FreeCAD CNC series. Aluminum extrusion modelling tutorial.

hi to all how is it going with this video we will actually start the cnc series that uh that's been long awaited we will start by modeling the the alumin aluminum extrusion that the frame is built off and this will be a more beginner friendly tutorial i'm using link stage free from real thunder but the same steps can be easily followed in freecadmaster also although this seems like a pretty complex model uh you we can actually analyze it and see that we have a lot of symmetry lines and during the actual modeling of our component we will take a great advantage from that so let's get right in start by creating a new file and let's move to the part design workbench as you can see we have an exterior outline and the the width of this extrusion is actually 50 millimeters and we will start by modeling this in our file let's create a new body we will create a new sketch on the xz plane click ok and let's start by creating a rectangle right click to dismiss the tool you will see that i have the constraining tools here on the left side of my screen but you perhaps have it like this i pre i prefer to have them uh here because it gives me a little bit more of a vertical screen real estate select these two vertices and the center one press s on your keyboard for symmetry we will select this edge and this edge and press e for a equality constraint and then select the top edge press shift h on the keyboard and we will give it a length of 50 millimeters click ok and close your sketch now with our outline sketched we need to actually extrude the the length of our aluminum extrusion so let's pad the selected sketch we will choose to pad it symmetric to plane and i will choose to have it something like 200 millimeters click ok and to because we are using links h3 we can take advantage of the shadow display mode which will help us better assess our scene now if we take a look at our component we can see that we need to start sketching the the pockets that actually form our extrusion if we if you analyze this pocket here you see that we have a symmetry line and we will take advantage of that during our sketching and we also can break the outline of the pocket in more primitive shapes so we will create another sketch we will choose always the xz plane okay and as a first step we need to import some geometry from our previous pad so click on the external geometry icon and choose this edge if you will click this icon here we will align our view again to to the sk to the sketch normal we need to switch the toolbar to the construction mode choose the rectangle tool [Music] let's create the first rectangle that represents this opening here a second rectangle that represents this opening here and we will sketch the bottom line so choose line and sketch the bottom line right click to dismiss the tool select the two vertices of the topmost rectangle and the y axis of the sketch click s on your keyboard for symmetric so select these two vertices here and the y axis of your sketch press s for sim symmetric this two vertices here as for symmetric we need to create a tangent trend between this vertex and this imported line here remember this is the external geometry of our extrusion select this vertex and this line press shift all on your keyboard and you see that the rectangle is now overlaid on top of our geometry press shift v for a vertical constraint and we will type in four millimeters now we'll do a similar thing with uh the second rectangle so select this vertex and this line shift o for tangent and this one as well has a height of 4 millimeters so press shift v for vertical for a vertical dimension 4 millimeters now i've already measured the distance between the top of our extrusion and the bottom of this pocket and it is 14 millimeters and we will set that right now so click this vertex and this vertex from the bottom line shift v for a vertical constraint and 14 millimeters you can move your constraints dimension out of the way for a better view of the sketch if we take a closer look at our sketch we see that we have another small pocket in the top wall and we will sketch that as well we will create another rectangle select the two vertices and lastly the y axis of the sketch press s on your keyboard and we have a symmetry line i know that this edge is uh has a height of uh one millimeter so we will give it a vertical dimension shift v on your keyboard for vertical one millimeter let's just move this out of the way let's go ahead and give a dimension to this also vertical dimension 1.5 millimeters and we're pretty much set up one dimension that i forgot uh i've uh the forgotten to give is this one and uh shift h on your keyboard this this one is 10 millimeters this edge that represents the actual opening here on the top is eight millimeter shift h for uh horizontal um constraint and it is eight millimeters wide notice how uh how the constrained edges turn light blue we need to give a horizontal dimension to this edge here also so by measuring i know that this is 22 millimeters wide and of course we need a horizontal dimension for the bottom edge as well and this one should be 10 millimeters so now that we've the actually managed to block out the whole outline of our pocket it is time to actually draw the working geometry of the sketch so create choose the create polyline tool and by hovering over the vertexes of the construction geometry start sketching now if we closely look at this area here we see that we have a small step and this one was not actually taken into account when we sketched our construction geometry so we will sketch it right now let's do this small step and go ahead with our sketch remember this notice how our sketch isn't fully constrained because we because of the small step that we've modeled in this area of the sketch so we will go ahead and constrain this one also right click to exit the current the current tool select this edge because it lacks the vertical constraint press v on your keyboard let's control the other one and these two seem to be okay let's select the four edges here and we will make them all equal by pressing e on your keyboard of course you can always use the icon tools toolbar here but once you get the hang of the shortcuts it is really a lot faster to work with sketches select one of the edges and shift h for a horizontal constraint and we will give it a dimension of one millimeter and with this we see that our sketch is fully constrained close the sketch let's reshow our pad and make the actual pocket we can see a preview of of our operation these two options are at least for now present only in the link stage 3 branch but anyway we will choose to make a symmetric to plane uh pocket and in the type we choose to make it uh through all press okay taking a look at our object here we can see that we have two symmetry lines and we can take a great advantage of this so we will take our list pocket and we will choose to create a polar pattern as the axis frequet has chosen the normal sketch axis but we can actually choose the base y axis for in this case and we need four of them click ok to exit the polar pattern tool it is now time to go ahead and create this second pocket here we will choose to adopt a strategy similar to the previous one where we will take advantage of construction lines so let's create another sketch we always choose the x z plane okay and we will create our helper geometry uh comprised of this rectangle here and an edge that will represent this kind of leg that stems from it we need to again import some geometry from the previous feature of our model so click the external geometry icon and import this edge right click to dismiss the tool switch the toolbar to construction mode by pressing um by clicking this icon we will create a rectangle and then we will create the edge that stems from uh from it right click to dismiss the tool select these two edges press a for an angle constraint and we need to of course we need to have a 135 degrees angle between these two edges if we look at our extrusion we see that the wall thickness here is smaller than the wall thickness that we've had previously in the previous pocket i've actually measured it and it is two millimeters so it's time to block the rectangle so select this vertex and this vertex shift h for a horizontal constraint two millimeters select them again shift v for a vertical constraint and two millimeters we need to first make these two edges equal to actually have a rectangle and we will give a height to our rectangle so shift v for vertical 10 millimeters take a look at this pocket here we see that we have an arc here at the bottom and the the diameter of this arc is actually the distance between these two edges and measuring it it is a four millimeter diameter so if we measure the distance from this angle here to the bottom of this um arc we only need to subtract two millimeters of radius and we will have the distance that separates this arc center to this vertex to give a dimension that is not vertical or horizontal we actually use this tool and its shortcut is shift d so shift d we need to give it the length of 20 millimeters now that we have our helper geometry sketched up we go ahead and outline the actual pocket geometry so re-switch the toolbar to normal geometry choose the arc tool start by making an arc that is that snaps to the tip of your line so start by by drawing the arc choose the two extremes of the arc and this vertex right here press s on your keyboard for a symmetric constraint we will give it a radius of two millimeters because we need that so shift r on your keyboard for radius so let's just insert two millimeters and now it's time to choose our polyline tool and start sketching the outline of the pocket okay now that we're here right click to dismiss the tool and let's start again right click to dismiss the tool let's hide our polar pattern to better see the the sketch select this edge here and the arc and press t on your keyboard for a tangent constraint let's do the same for this edge here and the arc t on your keyboard for a tangency constraint in another construction line that unites these two vertical vertexes and we'll give it a dimension of four millimeters shifting four millimeters and we have our sketch fully constrained again close the sketch unhide the the polar pattern and again we will make the actual pocket that needs to be symmetric to plane and through all click ok again we will take advantage of the symmetry of our workpiece so uh by selecting the last feature of our body we will create a polar pattern that needs to be around the base y axis for instances now let's click ok and take a better look at our aluminum extrusion it is now time to execute and execute the center hole of our object as before we will create a new sketch only always on the xz plane let's change our toolbar to normal geometry choose the circle tool right click to dismiss our tool click the circle shift r to give it our a radius and that will be eight millimeters okay close the sketch and go ahead to execute our pocket always symmetric to plane and the type will be through all click ok if we look at our extrusion you can see that we have these 10 small ridges that would be half a millimeter that would have a half a millimeter edge and we have 10 instances of done so let's move to the front view create a new sketch we'll choose the xz plane okay i will create a rectangle select these two edges and make them equal we'll give it a symmetry to the y-axis of our sketch so s on your keyboard for symmetry and we'll have this edge be something like one milli millimeter in length so shift v for vertical constraint uh i need to have a distance between between this vertex and this vertex of 7.5 millimeters so shift d on your keyboard and type 7.5 okay close the sketch and let's pad our small range we will make it symmetric to plane we will give it the same dimension as our extrusion and that is 200 millimeters click ok to exit the the pad task panel move to the front view and we will create another polar pattern i know that we have 10 instances of this small extrusion so i will always choose the base y axis and i need to have 10 instances click ok to exit the test panel using the link stage 3 branch we can actually click on the shadow mode display to bring up the light manipulator so we can actually better shade our scene press escape to reduce to register your your change we are now pretty much done with uh our model but we can give it some finishing touches if we take a closer look of uh at our model we see that we have these small fillets uh here inside here and here all around it and also we have these uh ridges that go the length of our extrusion if you click this icon here you can actually select the selection on top option let's select nothing select this one and by taking by pressing the control button let's go ahead and select all the edges that we need to fill it around our model now choose the fillet tool click ok let's create a new sketch that's on the x xz plane okay import an edge from our last fillet and draw our two rectangles we need these four edges to be equal we will always try to take advantage of the symmetry of our objects so we will give it a length of 2 mil perhaps 2 millimeters so shift h for horizontal 2 millimeters i need to make this vertex and this vertex symmetric to the y-axis of our sketch so press s force symmetric i want this vertex and this vertex to have a distance shift h of uh 15 millimeters click the create fillet between two lines uh tool and we will create four fillets right click to dismiss the tool select all of your fillets and by pressing e on your keyboard make them equal now i need this uh vertex to be tangent with our external geometry so press shift o for tangency let's uh just hide our piece for a moment to see how it looks okay close the sketch and let's pocket this symmetric to plane through all [Music] now of course to have the same feature of the model or around our extrusion we'll do the same drill we will choose a polar pattern around the y axis and we need foreign instances click okay and exit the sketch all right folks so as you can see although this seemed like a really complex geometry we took a great advantage of the symmetry of our component here and it was not that difficult to model hoping that this was of help i thank you for resting uh till the end and i'll see you in the next one

Channel: OficineRobotica

Views: 6,834

Keywords: freecad, partdesign, realthunder, linkstage3, 3dcad, free, cad, opensource, development, fusion360, alternative, diy cnc, cnc, modelling

Id: TqenXfqva5c

Length: 24min 24sec (1464 seconds)

Published: Thu Mar 18 2021

Reddit Comments

[u/justacec]

Love your stuff and I am super excited about the LinkStage3 features being eventually incorporated into the Freecad Master. (I am running the 0.19 daily on my mac. I would be interested in running LinkStage3 daily but have a hard time finding it)

When it comes to this demo you provided, I would have preferred to make a sketch of 1 quadrant of the symmetry, extrude that, and then add a circular array of 4 with refine. That way all the information about the extrusion is in a single sketch. Is there a reason you did not take this approach?

[u/masterkorp]

Thank you for you great work and sharing your knowledge with us!