Autodesk Inventor 2012 - Assembly Constraints

hi my name is John Calvin I'm the student expert program manager here at Autodesk for the Americas and today I wanted to go over how to put things together and end dinner I've shown how to do part modeling I've shown how to do dynamic simulation and other things and I've had some requests on my YouTube channel to show how to put things together explain assembly constraints a little bit so that's what this video is about what you see on the screen is my trusty trebuchet which if you've seen some of my other demos is is one of the models I use pretty consistently because it's simple it does a lot of things and it's fun to play with so anyway what I've done as part of the demos and workshops that I do with students around the country is I I've got the assembly all set up where it's assembled and then I have another version of it where it's laid out on that you can see here that's laid out as a kit of parts and I have one where the assembly is partly built so that you know depending on my time I can adjust the amount of time it'll take to finish this model so what we're going to go through today is considered a bottom-up approach to assembly modeling the other option would be a top-down so bottom-up means you essentially that you've built all the parts and now you've got them complete and you're going to put them all together and assembly to be honest and typically I don't start this way unless I'm really trying to explain things to people I normally work with a top-down approach and I use I build an assembly I might build one or two parts on their own and then put them in the assembly and use them as the foundation for example in this model I would have built this ground plane because it is the base that everything attaches to from there I would build parts in context of the assembly rather than building them separately and adding them in but I'll show you how to do both a little bit I'll touch base touch a little bit of each of those but I'm not going to really go into too much top-down modeling anyway to get started what is assembly modelling assembly modeling is essentially putting together your assembly what that means is right now if you go to the View tab inventor under the visibility panel there's a degrees-of-freedom button what that does is it lets you see the visibility or turns on the visibility - of the degrees of freedom degrees of every part has six degrees of freedom it has an X Y X a Y and a Z translation and then it's got an XY and Z rotation in order to properly fully constrain a 3d model you have to provide three constraints to lock it into place so I'm going to start with this piece here which is one of the AR components and I'm going to turn off the degrees of freedom just you can toggle it on and off so I'll be toggling it back and forth throughout the demonstration you know until everybody kind of gets a feel for what it's doing and then I'll move on to you know I'll stop using it so anyway if you go back to the assemble tab in Inventor on the in the position panel there are two things that are important here when you're talking about assembly constraints one is the constraint I our box and one is the assemble command I typically teach students to start with a constraint dialogue it's considered the old-fashioned way it's a little bit it's been an inventor for forever it is it has been the way that you've done assembly constraints up until 2012 maybe 2011 I can't remember when they added the assemble command but within the last two releases they added the assemble command and I'll touch base on that in a little bit but the reason I have people start with the place constrain dialog box is there's it's good information it shows the icons it you can hover over them and you can see that this is the mate you can hover over this and see that it's angle it's important to understand what these icons look like what they mean and what they represent and and and understand what the solution options are before you start using the assemble the assemble command is more for somebody who has a little bit more experience but once you get that experience using the constraint dialogue the assemble command is a really nice it speeds things up and it makes it a lot easier to assemble things so anyway back to getting started I've brought up the assemble or the the constraint dialog box it defaults to me and to be honest a mate is what you're going to do the majority of the time so that's the reason it's the default but you have the mate is their type of constraint you have your options you're gonna have to pick two things that you're going to make together so you've got two different selection sets here you can choose to offset those and I'll I'll talk about that a little bit just to show you what it does and then you have a couple of solution options so we don't have an inventor a mate and a flush constraint I mean technically we do because but essentially what they are just opposites of each other a mate puts two faces together and a flush aligns two faces and a flat orientation so I'll show you this in a second as we as we do this let's go ahead and start out I'm gonna zoom in so that I can very easily select this face I don't know what I'm gonna do is I'm gonna select to make this face and let me zoom out and the side of this plate actually I'm gonna turn on my edges just to make it a little bit more clear there we go here you can see what I did is I selected two and I've got these this little in the dialogue box these little glasses are a preview so it'll show you what's going to happen so you can see I've got okay cancel and apply all available to me if I have camp hit canceled that part is going to flip back into its original position and everything's gonna be canceled or I can apply it and move on and start adding new constraints but before I move forward let me explain what happened here so what I did is I selected the two faces the the this space here and the side of this ground plane and it a mated them that's what this solution is if you hover over this it says me the other option is a flush it's essentially flips that over it's just a matter of flipping over the answer right so they're very similar constraints and that's why we only have one it's called mate and the solution is a mate or a flush so what I did is I did a flush and I'm using this I'll show you in a second I'm using this as a temporary kind of constraint just to start getting this one main piece put onto this plate the way I want it and then I'm gonna ground it and I'm going to build from there and I'll explain it as I go along so I'm gonna go ahead and hit apply I'm actually gonna hit cancel so if I can show you what actually just happened so if I go to a front view let me get out of my perspective view so you can see see what that looks like you can see here that these two faces now are aligned if i zoom in here's the ground plane and here's the the a arm and you can see that they're flush in that that on that face and the way to test it is I can click and drag my I can click any part in Inventor and drag it to see what degrees of freedom it has remaining so if you'll notice if I drag to up and down it slides if I drag right and left it does not move it moves up and down still just because of my cursor is moving but it maintains that flush relationship so now that I've got that in place let's go and rotate around here next I'm going to go ahead and move this up a little bit okay so I'm just showing you that even though I'm moving it around it's still aligned flush to that edge so now what I'm going to do is I'm gonna bring my constraint dialogue back up and now I'm going to use this tangent option now this is an option you probably won't use very often it just so happens that this has no I need it in this case but I'm gonna select a circular edge and then the top of that flat plate I'm going to zoom out and you'll see here that it has made that tangent to that edge again this has another option where you can flip you know inside or outside of the surface so again you you this is common across to all of them for the most part that you might have a couple different solution options so it doesn't hurt to switch back and forth between these just to get a feel for what things look like and how it works so I'm going to hit OK and I'll show you what I did so see now it's maintaining that tangent if I click and dragging so I can rotate this up to be I want to end up with this something like this you know of course this edge is going to be tan or this face is going to be tangent to the top of the plate so that's what we're gonna do next but now what you can see is if you look at it from the left if I'm dragging this I'm trying to move it up it locks that into position and it's kind of floating in space but that's that's what we want it to do so I'm gonna go ahead and go back to my isometric view let's add that final constraint here so I'm gonna bring my constraint back up I'm gonna go to my tangent option and I'm going to select the circular face and the top of the plate and so now I can slide this back and forth I can't lift it off the plate because it's maintaining those tangent constraints and because we have the flush its lined up with the side of the the model what I'm gonna do now is I don't really want this part right up against the edge the only reason I put it there is just to explain things and just as a temporary orientation for this well you'll notice is if I select this part it highlights in the browser so here's my a arm in the browser now this is a simple model so I only have you know 20 parts or something like that if you've got a hundred thousand parts or 50 thousand parts in this assembly this arm may end up dropping off the bottom of the screen you might not be able to find it if that happens you can always right-click on a part and say find in browser so here actually let me do that again let me pick this projectile just so something else is selected if I hover over it it highlights but if I right-click on it and select find in browser oops I guess I have to select it first there we go and then hit find in browser it will find it and it's a bad example because of the size of this assembly but the key is is you can it'll scroll the browser to that location highlight the part for you you can also do it in Reverse if you don't know where the part is in the assembly but you need to find it you can right click and say find in window and it will highlight the part and zoom in on it in the window so it's just a tip that comes in very handy when you get working with larger assemblies so next what I'm going to do is suppress this flush constraint because I don't really need it I just needed it temporarily to align things I could delete it but just in case I want to turn it back on you do have the ability to suppress that so what that means is it's you'll notice that it Grey's out in the browser that means this constraint is turned off essentially so I can now move this model kind of out into the center of this part where I think I'm gonna want to build from if I ever want to go back and put that back on I can right-click on it on that constraint and hit suppress unser press or uncheck suppress and you'll notice it snaps back into place so it's just turning on and off the constraints all right so now that I have this part into the position where I want to build or start building the rest of the model the other thing I'm going to do here is I'm going to ground it so I select the part and right-click I can select grounded and you'll notice that in the browser you get a little pin icon next to your your part and if you click and drag you'll get the little pin icon here as well saying no go it's an indication that it's grounded again just like any other part you can go and unground it again if you want it you know so you from time to time you'll turn your ground things and on ground things just to help with the assembly process so next what I wanted to do is I'm gonna I'm gonna do a couple of things to prep for later I actually am going to delete this part whoops let me select that part I'm gonna try this again I want to delete that part there we go and I'm gonna delete a few of these screws just so I can show you some something in a little bit here as we go along because right now what you're seeing is all these parts in the assembly in a typical environment where you're not starting with all the parts in a file already you would use this place button in the upper left hand corner to select a file from your hard drive and you know what let me see this is the weight arm I'm going to go ahead and delete that as well so I'm gonna go back in and show you how to place parts in a few different ways as we move move along but first we've just to clean it clean things up and get started let's next look at putting this shaft into position up here this part is still grounded so I'm going to bring up my constraint dialog box and I'm on the mate command already so I'm gonna select the bottom face of this or the face on the end and the face of this part and I want to mate it as opposed to flush so I'm gonna hit apply and you'll see it locks that thing in a position so now I can click and drag but it's maintaining that mate constraint so even if I click and drag it's keeping it in position so essentially all we're doing is is working through a process of removing degrees of freedom again remember on the View tab there is degrees of freedom and you'll notice that this one does not have the ability it lost an arrow I don't know what arrow it might be the X arrow I think it's the X direction yeah it's the in the X direction it does not have an arrow any longer and as I go back to assemble and add a constraint you'll see these these change as we go so I'm gonna do mate now instead of a face here I'm gonna select the axis so if I hover over this it by default picks up the axis first I could if I know there you see the select other that's actually a good thing to show now so if I just hold my cursor in one place I'll get what's called the select other dialog and it gives me the option to select the axis or the face and this would come in handy I'll show this a little bit later a little more but if you don't want to wait for it you can right-click and say select other and it brings that dialog box up immediately so I'm gonna select the axis because I want to make that access with the access in this hole and by doing that I lock that into position and you'll notice the degrees of freedom changes now the only thing it can do is rotate which is hard to see because this I rotate you can see this the threads in that hole actually spinning a little bit but essentially it's locked into place on the axis and on this face so it can spin and I'm gonna just leave it like that for now that doesn't really matter in this case I'm going to turn off those degrees of freedom again so next what we want to do is we need to put another am arm on this side of this model and I deleted the one that was in this assembly and the reason I did that is I just wanted to show you that this is essentially just the same part flipped over on the other side so once you have parts in the assem I have this part I selected it and here it is in the browser rather than having to go back in place and click the place button and browse to my hard drive and select that part I can actually drag and drop it right from the diet right from the browser so if I left click and drag you'll see I get the little place symbol and when I release it puts a copy of that into the assembly and you can see that down here now arm 3 is down here on the bottom you can reorder things if you need to just if you want to keep your parts you know similar parts in proper orientation with each other in the browser and now I'm ready to start adding constraints to that diet or to that part so I'm going to bring up my constraint dialog box now I'm going to use my select other select other it automatically what what select other does and I'll explain it a little bit more as we go is it just takes an arrow and shoots it straight through the part so here I'm selecting the top face the only other face I could select if I went right directly straight through the part into the back of the screen would be the back face so if I right click and hit select other it's I'm in a bad place there we go if I right click and say select other it automatically picks the bottom face for me without having to rotate that'll come in more handy when you see some of these other parts down here but it makes it so you don't have to rotate the model all over the place to get to a face that you can't see next I'm gonna select the side face of this part I hit apply and now my part snaps into place and again I can test just to see make sure it's working you know to see you know when you're when you're learning I highly recommend clicking and dragging often just to make sure things are reacting the way you would expect them to as you get the hang of constraints all right so next I'm gonna go I'm a mate I'm gonna select the axis for that hole and the axis to this hole and apply it then I'm going to select the axis of this hole and the axis of this hole and apply it now what I've done is I've locked this into place and when I click and drag you'll notice now I get a no-go symbol like the no movement it's different than the grounded one see over here if I click this in ground and I get the pin with the ground symbol this one is is locked into place and cannot move because it's specific grounded right it's been pinned into place this one with a no-go symbol the no movement symbol is actually showing that it's not grounded but it has enough constraints that it is positioned a hundred percent and it can't move without other parts of moving with it or causing it to move so really this is just a process of rinse and repeat now right let's start with let's get down here to put these pieces on so these are the braces that run between these two holes on the inside and it has a little boss on the end so that these screws can screw into it a little bit easier so what I'm going to do is here's a good example of when you can use the select other and this is a good example so I want to get to the bottom face of this not the top face but it's opposite underneath this part but I don't want to move it I don't want to rotate it this is where you could use select others I'm going to right click and hit select other so I'm gonna hug but first you want to make sure you hover over the face that you you think you can get to the bottom face through and I'm gonna I'll just hover and load it bring up the dialog box now if I click the drop down you'll see there's four faces that I could pick the top of this face the top of the ground the bottom of this face and the bottom of the ground and you'll notice in the upper you know you can kind of see it up here it'll highlight that face just so it's a little hard to see let me let me reposition this so you can see it a little more clearly there whoops there we go select other so I've got the bottom face there top face of this part bottom face top face of the ground plane bottom face of the ground plane so without rotating I can get to any of those four locations so I'm gonna pick this bottom of this part and then I'm going to link it up to the face on this part and when I do that it snaps it into position and I can cancel and it I can drag it around so it's essentially doing what we've already been doing we're just rinsing and repeating the process so next this is something that's common across all inventor if you right-click you can hit the thethe top of the right-click menu is the roof the last command you used or if you just hit enter on your keyboard it'll bring up the last command you're using this comes in handy when you're using constraints because you're gonna keep going into this dialog box but again once we get into the assemble command this will be a lot different you won't need the dialog box anymore so I'm gonna select that axis and the axis of the hole that I want to align to it and now if I click and drag you'll notice that I can rotate this again just another way to test make sure things are working the way you expected them I'm going to hit enter on my keyboard to bring the last command up I'm going to select this axis and the axis for this hole and apply that and it locks into place now without even getting out of the dial at work so I'm gonna start moving and doing the same process again select other I'm gonna get the bottom face I'm gonna lock that face there hit apply up I must have picked the wrong face I think I picked the top face of the ground plane which is grounded so that's actually not a bad thing let me go back and show you what just happened because the last thing I want everybody to think is that errors are bad errors aren't you know that wasn't just a warning telling me that I had try to do something that the system couldn't do if I try to take this top face of this ground plane and made it to this part here I'm gonna get that error and what it says is I can either edit the constraint and pick a different you know I could go back to these selection options and select something different or I could go back I could just say cancel this I could say go ahead and I'm you say whoops I know that this was grouted maybe I you grounded it temporarily and I didn't mean to you and I know that's what's causing the problem I could just say yep except that constraint put it on there in a failed the fashion and then I could go unground this plane and it would snap it into position and it would be like you put on a proper constraint then there's also a diagnosed process that you can go in and suppress constraints and walk through a process to try to fix it but in most cases once you get the hang of it you'll know what's going on for example if two parts are assembled in a way that they can't complete the constraints so for example say for example I've got this shaft here that defines the distance between these two these two parts down here I've got another part that I'm gonna put in between here again and in a little bit but it's shorter than this one so it can't meet this face in this fate and in the back face of this part because this one's longer and it would cause a failure there so there's going to be little failures that happen you know depending on how you've designed your parts but these are all things that are you know it's not the end of the world so you just get some practice with it and you'll realize that it's not that difficult so I'm going to go back and continue where I was I'm going to select the bottom of that face and the back of this face no apply that constrain and then I'm gonna zoom in a little bit and get that axis and the axis of this whole and apply that let me zoom out a bit you can see it's hanging down underneath so I'm going to cancel this you can click and drag and it rotates into place and this you don't have to do that I'm just doing it just for visibility purposes so you can kind of see what's going on so I'm going to hit enter on my keyboard and bring the constraint dialog box back up I'm going to do that axis and the axis to this hole now you'll notice I'm going to go back and I'm gonna reselect the second selection I could pick the center of this hole or the outer face it's up to you how you do it if you know that this hole is always going to be concentric with this face it really doesn't matter which one you pick it's a matter of preference to be a hundred percent safe you should probably pick the center of the the holes because you know those are the things that you want lined up but again it really is a matter of design intent so I'm gonna select the center of that hole and hit OK and now I have those parts locked into place let me zoom out a bit let me kind of reset everything back to where I was okay so now I've got everything kinda in position it's the frames starting to come together everything's locking into position because this is grounded and everything's constrained to it next let's go ahead and put in this piece here it works pretty much the same way with one slight difference I'm going to go ahead and select that face in that face and apply select that axis and the axis for this hole and apply now the one thing you'll see here is I have this does rotate right so it does have a degree of freedom remaining now it may or may not make sense to put a constraint on there to prevent that from rotating I know when I assemble this though the pressure from these screws that are holding this together and the way this assembles this is not going to rotate like this so I'm gonna go ahead and add one more constraint to remove its final degree of freedom and that's gonna be an angle constraint we haven't done this one yet so I'll show it to you I'm gonna select the angle constraint it's pretty simple I'm gonna select the top face there and any other face that I want it aligned with and I want those to be in the same orientation with zero degrees of angle between the two I'm gonna select select the directed angle option and I'm not going to get into these options they get a little more advanced as you need them just remember there's alternate solutions for all constraints so if you need to you know something's not working for you exactly right look at these other solutions and the help file does explain these now but I'm not gonna get into them now so what I can do is let me let me show you here if I hit 0 and hit apply it's gonna lock that into place so this aimed this face and this face have zero degrees of distance the angle between them they're they're parallel to each other now if I select this and I say find in browser there it is right here the trigger plate what you'll notice is that as I've been adding these constraints it's been adding them underneath to each of the parts so it's gonna have this is another thing that comes in handy to know about if you need to know where this these other the other half of this constraint is it's kind of like finding browser this has a another face this is the face on the trigger plate and you can also see when I highlighted this it's showing me the other face that's involved but I don't know exactly what part that is I mean I can hover over here and I see it's the base link but I could also right-click on it and say find other half or here it is it's called other half and it will jump to that part and expand it and highlight the other half of that constraint comes in handy just for fighting constraints and doing some troubleshooting if you get a little too far down a path where things aren't assembling properly and you have to troubleshoot things the other thing you'll notice is this angle so the angle is important or the reason I wanted to show you a little bit more about the angle is it shows you the degrees in the dialog box if I right click on this and hit edit you'll see this degree right if I say 45 and then I hit OK now you'll notice this face and this face are 45 degrees apart right so it's just controlling the angle the same goes for mates in any of our other constraints I'll show you that in a better example in a little bit but one of the shortcuts you can do is if I select this angle you'll notice down at the bottom of the browser it's a quick there's a quick input area where I can say well let's do if you know let's see what 78 degrees looks like and when I change it you'll notice that it changed it to 70 degrees so I'm going to go ahead and set that back to zero and all I'm doing is typing 0 and hitting enter on the keyboard that resets it so that's just something that you can it does come in handy from time to time and it actually controls Drive constraints which I'm not going to get into here but oh well you know what I'll do just because we're in assemblies and I've got a couple parts that are easy to work with I'm gonna do a quick side tangent run here on Drive constraints because it's important to know and it comes in very handy as showing motion and examples for people who need to see your models I'm gonna really quickly set up a drive constraint and it really is nothing special it's just a constraint and you're changing the distance of the offset in an animated fashion so for example I'm going to take this part I'm gonna bring up my constraint and I'm just going to meet the face of this arm to the top of the ground plane and I'm going to apply it notice that there's zero offset if I set this to you know one inch you can see that it changes here's 25 here's you know let's go back to zero so all you're doing is I've created a meet constraint now let me find that in the browser I have the projectile arm here's my mate on any constraint that has an offset like that you can right click on it and select a drive that constraint let me bring the dialogue box in here so what this is going to do is it's going to say start at 0 inches which is where it's at now this constraint is 0 inches off it has no offset at all and then I'm going to say make it let's do 3 inches I'm gonna do between 0 offset and three inches of offset with no delay and this little double arrow is just more options that you can run one of the opposite options is just go from the start position to the end position that's it the other option here under repetitions is start and start so I'm going to go from the start to the end and back to the start once in this case I'm gonna do it three times the other options here are the amount of steps so if you did it in in one inch increments for three inches this would make three steps to get there I'm actually gonna do it in like let's do point one inch steps you could also choose to do it in the number of steps so you could say do it in 30 steps and you'll have to play with these just to see but I'm gonna go back to 0.1 and now I'm using it play and all it's doing is changing that offset value for me and actually you know what I'm gonna go to let's do point O five instead and play that again so by doing smaller increments it does slower motion or if you want to see it do things more you know a longer you could maybe make it five inches zero inches to five inches and maybe make it do five times back and forth so you'll notice in the top of this dialog box it's running and it's giving you the distance of offset it's just handy to kind of see you can also stop this at any point and see what that is so you could put that offset in if you know where that's what you could lock it in at that position so if I hit okay here let me go a little bit there okay so what I did is I stopped it at about one point six inches well exactly one point six inches if I hit okay what it did was it put the offset value in for one point six it's just like I went and typed it here so it's just the way you could do some test you could find a value that work and you could apply apply it quickly to your model or if you decide that you don't want anymore you just go back and hit zero here and you're back to where you started with no no harm no foul so I'm going to go ahead and delete that constraint sorry for the little you know side run there and the tangent I got off on derive constraints but they come in very handy and if actually you know what let me undo that the important thing the other important thing to remember here is that if other parts are constrained to that arm so say for example let me go and pick the top face of this bowl or this clevis pin if I were to make this to the arm here and apply that now if I do the drive constraint it keeps those constraints right I'm going to drive this mate again in both parts move so it does maintain these relationships between those parts even if you're driving constraints which again makes it so that you can do all kinds of motion testing and things like that so anyway I'm gonna undo put those parts all back to where they were and we'll continue with our example next what I want to do is put this arm here into the center here now there's a couple of things that are gonna happen here so let's well we that we can talk about so I'm gonna select this part in a browser or in the in the web graphics window and it highlights in the browser if I expand this you got to remember back to the part modeling examples every part has XY and Z planes and axes when I created this part I used symmetric in a symmetric extrude so I know that the X is e plane here runs right through the middle of this part and if I look through if i zoom in you can see it it's it extruded a quarter inch earlier 1/8 inch in one direction in a thin in another direction so I know that this part is exactly centered on that XZ plane now this is important it comes in handy it's again a tip and trick that it is useful to know if you have something like this selected in the browser and you start the command you'll notice that selection 1 has already been made and it's asking you for selection 2 so that's good to know that it's bi-directional and it allows you to pre-select things just you know it makes it a little bit easier once you get the hang of it it really speeds things up but the other thing that we need here is this part here we find it in the browser there it is the a arm shaft also has origin planes but in this case I did not use a symmetric extrude so what I need to do is I need to add a plane right in the center of this part that's always going to remain in the center of this part so what I'm going to do is I'm going to this is this is where we get into a little bit of top-down assembly modeling where I already have an assembly and I can go make changes of the model as part of a way to assemble things so I'm just going to double click this part now one of the things you can do is I can say I could go and I could say here's midplane between two planes I could select this specifically and there's a bunch of different options for creating work planes that you can do I almost never use this drop-down list it's good when you're learning right in the beginning to understand what options are available but once you have a feel for what they do you can just click this plane button and I know that once I select this face I have the ability to select another face and I know just from practice and just trying things out that when I select this other face it's gonna create a plane right in the middle and it shows you the preview for it it's hard to see here because I but you can see when I move away I'm getting the plane on this face that I'm selecting and it's showing me the plane that's gonna create right here in the middle so when I select that I get a plane right in the middle if these planes move apart this will always be centered between these two so that comes in handy when we're starting to do some modeling and I can go back to my assembly with the return button in the upper corner and I'm back in the assembly right where I was but now I have a work plane that I can use for mating these two parts together so let me go find this in the browser again there we go and here's my XZ plane I'm going to select that and then I'm gonna hit constrain and so my first selections already been made and I'm going to select this work plane that we just created and I'm going to apply that now one thing I kind of screwed up there which is not the end of the world again you're gonna run into issues not issues but places where you you maybe clicked apply too quickly or you know what not you can always go back to the browser right click on a constrain hit at it one thing is I don't like this flat plane on this side I want it flipped over so I really wanted the flush constraint not the mate so I'm gonna hit the flush solution and hit OK and all I did was flip that part over just so I can see these these indentions and things like that it's not it's more for aesthetics than anything but now I'm gonna hit enter on my keyboard and get back into the constraint dialog box I'm going to select this axis and the axis of the part or the shaft and when I hit OK it locks it into place and you can see that it can rotate now so what I'm doing is I'm just starting to assemble it just like you would get a kit of parts and start putting things together it works the same way here so now what I want to do is show you a little bit more about the assemble constraint you've kind of seen all this dialog box stuff and mates and flushes and offsets the assemble command does something a little bit different what it does is it let me get in and I'll show you it brings up a heads-up display here's your offset same thing you had in the dialog box before it has a drop-down here where you could select a mate mate mate flush and these are the different solutions for mate here's an angle directed and here's tangent outside and insight so these are those solutions that you can have for those and what it does is I'm going to start with let's zoom in a little bit let's start with this face when you select a face it starts looking for things you can solve two things you can mate two so what I'm going to do here is I'm gonna rotate around and I think this is the right way I'm gonna select this face yeah that's right okay and now what it does is it brings up the plus symbol the undo and the accept option or okay I'm going to temporarily apply this the plus symbol says yep I like that constraint go ahead and apply it temporarily if I were to hit escape everything would just cancel and go back to where it was but what it's letting me do is rather than keep hitting apply and launching the dialog and apply and launching the dialog box it's letting me whoops well here I'll show you what escape does cuz I picked the wrong thing I know it let me drop out okay here let me hit escape and get back to you what it did was apply I hit the wrong button there and it applied that constraint but it has not applied that the access constraint that I was getting ready to apply so let me hit enter again get back into my assembler command I'm gonna right-click and hit select other I want this axis and now it's gonna start looking for points or axes or things that I can mate to and I'm gonna select that let me do the center of that hole no you know you'll notice I can actually select it doesn't select anything on the part that I have chosen to start with so it's really like selecting through that part into that hole so I'm gonna select that and I'm going to hit apply and now you'll see these two things are locked together and I can start to position it in a way that would make sense and then again if you've seen my other assembly or dynamic simulations you'll see that this arm is is supposed to be flipped under because we're gonna put the weight up here and it's gonna throw a reject dial so anyway now that we've got that position that arm into place let's I'm gonna show you the assemblée cam in a minute again but one of the things I did was I deleted the weight that pings on this end piece so I'm gonna show you the place constraint or the place dialog just so you can see the process but it's it's pretty simple I'm gonna go scroll down through the my work and find that or through my list of parts and find my weight arm and I'm gonna select that and it just asked me where I want to place it I can place it anywhere and if I once I've placed it if I want multiples I could click it again and place another version of it when you're done just right click and hit done or hit escape on your keyboard now I place two and I don't need them so I'm going to select this one and I'm going to right click and just say it delete so I have the piece I need now I'm gonna go back into the assemble command I'm gonna assemble this face to this face I'm gonna temporary apply that and it's upside down which is no big deal I'm going to select other and I'm gonna get the axis for this place or this weight and I'm gonna select the axis for that hole now that I've got two applied I'm gonna hit okay and now I have the ability to well here here's a place where occasionally you might want to ground things when you start linking lots of parts together things get a little out of whack or can if you're not careful so you might select this part and ground it to give more predictable motion right so I know that I can flip this around now I can get this part and move it and it will you know I can position it roughly where I want and I can always go back and on ground that part right so there's no motion between those okay alright so now what we'll do is we'll add a few more constraints just to finish this off and I'm going to use the assemble constraint quite a bit here now move along a little bit faster now I'm gonna hit assemble if you select the circular edge of a part you get an arrow pointing down that's the insert constraint which we haven't talked about but what it does is it aligns a face and an axis at the same time so it mounts the faint bottom face of this stopper to the top face of this part and the axis of this hole to the axis of the threaded hole that we just attached to so it's kind of a shortcut comes in handy for putting nuts and bolts and screws together now I'm going to zoom in and pick this face there to insert that into that hole and again then we rotate around if I get the right angle here I can see all these holes and I can see all these screws so now I can do assemble and I can do that face in that face okay I'm gonna hit enter on my keyboard to get back into it that face in that face hit enter on my keyboard and that phase in that face so now I've got all three of those parts so what I did was with the insert constraint now if I click and drag you can see it spins which is what it's supposed to be but it can't come out of the hole now those little icons that are coming up those are called eye meets all our fastener and things like that in our libraries have I mates there half of one constraint and I'm not going to get into that here but I could hold ctrl down if i zoom in this is a mate this is a mate and this is an insert so if I have this part just laying in an assembly I could hold ctrl down and drag that and it would snap into position automatically but again I'm not gonna get into that into this example alright so real quick now we're gonna do a symbol and we will put that clevis pin into that hole and we'll hit enter on our keyboard will put this club as pin now while I'm moving this around what I'm doing to reposition is I'm just clicking my middle mouse button and panning I can also scroll my middle mouse button to zoom so while I'm in the middle of the command you can use those and makes it a little easier to get around so now I have those clever spins in position now I need these these pins to hold those into place so I'm going to do is enter on my keyboard to get the assemble constraint again I'm gonna select other to get the axis and then I'm gonna rotate around here and I'm gonna put that through the axis of that hole now I'm going to temporarily apply that because I have one more constraint I want to do here I want to right-click on that and select other and I want to get the axis for that hole that rounded piece of the pin and line it up with the pin itself and now I can apply both of those constraints at once and now you'll notice when I spin this the pin spins with it because they're linked like they're snap together okay so let's do the same thing on the other side with this pin I'm going to hit enter to get back into the command I was just using I'm gonna select other and get the axis zoom out a bit well I forgot it's on the other side so I'm gonna rotate around sorry for the quick motion there I'm gonna get that axis now temporarily apply it with the plus symbol I'm going to select other on the to get the axis of that pin and snap it to the center of the clevis pin itself and then I'm gonna hit the checkbox to apply both of those constraints at once and now when I click and drag they all move as one big huge system okay last but not least let's um let's get back to those screws I deleted a few of the screws and I just wanted to give back to this shortcut once you've started to do all these expand all these parts if you right-click on the top ass level assembly you can choose to collapse all children and it will quickly just collapse everything just makes it cleans it up a little bit so that I can find this where does these screws so I'm going to just click and drag from the browser and put a couple more screws in here I need three more screws to put into these holes so I'm going to get into my assemble constraint select the bottom of that screw the bottom of the hole and hit apply and around my keyboard center of that to the bottom center of that hole places that and one more time enter on the keyboard to get back into the constraint or to the assemble command and I'll select the circle on the bottom of that hole and apply that so now these are all locked into place to okay last but not least let's go ahead and throw these pins in these little c clips in they fall into this hole I'm going to temporarily apply that I'm gonna select the center of this it's like the other the axis that goes through the center of that pin and I'm going to lock it there and hit apply well just helps if I hit the check button there we go now I'm gonna go back out and hit enter again select this face rotate around to the other side well I'm just means my view of Cuba for that whoa just try that again there we go upper corner and I'm gonna select the inside face there let me zoom in there we go temporarily apply it with the plus then I'm gonna select other to get the access that runs through the center of this pin and I'll select the center of that and then I hate the checkbox to apply and now I have all my pieces locked into place so there you have it crash course in assembly modeling hopefully that helped everybody now that you have this assemble and work if you haven't seen the dynamic simulation video it'd be worth going to watch that now because you can actually see now that I've assembled it what you can actually do with it which is quite a lot actually so look forward to speaking with everybody again in the future hopefully this was helpful thanks you

Channel: John Helfen

Views: 192,429

Keywords: Autodesk Inventor, Assembly constraints, 2012, Drive Constraints, Degree of Freedom, DOF, Assemble

Id: Ssy7xPrjR2U

Length: 47min 4sec (2824 seconds)

Published: Tue Mar 13 2012