Learning FreeCAD for Beginners | 38 | Modifying STEP and STL files

hi everyone and welcome back to the channel and welcome back to another episode of The Learning free care for beginners today we're going to be looking at two file types and they're the most common file types that we see in the world of Cad and 3D and that's STL files and step files we're going to be learning the difference between those two files and how to manipulate those in free CAD so we can understand how to use files that we can download from the Internet or that are given to us by someone else and work on those and remix those I'm going to be using a part that I've made in freecad and the exported versions of those in both STL and step to demonstrate this subject so I hope you're enjoy these videos and let's have a look at these two file types if you like we've seen please subscribe to the site I also have a co-fire or a coffee site that you can donate to if you so desire and that's at Ko hyphenfi.com forward slash m-a-n-g-0 also run a patreon where you can subscribe and get extra content and that's at www.patreon.com mango jelly Solutions any money that's kindly donated will be used to span the channel so look at the model that I've designed we can see we have a body here now we've created in something like the part design number of operations and we end with the filler when I export this out from say file Expo we get a number of file types to choose from we're interested in the STL and the step file now notice that stls both STL and astl one's a binary version the STL and the AST is an ASCII version so that is text it's advisable to go for the binary version The Dot STL and that's defined by actually supplying the dot STL or the dot AST on the end of the file name we also got the step file it's got two file extensions one's dot STP and the other one's dot STP you can select either all so there's a case of just selecting it and using the save to export out there are settings in freecad go over to the preferences and go into import export and we look along here we can see step and we're going to decide what we want to change in there a step file that's exported is here on the right and you can see there's a difference between the step and the STL the step file looks very similar to what's been built actually in freecad for the part design but it doesn't have all the operations that will not come across in any step file this is the geometry of the object itself not the actions or the operations that make it up the stil file this one on the left you can see straight away there's a difference if I hover over the step file all the faces are separated and all the edges are separated from that model as per the free cap build whereas the STL it's all one face so you can see the whole lot is highlighting as I hover over it whereas the step we can select the edges the faces Etc quite important when it comes to editing these geometries now STL stands for standard triangle language or standard tessellation language and we can see that from this model when we convert it to a part so at the moment this is actually a mesh so we're going to use the part workbench to change the STL into a part if I click on it we can see that it is in fact a mesh so first thing we're going to do is convert this to a shape count to part and create shape for mesh it's gonna ask us to sew the shape and this closes any gaps in our object so let's click on the sewing and we get into the tolerance for the sewing of the shape I'm going to leave it with the defaults and hit ok now the shape is sewn we can see a number of edges and faces have appeared if we roll over this you can see it's still flashing as one face this is because the STL is still visible let's press the spacebar to hide it and now you can see the faces are being highlighted all we need to do is bring this around and reduce the amount of information that's in this shape you notice that these here or planar surfaces this one here and this one here and you can see the triangles in here and this is the tessellation in an STL file let's fix that by coming over to the part that's been created as a shape and come up to part and come down to create a copy and refine shape this will refine the shape it will also fix problems with the placement before we find the shape let's have a look at the placement come up to the view toggle axis cross see where the axis cross is now let's click on this demo part which we converted and right click and hit transform notice that the Handler for transformation is at the point of origin so this is where it's been built and handlers here that's move this so what we need to do is take the object and place it where we want it to be using our axis cross in our scene so I want the point of origin about here let's hit okay now when we click on this part go up to part a copy and refine shape not only will that fix the planar faces so our faces will be reduced on this top it will also fix the point of rotation now when we look at the object we can see that the planar faces are now all one face and we've got this one here so let's reduce the information in our model but we still got this tessellation in here these individual faces there is one more step we have to do let's click on our refine part cut part and convert to solid we now have a solid in here let's hide the previous part and with that solid we can create such things as Boolean operations splits Etc so the only way to work with this is by using split apart and Boolean operations to separate this out add new features in there add new geometry in there and I actually do this in another video where I look at a landing gear and I will place the link of that in the description and the thumbnail location on this video at this point so that's venturing downloading STL files from the web and remixing those via free CAD I'm just going to come over to Google and type in grab CAD free STL and we go to the grabcad site now this is a free site that we can sign up to and it has a large number of free STL file step files three model files of many different varieties and you'll find what type of file is normally underneath here so this is an STL file and what I'm going to do is find something to download and we're going to see the differences between the two and how easy it is to remix some of them so I'm just looking through and trying to find one so this is an STL file here this one so this is kind of something that we could download this is quite useful and we might want to remix that add extra holes extra ventilation or some kind of feature on that this is an STL file so we come down we can see the STL file here and we're going to download one of these let's download this one this part here and we'll hit download file so you can see I've downloaded a number of Step nestl files already here just get an idea of what's out there this one I haven't seen before so we've got our main STL file over in freecad I've already started a new document I'm currently in the part design that may change let's go to file and import and come down to the file and open that up now when we roll over this you can see that it's one single face first thing I do with these type of files is come over to the mesh design and see if they're made up of components when something's made up of a components this is like using the part workbench and the compound object so it's saving out a compound object a single output with multiple objects Within to check that let's click on the STL file and come up to meshes and go split by components as you can see there's only one component so we'll delete that so we've got no luck there the trouble with this is that we can't really split it down into faces we can use Boolean operations against it we can pull it into a part design workflow as well as a base object but the first thing we need to do is convert this to a shape do that we come over to the part click on the STL file and come up to part and create shape for mesh this is a mesh at the end of the day once we click that it's going to ask us to sew the shape I normally take the defaults this will close any gaps in the shape that could cause problems in the future let's hit OK this may take a little while depending on how complex the object is as you can see we'll we can see that as a number of faces in here if I come over and hide the mesh we can now roll over these faces and we can see them there now if we look these faces are all along the same plane we can merge faces that are on the same plane by clicking on the shape and coming up to part and come down to create a copy and refine shape when we click on that it will create a copy and refine it taking out all those faces that are along the same plane as you can see we've got a much cleaner shape and we can select the faces so we've got more of a chance of creating a successful Loft pad pocket Etc with this object makes our life a lot easier we could use the part workbench and say create a cylinder and transform that if we want to use a part workflow and say okay I want to keep the one we want to remove control select them both and use a cut so you can see simple balloon operations take effect quite easily on that control said that we can also select the faces as usual and create sketches on there map in the flat face and creating what we want on here using Boolean operations to extrude and remove that part if you want to use this say in a part design workflow we can come over to the part design and create a body and drop the shape inside the body and this will create a base reference the shape will be made invisible so this is the refined shape once that base feature has been added we can select the face correct sketch and create some geometry on here such as a slot hit close select sketch and pocket that notice that the object has disappeared this tells me something that there is another step what we have to do so let's cancel that I'm going to delete the base feature and the sketch from the body and bring back our shape our shape is probably not solid it's probably a shell so let's come back to the part and come up to the part and convert to solid that's now converted to the solid and we can hide the shape now when we take this solid and place it into the body he'll create the base feature let's see what luck we have now so I'm going to come over to the part design and select the face create a sketch this will map flat face to that object and then create our slot hit close and now we take that sketch and create the pocket one thing you'll notice is how slow this is running and this is because of the STL file this was a step file then this will be much quicker so we can see we've got that taken there so the pocket has now taken because it's a solid previously it was a Shell let's see the difference with a step file so we've got the step file back and you can see it's made up with faces edges vertices Etc we can use the same process of Parts split apart or Boolean operations in here for instance I can take this sphere pick the one I want to keep control click the one I want to remove and use Union and boothing options in here viewing that in there it controls that and let's say a cut so you can see how quick that is compared to the STL file controls at that and delete us here another way of breaking this apart and remixing it is coming up to the draft workbench within the draft we're going to we have a number of tools one of which is the modifications and upgrade and downgrade these downgrade the selected object into simpler shapes the result will depend on the type of object that you downgrade in or upgrading for instance if we take the step file if we downgraded this we get a number of faces so at the moment all the faces are connected together let's come out to the modifications and use downgrade look what happens with the tree View we have a number of faces in here if I click on one you can see the face is highlighted on the left hand side press the spacebar and we can see inside that object so this allows us to remove parts of the object for instance I may want to remove these top faces here by hitting delete and that's delete this part as well and maybe this part so we've got rid of the internals in here I can now come over to the part where bench and start filling in parts of this with say a rolled surface or even come over to the surface workbench and create additional geometry against this and create surface that link up let's come back to the part workbench start using something like the ruled surface to create surfaces against here let's close this Gap let's first start by creating a surface against here going across control clicking those edges rule surface and a rule surface against these two using the rule surface I'm going to close the gap by taking these edges using rule surface now I can close the gap across here which will leave me a nice curve because it's going to follow the Contour of these surfaces so we look at this we can see this is curved outwards so if I take this curve and this Edge and create a ruled surface you can see how that's gone in there we've got a bulge going outwards like so we could do this with a surfacing workbench and create say a sketch in here with an arc and surface against those so we've got videos of how to create surfaces with sketches in the learning free CAD series and the same applies to this let's come around to the other side and close this surface here again I'm going to use the arc and this edge control click those and create rule surface and we'll create this feature in here so we've changed our geometry we can obviously use the splitting to split this apart and we can rejoin these all back together by clicking them all oh that's an awesome making sure that if we come into the rolled surface we have the other faces as well like so control clicking those the same with this one I can see I've missed two so I'm going to control select those faces from here we need to be in the draft workbench modifications upgrade we now have a shell so we've got a shell there that means we've missed some faces so you can see two faces have been missed there if we've missed the faces then we can control select those faces and then come out to modifications and upgrade therefore we have this continuous object and I can come back to the part where bench click on that shell part convert to solid now we have a solid so I've start a new document and we're going to look at a step file now and I've chosen this one here and this can be downloaded from grab card again and I've just done a search for step this time so I've come out to the search and just typed in step in here and I've chosen this one here I've already downloaded it so let's come to freecad file and come down to the import and let's come down to the file itself and straight away you can see that we've just got faces in here and if this is also a solid object so we don't have to do any refinement we don't have to do any creation of a solid object to make sure it's a solid not a shell on the left hand side you'll also see that because this is part of an assembly we've got all those individual Parts in here so this is very similar to the STL file if we had something similar in the STL and we had components in there we would come out to the mesh design and split by components and each of these individual parts would be a component but there will be one face one face per component as you can see we've got multiple faces in here and we can use these in the part design in the part workbench quite easily and they're a lot faster so any operations done against these will be very similar speed to what we would be doing in a normal free CAD model as if they were created via free CAD if we want to use one of these parts saying the part design we would have to say take this part here and drag it outside of its container so it sits outside then we'll create a new body we can drag that in like so to create base feature we can't if I delete that base feature drag them straight from inside the container into that body it just won't allow us we have to drag it out first also one thing to be aware of in the part workbench if we come down to this drop down and select the power bench is that we got the featuring tool in the part workbench so if I took this part here let's hide the others by pressing the space bar on them and if I've got a feature in here that I don't want let's say I don't want these ears here or just one of them I can click on it and cut a part and come down to the featuring that will remove that face so you can see that face has been removed let's try another one let's take both of these part the featuring and you can see that wasn't removed so you can see we can have some success with this and other times some of the features aren't removed so that one's been removed there and it's left this I'm just going to control set that we could use a normal pocket in here so we could pocket these out sometimes the feature in wall gets to a stage that's beneficial other times not once we got this into say our body as a base feature then we can add sketches to here in the part design let's come back to the part design and select this face and create a sketch and we can select what we want on here so let's create a slot and add our constraints we can pull in geometry so for instance I can pull in this line here and make some symmetry okay to this point it's vertical strength that's close and we can pocket that so make sure that sketch is selected and pocket that in and set our depth features like this well we're going to have to use something like a pad to fill in that Gap so and then close that we'll pad that reverse and set the distance okay click on the pad and we can come down to the refine as true and that removes that from there so as you can see the STL file is quite easy to work with so I hope that's giving you a quick Insight of how to use the still files and step files the differences between them and how you can use those in the part design or the part workbench and reconfigure them how you want hope you enjoyed that video and I hope to see you again soon if you like what we've seen please subscribe to the site I also have a co-fire or a coffee site that you can donate to if you so desire and that's at Ko hyphenfi.com forward slash m-a-n-g0 I also run a patreon where you can subscribe and get extra content and that's at www.patreon.com mango jelly Solutions any money that's kindly donated will be used to span the channel thanks a lot for watching and subscribing and I'll see you again soon

Channel: MangoJelly Solutions for FreeCAD

Views: 29,356

Keywords: CAD, three, 3D, CNC, Printing, solidworks, autoCAD, freecad 0.19, freecad 19, freecad basics, basic course, fundamentals, learn freecad, freecad beginners, freeCAD 0.20

Id: ahJnfMxFlL8

Length: 25min 7sec (1507 seconds)

Published: Fri Apr 14 2023