Tim: Abram, we are standing in your apartment in Seattle, we’re about 200 feet, 300 feet from Metrix Create Space makerspace down the street. There’s something you’ve got here in your apartment that I want you to talk with us about, can you give us a little tour?
Abram: Great. So I have a 3D scanning and printing setup that lately I’ve been taking to local area conventions, getting whole body head to toe scans of cosplayers in their very elaborate fancy homemade costumes and then using my resin 3D printer to make miniatures of them.
Tim: Now most people who have homemade 3D printers are using Makerbot, so using filament printers.
Tim: The fact you have a resin home built is actually pretty interesting, can you talk about why you chose that?
Abram: I chose it because well, I started out with one of those filament printers, classic filament, melted down, use a hot glue gun essentially to lay it out. It just wasn’t working well enough, the resolution wasn’t there, it can’t handle tricky overhangs very well, and I tried for months getting it to work well, and it wasn’t enough. So then I said, “Let me look into making a resin printer” because of much finer detail and much more forgiving of overhangs and you can just do a whole lot more with it.
Tim: A better 3D printer?
Abram: So the printer is right over here. The box and the general frame has been scavenged from another design. And you see here a couple of motors, the build plate moves down into the vat of resin, there’s a projector in the back that fires an image up into in the underside of the tank of resin and the image from the projector, here is the resin, the build plate moves up, cures the next layer and eventually you end up with several stacked layers, several thousand stack layers to make the full model.
Tim: Now, in this case the projector is actually curing the resin from the bottom.
Tim: And it’s moving up in the build plate, that’s not the only option, so why are you doing it that way?
Abram: I’m doing bottom-up style because the alternative is top down, we have the projector above the vat of resin firing down into the build plate sinks into your vat of resin, but in order to make a large model, you have to have your tank of resin be as deep as you want the model. That means having a few gallons of resin in a big vat at any given time. And that’s A) a pain, and B) if your pigment in the resin starts to settle, which it does over time, you will then have to dump out the entire vat of resin to stir up and that’s a method you want to play with.
Tim: Resins aren’t that cheap either.
Abram: No, it’s much cheaper than it was. I’m using MakerJuice resin.
Abram: They’re run by Josh Ellis, a great guy. It is anywhere between $45 and $55 a liter, which isn’t cheap, but it’s on par with better quality like filament plastic. Which is crazy, because a few years ago you couldn’t get this type of resin for less than $300.
Tim: But companies like Formlabs have made this way different.
Abram: Yeah. Formlabs, I mean, it’s a great company and they make great resins, but it’s about 2.5 times of price of the stuff I’m using. So honestly if you’re looking at a cost to benefit ratio compared to filament printer you’re like, “Well, it’s really cool, but it’s really expensive,” and I’m just trying to make things as robust and cheap as possible.
Tim: Talk about robust and cheap. Let’s look at the side of your printer.
Tim: And explain a little bit about the hardware it takes and how different it is, if different, from building a filament 3D printer?
Abram: Absolutely. So in the back where you can see a power supply with your basic 12 volt power and right up front here is just a RAM port on an Arduino. So totally stock basic 3D printing control technology. The only real difference is that I’m actually running less of it than most people, your normal 3D printer has somewhere around four motors XYZ controllers, and then something for the extruder. This one only has two motors, just one either side of the build plate to move it up and down. So it’s actually less electronics and less hardware that way.
Tim: Because all the deposition, all the solidifying
Abram: Is done by the projector.
Tim: Very good.
Tim: Now, the control software that you’re using when you actually print something, you are talking about a standard SDL file.
Abram: Yeah, it takes a standard SDL. The software I’m using is an open source package called Creation Workshop, it is under active development, which is really nice. And it’s cool because there weren’t really any good solutions, there are a couple of cobbled together packages of different things that people were using, but this is the first really good open source integrated solution. And yeah, it is loading your SDL, your position on your virtual build plate, and it will do settings the way that you do with any other printer, it slices and you end up with your G-code that controls the actual motors. And then a folder full of a couple of a thousand image files that it sends like a slide show to the projector.
Tim: So we talked about the actual hardware over here but around that, let’s show the projector and you have in a very official setup over here.
Abram: Oh yeah. Super official.
Tim: I think probably you have to be the right kind of author.
Tim: You got your projector here that angles down and bounces off a mirror that is just inside that plate. And that’s when it hits the plate, that’s when it hits your resin, what sort of projection resolution do you need to make a project like this work?
Abram: Well, this is a 1024x768 projector because if you are going any less than that, your print starts looking really blocky because, the resolution of your print is whatever the resolution of your projector is, so with my setup my build area is this big and at that size each pixel is 130 microns, so 0.13 mm wide.
Tim: How do you get these models into your system?
Abram: So what I do is, I have a big motorized turntable, and you stand on the turntable, I switch on the motor and you do your action pose, it spins you around for about two to three minutes, while I wave a 3D camera around you and it generates the file in real time so I can see if you are coming out well. Once it is done, it just outputs it in SDL.
Tim: Can I take a look of your camera and your rotisserie here?
Abram: Of course. So, over this way, this is the 3D camera, it’s very similar to a Kinect and it just gathers visual and depth data and then the software constructs it in real time into a 3D model.
Tim: Let me have a close up look at the camera there. It does look like a Kinect. What is the source of this camera?
Abram: This is made by Acer. It’s exactly the same internals as a Kinect, just in a slightly smaller body; and I had it mounted on a piece of OpenBeam here.
Tim: Yeah, let’s see the end of that, not that I really know what OpenBeam is.
Tim: But it’s actually also one of things that comes from right down the street, some sort of home based in Seattle, it’s a reusable, repurposable machined building structure.
Abram: It’s just really simple, solid aluminum extrusion. It’s what I use to build the frames of my printer, it’s really handy for building all sorts of projects and like you said – it’s made by Terence Tam, whose home base is right here in Metrix.
Tim: Can you capture an entire person, you have to move the camera on that stick?
Abram: I do yeah, on that stick, okay. Well, the stick is thereto just give me a grip, I mean to put a rubber grip on it but haven’t got around to it. So basically you stand there on that turntable.
Tim: Actually here.
Abram: Yeah, here we are yeah, so this is the same motor.
Tim: Where does that motor come from?
Abram: That motor came from eBay, very fancy, very official.
Tim: What was it used for?
Abram: That was a rotisserie oven motor, so it was meant for spinning chickens around.
Tim: Chicken or person?
Abram: Yeah exactly. So we have a bike tire inner tube as my transmission belt 3D printer pulley, here’s the platform, you stand on here, I switch on the motor, you spin around and I just move the camera basically, starting at your feet and move all the way up till I’ve captured the whole thing.
Tim: One more thing Abram, which is if someone is building a 3D printer and they’re considering a resin base or a filament versus some other kind of printer, what is the particular challenge or what challenges should they be aware of when making a resin printer because you’ve obviously gone the route that very few have.
Abram: Yeah, mostly the big challenge, is it is less mature. Filament printers have been around for a handful of years now, so we’ve seen many, many iterations of hardware and software and interactions of the two, so it’s pretty stable. Like you can go on any 3D printing forums and ask a question, and have a dozen people say, “Oh, this is how you solve your problem.” With resin printing it’s getting there, but it is still a much younger technology and so a lot of these problems like you can go online and find a basic schematic, but if you run into problems there are far fewer people who are there to help you through your problems and give you answers.
Tim: Anything else you want people to know about this project you got going here?
Abram: Well, if you are in the Seattle area and you want to see how you look like as a miniature, stop by.