Design Better Handles for Mass Production 3D Printing

Added: 2026-05-22

[00:00:00]What's up, mold breakers? Today, we're going to be talking about how to design handles for mass-produced 3D printed parts. We're going to take you all the way through from just simple holes in the side of the part up to complex handles that need no support, and I'm going all the way into print-in-place flexible ones with live hinges and real hinges, all in one go. And oddly enough, this video probably should be good to show you basically every concept and how to design for 3D printing. But, let's just go ahead and dive right in. The simplest handle you can ever run into is just a simple hole in the side of the brick, something where you just hold cut a hole into the side, and then people can reach their fingers or their hands through it really quickly and easily.

[00:00:34]But, the problem with these types of holes through the side is that you can end up with stress concentrations. Where as people are picking and pulling it up like this, you end up with splitting along the layers. So, in order to avoid that, if you're doing a simple hole, which I generally recommend avoiding and we'll show you the better version of doing it here in a moment, but just go ahead and add a thickness around the outer side. Right here, I did just a 1-mm extrusion around the outer edge of the hole so that you end up with this nice reinforcement outside of the hole.

[00:01:02]It adds very little extra CAD, and you can just knock it straight on out. But, now you end up with the issue of this overhang underneath. Most people would just let support grow up there, but again, the bed is right here, so you have support up there, it'll cause surface defects right here. The better thing to do is just go ahead and add a chamfer around the outer edge. It number one, takes all of that material that would have been in support under here and puts it into the part, so now it's actually adding strength to the outer side, and just makes it look beautiful.

[00:01:28]Like this is a way better-looking type of part. Can we all just agree about that? But, that's how to do the side holes. But, the issue with these is that you now have overhangs. If you're printing this again with the bed right here, then you end up with overhangs that have to be bridged, and you can see that that can lead to all kinds of messiness on these types of things, cuz you have to bridge across like 1 in, or maybe further. If you're making this full size for a big old brick, then you may not be able to bridge that entirely.

[00:01:53]So, you have to have support generated inside of there. But, now you have the issue of is the support right? Is the support easy to remove? Auto generate support is very often not easy to remove. So, and very often will not even support it correctly. So, again, make sure to add chamfers to the outer edge of it all, but then make sure to use design support. You can design a very simple little brick into something like this that just sits there and is spaced.2 from the top and.2 from the bottom, maybe a little bit tighter on the bottom, but that depending on what material you're using. And then just set it in there. Make sure it sticks out a little bit that it overhangs. Right here you can see that it pops in just a little bit and pops out a little bit.

[00:02:29]Have a little bit of outside expansion there so that you don't have to worry about it missing the outer edge. And then you have this nice little brick and we add one more thing. This is a handle so that you can grab it with a pair of pliers and just pluck it right out. And that makes post processing way easier to where you get a really crisp thing. You don't have any residual lines there anywhere. It's really clean, it's really crisp, and you don't end up with this hangy draggy-ness of trying to bridge or just using support. And you make something that's really manufacturable because a machine, a robot, a person knows where to grab, can grab at the same place every single time, and the whole batch of support will come out.

[00:03:03]So, using design supports is a really powerful way to make your parts robust so that they can be printed anywhere, anytime, and not need special custom settings. And this will pretty much work universally with any material, with any print settings, at any print resolution.

[00:03:17]So, that's the most powerful way of designing support for some sort of supported area. But, we all know, if you've watched this channel before, that the best support is no support at all.

[00:03:26]Now, there's a couple of ways of doing this that a lot of people aren't really aware of. There is just eliminating the hole and then also changing the geometry of the hole. If you're eliminating the hole, well, if you're looking at a handle, if you're looking at this standard type of handle right here, you don't need a through hole. My fingers aren't going to reach all the way through. I don't have to wrap rope through here or something, so I don't really care if it's a hole. So, you might just go for an indent. Right here, 3D printing lets you create an geometry that people wouldn't like. In the old days, if this was molded, you literally could not get a cavity into there so that you could eject it afterwards cuz these would hold it in there. But now, since we're using 3D printing, you can create whatever geometry you want. So, what we did is we just go ahead and rotate out a small little cavity and then shell the whole part and then you have a place that has no overhangs and you have it all reinforced already cuz now there's no stress concentration where the layers will start to split there as easily because it's has material all the way through. So, every layer is fully complete rather than having a place where it could split out here on the edges. So, this is a great way to make parts that are a lot more durable is just using these indents rather than doing a full through hole.

[00:04:29]It's a little bit more complex modeling, but it's a lot more reliable overall.

[00:04:33]But maybe you do need to have the hole.

[00:04:36]You're right here and you're like, "We got to have a hole through there cuz we got to be able to run rope or a strap through this or something like that."

[00:04:41]Well, then just go ahead and angle it a little bit. You can go ahead and do stuff like this where rather than having this side hole where you're going to need support inside of there in order to keep it alive like on this one over here, you can instead just angle that slot a little bit while still reinforcing it the exact same way and then you end up with this angle where you don't have to deal with the overhang. Right here, we tried to make it as steep as we could, but you still end up with a little bit of draggy-ness there, so you might angle that even more, but you can ultimately eliminate support because rather than having this full draggy area right there, you end up with just a little bit of roughness if you're making it too steep for the layer resolution. So, generally you want to keep this around 45. Right here, we tried to drop it down to 30, but you want to stay around 45 if ever angling these types of slots or overhangs. And then you end up with something that looks really good. You didn't have any support at all, which makes it cheaper than like a design supported part, but you can still get the same function as just a regular old slotted part here.

[00:05:36]So, when choosing between these two options, you generally want to angle a hole. The issue with this is that you've now changed the strength because up here you have a little bit more weakness and a little bit more potential leverage where the layers could split, as opposed to this, where there's two very localized known areas. But, this does give you a lot more layers. So, if you can put the force right there, you have more layers supporting you up there, whereas up here, you just have these few layers. So, breakout could be a bigger issue with these thinner tops than with this angled version. So, those are all things to be considered, whether you're focusing on aesthetics, manufacturability, cost, or function.

[00:06:10]All of those have to be considered when designing any of these parts. And this is super important. The reason this is important to know how to design this is because you might want to send this off to a service to be mass-produced. You might want to have it print on demand.

[00:06:21]If you're doing things with print on demand, things with design support are very useful, cuz you know it will work on any machine in any color at any time.

[00:06:28]So, you can just upload the file to a service like Teleport, and then instantly have it mass-produced.

[00:06:32]Teleport is a service that gives you a thousand 3D printers on tap. So, you can just plug it into your Etsy store or your Shopify, and when you get an order, whatever item it is will be printed and shipped directly to your customer for you. So, you instantly get a thousand machines supporting your Etsy store, which was never possible before. But, you have to make sure that your parts are good and designed and manufacturable, and not something that's bespoke to where your specific print settings, your specific material, and your specific ambient temperature in your room don't mess with it. So, that's why it's so important to design really reliably. Now, we've gone through kind of the standard ways. If you're starting with just a little side slot hole, that's fine, but there are way more other types of handles that can get that same function across that might be more useful for your given context. Now, again, printing lets you make parts that are thick and chunky and have geometries that were never possible before. Rather than simply using an indent, where you have a thin wall and some stress concentrations, where it could split out right along here, maybe you want to go the opposite direction and have the handle extend outward. With this whole thing, again, you still want to have the chamfer down along the bottom to make sure there's no overhangs, cuz even if you have a half hemisphere on something like this, that bottom part is basically horizontal, so you could have sag there.

[00:07:42]But, you can go ahead and just make this bump where you have it fill it down on the bottom, round it out on the top, but now you have the stick area. That is not hollow on the inside the way this one is. Instead, you actually have a thickened handle that doesn't create a stress concentration, and you have way more material to hold it there, and now you have a whole handle that people can really get a hold of and not have to worry about hurting the part. And that's also a very simple thing to model, adds a little bit of material, not a lot, especially on a part like this. If you're making something bigger, then it could be a big deal. And one weird sort of handle are actually these two side grab handles. If you're making something weird and fat, um you might want something like this. Rather than people grabbing it like this, you might want to let them grab like this, which is great cuz you have two nice handles, little bulbs on the outside to grab them. But, the issue that comes up with this is that you might have to have something go down to the print bed. And if you look down at the bottom of this, this is a nice simple first layer, very simple clean square. But, if you add those on there, then the first layer becomes like that, which can add cost and make stuff more unreliable. So, what you probably want to do is just keep the first layer simple, is just chamfer off those edges like that. Now, you don't have any overhang, the handle still exist up near the top where you want them. The first layer did not get more complicated, and you still have all the function that you had from these handles. So, this is a really good trick of basically taking stuff off of the first layer, while not adding supports or anything else, but ultimately getting the thing that you wanted. This is also a really simple handle to add because this little I shape is just a quick extrusion, and then you crop it off from the bottom there so that you can just get it without any supports. And of course, as always, round off all of the edges all of the time. Every vertical edge on any 3D print should be rounded, and any bottom first layer part should be chamfered so that you don't have things like elephant footing and that kind of problem. Okay, so what if you want to make handles like this? Just tabs up at the top. These actually can be terrible because you end up with support underneath here. If this is the layer bed layer, then you have support coming all the way up and supporting underneath those cuz there are overhangs right here, they're hanging down. We're going to come back to that cuz there's actually some weird stuff that I did with that one that you just not have caught the first pass around. But, let's look at the first way of doing that. If you're doing tabs on top, rather than doing a simple straight tab, just sticking out the side, and you have to print it like this, where this is the top layer, and everything else is going down, and this is the the bed surface, just angle them. Turn them into a triangular pattern. But, what you can do is design the regular tab, put ribs underneath it, so that you now have support for the bridging, but still areas for people's fingers to fit into right there if they need to be able to grab it, or maybe a full hand. And then, you end up with this angled edge that doesn't need any sort of support. You have something that looks really crisp and nice. Look, holds right there. It's really strong and robust, and you have this tab straight up at the top. Now, of course, you could put this tab, or like these tabs, on the first layer. You could put it down like that, where the print bed is like this. And that's fine, but then you're messing with support on the inside, which we're going to get to.

[00:10:22]If you want to have the handle anywhere without support, this is a really good handle to use, cuz I can slide this up and down, and it will always be perfectly supportable, and doesn't need any special settings at all, cuz we have that angle to where the overhang is an issue. You can move it up and down, and it can be anywhere on the part at any given time. And then, we have these ribs inside of there to make sure there's no bridging issues. Cuz if I remove these two center ribs, you would end up with potential sag underneath there, but you still want to have some place for your hands to go, and maybe want to have other sorts of things inside of there by having those cavities. It can also help to reduce material, rather than a fully solid area. Okay, let's get back to this one. This one is weird. The ones who are very astute will notice that you don't really know where the layer lines are going on this. They seem to be going like a this. Um, but that's sort of odd, because every single surface has the same surface finish. And even underneath here, there's no support lines underneath here, there's no support or weird rastering on top of here, there's no different surface. This is a 3D printed part, but every side of it is identical. But, we also have these handles up at the top. So, if it was printed like that, you would have to have support underneath here. And if it was printed under like that, you should see a bed surface right there. But, this is a special thing. With these tabs, these sort of flat tabs, if you're designing the part appropriately and getting ready for it, then you can actually print it in an orientation that most people are not used to, which is to put the print bed right to there. This is exactly what we did is it was actually printed on this edge. You can see just the bed texture right there, which is slightly different from that corner, that corner, or that corner. So, the bed texture is right there. So, we print it right there, which means it has very minimal surface bed contact, but it's printed at this angle, which means that all of the handles are in the plane of the layer lines, which means that this will be just as strong as you can possibly want it to be by just pulling on it because the layers are going through the handle and back out. So, it's as isotropic and as strong through the handles as any other process would ever be cuz it's basically solid. And then on the inside you get this nice uniform surface finish, and you have this one slightly different face that almost nobody can notice because it's just the corner edge. You have no support anywhere cuz it's printed at a 45° angle, so you don't need support supporting anywhere inside, outside, anywhere. This is probably one of the biggest and most powerful tricks you can do inside of 3D printing, which is to angle your parts, print them at an angle. And when you're doing these types of flap handles, you have something that is a natural support fin. Go ahead and check one of our other videos where we talk about support fins, but this is a natural support fin that is a part of the part. And now you get something that has multiple functions and ends up with a basically perfect part that is indistinguishable from any other process. And this is a giant unlock, but we're going to get to even more cuz we're only about halfway through the list right here. What if for some reason you can't print something on its side right here? You need the handles in a different area, kind of like a scenario like this where you need the handle down lower and you can't go out to the edge or there's some clearance issue. Maybe you want to do something a little bit different. Again, angling is important.

[00:13:13]If you were printing these, you could put them again face down on the bed. You could put these on the bottom layer. You can move these to one end or the other, but maybe you need them dead center and you need a thin flap. Well, you can do something like this, but what we've done here is we've gone ahead and made the thin flap, but you can see that it is at an angle. But, it's two different angles. If you do just a square handle like that, then you have an overhang that has to be supported straight down here. And, you can kind of see in the CAD where that looks like that. But, if you first chamfer this edge and then angle the handle, you end up with a scenario where you have no support again. There is no reason for there to be support underneath here because it is all ultimately angled upward to where where uh however you print this, there is not an overhang that is so steep that it will cause sag. You can see a little bit of give right there just from the layer height, so we might have made that a tad too steep. But, ultimately, just angle the handle down like this and then chamfer the two outer edges and you end up with an again a handle you can place anywhere, much like this one, that you don't have support and you don't have as much modeling as these underside ribs.

[00:14:16]This handle design has existed for a long time where people have designed them for injection molding and all kinds of other things where you use ribs in order to reduce material. But, with 3D printing, you can now create really complex shapes and have a lot more geometric control, so you can create these types of thing. Now, this handle is harder to get a hold of cuz since it's not horizontal, you got to grip it a little bit more so you don't slide on past it. But, ultimately, it is a more beautiful handle cuz it doesn't have all of this engineering attached to it, so it's more subtle. But, then of course, you also have the one that is just like, you know, universally good. But, there is one more handle that is more odd and doesn't have the slip-off problem with this one or the overhang problem that these types of handles can have. It is uh this one. This is a half hemisphere semicircle where you just create a curved handle and then you end up with something that has as much grippage as something like this where you can just get your fingers underneath it and it holds you. It's in fact even better. You have no overhangs because it's a dome, it's a circle, so you don't have to worry about messing with any of that stuff. And, you end up with something that just looks really good and is very functional. And then again, of course, you chamfer these outer edges on all of these so that you don't end up with any sort of issues where you have overhangs at the outer edge we by just extruding it straight out. And then you would have support coming up right there. So, these types of handles are really good way of redesigning the thing to create something where you can have whatever you want without support. It's super durable, but then you don't have all the engineering modeling and kind of weird industrial look of this. You can create something a lot more subtle. Okay, that's all great. These are all standard types of handles, but none of them flex or move. You can't fold them away. What if you want a handle that pops out the bottom of one of these boxes and flips out there or flips into the top and doesn't take up any room at all and it's just an addition to the box. This is an interesting sort of problem cuz to still have two handles on the top where you grab it and carry it around like a grocery bag. You need some flexibility on there, but then you want the handles to flip back down and out of the way.

[00:16:08]Maybe into a side slot. Maybe you want them to fall into the box on the side.

[00:16:11]There's a couple of ways of doing this.

[00:16:13]The simplest way is still sort of reminiscent of printing these things flat on the build plate like this. But then you go ahead and make the surface really thin in one area. These are called compliant hinges. And these sorts of compliant handles are really really dangerous because they're dependent on the material. You have to really know what your material can take to engineer these compliant hinges so they don't just eventually fatigue and break off.

[00:16:35]That is the issue with these types of things. But you can get them to where you get good flexibility on them all and if you use a material like PETG or or PCTG or like our Tangle Tough filament, you can get all kinds of performance out of it. This is a matte PLA. And matte PLA is one of the most brittle materials you can possibly have. So, you do not want to do compliant material hinges with these kind of things. And compliant hinges in general eventually wear out.

[00:16:59]They are a wear point, a flex point where everything will eventually just kind of go wrong. [music] But if you're keeping them together, then there's uh they can be powerful. A better way is to just use a standard hinge. And this is what that looks like right here. So, this is a simple print-in-place hinge.

[00:17:16]So, this came off of the build plate exactly like that. Designing a print in place hinge is a little bit challenging.

[00:17:22]And before we get to that, actually let's talk about something. Printing the box like this, you have this whole giant cavity on the inside of here. You might notice that in many of these boxes, you don't see you see a nice big giant cavity there. That's cuz they're printed like that. So, there's no need for support inside of here. But, this is printed upside down. You'll want to support a big old surface like that. We may or may not have here.

[00:17:44]Looking inside, you can see that there are these giant fillets. And preferably they would be chamfers. If you can see that inside of there right there. These uh eliminate the overhang. But, you can still see in that center pocket pocket, you have some bridging that can create some sagging. So, whenever you print like this, you want to make sure that you don't have something that could get contaminated or anything else. This is fine for like a screw organizer box, but if you have to print something upside down, you want to be aware of this. This has to be printed upside down.

[00:18:12]If we printed this hinge like this, where it's on the build plate like this and sitting like this, as you're printing up like this, you end up with the layer lines going across the hinge, which means that if somebody grabs it and pulls on it, they could snap across there. For these types of handles, you want the layer lines going along the handle like this, which is way stronger.

[00:18:30]Which means ultimately, you got to print it on the bed like this, where it's laying flat.

[00:18:35]Okay. So, if you're looking at that just like this, it's laying flat. We made a cavity there so that your fingers have some place to grab. How did we do the hinges? Well, you cut a hole and you put a pin through the middle of it, right?

[00:18:44]No. We never do that kind of stuff. Pins through the middle create friction, create a really bad fit and feel. You don't want to do a through pin on one of these when designing 3D printed hinges.

[00:18:55]Instead, the ideal situation is to use cones. You might have noticed we really like chamfers. Chamfers are the best feature in 3D printing. They solve all the problem. They're like the eagles in Tolkein. But, chamfers create a cone inside of there resting inside of a nested cone. It's like the little It's like the cones alongside of the road. They sit on top of each other.

[00:19:15]This makes it very easy to model because you just offset a plane and then design the exact same cone and you know they will fit together with a really good tolerance and fit.

[00:19:23]But, they're also really strong cuz you have a big old cross-sectional area inside there to where this is not going to rip off ever and you get really good smooth motion all the way around without some sort of grinding, which you generally get by putting thin 3D printed pins there. Most people would design a hole in this and then give this a pin that goes all the way through, but then you get the layers crinkling across each other, which you don't want as it rotates through, which is something you just don't want to do. Now, on the sides, we go ahead, take all this, we chamfer the outer edges first, and then you can fillet them a little bit. If you fillet things on the first layer, you end up with sag there at the first layer cuz the part goes from a perfect flat up into a curve, which means you have these early areas where they're curving a little bit. So, if you look at like these fillets, if that was on the print bed, those first couple of layers would sag because they're basically horizontal relative to everything else until it finally levels out on top. So, make sure to always chamfer start with a chamfer and then do a fillet here on these outer edges. And then you got print it like that with overhang protection inside of there, and this prints with no support anywhere at all, and you can go ahead and knock out this part as quick as you want. So, ultimately, that is how you design handles and really how you design anything inside of 3D printing. When we started this video, we thought we were just going to show you how to make a filing box, but going through the sequence of the difference between through holes and indents and thicker parts and then just the design to eliminate overhangs, these are the things you want to do with 3D printing.

[00:20:49]With any 3D printed part, you want to make sure that you eliminate overhangs, make stuff chunky where you can so that it's stronger, and then be aware of the orientation so that you can end up not just with a good solution that's okay, but something that is better than anything else that has ever existed before. Because now, when you design with 3D printing, you get the power of being able to use 3D printing, which means that you can run through these 10 different designs and find the one that works best for your situation. And you did not have to cut a mold for each one of these. You could use a service like Teleport, and you just uploaded the new version, and when a customer tells you, "Ah, there's a problem with that. I saw it break." You can design a new version, upload that, and then every part going forward is updated as well. So, 3D printing gives you the power to create products that were never possible before and improve them at a speed that was never possible before. So, if you're running a business and you're looking to expand and get more products and stuff, do check out Teleport over at slantpod.com, or reach out to us over at Slant 3D, and we will talk to you about how to get your product mass-produced using 3D printing. Have a great day, everybody.

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