

In time I would like to learn how to produce a toolpath and G-code (not sure if my terminology is right) and send it to a specific mill. I would like to master the CAD first however. I am actually not sure what I am up against in terms of learning the CAM side of things. 

[Anonymous]

Hi again.  I think what you're missing with the loft, is after unchecking Chain Selection, and using New Input for for the rail (so try selecting first and second profile, and then just one rail), is that after you select the rail spline, as a new input, you then need to go to the Swap drop down field and select Convert to Rails.  You have to do that after each time you select a new rail spline (always pressing New Input button first). 

So for your other efforts, a good way to start would be to go to Patch environment then use the thicken command to add a desired thickness to your surface, making it a body rather than a surface.  You can fillet the edges to be rounded.  Also you can make sketches that use Split Body to use the sketch as a "splitting/cutting blade" that extends out perpendicular from the sketch plane.  To make molds, you can use your thickened insole as a cutting tool in the Combine operation in Model environment.  Just depends specifically what you want to do next. 

Vacuum forming sounds awesome.  What it sounds like you really need is a Hobbymate CNC and multifunction machine 😉  I was surprised how user friendly Fusion 360 CAM is to learn, but you definitely need a CNC machine for yourself to get started.  Be sure to sign up for email updates at hobbymate.net concerning an extremely capable and affordable multifunction machine, and the free comprehensive educational system (open source) that goes with it.

Jesse

[TrippyLighting]

Just came across this therad by browsing through the gallery.

The workflow @Anonymous is describing is what in the mesh modeling world is called re-topololgy. I work with Blender and it has excellent tools for retopology that would temendously speed up this process.

In essence you would import this STL into Blender and draw outlines of a low polygon mesh with the grease pencil tool that will approximate your foot/sole. the mesh that is then created by Blender can be exported from Blender and imported into Fusion 360 and will serve as the base mesh for T-Splines.

If you have the mesh in a digestable size file format I can try to make a screencast to demonstrate.

Given the very similar modeling process between modeling in a mesh modeler such as Blender, Modo, 3DS, Maya etc. and Fusion 360 T-Splines (sculpt) some retopology tools would really be a tremendous asset for projects like this.

[Anonymous]

Hey, great seeing/hearing you you again 🙂  That sounds pretty cool to have a more specialized software do that mesh fitting, especially if say a bunch of custom insoles needed to be modeled.  For now though I'll probably stay with just knowing Fusion 360 in and out, which is such a versatile program, that I've found it can do about everything, even if may not be the most absolutely efficient choice for some purposes.  I just think it's extremely rare to find software so broadly applicable yet user friendly, hence being very worth while to learn thoroughly (and for other great reasons). 

Jesse

[Anonymous]

Hello, I am very new to this and I am trying to figure out how to get a scan into the mesh mixer. I have purchased a structure scanner and can not figure out what software/program to use to get it in mesh mixer. I am going to be scanning arms, legs, feet etc, and would need to modify in mesh mixer. Also I would like to be able to print a orthotic device, what would i need to look for when buying a printer thats compatible with mesh mixer?

Any advice would be great!

Thanks,

Tim

[laughingcreek]

Hey @Anonymous-just noticed your post from november.  First bit of advice, don't tack new questions onto the end of old posts.  You'll get very few eyes looking it your question that way.  Post a new topic instead.