FreeCAD: Sketcher symmetry constraints and ways to mirror geometry Beginners tutor / tips and tricks

hi viewers welcome to the channel and today we're looking at all things symmetry we're looking at mid sketches and symmetrical constraints and actually how to create those and tips and tricks around those so this could be quite a short video hopefully so it's all to do with sketching so i'm going to jump over to the sketcher and i've already created a new document as you can see down here let's get rid of this start page and give us some space to work with so full screen on that and i'm going to create a new sketch and it's going to go on the xy plane so okay that now i'm going to start with symmetrical constraints which is this one here so create symmetrical infrastructure between two points with respect to a line or a third point so we're going to start with something extremely simple so i'm going to put two points can't really see those can we nice control there right so i'm going to create two points so those points are going to be inside these circles you can see where those are and i'm going to crack now create a line hit escape i'm going to put a vertical constraint on that now if i wanted to constrain this line in between these two points of this circle then the first thing i need to do is actually select the two points and then select the line so it's the two points you're constraining the actual item within and then i hit the symmetry constraint and then that places a little arrow on wave create symmetry constraint a little arrow here now that line can move up and down in between that constraint but it can't move side to side see the whole lot is moving and if we anchored this one down somewhere so let's put a lock constraint on this one so we've locked that one in and locked this side in so lock these two down in constraints i can actually move this up and down i can't move it side to side okay and the same if we do the reverse so let's remove those lock constraints if i lock this line down i can move oops i can move this backwards and forwards and along that line so they will even cross but you'll see they'll keep the same distance away and also the opposite each other now for a circle say if we wanted to do a circle in here so i've got these two points on here if i place another circle on here we've only got these points to actually play with so i'll select one point and the other point and then the one that i want to stay in the middle hit the symmetry constraint and then that will stay in the middle but you can see it's locked them opposite each other like so if i wanted this to actually move up and down here then i would need to attach this to some other type of geometry and we can do this by attaching that to a construction line so let's bring back my circle and let's get rid of this constraint so click on the constraint and delete it and what i would need to do was is actually attach a piece of geometry to this and then constrain these to that geometry so if i want this to move up and down in this direction i would actually use a piece of construction geometry because construction geometry when we're padding or pocketing doesn't actually get affected and it won't affect the actual paddle pocket we won't get a pocketing error or a padding error with that so so i'm going to connect that point onto that point of this line so we connect those up and we can give this line an arbitrary length if we want to stop it from moving up and down we only need a small line to actually allow for this to work so at the moment we can actually place this anywhere we want so i can place it up and down or over here this line is attached now i need a small distance on here there we go so even something like just five mil although i can't really get to that one that's about 20 millimeters okay so i've got a distance on that so we can actually move this about now to allow this to actually move in between these two points here i'll select the two reference points that i want to move in between and then lastly we select the line not the point the line and then create a symmetrical constraint on that and that will allow us to actually move up and down between those two there and what we'll also do is take this and we'll lock them down to lock those into position so we can no longer move that but we can move this up and down now where is this handy well let's get rid of these if we're doing some kind of complex i'll say complex i'm going to throw some shapes down onto here so i'm going to create a padding pattern or pocketing pattern i want to create so i'm just going to throw some lines in here so trim that out now the trouble is i really want this to be movable and i also want this point here to be slap bang in the center of these so i'm just going to add some equality constraints to these getting the same length and at the moment this can move about so i could go for that and constraints but they get messy and also i tend to like using the geometry constraints because they're much more useful so we can actually have geometry that moves in certain ways and keep constant with other parts of geometry so if we're looking at this how did we get this in the center well do you remember when we were talking about the construction line so i'm going to place a construction line along here so just move to construction mode click on the construction line and place a line in here only needs to be small connect this middle so connect the middle there get the constraint in the middle and make that horizontal and don't have to give it a length but i'm going to actually give it a bit of a length in there so around about 10 there we go so 10 mil so what that allows us to do is now we've got a kind of handle but we can also click on our two reference points this point and this point and this line i'll place a symmetry constraint in there so that will keep that in the middle so you can see this side is moving but this side isn't you can still move in and out because that's even if i'm moving this way i'm still right in the middle of these two and we can do the same on the other side so let's take these two at the moment it's let's do something like that so it's out out of symmetry so we've still got these two selected select the line and place a symmetric constraint in there those can move in and out but our circle will always stay in the middle the minute we start locking these down and we can actually allow this sketch to move every so desire and we can do the same for the actual vertical as well so if i come in and place a couple lines and trim those out and here that you can see this can actually go anywhere it wants the minute we place a line so what we need is line along here because remember if we try to constrain this one this one and the center point like so then that line will come down here of course we can't constrain this line because this will actually jump across this line like so because that's creating a symmetry between those two points and that line on the horizontal which we don't want so i need to create a line in here escape connect those two together let's get rid of those like so and then take these two points and this one and create a symmetry constraint on there the minute we start locking these down with height say then we start getting a more movable sketch obviously the top needs to be locked down so that's symmetry constraints and they're useful for uh many things get rid of that and get rid of that but also it's worth remembering that we can actually do a symmetry like this so we've got our lines and this these are disconnected from each other let's make these nice and straight and we create the symmetry between these points so select the two reference points first and then your normal point create symmetry that when we move these up and down let's just fix the height of that a second okay and do the same for all the others make those equal so when these move up and down even if there are angles they are still in symmetry with each other like so so so now we're going to look at creating symmetrical geometry and mirroring sketches as well and we're going to be using a very simple shape i'm just going to put a fillet in here so we can tell around about there fill it that and make those two equal and get give that a bit of a length let's move that out the way and i'm just going to the last straight i'm just gonna hide it so we can't see it it's got a nice clean space so we've got this sketch here still mobile but that's fine that's absolutely fine now i want to take this sketch and flip it this way and create basically a mirror now how do i do that well there's something in the actual tools menu here so let me just highlight all that so these come available and you've got the creates a symmetrical geometry with respect to the last selected line or point so what that means is that if i select all these lines like so and then the last one that i've selected is this line then when i click that tool will happen it will flip it to the right like so but if you look at it see we've actually lost this line so this is good if you creating a sketch that requires a connection in the middle or you're just going to delete that connection like so but so if we wanted to keep that connection well this is where our construction geometry comes in we click on the construction geometry and we can actually add a line like so hit escape create that make that vertical constraint so it's nice and straight and we can just place it wherever we want so i'm going to place it there now highlight the shape select the line so that's your last selected and then hit the great symmetrical geometry or we can go up to the sketch and down to sketch tools and in here you'll find down the bottom symmetry there so click that and that will flip it and keep it the same length away as there click that and that's flipped and that's the same distance away from that center line and we can just delete that center line if we say desire now the good thing about this if you think about it is that if you had let's get rid of that if you had a shape say let's place a square on on here and give it some arbitrary values in here so i'm going to place that there and i'm going to constrain this that's 5.87 so i'm going to constrain it to that edge there let's do the height on there as well so we've got it constrained to that corner there and i'm going to place actually in there i'm going to place a circle escape see where that is right i want that constrained to the same place as well so i want it 5.8 in so just hitting those constraints so if we think about what we learned in the symmetry constraint then what we should be able to do is be able to flip this and get it onto that point there so if i take this and try to flip it at the moment by the last lettered line which i can select off and slide on again so that'll be the last lettered if i try to do a symmetry on that then it's not going to actually hit that point and we also lose that line i'm going to stop that from moving so so i want to actually create construction geometry so let's go into construction geometry and i'm going to connect this point to this line and this point to this line like so and i can either use a symmetry constraint on these two points or these points and that line to actually get it centered now i'm going to use the two points so the two references and the one that we want to get centered and make sure that's horizontal there we go so that's dead in the middle of these two now so if i take this and select house circle i want this to hit that point on that circle so i can select this line this last one selected and we'll come over to the symmetry tool here click it and that's connected now well it's not connected it's actually place that on top of that point there now i can just do a point constraint on there and get rid of my line like so so that's a way of actually targeting an exact point by using the symmetry we also can do symmetry on the other side so it's the same for selecting say a line across here if i select the whole of this and select that last line so click the line then click it again so that last slide selected and do a symmetry on that and that flips it at the top there like so you can also do it for points as well so the last point selected i'll take this and just select that point there and do a symmetry you can see it's flipped it a symmetry of this to that point there and placed it all up here so let's get rid of our square let me just look into that a bit more it's nice and clear so you can see what's happening now so if i take this and click that point that's the last selected point then you can see it's put it down there and that's because we didn't actually select that point now what happened is that i only clicked that once it looks like it's selected even though it's only clicked but it's actually unselected that point so select that point again and then do the symmetry that flips out that way like so if i wanted to actually create a bit of distance between these two i can actually use a construction geometry so we've got our construction geometry here and we can stick a line in there say and then place that there don't even have to worry about if the lines only want the point from this line so that'll do and just place that somewhere we could even use the actual point over here correct point in sketch so let's do that actually let's get rid of that great point in the sketch let's put the point here and we can place the point however far away we want so three millimeters and push that up three mill there so that point is there so that point is there so if i select this and then select our point and then do our symmetry then i'll place it the same distance away from here so this point to this point should be three millimeters which it is so for the next example you need a fully constrained sketch or at least a sketch that won't deform when you actually move it so i'm going to make a symmetry but at an angle so i want a 90 degree angle so i'm going to bring this around to down here to do that we need to go on to our construction geometry we'll create a line and we're going to connect the two points here point constraint and then we're going to use this line and our construction line and create a angle between two lines on there i'm going to put 45 so we're looking at creating a 90 degree angle so we need 45 in there and what this will do we will actually do a symmetry across this line when we select it everything in our geometry the last selected is the construction geometry and then using the symmetry on there to place our geometry down the bottom now there's other ways to actually mirror a sketch and we'll show you that now we can actually mirror the whole sketch let's delete that off so our sketch is here no a model there's a sketch there let's close out there so that's our sketch let's zoom in so zed is down y is this way and x is this way so i'm going to actually create another sketch in here and this is just going to be on the x y plane again and i want to actually just put a piece of geometry in here just shows an arrow to just give give us a reference of where this is going for the actual demonstration so i'm going to use the polyline and i'm going to place a line here like so hit escape and that's going to be where x is let's close that sketch so that's just our reference sketch okay and the sketch we're interested in is this sketch so let's zoom in slightly so we know x is that way now if i take my sketch and go to sketch and mirror sketch it's going to ask me along what access to actually mirror this on so let's go x-axis now where's the sketch so let's put sketch over here so we can see that it's actually mirrored it's taken the x-axis and flipped it over on that axis so so if i bring this sketch down so the reference sketch and we're looking for placement along the position along the yeah along the y so i'll move this down you can see where it's mirrored the actual sketch on so it's actually mirrored along this way so let's mirror in this along the x and if we so desire we can actually take our sketch and use the position and place that so base placement open that up position open that up and use the x and y and move that into position like so so let's do the same mirror along the y so i'm going to get rid of my mirrored sketch i'm going to use this sketch here let's zoom in a bit i'm just going to move this sketch up so i'm going to reposition it at zero and we're going to mirror that on a different axis now so we'll click the sketch got sketch mirror sketch this time the y-axis and it's placed it over here so there's the x there's the y now let's place it over here and the origin if you haven't already guessed sketch mirror sketch click origin and that places it actually flips it over on the x and y so it's now down the bottom okay so that's a quick tutorial for mirroring and actually creating symmetrical constraints on sketches hope you enjoyed and i'll see you again soon if you like what you're seeing please subscribe to my site and also i have a co-five site um where you can actually donate a few pence or a few pounds dollars or whatever your currency is and that's at ko hyphen fi.com ming0 and there you'll be able to help me fund my site and all the money that i actually get from any funds will actually get pushed back into the channel thanks a lot for watching and subscribing i'll see you next time

Channel: MangoJelly Solutions for FreeCAD

Views: 22,299

Keywords: three, CAD, 3CAD, AutoCAD, Solidworks, sketching, constraining, tracing, reflect, reflection

Id: gBXl82Uhr4E

Length: 30min 27sec (1827 seconds)

Published: Tue Apr 06 2021