3D Printing_ What's Realistic for TVIs__0_0
OK, welcome, everyone, to Perkins e-learning webinar series. Today is Wednesday, February 28, 2018. My name is Valerie Weland, and I'll be your host for this webinar. With me is Killiana Lugo who'll be running the controls. We welcome you to today's presentation on 3D printing, What's Realistic for TVIs?
We have a little housekeeping before we get started. Perkins e-learning webinars are presented throughout the year on a monthly basis. The webinar series is just one of the offerings in our professional development program, which includes publications, e-newsletters, webcasts, online and in-person classes, and even self-paced study. You can see our entire listing at our website, at perkinselearning.org.
Today's presentation, by the team at Nonscriptum, will address costs, material uses in design technology for creating 3D tools to the classroom. Before we get started, I'd like to review a couple of things about the technology. To keep noise levels in control, we have muted your lines. A question and answer space will be provided on the screen shortly, and we encourage you to post your questions as they occur to you. If there is time at the end of the webinar, we will answer as many as we can.
This event will be recorded, and available soon on the Perkins E-learning website, with a copy of the slide presentation. You also have an opportunity to earn professional development credits by completing an assessment. More information about this will be sent in a follow up email.
And now it's my pleasure to introduce today's presenters. Joan Horvath and Rich Cameron are the co-founders of Nonscriptum, LLC. Their Pasadena based consulting and training firm focuses on teaching educators and scientists how to use maker tech. Joan is an MIT alumna, recovering rocket scientist, and educator. And Rich is an open source 3D printer hacker who designed the RepRap, Wallace, and Bokito printers. Let's get this webinar started with a quick poll.
Who is here today?
Looks like we have a lot of TVIs with us today, so it's perfect. It's a good selection across the board of different roles. OK, Joan and Rich, the floor is yours.
All right, well thank you very much. And we're really glad to have you all here. So what we'll cover today is that we'll go over what a 3D printer is, for a lot of you, may not have seen it. We'll have a poll about that in a minute. Some of the technology issues, there are a few different common types of printers and different kinds of materials. What the workflow is, and some issues that come up, some things that make a model, a 3D printed model, a good thing, or a thing that maybe isn't so useful. And because we only have an hour, we're going to have to defer a lot to other resources, and so hopefully this will be a place for you to get started.
And so we have a couple of polls here.
OK, so some of you've never seen one, and some of you've been in a room with one. I figured that would be about the peak.
OK, and then we have another poll behind that. Which is we want to see if you have done a little bit coding or programming.
So sort of half and half. None and little. Cool. And I have a few ringers here. Cool. All right, great.
So for those who haven't had much experience with 3D printing or anything yet, we'll go over a little bit of basics. What I'm showing here is a photo of a kind of a curvy plastic piece that is on the bed of a 3D printer, which is a square root of material, or a rectangle of material covered with blue tape. And so basically what happens is, a piece like the piece that we're showing here builds up a layer at a time from that platform. And so the key thing is that the piece gets bigger as you work on it. If you've ever worked on subtractive technologies like milling something, you start out with a block of material and it starts to get smaller. But here it builds up and it becomes bigger.
And you have pieces that are hanging over. If you think about it, if you start off with a platform with nothing on it, and then you're gradually adding layers onto that, if something is overhanging, like imagine a person standing holding their arms out, those arms would have to get supported. So there are some things like that that you have to think about when you are designing.
So first we're going to talk about printers that are based on filament. And here we have a picture of a typical one, and we actually have the physical one here, live and in person. But what we're looking at here is that there is a spool of material that looks like weed whacker wire, if you have experience with that, but isn't. And that spool of material will turn. It's on a little lazy Susan type thing for this particular design of printer.
And it goes into the machine, about half way up, and there is a little drive gear there that will drive it into an area where it gets heated, and then the platform, in the case of this particular printer, we actually can show you on the live one, and for those of you who maybe have trouble seeing the video, what we're doing is taking a flat piece where it will build and moving it forward and back, because it can move like that, and also this part can move from side to side. And then that whole assembly I just moved will move up and down.
There are variations on how the printers work, but they're something like that. And at the end, we'll talk a little bit about our experience with having people who are visually impaired themselves use a 3D printer, which is a little challenging, obviously, but people have done it.
And so this particular machine, interestingly enough we got into this partly because we were at the company that designed this. They aren't sold anymore. But it was popular because people could stick their hand in it easily and get it things, which terrified us, but let them work with it.
So this is a close up picture of the layers as they lay it up. This is not from the printer I just showed you, the little one. This is from a printer that can print things like 30 feet tall that the makers take to shows as kind of a carnival thing. But you can see that it builds up layer by layer, and the layers don't have a perfectly smooth surface, which can be an issue for some of the tactile things that that's a concern.
The other thing is out at the moment, the printer is stereolithography or the direct laser printing, otherwise known as resin printers. I'll just say resin from here. One and more common ones is from a company called Formlabs. And the way those work, they look kind of like magic, is you have a little tub of resin, which is at the bottom, and a laser shines through that, and as the laser spot hits the resin, it's a resin that's cured by laser light, and so the material will cure right then and there. And after a whole layer's worth of laser spot moving around happens, the whole thing is pulled up, and so it builds upside down and attached to the platform on top.
You can get incredibly fine detail with a resin printer, but you're kind of dealing with a chemistry lab. You know, you have to-- the resins themselves are not something you want around kids, and then you have to wash the piece in alcohol, and it's the sort of thing that you probably would do near or in your school's chemistry lab, in a K-12 environment. But the plus is that you can have extremely fine surface detail and there are a lot of different resins available with different types of characteristics here, and these are some pictures, again, courtesy of Formlabs, which is not very far in Massachusetts for Perkins, actually.
So why would you buy one kind of printer or the other? And so here we have a little chart that talks you through that, or a filament and SLA/DLP, which I'll lump together. So the main one is that the cost of the machine, a filament printer these days is between $300 and $3,000. Price isn't really a guide to quality anymore. I would say that you want to look at Amazon reviews, is kind of a good metric to see what you're dealing with. Although we'll come back to that.
SLA tends to be more expensive. A unit of material, a big spool of two kilograms of filament, which makes a lot of stuff, because the prints are usually mostly hollow, is $30 to $50 retail, depending on the material, whether it's a specialty material or a more common one. The resins though, are a lot more expensive. They are $50 to $150 per liter, and probably a liter is equivalent to quite a bit less than a kilogram. Probably about half a kilogram equivalent or so. So you're looking at probably about 5 to 10 times more costly materials for a model.
The material handling for filament is easy. You have a spool of plastic, and that's it. Nothing happens to it as long as you don't put it on the sun on a dashboard in California, or maybe grease. But materials handling for the resin is moderate. You are dealing with chemicals that are not things that you can drink--
And that you probably don't want to get on your skin.
And that you don't want to get in your skin. That's a good point. Yeah. The feature size, sometimes for models for educators here is an issue. The smallest feature size with a filament printer typically is about a millimeter. Rich has done some work which we'll give you a reference for on how to print braille. But you know, it's sort of pushing it a little bit to print braille. If you want to do that with SLA, that's not really a problem. So it does have the resolution to do that.
For a filament printer, there is a file format called STL, and we'll talk about that when we get to workflow. And basically the two types work the same, but you have to print them a little differently because of how it works. If you want to print something and get rid of the lines and clean it off and all that sort of stuff, how can you do that? You can sand most 3D prints. You can paint most of them, and that's true of the SLA/DLP.
And so the bottom line of each one is that the filament printers are easier to use and quite a bit cheaper, and the SLA has better resolution. And so if you don't have a lot of resources or support, buying a little filament based 3D printer is probably the way to go. If you're thinking about putting in a lab that will be serving a lot of other people, then the tradeoffs might be different.
OK. So when you make a 3D printable model, one thing that you'll be thinking about is do you need to have a very smooth surface for some reason? Do you need to have a feature size that is less than a millimeter? Are you making something that will have very complicated supports, that will be time consuming for you or a staff person or somebody to clean up? And we did a project with Pasadena City College here, and I should acknowledge Laurie Shindler and Mike Shivaree of Pasadena Unified, and Ting Tsu, who is now at San Francisco State, for helping us with this.
And we did our first project for visually impaired folks, which is a map of the campus. And we started off with braille labeling of everything, and in the end went to pasting on labels instead, because you could much more easily change things. You make a map of the school and you 3D print it, and it's being used, there was a portable map that you can walk around with. And then somebody changes a building, right, it's a big deal. But if you have the labels you can do that.
So what's the workflow? So the first thing you do is you make a 3D computer aided design file. And we'll talk about CAD in a minute. Or you can download a file from a database. There are a lot of databases out there, a lot of effort in various quarters to have specialized databases. An issue is that a lot of the big databases that are out there probably have either things that don't print very well, a lot of them are made by well-meaning 9-year-olds who are impressing their friends and may or may not have a 3D printer. And you can't tell-- it's like there's an old cartoon, on the internet no one can tell you're a dog. It's sort of the same thing on these databases.
We've looked in a lot of the math and science models and a lot of them are wrong on some these databases, or at least misleading at best. So a model in isolation isn't all that useful. We've kind of decided to-- we've written some books and collections of models in context, and we find that more useful.
You can scan an existing object. It's not all that mature. When we meet with blind folks Rich has a little scanned version of himself here which was made by a friend of ours, which I'm showing here, and we had this to blind people when we say hello, and it's kind of fun. So you can do that, but it's expensive to get a good scanner and is still a lot of hand labor because you need to allow for things that are shadowed, and it's a lot of computer manual labor, putting everything back together.
So once you have a model in a format that is usually called STL to its friends, for stereolithography. That's not the end. You just have a model of the outside of the object. And now what you need to do so that you can build it up a layer at a time, is that you have to do what's called slicing the file into layers. And some printers have proprietary software that does it all for you, but limits the options. Other printers have a lot of options and let you do a wide variety of things, but you have to learn how to do that. And so that's kind of the trade off.
I think the single biggest misconception that people who haven't done this yet and they get disappointed is that most printers do not have a print button. It's not like printing in paper. So it's not like I made a model and now I hit print. It's much closer to cooking. And so when you're cooking something, you don't say, oh, I have a cookies button on the oven and I'm going to throw my cookie dough in there in some random configuration and out, poof, will pop perfect cookies. You don't expect that. But people do expect that here. And that's not how it is.
So if you think of it going forward as cooking, the CAD file, I guess, is some mix of the ingredients and the recipe, and then the slicing process is saying OK, you know, how do I actually make this thing? I have to think about temperature, I have to think about how organize it on the printer, and things like that. And so that stage is-- sometimes freaks people out a little bit, but if you're systematic and you have a good piece of equipment, it is not as scary as it looks.
And then you have to actually print it. That has some issues about keeping a printer away from dust. The other thing we see a lot in schools is that we do a lot of consulting, and often we walk into a school, and there's a 3D printer sitting in the middle of a wood shop. And they say oh, you know, it worked once and it hasn't worked since. It's just a piece of junk. And it's coated with an inch of dust. And 3D printers have a lot of very delicate parts. So if you're going to have one, it shouldn't be in a place where it's going to get coated with-- particularly with dust, is nasty. So don't do that.
So there are a whole bunch of 3D computer aided design programs. Ones that are commonly used in schools that we can see are OpenSCAD, and OpenSCAD is, we'll show you some examples of, OpenSCAD is the only one that we know of that has a non-visual interface option, because OpenSCAD lets you make a model by writing a computer program. And we'll show you some examples that coming up in a little bit.
The minus is that you're writing a computer program. But it has a lot of examples. There are a lot of examples out there, and you can always start with an example and make some minor changes and see how that works. So that's an option. OpenSCAD is open source and free, which is a good thing.
Another program that a lot of people use is called Tinkercad, that's available at tinkercad.com. And if you want to use Tinkercad, it has its pluses and minuses. Tinkercad has a purely visual interface, and has a lot of shapes, like cubes and spheres and things like that, and you just drag and drop them and add and subtract them.
That means if you want to do something that's a little more complex, a little more organic, it's hard to do in Tinkercad, but for basic stuff, I like to say that a kid can learn Tinkercad in about 15 minutes and a teacher in two hours. You all know what I'm talking about there. And so that's a very good solution. It's free, also. It's web based, so you're not downloading anything, but you do have to have an internet connection.
Onshape is a newish engineering type CAD program that also is a company pretty close to Perkins there. And the folks who did SolidWorks, which you may have heard of, spun off and started this company called Onshape. I think it's free for educational users. And it's a lot less expensive than a lot of the other engineering options. So if you're doing things where you would like to do engineering type models, dimension models, get drawings out of it, things like that. If you're working with a robotics team, Onshape is a very good choice these days.
Blender is an open source artist type program that's been around forever. It terrifies us just for scale. Blender is an acquired taste, and it's not like anything else. They do Hollywood movies in Blender, so it's a program that can do anything, and if you've ever worked with software you know that that means that the learning curve is long and steep. But if you're ambitious, Blender is free, open source, and unbelievably powerful to do things. And people who like it really like it. And people like us who have come up with other things don't, so that's our bias.
You may have heard of the program Sketchup, which is an architectural program. And Sketchup tends to make models that don't print very well unless you're lucky. And the reason for it is that it was designed for architects, and so if you're making a floor of a house and the wall of the house and you make a little drawing that has those penetrating each other, in a drawing you know that you don't do that, right? It's an architect's drawing and you want to allow a little extra material, probably.
But if you do that in a 3D model you have two things occupying the same physical space, and so what can happen with some of the programs that slice it is they do weird and creative things to fix that. And so the programs are getting better to allow for that. But we usually say Sketchup is kind of asking for it.
There are a lot of other programs. Maya is used by a lot of professionals in the entertainment industry. It also requires some tweaking and knowledge of what a 3D printer is going to do to use it. But any of those, and and CAD program really, can be used. A lot of people use SolidWorks. I didn't really mention it here because it's expensive, and it also has a long learning curve, so probably most of you wouldn't want to go there.
So here's a picture of what OpenSCAD would look like. This is a screen capture of OpenSCAD, and it's available from openscad.org. And so what I have here on the screen is a rectangular solid thing and a little cylinder that are attached to and penetrating each other. And so this is intended to show you how simple it is to make objects with some easy code in OpenSCAD. And so the way I would read this is it says I'm making a cube that is 30 by 20 by 10, and by default it's in millimeters, which is what 3D printers use.
And I'm putting next to that a cylinder, which is radius 10, height 10. And centered at the origin there. And if you wanted to at this point you could output something to print that was just like that. You can get far more complex than that, but that's a pretty straightforward program. And the accessibility of OpenSCAD is that it does have a command line workflow. So in a macro Linux machine you can open a terminal window and launch the program from the command vine.
On Windows, we don't have access at the moment to a Windows machine, but we are told that the online documentation for how to do it does work. And so we leave that as an exercise for the student. We have also been told that screen readers work for the menus but not entirely for editing code. And so that is a thing that's still kind of out there. And if you wanted to take a look at it, the manual at openscad.org does have a discussion of the options and capabilities.
So we do know of at least one person who is completely blind who does program in OpenSCAD. And so if you want your students to be able to look at some of these things, you know, certainly we're happy to help cross people over who are trying to make that work. And it's an open source program. So if you ever want to work and add some capability, certainly you are able to do that.
So we have another poll here about CAD programs, just to see what folks are doing.
Let's see what you folks have done.
That's interesting. Nobody's used OpenSCAD. OK. Some think you can.
So, you know, looking like a few of you used Tinkercad and the majority have not. So you know, a good place to start is Tinkercad, just to see how it works. And OpenSCAD, only a few of you have tried. But again, if you want to get students who are visually impaired, that probably is the only non drag and drop option. Interesting.
So I'm going to show you some teaching models which we've created an OpenSCAD, some things that you can do. I have a link on the screen which will be available to you. We did a project for a group called Hackaday, which has a hacking for good contest once year. And what we did for that is we tried to put together some standards and some narrative about how to print braille, how to think about models being simple and reasonably self-contained, and easy to print. Everything we try to do is to make it easy to print. And so the link there has the discussion of our travels and some acknowledgments to the various people that we worked with along the way on that one.
And so the model that we're showing there is an assortment of geometric shapes, and they are all the same volume as each other. And so thanks to a Laurie Schindler, L.A. Unified, for asking for these and giving us this is a place to start. And it also is good for starting discussions in bars, because nobody believes that these shapes are all the same volume as each other. They don't look it. We have a cylinder and a cone, and if you remember your basic geometry from high school, a cone three times as high as a cylinder has the same volume, but doesn't look it.
And so this set has been very popular. It's available for free download and there's a sublink at the project for it, or it's on our webpage linked under projects. And so it's been downloaded like a couple thousand times now, at this point, probably. It's 1,000 something last time I looked.
A little bit more sophisticatedly, we have two books of 3D printing science projects from APress, which is a division of Springer Nature. It should be available anywhere in the world, within reason, and certainly on Amazon. And so what we try to do in that book is come up with some models, like this airfoil that you could create a model that was very easy to alter, but alterable based on the science or the math, not just arbitrarily, or you know, without honoring the science and math behind it.
And so NACA stands for National Aerospace Council of America or something. Its a predecessor to NASA. And the airfoil is the part of a wing, the cross-section of a wing, the part that's rounded on the front and pointy on the end. And so what that shape is determines how much lift your wing has. And so what we've done and are showing here is a model of a wing that prints was a little stand, and a little stand will allow you to change the angle of the wing so you can simulate taking off or steady flight or whatever.
And what we show here in the picture is that the little stand is weighted down with some coins, because these generate enough lift to take off. We put it on a postal scale and put it in front of a fan. And so the idea is you turn the fan on, the wing generates lift, it lifts up and gets lighter and so you can measure the lift. So depending on where you buy your plastic, probably about your $1 wind tunnel here, not counting the fan and the postal scale. So it's a way for students to do a lot of explorations on a reasonably sophisticated topics with a lot of variability and obviously a models like this would be very handleable and manageable.
And so this is what the OpenSCAD for that airfoil code looks like. This is again, available for download from our publisher's site, and there's a link on the copyright page of the book. So what you would do to have a different wing is there are parameters that if you look up NACA airfoil on Wikipedia or wherever, it will tell you what those four numbers mean, how long the wing is, how wide it is, how much it tapers and so on. So basically again, your wing, you go into the code you change one of those four numbers in a way that's documented and then you can get a different wing. So there are things like that you can do if you have a good piece of code to start with.
We also have been looking at the orbit of comets and planets, and how do you visualize a relatively abstract thing for someone blind. And we've shown these to a couple of blind scientists who have gotten kind of excited about them. So there's a picture on the left which kind of looks like a shoehorn. It's an oval sitting on a desk, and a curve that runs along the oval is higher at one end and lower at the other.
And what that is is the orbit of Halley's comet. And so Halley's comet goes around the sun. And as it goes closer to the sun, it goes faster and faster and faster, in a way that was determined by Johannes Kepler. And as it goes way back into space it gets slower and slower.
And so that is a way of showing the relationship between two mathematical things and taking advantage of the fact that with the 3D printer, you can really do 3D relationships, and on the other side, we show the orbits of Earth, Venus, and Mercury to scale. And mercury is a little bit of an elliptical orbit, so it goes faster at one end of its orbit than the other. And so this is a way of taking different concepts that are not easy to explain to sighted students, even, and to put them in a way that will be good for tactile learners generally.
We also have a project called Hacker Calculus, and I have a link there for people who are interested. And it's to teach calculus without algebra, or to teach the concepts of calculus. And so we have some projects going on with that right now that will be-- if you follow our website and Twitter feed, we have some things going on there that will be kind of exciting pretty soon. But what you're looking at there is Isaac Newton back in the 1600s developed calculus and explained it with all pictures, and so we are trying to recapitulate some of that. And so we have a picture here of a curve, and the curved surface on the upper left, and we show a progressively less smooth filled in surface that you can try fitting it onto.
And Newton talked about how a curve can be made to fit another curve more and more closely, as you can break a curve up into pieces and fit it better and better as those pieces get smaller and smaller. And so that is a concept that's usually explained with pages and pages of algebra. But with a model that you can take something, two things and fit them together, and say oh, yes, it fits together much more easily, it seems very obvious. And so that's a project we're working on. And there'll be some announcements about that soon.
Another thing we get asked often is should I buy a laser cutter or should I buy a 3D printer? And if you don't know what a laser cutter is, it's what it sounds like. It's a big machine, it's a box basically, and you take a sheet of material, like a slab of wood or a piece of acrylic or whatever, and a laser will cut it for you. But it works on slabs, so it requires a 2D model. It can't make things that are too 3D, it can make things that are basically cookie cutter. If you can make it with a cookie cutter, you can make it with a laser cutter, you want to think about it that way.
So a laser cutter requires a 2D model, usually what's called a DXF file. 3D printing requires a 3D model. Laser cutters are fast. They can make a bunch of parts pretty quickly. 3D printing, if you haven't been around one, take a lot of time. This is a model, I'm showing a fairly complex flower model from another one of our 3D printing books, and this is about probably a four or five hour print, something like that. And so they take a long time.
Laser cutters produce a 2D part, we call two and half D because it has some thickness to it, and a 3D printer produces 3D parts, so you can do things like we've been showing. A laser cutter is typically a fairly expensive machine, although there are some new ones that are quite a bit cheaper, typically $12,000 to $20,000 is sort of where a laser cutter's at, or the Glowforge, I guess is about $3,000, something like that. So there are some machines now, there's a kickstarter machine called the Glowforge which is quite a bit cheaper. The reviews on that are still kind of coming in.
3D printers run below $1,000 to $2000 or $3,000 if you are getting something more complex. And it's less preparation. So a laser cutter can cut lots of different things. You know, wood, acrylic, paper, cardboard, some plastics it can't cut. And it can etch metal, most of them. 3D printing and can print in various plastics and nylon, which is kind of an interesting material to print in. It can be flexible.
The big minus, besides the cost of laser cutting, is that laser cutters have to be ventilated. You really could not let somebody visually impaired use it alone, because what happens is you have a laser essentially burning something that it can burn, and so sometimes you get fires in a laser cutter, and you have to watch them. So you would have to have a teacher or somebody there. You really couldn't let a blind student use them alone.
The other hazard with them is that if you cut the wrong kind of plastic you can release chlorine gas, so you have to manage very carefully what goes in there. If you cut a PVC pipe you release chlorine gas which is poisonous, and will damage you, the laser, and a lot of other things. So you have to really be very careful about managing what goes in it. The 3D printer, for some materials you'll want to have some ventilation, but other than that it's a lot safer, although you do want to be careful about students burning themselves if they're going to be handling it themselves.
So we're going to try and leave a lot of time for questions here, so we've written six books at this point. We're working on our seventh at the moment. And Mastering 3D Printing is an introduction to 3D printing. The 3D Printing With Matter Control book is about a piece of software that's used to do slicing. Our shop class book talks about the general introduction to all kinds of maker things, and then we have the two books of science projects and a book of interactive electronics. If you are interested in making, perhaps, clothing or devices for your students that might be interactive, that is also something we do. And the fashion textbook talks about that.
So our website is nonscriptum.com. It's Latin for unwritten. We try to write down a lot of things that haven't been written down. We have done now two classes for lynda.com. One isn't up yet but will be soon. We have classes for LERN network, L-E-R-N.
And depending on how you come into them, they are outsourced online extension classes that are offered by a lot of different community colleges in particular, and we also have a direct link on our site. And so we have a best practices in 3D printed math and science models class that starts with LERN on Monday, actually, so you could still sign up for that if you wanted to. We also has a basics of 3D printing classes and a basics of open source electonics.
We have created a Google group, and it's linked under the projects tab out of our website. And that Google group has been around for a year and a half now or something. And so what that group is about is for TVIs to post models they'd like somebody to make, and for people in schools who are looking for a project, who are looking for something useful to do with their students in their maker space, can sign up to actually fulfill one of those models.
And so that has been there for a while. We have a lot more requests in fulfillment. We're working on that. And so feel free to join that group and be part of this community we're trying to create. And I have our e-mails there, so joan@nonscriptum.com and rich@nonscriptum. And so with that, we're happy to take questions.
Thank you so much. We actually did have a few questions come in. And do you have a recommended method for printing braille? Linda, she's having some trouble printing Braille with the size, it gets pointy or breaking off. Or is there a reference you can share that can help her?
Yes, I believe we have a link we're going to share to that, but essentially what I found was that braille printed on the side of a print rather than printed on the top surface is better for a lot of reasons. The technology of the printer allows you to create smoother curves on the side of a print rather than on the top, because you're not dealing with the layering effect in the same way. And of course, it's also a lot smoother so it's easier to handle, more comfortably to handle. And also you don't have that small contact area where the dot has been literally printed onto a flat surface. So it's much stronger as well.
And we do have Rich's summary on the link to our visually impaired process project there, and if you go to our website under projects, we have a link to that.
Great. Questions are coming in fast and furious now. We have one from Ting. Since OpenSCAD is the only non-visual interface, would you recommend that this is the one TVIs learn so we can use with students?
Well I think there's two answers to that. And I think one is that if you're going to make models yourself, and you want to make some quick and dirty things, you might have an easier time learning Tinker CAD yourself if you want to make sort of triangles and squares and round things and square things and relatively simple combinations of those. The learning curve is fairly shallow, and I think you'll learn it by messing with it in the tutorials. So if you want to make simple things yourself, that might be the way to go. If
You want your students to be able to do it, probably, as far as I know, and I may not know everything, OpenSCAD is probably the way to go. And you just will need to get comfortable with a little bit of programming, but there are so many examples out there, and a lot of people doing it. We also cover OpenSCAD in our online LERN network classes.
We have a couple of questions on how to position this towards the school. So what are some points that teachers should make when trying to convince the school or district to purchase a 3D printer for students to use?
So I think-- you know, we're a training company. So I'll say that as my bias. Usually schools can get a 3D printer donated somehow. But then often they don't allow for training, and it is hard to learn this stuff completely on your own. So make sure you allow some time for yourself to have some time to learn how these things work, to do a bit of reading, obviously we have classes and we'd love to have you in them but recognize that not everybody can. You know, maybe get a book first and read around a little bit.
So I think schools once they have them, like them. The question is always, then what? What we've tried to do in our books for math and science is to not just have random models out there, pick a thing and we've done the model. So what? Or kids can download a model. So what? What we've tried to do with the-- I don't like to call it a curriculum because that implies it's by grade level, but in our science and math modules we've tried to create models where somebody can really go in and change things and get a visual representation that will help them learn something.
And I think the numbers I've seen are that 10% of the population are tactile learners, ignoring the community that you guys are particularly involved in. And certainly when Rich and I developed these things, Rich thinks very geometrically. And I think students who learn differently from others, I think would really benefit from being able to go in and help develop models and work with it. Some schools who are low resource start out with one teacher who gets familiar, and then that teacher somehow dragoons a chunk of students that are interested.
One method we heard works quite well is that you get a bunch of students who have an obligation to teach other students to keep their privileges, because you make using a 3D printer a privilege, right? And then they have some accountability to train more, and then somehow there's a prestige privilege thing where the kids will run with it. Because I think over about maybe, you know, most print 3D printers are rated for 13 and up. And that's probably about the age, certainly high school kids can handle it. So if you don't want to fiddle with it yourself but you can facilitate some students that perhaps can kind of be in charge, that's a good way to do it too.
So you're recommending even with the OpenSCAD program it's more appropriate for older age groups, so more high school age rather than elementary?
Well they can learn coding. I mean, certainly some younger kids do learn coding. There are some interfaces, some scratch like interfaces to OpenSCAD that we are not expert on. Younger kids typically use Tinker CAD. But that's a completely visual interface. If you think that the kids could learn some coding and be comfortable changing some code, certainly I think they could do that.
Most 3D printers are rated for 13 and over just because if you say something is for kids under 13, there's a whole bunch of product things that kick in that just aren't realistic for 3D printers, so every 3D printer will say 13 and over, and I think by and large the average kid, that's about the age you'd want the kids to start running it unsupervised.
Yeah, middle school seems to be the sweet spot.
So you know, 13-ish. And below that you probably want to have the kids developing the model. What we see mostly is below that the kids might develop the model. We've been in situations where we've helped a teacher learn how to come up with a review process. Because kids will make models that won't print for various reasons. And we found that if we are scary Joan and Rich that come in and sit-in judgment on their models and say who gets to be printed, then pretty quickly they learn how to fix their own mistakes.
We have not done that with blind kids. But if you come up with some kind of review process where the kids make models and only some get to be printed, they're pretty good at getting competitive about that. So that's one way to handle it. Probably won't be able to print something from every kid anyway, because it takes time. You know, the main thing that we see in schools as an issue is that the prints do sometimes take a whole day. So you have to manage a queue and have some system for not having everything go straight to the printer. You want to make sure if something actually goes to the printer it will print. And that will be a lot of your role.
So the TVIs, I guess they could use this for positioning it as well, like what brief examples on how they can use the 3D printer, and also when the piece is done, do you need to sand the finished piece to make it safer and less sharp for kids?
So I don't think we've ever printed-- I mean, Rich has done some beautiful things he's printed that he's sanded as art pieces on principle. But by and large everything we're showing is, you know, you can see how shiny this is, and I'm showing a print of a scan of Rich, and that is not finished. That just comes off the printer like that. So you don't have to do anything for safety unless you design something that has pointy things in it, so just don't do that.
Because the plastic is coming out of a nozzle, it's about half a millimeter in diameter. Everything's going to have a radius on it of no less than about a quarter of a millimeter. So it's not going to be super sharp, unless somebody's breaking, like if you're removing supports, that can leave you with jagged edges you have to clean up a little bit.
When we did the cones actually, they wanted to go make some and use them in elementary, and so they came back and said the point of these cones is kind of pointy and the first thing the kids are doing is they're slapping them into their hands. And so we added a little ball to the top on those models. When you go to the site to download them you see, I think you have the option with and without those little covers on top. And that was because they were using this in elementary, and they said can you do something about the fact that these cones have points on them.
So some of it is just experiential, knowing what kids will do. And we're about to start helping a start up TK through five charter school who wants to be all maker all the time, so I'm sure that a year from now we'll have a lot of lessons learned. Hopefully good ones. And you can follow us for that sort of thing. This is still a frontier and it's still early, and a lot of stuff is very piecemeal. What we're trying to do is to see if we can get some scaffold and bodies of knowledge out there, and that's what we're trying to do.
We have a couple more questions. What are the advantages or disadvantages of 3D printed tactile maps compared to handmade ones?
Well what we try to do, and we have some pictures in the Hackaday project, the idea with this one was that it would be a map that the kids could carry around and be pretty durable. So it was the size of the big-ish loose leaf binder, and it was two slabs of 3D printed material that opened out, and so the idea was that you could hand this to a kid who was learning to navigate school, and that it would look kind of cool.
It was made by students at Pasadena City College, and they made it bright colors, it was very attractive, and so the idea was that this was a school that had blind kids mixed in with mainstream kids. The idea was that it would be a cool thing for this middle schooler or younger who was learning to navigate to carry around. And so that was the intent.
OK, the last question I have, unless anyone has any other questions, please post them in the Q&A, is 3D printing moving away from STL files?
So there are a couple of proposed formats to replace STL. There's AMF has been around the longest, Advanced Manufacturing Format, and there's a Microsoft one as well, 3DM or something like that. It's competing. These formats have additional features for, say, color for printers that support that, or multiple materials for printers that support that, and in some cases even adding curvature. So rather than being made up of very small, flat faces, you can actually have curved faces.
None of them have really caught on yet. Most of the slicing software, the software that generates instructions for the printer has at least minimal support. They might not support the curved surface feature, but that's designed to grade well. And so they can use those formats and they can save, you can bring in STLs and save them out in those formats, but there's not really yet any working tool chain that can actually design and make use of those advanced features in your design program.
You can use those, like if you have a multi material design, generally what you have to do with your CAD program is export two STL files for the sections of the print that are in each material, and then combine those in the slicer program.
So the bottom line is that there is not really yet. I think that will probably be the standard for a while.
I think we have time for one more question. What filament or printing material is best for 3D printing braille?
Well certainly PLA is the easiest to deal with in a school environment. There are kind of two common ones. PLA is polylactic acid. It's pretty easy to-- it's compostable. People often ask, you know, are we getting a whole bunch of plastic nonsense in our trash because they're so-- you know, the fact that PLA is at least commercially compostable is kind of a good thing. ABS is the other one, but ABS has sort of nasty fumes, and so you have to be more careful in a school environment about ventilating it and things like that. And it probably wouldn't be any better, anyway.
The other one is PETG. That's gaining popularity, replacing ABS for a lot of purposes. It's essentially, roughly the same thing that soda bottles are made of, and that prints pretty nicely. And as it is not difficult to print, it doesn't need a heated environment like ABS does. But it's going to handle more temperature and have higher temperature handling ability than PLA. PLA tends to warp if it gets too hot.
I see a lot of people here from the southwest, and so a PLA part, you have to take it out of your car half the year. Or you might have interesting Dali versions of your prints. We do almost everything in PLA. We started moving to PETG for a lot of things. PETG also has translucent versions, which is quite nice.
It doesn't do anything.
Well, no. But you know, they're attractive. If you have low vision people, I don't know whether you might be able to do some more or less contrasts. We have to think about that.
OK, thank you very, very much for all the questions, and thank you to Joan for the great answers to the questions, and on behalf of Perkins E-learning, we thank you for sharing your knowledge on this and we really appreciate your time. And also thank you to all our participants for joining us today. We hope you found this webinar to be informative, and we hope to have you join us for future webinars. Thank you all.
Thank you.