FreeCAD Constraints Part 1 | Easy Beginner Tutorial

hey guys it's quinn from canada today i want to show you my favorite feature of freecad constraints when i first started i wasn't quite sure on them you know they were a little bit weird and weird things kept happening but i'm gonna show you how to use this as a pro i'm even gonna show you some workarounds for the most common constraint problems you're gonna encounter grab your beverage of choice boys and meet me at the computer all right guys first things first let's go into our sketcher workbench the easiest way to do this is just create new let's go down here to sketcher now let's create a new sketch and it doesn't matter which plane we select so just click ok so let's start out by making a line click here and put your line at a let's say 20 degree tilt now you see that we have four degrees of freedom what that's telling us is that in this sketch we could take the object and we can move it horizontally which is one degree of freedom vertically second degree of freedom i can make it longer and shorter third degree of freedom and i can also rotate us around which gives us the fourth degree of freedom so the whole point of constraints is to essentially lock in the shape so it can't be manipulated so let's start out by adding the most common constraint which is the horizontal distance constraint and a vertical distance constraint i'll start off the horizontal and i want to click on the edge of this line like the end point you'll see it light up yellow when you're there if you see the whole line light up yellow you're not quite there yet so click there and then go to your origins and wait till it turns yellow as well the origin is always available to us in every sketch so click there and you will see the distance popping up the value here is based on where you positioned the sk this sketch so if your numbers are different it's all good but i will change the number here and watch what happens i want to make my origin 20 millimeters or my distance there you go now you'll notice that we only have three degrees of freedom i can now move the sketch up and down but i can't move it left to right i can of course rotate or make it longer and shorter so let's apply the vertical constraint in the same way to the same point so click here click the origin look at that same thing as last time measured it out just fine i want to change it to 30 millimeters though beautiful and as you'll notice two degrees of freedom we're now down to length and rotation so let's restrain the length next and i'll show you the wrong way first because this is what gets a lot of people if you click on the horizontal distance constraint and you apply it to that line you'll notice that it's locked at 31. well watch what happens if you try to move it up or down the line gets longer because we're only constrained in this dimension so this point can only travel up and down along the horizontal axis that is not what we want so let's just undo this and do it again the constraint that you want to use is this guy right here the fixed length constraint when i apply this and let's use 40 millimeters you'll notice that when i rotate this around the line cannot get longer or shorter now that being said look over here and we have a list of constraints in our sketch this list also helps us out by listing the values so we can change our constraints double click on here let's change up to 35 and you'll notice it changes in our sketch you'll also notice that again once we apply that constraint we're down to one degree of freedom which is the rotation let's do something about that there's two very common constraints that we could use here if you want to make this exactly horizontal you can use the horizontal constraint click here click the line and you'll notice this icon right up here that appears this tells me that that line always has to be horizontal and with that we're fully constrained and you'll notice that this has gone green that's our indication this command does have a partner and that is the create vertical constraint let's select it now and try to apply it to the sketch it says it already has a horizontal constraint basically it is impossible to constrain this line in a horizontal and a vertical axis at the same time so we need to delete that constraint and of course we can either click the icon here you'll see it's selected over here or we can select it over here so let's hit the delete key get rid of it and as you see it goes back to being white and of course one degree of freedom so let's try to apply the horizontal to this and look it's gone orange and we get this nasty red message saying that we have a conflicting constraint oh my god what's going on end of the world end of the world end of the world and i'll just undo the constraint and i'll tell you what's going on because this is exactly horizontal it is confused on which way to flip it whether to flip it up or whether to flip it down if you take this line and you move it down just a tad and you apply the vertical constraint it will flip this down no problem i'll just undo that undo it again now if you move it slightly up it will flip it up so just be aware that this is something that got me when i first started out with free cat it was a source of frustration but now that i know makes life a lot easier so the next one that we can actually apply here is our fixed angle so i can click on this guy here and i can use a reference of this line here my horizontal axis or my vertical axis i'm just going to use my horizontal axis and i'm going to apply a degree of 30 degrees now notice i don't have anything here well he's right here if you click on the constraint here and you right click and you go center sketch it will jump right to that constraint and again we are fully constrained now we're green hey guys this video is starting to run long next part we'll release next week and if you haven't already boys scott subscribe and like always stay smart stay safe and cheers boys

Channel: Q

Views: 11,852

Keywords: FreeCAD, Constraints, Horizontal Constraint, Vertical Constraint, Horizontal Distance Constraint, Vertical Distance Constraint, Angle Constraint, Distance Constraint, singularity error, Sketcher, freecad tutorial

Id: TyxePqU8Acw

Length: 7min 54sec (474 seconds)

Published: Mon Nov 29 2021