Transcript:
Hi, I’m Michael. Ever look close at a coin. Sometimes the detail is amazing, but what’s really impressive is how in just a few millimeters of thickness. You can get a lot of depth and detail, and hopefully after watching this video, you’ll have an appreciation for the artists who made these coins who didn’t have any of the modern tools we have now, but also hopefully you’ll know how to do this yourself. [MUSIC] So far, my channel has been a lot about 3d resin printing and specifically the frozen transform Because that’s the printer that I own, but what I really want to do with. This channel is work on various projects. I have a lot of cool things in mind actually. And often 3d printing will be a part of those projects. Well, this is my first project oriented video so today we’re going to be designing and 3d printing. Some custom dog tags, which will have a relief on them, Just like a coin. The techniques here can be applied to making coins as well. I’ve been making these dog tags for my kids school. For about five years In previous years, I’ve designed them and then had them manufactured in China. Those were metal this year for a couple of reasons. I decided to try 3d printing them. I will be using the frozen transforms dual 5.5 inch setup. For this in my last video, I set up and installed the dual 5.5 option in my transform. Check that video out. If you haven’t already also for the resin, I’ll be using the Sierra blue clear, with some monocure pigment added, and in a bit, we’ll mix up some resin and then at the end, I’ll compare the cost of printing them myself to ordering them from China. When my daughter was little the school, she went to gave out these dog tags as prizes for making the honor roll list. I thought it was a really cool idea. Then we moved and her new school was actually just starting up. It was a brand new school, and I sort of wanted to copy that tradition from her old school. Although here we give the dog tags to every student at the end of the year, not just to the kids on the Honor Roll For the first few years, I would design the dog tag and send an STL file to a manufacturer. In China, those were made out of pewter plated in brass, given a stain and then polished. This brings out the details because the ink gets caught in all the crevices and textures, and the highlights are nice and shiny, and that gives it depth. If you put a coin in circulation, this happens naturally. The crevices tend to get dirty and all the highlights end up getting polished from use, so lets. Jump right into how to do this first. We need to design a dog tag base, a blank slug with nothing on it. So when I was using the Chinese manufacturer to do the dog tags, I didn’t send them a full STL file of the entire dog tag. I only sent the STL file for the artwork. So in the past, I’ve never needed the 3d model of the dog tag itself, but this year I do so real quick. Let’s make the dog tag base and for this, I’ll use fusion 360 Our dog tag is 30 millimeters wide and 50 millimeters tall, so we’ll make a box 30 by 50 by three millimeters. [MUSIC] There are a few different styles for the curve at the top and the bottom of the dog tag. I wanted mine to match all the previous years So basically, I brought that into fusion As an image, scaled it to the size of my dog tag and then traced half of the curve. Extrude the shape, then mirror it over to the other side and also across the other axis, then use it as a tool to cut the box, then soften these corners here with a small fillet. Okay, now we need to make the ridge around the outside. If you just shrink the current dog tag to use as a tool that won’t be right because the ridge wouldn’t be a uniform thickness. What we want to do is outline this face. The ridge is 1.2 millimeters wide. Now we can use that as a tool to split the body. Then push the inside in one half a millimeter on each side. That means that the inner part of the dog tag base is two millimeters thick, but most of this will have a design on it, which will make it thicker. In some areas. We do need a circle cut into the top for a chain to go through. That’s a three millimeter diameter cylinder and it lines up with the ridge at the top, use it as a tool to cut the hole. And that’s our dog tag base. I’m going to save this as an STL file, and then we’ll put the artwork on it in another program now on to the design. Our dog tags are double sided on the back of ours is the name of the school and, of course, for privacy reasons. I won’t show that, but just to show you how I did that side. I’m going to do a Nerdtronic logo so first we’ll duplicate the Dogtag base, then in Adobe Illustrator, I’m going to take my logo design as an outline and then I’ll export this as an SVG file. Then I can bring that into fusion, extrude the shape and scale it to how I want it on the dog tag because the logo is wider than tall, I’m going to do it as a landscape and then add it to the base so that it’s one object. You could also add texture to this back plate. When I have them manufactured, they do a sandblast texture on here and that will absorb some of the stain to make the logo stand out more, but for this one, I’m leaving it flat, okay, now, for the other side, Usually I’ll make a previz of the design in Photoshop. I usually put the year down here below the lion. So for this one. I need to make the 20. 20. For the year. I usually try to take advantage of the stains So that the year is very visible for 2016 I made the year an emboss where the numbers are pushed in so that the stain would get stuck inside the numbers for 2019 I made the numbers raised with a well around them, so the stain would get trapped in the well and give it a dark outline this year since I’m 3d printing them, I’m not actually using a stain, so I did the outline in illustrator and then made it like I did the logo I just extruded the year, placed it where it goes on the dog tag, and now I have the dogtag base with the logo on the back and the year at the front bottom. So the only thing left to do now is to add the lion. I’ll export this version as an STL also. I put version numbers on everything when I remember to the school. Mascot is a lion. So usually how it goes is that I purchase a 3d model of a lion. Find the angle and framing that I want, But then what? While the 3d model is a full 3d object, it has depth, but the relief on these dog tags or like the one on a coin is only two millimeters thick and here’s the challenge. If you just take a 3d model and squish it down to only be a few millimeters thick, you’ll have two main problems. First is that it will lose all definition. Basically, it ends up looking like a piece of gum stuck to your shoe. So, for that reason alone, it doesn’t work if you simply scale one axis down to a few millimeters, it just won’t look right, but the second reason is also very important, and that is that you’ll end up with pockets and overhangs like the opening of the mouth, the teeth or furthest out in front, and that doesn’t work when you’re 3d printing it and it doesn’t work for a coin or in this case, a dog tag, so we’re going to work on that second problem first, because I see that as a methodology issue and then we’ll work on the first problem, which I see is more of a design issue to solve that second problem. How do we avoid pockets and overhangs? Well, what we need is called a relief and with a relief. The geometry is pushed out from the base, so there can’t be any pockets or overhangs. It’s sort of like that old toy with the pins. You push it against your hand or some other object, and it pushes the pins out. There’s no way with that toy to conceal geometry behind other geometry. There are a lot of popular 3d programs out there, But I’m gonna use one that you’ve probably never heard of why, because it’s inexpensive, It works on a Mac, which I have, and it’s the one that I already own. It’s called Cheetah 3d What about fusion 360 I use fusion for almost all of my mechanical design work for 3d printing, but in my experience, fusion 360 just can’t handle super large meshes cheetah. 3d is much faster at working with meshes. I tried doing this project in fusion, but I hit some serious walls. When dealing with complex 3d mesh geometry fusion just couldn’t handle the high vertex count that I’m using for these reliefs. What if you don’t have cheetah? I’m sure you can do a little googling and find out how to create a relief in your 3d program, but I’ll show you how to do it in cheetah, and this will give you an overall idea how it works in cheetah. The function is called relief, it creates a mesh and then it takes an image file as input and it uses the brightness or luminance of the image to set the height value for each vertex of that mesh. I’m sure you’ve seen Lithophanes. This is similar to a lithophane but is reversed in a lithophane, the darker the pixel, the thicker the relief, so that the part will pass less light through and make it appear darker with a relief on a coin Or here on my dog tag. It’s the reverse to show this here. I have an image that’s just a gradient with some black and white boxes. If we apply that as an input to the relief, you can see that where the image was bright that part of the relief is taller or higher and where the image was dark, the relief is lower or thinner. The input image is black and white, and in an 8-bit, black and white image, Each pixel has a brightness value of 0-255 and that value is translated to become a height for the vertex in other words. The input is a height map and a height map is an image where depth or distance is displayed by pixel brightness. Closer things are brighter farther away. Things are darker and, like I said in an 8-bit image, you have 256 shades of gray. So in an 8-bit height map, there are 256 steps of depth, which isn’t a lot, but for our purposes, it’s enough if the relief was 256 millimeters tall and you have 256 steps of depth, The resolution of each step would be 0.01 millimeters or 10 microns. We are printing at around 50 microns, depending on the orientation of the dog tag when we print it, so it’s like five times the resolution that we need, so we need to make a height map of our lion. Here’s our lion, and this is the pose and the scale. I want him in what I’m going to do is render out a couple of different images all at this locked off camera position and then creatively mix those in Photoshop to get our desired results and that creativity will solve that first problem of the design Looking like squished gum, but we’ll get to that in a minute, so we just want to set up the depth map so that the closest point on the lion is almost pure white and the farthest point is almost pure black. If you clip any of it, you’ll get flat geometry, and we don’t want that it’s better to be a little conservative with it and make sure you can see this gradation here and let’s render that out. [MUSIC] Now I’ll show you What happens if I stop there? If I just use that height map as the source image for the relief, we have the same squished gum on the bottom of the shoe problem. There’s not enough detail. This alone would not make a good relief on a coin or the dog tag. Here’s a dog tag. I did in 2016 where I didn’t do enough work to add those details back in. It’s okay, but it could have been a lot better. Compare that to my favorite one. The 2018 dog tag. And you can see that it looks like it has a lot more depth, so that’s the next step to create these crevices to bring out the depth and detail more, but in an overall sense we do want the closer stuff pushed out more than the farther away stuff. So this depth map is where we start. Okay, back to cheetah 3d The next render I do is ambient occlusion. All the places where surfaces meet all the cracks and crevices will have some shadow in there. The ambient occlusion works really well for a relief. Now I take these two images and mix them in Photoshop. The render of the depth map is set to normal and it’s our base. The ao layer is set to multiply, and then I use some adjustment layers to tweak the levels. So we get the max range out of it. Use the histogram to see how much of the brightness bandwidth we’re using. I said earlier that I mix them creatively. It’s just a lot of trial and error to get it right, okay. I’m going to add a little gradient to the bottom of the line to kind of fade it out under the year. You can do other creative things. One year I added, a circular gradient to make the eyeballs appear round. You have to think about how the brightness will be used to create the heights and the relief. You could do some pretty cool things. This is something to think about. When making this height map in Photoshop, I’m not adding a stain this year, but normally I do. And if you think about how the crevices are going to have that stain, you can sort of see it. In the relief map, here’s a relief map for one of the dog tags compared to the finished dog tag. The darker areas in the height map is also darker in the finished product because of the stain back when the artists forged our coins, they didn’t have computers, height, maps or any modern technology, they had to carve designs by hand. I’m not exactly sure how they did it back then. Maybe they did a larger carving and then shrunk it down. Somehow, if you know how they did it back in the day. Please leave a comment, okay, so now we go back into Cheetah. Create a relief set the number of vertices import the image and boom, we have a 3d relief, and now there’s some tedious cleanup work to do first is just that I don’t want this square shape. I only want the artwork, so I’ll remove all the geometry at the bottom so that it’s just the relief second is that it’s not an enclosed shape. It’s just the top surface. I’m not sure what would happen if you just exported it like this and tried to print it to be safe as an intermediate step. I took it into mesh mixer to cover the back of it. Then I brought it back into cheetah to merge it with the dog tag. There’s probably a way to cover the back of it in cheetah, but I just did it in mesh mixer. We can also scale the depth to make it the exact height we want. I usually go with about two to two point Five millimeters, so now one last little detail. I did need to tuck this side of the line in under the edge of the ridge. I did it the slow and tedious way and edited the mesh in cheetah. If I had planned ahead a little bit more, I could have done it with a gradient in Photoshop like I did at the bottom now export it as an STL, and let’s print it In previous years. I sent the STL of only the artwork to my supplier. In China, they added it to the dog tag and manufactured them. This year things were a bit different for one. China manufacturing was basically shut down for a while covet happened but also because it’s 2020 I wanted to do something a little more futuristic and thus 3d print them. It’s funny, of course for me. 2020 felt futuristic to the students. It’s just another year. I think 10 year olds probably don’t think of 2020 as all that futuristic, but still, I’m the one making the dog tag. So the school colors are maroon and gold, so I wanted to do an amber colored resin. I’m using the Sierra blue clear. I have some of the v1 and some of the v2 I also have the monocure pigment set, So I added some yellow and some red. My takeaway here is that a little color goes a long way in the end. Some of the dog tags came out too orangey and we preferred the less tinted. Ones keep in mind my goal of reducing post processing. I didn’t want to deal with any supports. No matter how you print it. There’s going to be some overhangs, but I decided to print it this way with the long edge, touching the build plate. There are some overhangs, but like this overhang here. On the top of the ridge, it’s only 0.5 millimeters thick and the printer was able to handle that on the lion side. The artwork creates its own angles and the face of the line is sort of self-supporting and yes. There is a little elephant’s foot on the bottom edge, But I just left it there. Sanding it off would take too long. And you really don’t notice it. I was able to fit 23 of them on the build plate and then by printing on the transforms dual 5.5 option. I could print 46 dog tags at a time. I did learn a lot about resin printing on this project. It was the first time I used the dual five fives and it was the first time I used the Sierra Blue resin. I do have a video on the dual five fives that shows the installation and some of the issues I had with that. The link will be in the description. I also learned a lot about cleaning up parts, but because this video is long enough already, I’ll leave it for another video. If you’re interested in me doing a video about cleaning parts, let me know in the comments, and if you haven’t done it already, please, like and subscribe and hit the bell icon. I’m working on several projects right now, and there will be more videos coming. Okay, let’s talk about the costs. Let’s start with the metal ones. Last year I ordered 150 units. That’s not very many the more you order the more you can amortize. The setup costs and shipping, But that’s all I needed. So the cost was 458 dollars for 150 dog tags, and that comes to about three dollars each and I think that’s not too bad of a price and that’s complete. They have chains and they’re already in Baggies and that includes shipping the 3d printed ones. I also needed 150 of them. This year I was only getting 46 per batch so right away. I would need to print four batches, which would get me 184 but because of a few mistakes I made with the color and then later with not cleaning them correctly. I ended up needing to print a few extra batches to make these. I bought two liters of the Sierra blue clear resin. So that’s a hundred dollars. Although I did have some resin left over, then the jump rings were ten dollars. 150 ball chains totaled about fifty dollars, and then the Baggies were just five dollars so all total. I’m in it for around 165 dollars, so that’s just a little over one dollar each. The 3d printed ones at this quantity was about a third of the cost of the metal ones. And I have some resin left over. I have to admit that I sort of, like the metal ones a little bit better. These have their own. Look which I think works well for this year. My own kids like the 3d printed ones just as much as the metal ones. So I guess it’s a toss-up. Well, that’s it, check the video description for a list of all the parts. Thanks for watching you.