Inventor Constraints and Joints | Autodesk Virtual Academy

good morning everybody this is Jorge with khatib technologies bringing another session of av a and first of all I'd like to thank everybody who's been on on our sessions and continues to go to our sessions we have over 750 subscribers I really look forward to hitting that 1000 mark so by all means please continue to share the links for this so that more people can benefit from a VA so today's discussion will be on metric constraints and joints the focus being more on joints and what the difference is between them so you might ask yourself why are we showing this session first of all we're doing this because when it came in our surveys by the way so again keep filling those out at the end of the sessions it does let us know a little bit more about what you'd like to see at the same time as we do training classes and support for a lot of our customers we end up finding that one of the biggest struggle is assemblies and trying to put the parts together really well we want to focus on today is making sure you know what those joints are what the difference is between them and hopefully alleviate some of the headaches you might have sometimes with trying to you know put relationships between the different parts so that's our goal for today looking at joints knowing the difference between constraints so let's go ahead and dive right into it all right so first of all what is the difference between constraints and joints constraints think of a more as removing degrees of freedom so for those of you that might not know what degrees of freedom are is how much action apart might have can it move up down left right in out and rotate in the XYZ directions so what constraints really do is they remove those degrees of freedom and kind of locks down the part so there there's no movement now traditionally we've used constraints in the past to also give parts move it and tell it how we want to do these things but I believe it was inventor 2014 where they brought around joints and joints are going to allow us to be able to fully define that degree of freedom so we can tell it what we want to do how do we want it to spin or do we want to fix it and what do we want to fix - so again constraints remove degree of freedom usually going to be used for a more static type of assemblies and joints will define it and give the ability to describe the motion for it now this doesn't mean we can't use both at the same time by the way we can certainly do that - and we'll see examples of that today as well so before we get into the actual life part of it I just wanted to discuss a little bit about the different options you have when you're looking at joints the first one is rigid so think this as the fixed constraint almost so what this will do is it'll allow you to put two parts together kind of like you're seeing that first picture on the upper right hand side of the screen here and think of something that's well they were bolted together you want to align it you want to go ahead and make sure it's the faces or meaning up next to it and so forth you'll be able to do that with this rigidity the next one is rotational what this does is it allows to you freedom for one rotation I'm sorry for the actual rotation movement so in this case here you're seeing this cylinder for example and it's aligned to the center of it and it's rotating you notice there's a green arrow there actually that tells you that's the that's the way that it can actually rotate the third one we see here is the slider and this is a transitional one meaning it can actually move in and out what you're seeing on this image is a green arrow pointing out towards us showing us that it can move in that direction in and out the orange arrow lets us know that that's where it's that those faces are the ones that are fixed to each other us to make sure that actually stays flat right the next one is cylindrical and apologize some of these might be you know they might be pretty straight forward but I want to make sure we're all on the same page the cylindrical one is a lot like aligning the accesses of two different parts along with the actual edge that needs to meet up - so you're able to see in this image for example that rod would move up and down and will actually take a look at this in a little bit as well the planar one is a true to translational ones and one rotation I think a lot of like a cam now again things had some ability to do that and we still would use it in conjunction in this case we're saying this this part can move on that one plane and it can rotate as well now again we'll see that as well the last one is the ball so think of a bearing or maybe some kind of ball joint or something like that and trying to align to the center of it to make sure that it rotates in the right directions so we'll be able to do that with joints as well the last one is automatic so as you may think automatic sure it creates different ones depending on what you select but what I want to make sure you are aware of is that there's only four different ones that it will pick for you so there's rotational cylindrical ball and rigid so all the ones that we just those ones that we just discussed right now basically it's going to create these for us depending on where you pick of course so you know definitely want to note that these things are in the help menu by the way this information that I'm given to you right now it does give a deeper description of course but order make sure again we're all on the same page so let's go ahead and dive right into it the first example I'm going to show you is this excavator arm here so there's already some constraints in here you know most typically most people would use constraints try and figure out how you can limit the degrees of freedom you know you like a cylindrical or I'm sorry an access constraint on this usually maybe you'd have to get a mid plane going something like that but I'm here to show you that you might not necessarily have to do all those things so I'm going to be brave here and I'm gonna go ahead and delete all these constraints and start all over again so the first one I'm going to apply is right here where we get to the joint command it's up at the top when you're inside of an assembly and you'll notice you have a dialog box you can use or you also have this mini toolbar you can use both of them really give you the same options over here you also see there's a limits tab though too so you'll see the different types in here with little graphic representations to let you know what each of them will do you can always use automatic as well and you can still move from one to another so in this case here I want to use a rotational one usually use like a hinge really so I'll come over here and you'll notice that as I start moving over the geometry here it picks up different points on it I'm going to rotate this or else we can see a little more clearly that if I select over the approximate midpoint of this it'll actually pick it up for me I'll go ahead and click this outer surface it'll pick that edge for that center point for me and then I can start aligning it now you might start telling yourself well wait he didn't make a mid plane to be able to put this together to align the mid planes and then do an axis well luckily we don't have to do that with joints we can right click between two faces so this will now allow me to select this face I'll go ahead and rotate this around so we can see this very clearly will select this other face and now if I hover over the geometry you'll notice it'll find the midpoint of that for us so again I'm just hovering over it I click it and now I can see preview of what's going on so this preview what's allowing me to see it is in this dialog box this animate section right here if you prefer to have it you can turn it on or if you want to see it again you can just hit the animate and it will show you of course it's not fully defined just yet we'll get there here shortly then notice that at the top here there's connections and this allows you to actually set those connections that we just created and in a moment we'll use a line that actually allows us to put these parts together there's also a gap so if you wanted a gap between those two selections you could type that in here and there's also a limits that allow you to put an angular or a linear limit and allow you to say where it starts look at what the current value is and then give it an end if you wish so go ahead and say ok to this and we'll go ahead and rotate it around we'll see that it's simply rotating about the selections that I just created I'm going to just a little bit more usually this piece here think of how you would do it traditionally you probably go to a constraint hopefully you use like the insert constraint put it on there then I rotate yourself to do an angle or something like that well with joints you can take care of all of that with one shot so a lot of times joints will be able to take up what you would normally do with two or three different constraints - so I'm going to come over here and pick rigid I will now hover over this edge right here which picks up its center point as well and then I'll pick this one over here - and Lettuce it moves over and it just kind of shakes a little bit letting me know where it's trying to put it that's great but think about it we've only aligned the center points we haven't actually aligned if this can rotate or not what's going to happen and chose it for us it did a pretty good selection here as you see in the preview however if you want to go ahead and align it we click on the first alignment option here notice I can use the meaning toolbar or the dialog box of course I will now pick this edge and then the edge on the on the part and now it's completely aligned I can click OK and if I try and move that part you'll notice it's simply moving with the rotation of that cylinder all right let's do another example I'm going to turn off the visibility of the cylinder just for a little bit so we can place this rod using this component right here which is you know already with the cylinder so again we'll go to joint in here we'll go ahead and choose a cylindrical now what we'll do is this kind of works like the insert constraint so those of you that have used the insert constraint you typically choose the edge that you want to made up to it so that's kinda what we're going to do here actually we're going to go and pick this component here by the way the first component that I pick is the component that tends to move to the second one it does depend a little bit on your jump what other joints you have if it's a grounded part or not it'll give you that warning by the way but here what we'll do is we'll click this edge here we'll click this edge here now aligns those two centers and moves in and out a lot like access constraint and insert constraint but you may want to do just a little bit more now we can add limits to this and allow it a certain amount of movement maybe we only want it to move let's just say 10 millimeters for the start point and maybe for the end point once we activate this we can say 8 milimeters we'll hit okay and now we can see this part move even though the cylindrical part the cellent cylinder tube is not showing let's go ahead and turn that back on so as we're trying to to play with this assembly and see this action what might happen is depending on how you move your mouse that part might moving you might not want that so what's really great about this is I can go back to these joints if you remember constraints get saved under the actual part I can go to this rotational one for example and say with the right click that I want the lock or protect it so what does lock can protect do well lock does is it locks the part in place it still allows parts around it to move so let's take a look at that will actually protect that one and now you'll notice if I try and move it it's not going to move it will stay stationary but the cylinder will still move according to the limits that I've set for it so a really nice feature it will let you know that it's locked by having a little padlock on the actual feature in the tree here I can always right click and take that off if I want now what protect will do is it will give you a warning if you've kind of like over constraining if you will if you remember when you over constrain something to bring up a little dialog box and that dog box lets you know what's going on you know basically there's some constraints that get in the way of each other so that's the same thing with this cylinder I maybe I want to protect this because this is the one I do want to keep and I don't want to negatively affect this I want to make sure that that one sticks and it's going to give me a warning if something's going to basically override that or interfere with it let's remove the lock from it so that's a quick example I'm not planning to do all the constraints on these I wanted to show you some when you're using this assembly here again you can continue to use other methods such as constraining there is the assemble command by the way too so for those of you that don't know this is kind of like the automatic version of constraints by the way which will pie discuss in a separate session but here once we've done this let's go ahead and look at another example here have this vise this one I think shows the sliding ability very nicely this is a vise that hasn't been completely constrained you'll notice here in the browser there are no constraints for it right now so if I go to the joint command here instead of using automatic I like to specify myself what I wanted to do so I want it to slide I'm going to move this part out of the way just for a little bit so we can see a little more clearly we'll go over to slider what we're going to choose here is very very important I'll tell you why what happens is if I choose an actual edge here it might not necessarily move the way I want it to I might like a kind of flip itself or something like that so aligning is going to be very important in here as well what I like to recommend in this case is to pick an actual face instead so you can make sure that these two faces are kind of like mated to each other basically again let's think about how we would do this with a constraint I'd probably do some kind of make constraint between these two faces maybe a flush constraint if that's what's accurate or maybe an access to access constraint here instead I say let's do a slider where we pick this surface here and this surface here so right away you notice it doesn't necessarily pick up the way I want it to slide we need to tell it how we want it to slide so that's when we use the align tools again I'll come over to my first alignment and I'll pick this edge here alternatively I could have also picked this surface right here by the way it will take either one I like to use this edge the second edge that I want is this one right here every now and then by the way it might it might be the wrong way right the depending on which way the arrows are pointing it might actually be flipped this part could be on an eighty degrees so we have an option here where we can invert that alignment and make sure that we actually have everything in the right to refraction by the way I just like to take a little moment here if anybody has any questions at all there's a questions panel inside of GoToMeeting here so we'll definitely have a Q&A session at the end and answer those questions for you as well so again this part will now move in that direction I can see it move in that direction by just moving it now I can still continue to constrain you know if you imagine this part I need to constrain to this face I can still do that by the way I'm not constrained to just doing the two phases no pun intended on that we can go ahead and constrain those two and move it around as we need to so by all means feel free to use both of them all right let's show you some of the other options we have I'm going to open up that ball joint one for example that I was talking about a little while ago I hope I hope you'll see that it's actually really easy to use these joints I go to the joint command here again and we activate the ball type as I hover over this you'll notice it does pick up the center point of that sphere so it'll automatically pick that up for you the thing you're going to notice now though is again I don't have a mid plane I don't actually have somewhere to select inside the middle it doesn't know I want to do that if I were to pick this edge right now it would actually place this this point on that point right there technically not in the middle not to worry again we can use that mid plane option basically which is between two faces by just right-clicking so I can right-click this I can go ahead and select the two faces now I'll be able to go and hover over the edge it'll know what I want to pick that mid plane and put that ball joint right in its place well click OK and sure enough we see that it rotates again this is for like an example like a bearing or a ball a ball socket that you might need to use in your assembly just a quick reminder again you can see all these joints in the browser so at any time if you wanted to suppress it I can remember if there was that lock option or the visibility of it we can always change that in there and it will also show up in my relationships folder we're constraints traditionally show up as well let's look at another example so we have this an example kind of like I can so let me delete the ones that are in here already actually and show you the way this would work so if we go into the joint command again we're going to come over here and choose which one we want I'm going to use planar in this case again you want to pick the part that you're actually going to move first if I were to pick this one which is the grounded part I will get a warning it will let me know this is the ground component and my sure I actually want to do this right so you'll get this pop-up if you if in case you do that so we'll go ahead and kind of like again that insert or some of the other ones we've seen you're going to pick the reference point here by going close to the edge that you're going to want and I'll choose this edge right here but in this case it's not actually aligning the edge or the center point it's just picking that as a reference to know how you're going to put these together as you saw in that little animation and hopefully you're not getting too much lying and you're actually able to see that animation life it goes ahead and moves in that direction I'll go ahead and hit OK here and we'll actually move it around doesn't move up and down but it moves left and right or in and out it also rotates actually as well but we can't see that just yet let's see that happen using one of the traditional constraints I'll call it traditional maybe you don't know much about it just yet but this transitional one for example will allow me to move along this slot here as long as I have tangent edges just a little tip for you there as long as this is tangent edges I've seen people try to do this maybe to a sharp corner or maybe the edge they thought what's tangent it actually wasn't that's why I use Phillips to make sure it was tangent so what we'll do here is we'll simply select the component this is the surface I actually want to write along this surface here puts it in place I can click ok and actually move this now along that edge so again showing you that you can use both in one shot you don't have to stick to one or the other just a couple of things while we're inside of this assembly I always have we have just a little bit more time we can still use some of these other tools that we traditionally would use when we add relationships to parts so if I decide to do like a free move by the way on this part it's still going to show me correctly for those you that might have not experimented with this just yet some of the newer features since 2014 2015 2016 we can see the relationships here and where it's actually all attached you'll see a little icon for the joints and the constraints as well so you can see exactly what's going on hit update and you'll still put it back in its place so again still works very similar to all of these we can also still show constraints on the screen here so we can actually see what's going on and not have to necessarily go over into the browser as well we'll just hide those all again while we're working on this something else that I'd like to bring up I'll go back to my vise here and that's the ability to assemble I know we didn't talk about assemble here I saw we have a couple more minutes and I thought it'd be a really good place to show this I'm going to bring in this slide jaw one more time just to show you a nice little feature a little tip for you guys so I'm going to turn off the visibility of it and place the sliding jaw back in here when we first bring in this component usually you can put it in its place you have a right-click menu here where you can rotate in different directions or place it ground it an origin but the other thing you can do is also if you hold down the shift key it actually brings up the assemble command so this comes up with any part that you're creating the reason I also bring this up is I've had the question before when I use the assemble command does that I'll shall actually take in joints as well it actually doesn't it doesn't necessarily bring that in it only uses the actual constraint dialog box for this not the joints if you want to do automatic joints then that's what we have this automatic feature for so the assemble command only works with constraints not with the joints I just wanted to make sure I made that clear as well that distinction between the two of them so in summary what we looked at is constraints and joints a little bit the focus on this was joints and what the difference are between them the constraints again remove motion the flood restrict the degree of freedom and joints really defines the motion what you want it to do how do you want it to move in a lot of cases two or three constraints usually will make up that one joint right so it could take you know a little bit of time off your hands it could also allow you to just see the movement and think about it just a little bit differently as well we also talked about lock and protect so lock is really great to maintain the part in its current position and then still be able to move the parts around it and see what's going to happen around that part protect will add a warning so that if you add any relationships that are going to get in the way well that will go ahead and make sure that you keep the relationships that you actually want alright so let's go ahead and move into the Q&A session let me go ahead and open my questions dialog box here and see what we've got going on so the first question I see here is can joints be you to drive assemblies in motion you know I'll have to double check on that for you I can definitely get back to you bright but I believe I saw that when you right-click you have a drive option but I'll make sure to double check that and answer you after this session I have another question here is insert better I wouldn't say insert necessarily is better or not actually it depends on what you need to do so like let's say you're putting a bolt into it and you do want it to rotate you want to be able to see what kind of things rotate make it both not the best example but just think of a rod going into a place where it does need to rotate that that will work just fine there's nothing wrong with doing the insert instead you can't do the cylindrical one also right but what the insert will do differently is it'll definitely put it in its place and only allow rotation right if you use the joint of the cylindrical joint it actually allows it to move in and out so in some cases the insert just may be better we have another question here that says can movement be constrained or limited by interference detection or limited by interference detection so you might think of like collision detection or turning on the contact' solver for example so you can still use the contact solver with this inside of inventor that should be I believe it's in the tools and inspect a panel if I'm not mistaken so you can still use that and that's what I would still recommend in order to be able to see collision or interference detection as well I have a couple questions here as well on dynamic simulation it looks like so when I see is are these the same joints in from dynamic simulation so it actually is a little bit so that's kind of where this idea came from of joints for those of you that haven't been to professional there is an environment called dynamic simulation where you used to convert the constraints into joints so that's where the idea came from it's not the exact same one but it will still be able to take in these joints from the assembly mode and convert them into the joints that you might need in dynamic simulation someone's asking if we can have this presentation as reference so we do record these sessions thanks for asking that question we will have them on our youtube channel if you just go to youtube and then type in qatif we have a playlist and therefore our ABA sessions and sometimes we have highlight videos as well we have a just a comment I guess you might say as if it would have been better to maybe or more accurate to align the sliding part to the shaft instead yeah it definitely could have been again it always depends on what you're trying to do what you're trying to accomplish what type of movement and what you want to drive another way of looking at it is maybe you wanted some kind of ratio where as you spin the actual rod that Vice would have moved in too right so again these are just a few examples of how you might want to do something like this I have a really good question here and maybe a lot of this too the comments on YouTube question here on on a very large assembly which is lighter to compute the constraints or the joints on the top of my head I would think the joints but you know what I'll look into that and make sure we put them in the comment section of the video for for everybody when we post this to YouTube and I'll also make sure I send you that answer separately Seth all right break getting here to the top of the ten thirty here what would I recommend as a next step is I would definitely say try it out yourself we do have a blog by the way and we'll post this on a YouTube video on how to get to you know how to kind of get started with join so I definitely would say good put it to good use I'd say get ask us questions let us know if you have any questions on that of course again as I said this is something that typically comes up in training and even after training that people want to know more about so I'd like to thank everybody for being on subscribe to our blog and you'll get more information on this as it becomes available of course and I hope you all saw how you can use joints you'll start via with being able to put it to good use don't forget that our next session next week is on structural designs where we'll have Greyston from our team showing you how to use frame generator for example how you can do cut lists how you can do frame analysis even inside of inventor so thank you all again remember to subscribe send more people to to these ABA sessions let us know if you want us to subscribe them as well thank you and hope you have a great day you

Channel: KETIV Technologies

Views: 36,961

Keywords: akn_include, Inventor, Autodesk Inventor (Software), Autodesk Inventor, Autodesk Inventor 2016, Inventor 2016, Inventor Professional 2016, Autodesk Inventor Pro 2016, Inventor Pro 2016, Inventor Pro, KETIV, KETIV AVA, KETIV Technologies Inc, Autodesk Virtual Academy, Software (Industry), Technology (Industry), AVA, Joints and Constraints, Joints, Constraints

Id: lCkyYWnUx0s

Length: 28min 27sec (1707 seconds)

Published: Thu Feb 25 2016