FreeCAD 0.19 - Converting STL files to Solid models

hello and welcome to another tutorial with me andrew today i'm going to be showing you how to convert an stl file into a solid model which will then allow you to edit and alter the geometry to your specification if you were asked how to do this and i thought it would be a good video idea but also add some comments about what i've found works what doesn't work and how to get around a few things hopefully preventing some headaches now i will forewarn you that this doesn't always work especially on models that have simply been placed together and then exported as an stl file but i'll come to that a little later so first how do i create a solid model from an stl file in freecad now it is advised that you analyze and repair your model within the mesh workbench before creating a solid model you can also use a piece of free software called meshlab for this depending on the complexity of your model however i'm going to skip over that part due to the fact that i've found it adds more problems than solutions which again i'll come to later in the video so i've already got my str model within freecad just by simply clicking on the file icon up here and opening the stl model i'm within the part workbench and with our model selected i'm going to go up here to our toolbar and click on parts this will then give me a drop down i'm going to click on create shape from mesh and we'll then get a box here which is our sewing tolerance now i've read the higher the tolerance the less time the model takes to process obviously depending on computer speed however i found it to be the opposite way around the lower the tolerance the faster the process i tested geometry with a high number of faces if i set the tolerance to 0.5 it took 15 minutes but if i changed it to 0.1 it took less than a minute this doesn't really make sense to me and in my mind a lower tolerance should be higher accuracy meaning more processing time i don't know if anyone can clear this up for me and shed some light on the situation let me know in the comments below so the default value is 0.1 and that's what i'm going to leave it out i'm going to say okay and you'll see that we've now got another piece of geometry in our model tree so we've got our simple sdr file with no lines on it and if i hide that you'll see we've now got ourselves a mesh of our part i'm going to click on our new piece of geometry and again i'm going to come to the parts drop down which is on our tool ribbon and i'm going to click on convert to solid this will then create another part in our model tree so i'm going to hide our previous piece of geometry so this is now a solid as you can see we've got a lot of different faces separated by edges so we can actually clean this up now on some models this work will work in other models it'll clean up a couple lines but it'll still leave a few lines left around but it's just cleaning up as much as it possibly can if we have our piece of geometry selected again we can come up to the part drop down click on that move down to create a copy and down at the bottom here you'll see refine shape if we click on that you'll then see we create another piece of geometry all of our lines are now gone this is now a solid refined piece of geometry which we can now edit within freecad so if i was to come over to our part design workbench go to our model tab select our solid again we have to have an active body for us to be able to edit geometry i've got our cube selected and i'm going to click on this icon here which is create a body our model is now put into our body and it's called base feature so now if i was to click on the top here create a sketch add a simple circle just on the center and i'm going to pocket that through and as you can see we've now got ourselves an editable piece of geometry so as an example of what we can actually use this for let's say i've downloaded this model from grab cad or thing first i really like the model but let's say i want to change the size of the hex head so what i've done here is i've obviously gone through the process i've just spoke about and i've created a sketch on our top face and it's just a simple three mill hex like so but i want to also fill in what a previous user has created so i can do is i can click on this icon up here which allow me to select geometry from our part so i can do is i can select around that which can give us a reference point and what i can do is then is i can create a hex like so attach it to the previous geometry close out of that i can then go up here and click on the pad icon and as you'll see our geometry has disappeared i'm going to go to type and i'm going to select up to face i'm then going to move it around to the bottom of our part and select this bomb face and you'll see how it is now filled in the original hexagon so i'm going to say okay i then want this to be a little bit cleaner so i'm going to click on our pad and i'm going to go down to refine and i'm going to set that to true and click back on our window and you'll see that's now cleaned up our geometry now i've already refined this shape and you'll see what i was talking about earlier where sometimes it doesn't clear up all of the edges now i believe this is just something that we have to live with but if that's not the case please let us know in the comments down below i did look into a couple of macros especially as the process from creating an stl file into a solid model is a little bit long-winded and i think just having a button to be able to select the str model and click that button and instantaneously convert it would be so much easier i did find a few while doing my research which worked on some geometry but failed when coming against complex geometry like this part i don't know much about macros right at this moment but after seeing what we can achieve i'm really interested with getting involved i'll leave a link in the description to a macro for those of you who'd like to try it out so in this next part i'm just going to talk about a couple of errors that i found while trying to convert sdi models into solid geometry so what i was saying earlier about the mesh workbench being temperamental about analyzing and repairing certain faces so as you can see here i've got my solid model that i created from an stl file that we imported i haven't used the analyze and repair onto this yet but it's worked perfectly fine there's been no errors it hasn't told me there's anything wrong with it and i've actually tried and edited it and it's worked perfectly fine so what i'm going to do is now is i'm going to hide that and i'm going to bring back our mesh and what i'm going to do is i'm going to go and i'm going to use the analyze and repair so again i'm going to click on analyze all and it's going to come up with all of these errors telling me that there's something wrong with the geometry now personally i don't really know what's wrong with it it's saying something to do with two flip normals 17 non-manifolds 21 degenerated faces and a couple of others so if i click repair you'd think it would solve the errors using its magical abilities ending with the same model minus the errors but instead it gave me back half a model which i now definitely can't turn into a solid i would say if you're receiving errors when trying to turn your str model into a solid this could be a good place to start even if it's just to see where freecad thinks the errors are and then possibly moving it into a mesh lab if the repair tools in freecad don't give you the results you're looking for so for my second example what i've got here is this aux face and i've already created a mesh from the stl file that i imported now if i click on that go on to our part drop down and say convert to solid what this will do is it will throw up an error at the bottom of our screen here that says cannot convert 001 because shape is not a shell so i've seen that a couple of times in the forums people not quite sure what that is so i convert this to a wireframe and what you'll be able to see is you'll see that this is actually not one whole piece of geometry so for those of you who are actually creating your solid pieces of geometry you need to join everything together at the end so like i would in blender so this is the face that i created we've got our eyes and we've got our teeth here and the way we get around this is by creating a boolean and unifying all of this together so that it becomes one whole shape now remember to delete the shape once you've actually uh attached it to your main geometry otherwise uh that will still get exported as an stl file and when you import that into freecad that will also still cause an error so once you've booleaned whatever you're creating you should end up with something like this so it looks very similar but as soon as i turn it on frontwards and i save wireframe you'll see that there's no surfaces on the inside of my piece of geometry and i can actually create myself a solid so that's the first way of getting around something that you may have created yourself in something like blender a few of you may be wondering why i'm not using real fundus mod and that's only because everything that failed in the stand freak ad worked perfectly fine within the mod so i didn't want to mislead anyone but also i was a bit skeptical because everything was going so smoothly it's like this one i've still got the same face with the internal wires but yeah it works flawlessly and i've edited it and then i exported it into cura for 3d printing just to see if it failed at any point so if you're still having trouble perhaps try real thunders mod and see what results you get there so remember if you're editing another piece of geometry sculpting your own 3d models in blender creating a chess q ring or mapping the surface of the moon when they are all created correctly importing stls can be relatively pain free and actually extremely rewarding although there are sometimes you just want to rip your hair out and shout that'll be all for today's tutorial and hopefully i've taught you something that you may not have known but also something you can go out and try yourself if you liked the video give it a thumbs up and if you disliked the video give it a thumbs down thank you so much for watching i really appreciate it and i hope you all had a fantastic weekend and i'll see you in the next video

Channel: Andrew CAD

Views: 108,967

Keywords: fusion 360 alternative, FreeCAD, Tutorial, Learning, design, 3D, engineer, CAD, Quality, how to guide, create, datum, detailed, version, learn, explained, sketch, workbench, part design, module, tool, freecad, cad, modifier, educational, descriptive, creating, part, how to use, Freecad drawing, plan, geometry, plane, examples, how, to, 0.19, 3D model, 3D builder, 2021, easy, beginner, new, simple, problem, mod, realthunder, STL, stl, solid model, mesh to part, shape is not shell, convert to solid, refine

Id: GYc3BtkUtfI

Length: 9min 56sec (596 seconds)

Published: Sun Apr 18 2021