Designing Buckles, Clips and Snaps for 3D Printing - Detailed Guide

in this video I'm going to show you how to design locking mechanisms right into your 3d printed models to give you that oh so satisfying snap let's get started [Music] how's it going guys angers here from makers Muse if you're 3d printing objects that need to join together in some sort of way in a permanent or semi-permanent basis you have a few options a lot of people will use like fasteners like nuts and bolts or maybe even glue however if you're clever during the design phase you can actually design locking mechanisms right into the part and then 3d printer without any additional hardware and what I wanted to do for a while so make a video on my process for creating locking mechanisms because I've used them many times in the past on projects here on makers muse but consider this a part one because there are oh so many designs out there however this video is gonna be focusing more on a style you might find on boxes with catches or on buckles you might find on backpacks however before we proceed what I think is a great idea is to get some inspiration and research from existing objects you probably have lying around your house that have built-in locking devices so let's go over to some that I've got set aside alright so what I have in front of me has some great product examples of snaps or claps clasps or clips or whatever you want to call them ways of keeping things closed or snap together if there's various components and there's different approaches many many different approaches but also different design intent because some of these are designed to be opened regularly some of them are designed to be locked together permanently so let's start with this box here which is a great waterproof case and this has these two clips here and these have a really satisfying snap like that so in this circumstance these are designed to stay closed by themselves nothing no external force will open them unless the user actually intently intentionally opens them up with a fair amount of force now the way the designers achieved this is by creating these components with a very small lip here on the other side of this part there and that comes around it snaps - this component here on in the injection mold so this has been reinforced with ribs and it comes around and deform slightly and then snaps underneath it so because of the way that box opens this will not try to open it this way will not do anything but you actually have to intentionally undo this and again deform the plastic slightly to get it open and you have to do it twice which gives a degree of protection which is what you want for a waterproof box so in this case it's quite a well-designed snap and because the plastic will only deform slightly this is going to last a long time no so that's this little box here it's a great example of a fairly high-end snapping design so let's look at signing a fair bit cheaper let's look at it this pin box now this actually has two snaps one there one there and it's designed to snap this plastic cover in place now this is just packaging and it's actually quite clever how they've done it because it has to be as cheap as possible and the thing about this design is it's just a sort of semi-permanent snap like you don't need much force to open this it's not really designed to be all that strong it just kind of holds the cover in place and that's it's only purpose it's not really holding any load and the way they achieved this is similar to the waterproof box in that there's a little tiny snap here and if I can show that on the camera it's again a very very small bump which comes round and on this part of the case there's a little lip and the bump comes round and then deforms into that lip and then once it's underneath it the bump will kind of lock into place so it's not going to be the easier the strongest thing you can see there doesn't take much to put it into place but also doesn't take much to pull it out but again in this circumstance you don't want a pen box that no one can open next we have this and this is actually designed to never come apart again this has internal snaps that you can't access once the product is assembled and it's just a cheap like wall light with a battery in it you can access the battery component thankfully but to into this we're going to actually have to use a screwdriver to jam into it to show you the snaps so if I get my screwdriver here trying to be as careful as possible working in here that snap that's the internal catches releasing pretty violent and you can see here and there are these internal snaps exactly the same approach as the boxes but once they snap in place you're going to do again here you can no longer access them and they're not removable so this is an example of a permanent snapping design permanent locking design built into each half the case to lock it together without any glues or fasteners and finally the star of the show we have this which is a buckle design now this is what I'm taking my inspiration from and although this looks very different to the box designs it's actually quite similar what we're gonna have is these these prongs deform as they go into the other component and then they'll spring out once they reach the point where they actually can lock in and this part here behind these prongs will actually be what locks into the buckle here and that's a bit of an exotic design you don't need to make it this complicated but there you go so that's snap they've deformed and then snapped into that edge right there and this is now permanently locked unless the user comes in and releases them so minister on paper for you the basic principles of how all of these mechanisms I just showed you work you have a ramp like this on a prong and this comes up and then it meets some plastic which will be like that and then as it comes up it'll deform to go along the edge of that plastic until it reaches a Ledge so this will actually deform and then it will snap up into this ledge like this and then once it snaps into place these ledges this edge will actually prevent it from going back house again and this is how all of these designs work and it's very easy with a bit of careful consideration to design a 3d printed part that can take advantage of this system where part will deform slightly and then snap into position and then stay there or if you want make it be able to be removed by either by the user interacting with it or if enough force is applied in the opposite direction before I draw anything in CAD I like to research exactly how it's going to go together so this is a exploration into the buckle that I showed you from the bag and that design was a little bit exotic as I was mentioned it's got some weird shapes you don't need but this is the more simplified design so this is using that ramp which rides up and then hits a Ledge and then we'll go from being deformed to Staffing back out into that ledge but something I didn't draw in this case was the ability to release it because you need to get your fingers in you need to snap it free and my first version of this didn't allow for that and I couldn't snap it free and you can see here this is my exploration of how the actual plastic cases worked and this is the snap from the top of the box so this is the top and it's got this snap here that has that little bump and then the plastic case bottom part had that receptacle that allowed for that bump either by having a form like that or it just literally had a ledge like that above it so depending on the shape of that nut for example if it's like this with an angle top and bottom it can be removed and put back in place or just force but if the top part is just flat or in some cases may be a little bit angled negatively it's going to completely lock into place and you might be able to remove it okay here we are in fusion 360 and this is my final buckle design and what I'm going to do is roll back the timeline and step you through my steps to creating this in fusion 360 it's not gonna be a full tutorial on how to draw it because this is considered an advanced kind of thing but I'm going to show you my considerations to actually making it work especially considering that we're using 3d printing now the buckles on the bag were made using mass-production techniques injection molding which has very different considerations to the design then what we're doing with 3d printing we have very different constraints and very different benefits to using the technology so let me just roll back and I'll show you from the first sketch to how I actually drew this buckle to begin I drew the internal part of the buckle and this is created using a single sketch and an extrude so I'm going to show you the sketch here and something I do recommend is to have a ruler on hand when you're ever your 3d modeling stuff because on the screen it looks way larger than it does in real life as an example this buckle we're taking the idea of the sort of ledge here that hooks in and then snaps into place this is two millimeters across and two millimeters in the screen looks massive but in real life it's absolutely tiny and this means that when we insert this buckle those prongs are going to deform by that two millimeters until they get to that point where they can snap snap out onto the ledge and because they are deforming we need to give the plastic room to deform that's the most important thing about these snap fasteners the plastic has to be able to deform which is why this distance is important because we have this long thin piece of plastic here which allows this to the form slightly and then snap back into place so we're using the elasticity of the plastic to make the snap fastener so that distance is important too because if the the ledge was for example just down here and it was on solid plastic it's not gonna work the plastic can't deform and snap back into place it's just gonna crush and it or it won't work at all basically so that's why we need to have this gap here and allows this this sort of rod here to deform this prompt to deform slightly I went with two point two millimeters you might want to play around with this depending on how thick the fastener ends up being and what works for you and changing this to be thicker means that it will deform less because it's more plastic but it might have a stronger snap back action and then thinner means it will deform easier but it might not be as strong also that distance is important to I played around with a little bit and I found that this distance was quite good for working with the ABS plastic and probably work of PLA as well but you can't have it solid that's the most important thing the plastic needs to be able to deform this middle post as well is important it's actually not used to fasten it in any way it doesn't snap into place it's simply to guide the buckle in and again I got inspiration for this from the bag buckle but it's important because when you're sliding this in place if this post wasn't here and well it wasn't guiding it in you might go in and we skewed angle and it might easily snap the prongs on each Sykes only two point two millimeters thick across which is quite thin so this post actually helps guide the buckle in and keeps it perfectly straight and parallel till it snaps into place and also helps us release it because we can release both sides at once and then pull it out I then extruded this buckle by four millimeters which again looks quite chunky on the screen but have your handy ruler it's actually pretty small and then I started drawing the outside component that acts for this buckle to snap into place I then added a simple radius there which actually removes the stress risers from those internal corners so you're less likely to get the plastic to crack there you could have I could have added this in the sketch stage but for some reason I prefer to use Phillips separately to the sketches in fusion adding fillers to the sketch itself can get rid of your dimensions sometimes and it means I can change it easily but that's just simply to remove any stress risers and then the next step was to draw the outside buckle there receptacle for the internal buckle to snap into place and I started by doing that with this sketch here now people who use fusion 360 would be like well you didn't mention that Angus well I did and it's locked into place but for some reason the latest version of fusion doesn't turn the sketches black which means they're to find when they are projected off something I'm not sure why but the reason I did project this from the internal buckle is to start getting clearances and as I mentioned clearances are really critical for 3d printing because 3d printing is not perfect and you need a bit of wiggle room for the parts to actually you know go in with consideration that plastic isn't going to extrude correctly all the time it's not gonna be completely accurate so I actually went with the 0.3 millimeter clearance here I thought I might have mentioned 0.2 that probably will work as well but 0.3 is nice and generous and you can easily change that if it doesn't work for you by just editing this and because it's projected it will automatically snap to that projection off the internal buckle so you know 0.2 for example makes the clearances a little bit tighter then I gave it a wall thickness of 1.8 from the buckle but because we've got that clearance it's gonna be 1.5 but again that's okay that's fine for the strength of the external buckle then I extruded this out and I extrude this out way up here because I wanted room to add like a little little area here as if it was a real buckle where you'd have maybe a bit of material that attaches to it again this is not designed for any real use it's not gonna be strong enough but just to get that look I extended past where I would need the buckle to actually function because I want room to add that little loop next mean to cut some slots into the outside of the buckle to allow for our little snaps to snap into place and this is what allows this to function so again I did a sketch where I added a bit of clearance so I projected off that original little hook and I projected off that a offset of 0.3 so nice at 0.3 moment of clearance and then I extended that up to the top of the buckle here with another projected line so what this ends up with is a slot so what you can see here using a cross-section analysis is we've got that original internal buckle with the little little hook that goes out and then we've got nice a 0.3 millimeter clearance there to give it enough room for consideration with the 3d printing process and you can see already that this will deform as it comes up and it snaps into place and then I simply mirrored that extrude to the other side and this would basically work now if I just turn off the section analysis that would pretty much work but it's not going to be stopped from continuing onwards so that's what we need to do next we need to actually add in details that will stop it from going too far oh and I also added some champers here just because if you're going to add material you'd want it to be a little bit more rounded and Shaffers a better fits really printing them fill its but that's not really important for what we're doing now this however is important this is where we actually are going to constrain that middle post and look I understand this might be pretty messy but it's the way I model stuff and it's done by projecting if I do an analysis I got some projected lines off that internal post and then I offset that to give us some clearance so I offset it I believe you guys 0.3 again so I use the zero point three millimeter clearances for everything on this model I think so I offset that line by 0.3 and then I offset the curve as well 0.3 I gave it an overall thickness of 2 but again there's a little bit less than 2 because of that 0.3 clearance and then I just brought it all the way up to the top here this is a little bit messy because I things over time originally these posts were just they stopped here but I decided I wanted to give the back a little bit of a different design so they don't need to be rounded like this they could just go all the way up but when you're working with CAD sometimes you end up with messy details like that and then it's extruded to both halves of the outside buckle and to show you the how the extrude works there I'll just turn off section analysis you can see that I've extruded from that point so the plane was the bottom half of the internal bottom half of the buckle and then I extruded to object you see here to object and then with that you can select the surface you want to extrude to like this and I extrude it to that and what this gives us is that guide so that internal post is really critical to guiding the buckle up and not deviating and possibly breaking the prongs off of our little caches here it was at this point that I sort of realized after doing some tests that it was difficult to undo this buckle by hand so what I ended up doing is just adding a bit more of a catch to it so I could get my finger in you could have done this right at the start but I didn't want to damage any of the projected sketches so I just added this here as a separate component because I didn't know if I want to make it bigger or smaller or get rid of it completely sometimes you want to do that when you're doing extrudes of things that you might want to change you might want to do them separately instead of all in one sketch because if you change too much of one sketch that everything's based off it can blow up the the CAD model and it can stop working so I just did it separately like this to see how it felt with my fingers and then I just did that as a mirror like this so I could get in and grab it from both sides next I decided to add some aesthetic details so I decided to add cut throughs through the model so turning off these these section analysis there I just added some cut through holes like this they're very much just for aesthetic purposes I could see the deformation of those prongs inside the buckle you don't need them they just added there as a simple sketch and then I added some Philips I'm not sure where those bullets are what are these abilities oh yeah that's right I added some Phillips just to blend in that catch a little bit easier again that could have been done in the sketch phase files you'd like to add fill it separately and again this might not be the best way to model but this is how I generally do these sort of components that don't need to be related in assemblies and joints and that kind of thing you know they're very simple really but I can hide the outside body here when I'm working on the inside buckle and I'm likewise I can hide the inside if I'm working on the outside so next I decide to add a chamfer around the entire internal part of the buckle and the reason I did this is because when you're printing on the pressure mark 3 or most 3d printers the first layer tends to be a bit too close you do that for better adhesion but it means it can sort of squish out a bit so adding this tiny little chamfer means the first layer is a bit more in and it's not going to squish out too much and ruin your clearances and tolerances because if we didn't have that and I show you here it might squish out too much and then it won't be able to go into the buckle but by adding that that sham for around it it just gives us a little bit more clearance for the edges of the buckle even though we've got a good generous clearance of point 3 all around it still can stop it working in my experience ok turning on our section analysis again we've got a great buckle but you can't get your fingers in to release it yet can you well we can do that by adding some cutaways so I just added a nice easy sort of circular cut away to where the prongs are and they basically allow you to get your fingers in from both sides and release it and at this point the buckle would work perfectly it's going to go in deform there's enough room here for it to deform and then once it gets into place you see this prong is actually being stopped by these posts so it's not going to go too far and then when you want to release it you squeeze it it's going to be form again you can pull it out again so everything from this point onwards is just me printing it up and making it have the same sort of belt loop on the top than the bottom so I just added a top top shelf here and it's simple extrude then I added the cut and then I did another extrude which filled in around that cut so this is only affecting that outside part of the buckle and just letting me add a bit of detail then I did another cut which actually cut down the thickness of that buckle just by doing extrude along the side and then I added some nice pretty champers like this and like that yeah that's how I drew this buckle so again showing these section analysis you can see clearly how the buckle functions and I highly recommend having a ruler on hand to check your dimensions as you're going to make sure you're not doing anything too small and again to recap what you need to consider is you need to consider the material has to deform and also you need to consider that your 3d printing so you need to figure out is it going to be able to be 3d printable without knitting support material on that so I'll just very quickly show you in the slicer how I printed these and why they don't need support material okay what I have here is the latest precious slicer from pressure research and this is a great little slicer and I use it for my pressure mark 3 so here we have the 2 belt buckle parts the inside and outside and we need to consider how we're going to 3d print them for good material strength and also we don't have any support material so the inside is easy it just prints flat on the bed and the reason we want to do this is because we want these nice long prongs to be strong if they were printed vertically that B have very small layer very bad layer adhesion because each layer is like a wood grain and we want that grain to work in our advantage not against us so lying flat very easy buckle though we don't want it to lie flat do we because it's got these openings and all that and it's not going to print without support material so we need to actually change the orientation of the outside buckle to be like this there we go so that way it's going to print vertically and these overhangs can bridge for the most part this one does have a little bit of a messy inside which you don't really see but your when I do the slice of preview you will see what I mean about being out of bridge without needing support material so in terms of my settings I like to print these buckle parts with as high infill as possible and I do that by actually increasing the perimeters so actually six is a nice high number and that that inside buckled part will actually be all perimeters basically and very strong almost going to have no info at all top bottom layers the same that's all fine and layer height this isn't the precise part 0.4 0.2 sorry is totally fine for layer height so I'm going to slice these bad boys and you'll see here exactly how they printed and I highly recommend watching a gqo preview to make sure stuff works before committing it so you can see this high amount of permanence makes this part almost solid which is going to be very strong and you can see how as we build up the buckle has various bridges at various Heights so it starts a bridge here goes up keeps going does some steep overhangs does a bridge there across the whole thing keeps going and then does another bridge at the top there now that those bridges are pretty much fine except this one is going to be a little bit messy it's over it's over hanging a fairly open area but it's inside the buckle we don't really care it's gonna be a very strong print very high perimeters and shouldn't take too long to print an hour okay now as I mean it's this protis slicer settings are pretty pretty conservative but that's going to be pretty good to print and pretty easy so I'm gonna show you my results alrighty so these are my buckle designs so like I mentioned there might be one of three main use cases you might have a buckle that you want to be locked except when the user interacts with it and then they remove it you might want one that remains locked for tamper resistance or you might want one that actually can self release with the right sort of force in either direction to make it something that you can just push on or pull on and it'll come off with enough force applied otherwise it generally holds its place like we saw in the different case designs in the mass-produced objects so let's begin with one where it's locked in place until the user interacts with it so you can see here with this buckle design there's a nice long thin section here which allows for that deformation which is critical for allowing this to work if this was solid plastic like I showed in the CAD I mentioned during the CAD process this wouldn't flex and it wouldn't work so you need that ability to deform to make these connections work so with that in mind it goes in place and then snaps in you can see those little snaps come away the buckle is now locked and they're snapped into that position there so these have a flat bottom which means that it's 90 degrees from the direction here which means it locks in really nicely and you employ lots of force it's not going to come off until the user comes along pushes on them to push them off that ledge and then they come out so again showing that nice and closely this is the ledge here this is the buckle inside pushes up and then snaps in and now that's locked all right but what about one that can lock in place but then be removed if enough force is applied well I've got a few versions of that so I tried different angles on the underside instead of just flattened 90 degrees which gives us various different forces required to remove the part so that start with this one which is the easiest to remove because it's got the most subtle angle here it's way off no degrees it's actually 45 degrees so when you put it in place its there's barely snap at all and also adjustment of force comes away now you still didn't do need force to pull it away but this might be a great safety catch where you don't want too much force to remove it but you want something to just kind of stay in place you know under its own weight but then you can pull it off but you can change the angle of this to make it come away at different amounts of with a different amount of force so for example these four have different angles from 20 degrees up to 90 and 90 degree one will lock in place so we won't use that one yet but let's start with let's find out just by trying them which one locks in the most let's try this one first all right that one need it quite a bit of force so I'm gonna say this one's the twenty degree one that's 20 degrees from from that flat by the way this one a lot less force this one I'd say middle of the ground so I'd say we've got twenty twenty-five and thirty degrees and I can tell that just by the amount of force I need to pull them apart and this can be really useful for fine-tuning just how much force you need to remove something in terms of a locking device again you might have a catch that you need to hold something strongly but if you know if the load exceeds what the components can can survive then why not make the buckle release they're doing a stress that none of these should be used for life dependent applications oh my god please this is not designed to hold anything important the strategic the 3d print will fail fairly easily this is not nearly as strong as an injection molded buckle please do not use this for anything critical this is just for fun to be printed projects and a great example of how you can design things with various use cases with different slight just very small tweaks to the overall design and let's finish up with a permanent buckle so one that goes in place and then you can't easily remove this might be useful like we saw with the light where you know this is designed to just snap in place and there become apart you might want a connection which can't be easily removed by the by the person using the product and in that case we're going to use our nice 90 degree angle buckle and in this case I've changed this receptacle to have a very small opening so you still need that lip for the buckle to land on and lock in place but in this circumstance compared to this one you can see that there's no big opening to get into it so it's going to be difficult to remove and if this was completely covered this would be a one-way trip there's no way to ever be able to get this to open without probably breaking it so let's try our buckle put it in and then you should be able to see it goes in sin and now that's done that's very much in place and I cannot remove that I can't get my fingers in to remove it the only way you can probably do it is using a implement which I'm sure people are familiar with taking apart electronics to get in push it down out of the way and then try to push this one out of the way and then try to just kind of nudge them out like that and even even doing this with a large 3d print it's difficult there you go all right so I managed to just push another way you can see how they're deformed there you can see they're deformed out and that means they can easily pull them out again now just to recap like I mentioned during the CAD phase the most important aspects to consider when designing snaps and locking mechanisms and 3d prints the fact that the material needs room to deform so you need to give it a nice amount of room to deform and you need to give it that clearance required to fit together so this is all designed with a 0.2 millimeter clearance you can hear the parts a little bit loose inside and then you also need consider the material properties so this is PLA but in this circumstances abs which gives us just a little bit more flex than PLA in my circumstance PLA probably works fine I mean this one this one was PLA but I've made that a little bit longer this one's a little bit shorter and a little bit thinner and in this circumstance abs is probably a little bit more suitable and finally you have to remember that when he designed stuff things look huge on CAD that will be absolutely microscopic in the real world this actually has a chamfer all around it and you can't tell and like when you're working with millimeters things can look massive in the drawing because you scaled right in but keep in mind that this buckle looked massive but in real life it's pretty small so when you're designing stuff give yourself a reality check now and then grab a ruler check the size of stuff in in the real world and see actually hey that's pretty small I'm sweating the small stuff actually I need to worry about making this usable and when you get those things correct after a few attempts of just trial and error you'll get really really good results I guarantee it so if there you have it that's my belt buckle design and I'm really really pleased with this I can easily incorporate it into it my future projects but why stop there this style of catch uses that ramp and it locks into position so why not have lots of them so this is sort of a linear ratchet and this is actually how a zip tie works the zip tie is a lot smaller and injection-molded but it's the same approach we have this linear action it's a locking device that deforms and locks into position as it moves along and normally these aren't removable but I thought to myself with 3d printing because this test worked can you 3d print a functional zip tie well it turns out you can and this was the result and selection really interesting for a number of reasons for a start the design actually worked but notice how flexible this is this is not your standard 3d print filament this is actually glass filled polypropylene so polypropylene is a really tough plastic often used in like the cases I just showed before but for 3d printing it's fairly uncommon because it doesn't really stick very well to the print surface well I found out that if you just use polypropylene tape like packing tape it prints really really easily and stefan drew at cnc kitchen has a whole video on 3d printing polypropylene once you get it down it's actually pretty pretty easy to print and really really in really unique because it's so flexible and tough so this 3d printers if toy works just like the real deal you put it together and then it zips up and the point propylene with the inner glass fill is actually tough enough and rigid enough to hold that locking mechanism in place but it's flexible enough to actually form that zip-tie shape and that's gonna do it guys thank you so much for watching it's been really fun exploring these designs this is crazy 3d printer and these are belt buckles style connections and if you want to test out these models there's a link below and they're also free on patreon as a thanks to my wonderful patreon supporters you can 3d print them or they'll also be the fusion 360 source files so you can go in dig deep find out how I made them reverse engineer it and modify it for your own projects if you did find this video useful please do consider subscribing to makers moves because it is my aim on this channel to empower your creativity through technology and hopefully I've done that in this video today and i look for seeing again very shortly catch study guys bye

Channel: Maker's Muse

Views: 277,106

Keywords: 3d printed buckle, 3d printed zip tie, design tutorial, fusion 360 tutorial, how to design snaps, locking mechanisms, maker's muse, tutorial, guide, walkthrough, makersmuse, angus deveson, australia, stl download

Id: tw4iP0luFVU

Length: 33min 20sec (2000 seconds)

Published: Fri May 31 2019