What is the workflow to reverse engineer an STL-based body?

[Anonymous]

I must do the following:

1- Import many stl files representing a robot---DONE

2- Reverse engineer each stl mesh body to create a real CAD component (not converting to BREP since such a workflow is not recommended)  so adding joints to real holes(real geomteric circles and not a fake circles formed by polygons) and many other component-based operations..etc,,,are supported.

Assuming that reverse engineering is really implying a complete duplication of the mesh using F360 facilities, what is the workflow for doing this reverse engineering on the stl mesh provided in the attached file? Show me how to create this one component so I may do all the rest myself.

BTW---This is a really fantastic product with absolutely exemplary technical support!!!

[jeff_strater]

unfortunately, I don't have time tonight to reverse-engineer your component, but I did have this screencast already created that shows the basic tools.  The process is a bit manual, but the tools make it easier.  And, you wouldn't have to reverse engineer your entire component.  You might be able to get away with just the critical portions where the joints go.  It's better if you have the time, to re-model the whole thing, but you can cut corners in some cases.

Jeff

P.S.  If no one takes your challenge by tomorrow, my time, I may be tempted to give it a shot...

[Anonymous]

Ok I would appreciate it if you would give it a shot....Also, I know reverse engineering buys me joints to holes, but is there really anything else a total reverse engineering buys me?

[jeff_strater]

Hi @Anonymous,

Here you go.  It took a bit longer than I had planned, mostly due to other distractions during the day.  But, in all honesty, there were also some challenges that I had encountered, including a few crashes along the way...

Anyway, here the result and a video leading you through the process:

If you have any follow-on questions, please let me know.

Jeff

[Anonymous]

All I can say is WOW!!.......and let me say it again...WOW!!!!  You have definitely mastered the art of explanation by example!

No one could ask for better.

I am totally sold on Fusion 360 because besides being a great product, the community forum support demonstrated by you and others like you is truly outstanding!

The support you've just demonstrated elevates a great product to a world class product.

I usually don't give praise like this, but after spending decades as an IT consultant interacting with many different support groups for a myriad of products, your support is without any doubt the best.

I will now replicate your work based on your example.

Thank you Jeff, and Autodesk for such great support.

[jeff_strater]

So, one more way to do this.  The full reverse engineering process is quite tedious, as I found.  So, I tried another approach, which is kind of a hybrid one.  Unfortunately, there are some Fusion bugs that make this clunkier than I would like, but it is still easier than doing the whole thing.  Just another option:

Jeff

[Anonymous]

These are the steps I took to replicate your reverse engineering of the STL component:

1. RMC Root of tree…select "Capture Design History"
2. LMC STL component name in tree
3. LMC light bulb icon to turn on origin (this is needed to observe the available planes of the component [XY, YZ, and XZ])
4. LMC "Your Name" Drop down" menu and LMC "Preferences"...LMC "Preview"…LMC "Mesh Workspace"…. LMC "Ok" button
5. Skip this step for this component-- LMC on "Construct" dropdown menu and select "Offset Plane" and then LMC Cancel button
6. LMC on "Sketch" dropdown menu and LMC on  "Mesh"….LMC "Create Mesh Section"
7. LMC on portion of body that coincides with one of the planes of the origin geometry depiction (in this case the YZ plane)
8. Rotate the sketch along the XY plan  or the YZ plane….and move it to desired position for eventual extrusion and LMC "Ok" button
9. LMC Sketches Branch in Browser tree then LMC Sketch Branch to select sketch
10. LMC on "Sketch" dropdown menu and LMC on  "Mesh"….LMC "Fit Curves to Mesh Section"
11. Use Spline icon to assign dots that define the sketch
12. LMC "Stop Sketch" button
13. RMC inside face of sketch and LMC "Press Pull" ---This is where I am unable to select a face to extrude…what am I doing wrong?

The file for my attempt is attached.

[Anonymous · Accepted solution]

Ok, I finally figured out what was wrong.

The faces were not created because the sketch was not a closed sketch for some reason.

There are two sets of tools (or two different ways) ) for drawing lines and arcs and.... etc available to create a closed sketch. One set is presented in the "Fit curves to mesh section" dialog and it isn't as easy to use as the second set of tools located under the "Sketch" dropdown list.

The second set of tools located under the "Sketch" dropdown list seem to offer more  precision, so I was more easily able to create a closed sketch and thus a face for extrusion purposes.

[masterskywalkerog]

has anyone done it with a complex scan ??