I’ve got a great interview with Scott Tarcy of CAD Design Help. Scott has been on the podcast once before and it was just a general discussion about his company and what he does in the 3D printing industry in general. However this time, I’ve got a really interesting interview regarding something that we’ve been talking about on and off in some episodes here on WTFFF recently but from a different perspective. In the last couple of months, we’ve had two episodes on scanning of 3D objects. One where the review of the Matter and Form desktop 3D scanner and then a more recent one with their Bevel product. One of the things we did not get into in great detail was working with CAD files that have been 3D scanned.
Scott Tarcy of CAD Design Help is an expert in doing engineering and CAD work in general. Scott has a lot of experience working with CAD files in his CADDesignHelp.com company. He has a unique perspective and has a lot of experience. Scott was very interested on our recent episode on the Matter and Form desktop 3D scanner. He was surprised that we were so pleased with it and that it actually worked for us because his experience with desktop 3D scanners has really not been that great. We’re going to talk about that in this episode. Also about really the details, ins and outs of working with CAD files that have been 3D scanned and how you can and cannot work with them.
He’s also going to tell us about this new 3D Print The Future TV Show that they filmed several episodes of the first season and it launches on Amazon Instant Video. You’re going to hear about that as well. Let’s go to the interview with Scott and we’ll talk a little bit more about it on the other side.
Listen to the podcast here:
Working with Scanned 3D Models with Scott Tarcy
Scott, thanks so much for coming back on the show. It’s good to have you on WTFFF for the second time.
I’m glad you guys are back running it. You disappeared for a while so I was like, “Maybe they’re not going to do it.” I never unsubscribed because I figured if you do come back, I’d get it. I saw last week you started doing them again. I’m glad that you guys are back and there’s certainly a lot more we can cover that we didn’t cover the first time.
It was one of those really unintended long breaks in our show for a lot of reasons. One of those things where life just got in the way and as much as we wanted to, we were forced to take a hiatus. That’s why we really didn’t announce it because it wasn’t really planned. I kept saying, “We’re going to get back. We’re going to start doing it soon,” and life got in the way. Here we are, we’re back in the regular schedule and it’s great to have you back. I want to start today by talking a little bit about your 3D Print the Future TV Show, which is going to actually be live on Amazon Instant Video sometime soon, right?
When we last talked, me and my team were still at the beginning phases of organizing this thing. We simply had the poster on the website and I had emailed my list and some other people, just trying to find some guests for it. Ultimately, we ended up getting three guests for the show. One of them was myself, just because people pulled out. It was difficult to arrange because my production team was in Florida and I live in Charlotte. We ended up having to get people here and have to cover their travel to get here so that we could just do it all at once. It would be too expensive to fly to each person unless they were willing to spend more money to be on the show to cover the travel cost. We ended up doing three episodes. Everything has been recorded. We did it all in one week.
One episode is with a guy named Jeremy Proffitt who has about twenty different FDM printers. He’s got a lot of interesting things there. He doesn’t even do that as a business, it’s a hobby. It’s really advance setup and he’s got some neat inventions he has made. The one episode is with me in my home office and we just covered a lot of stuff, like how does CAD work? How do I do that? How do my 3D printers work? What do I have? Then three or four inventions that I’ve come up with that use 3D printing. The final one is a guy who has an invention that’s already 100% finished, he injection molds them now. He used another local company, not mine, for the development but there was still 3D printing involved. Then we go on the streets and this will be a little different episode, probably more entertaining than educational because we go around and try to interview people to use this. It’s like a clothing device product.
I don’t want to give too much away but that’s the summary of the three episodes. Our team has a lot of experience with Amazon so I feel like it’s going to be a pretty successful show. There’s really nothing else out there on what’s called a legitimate platform like this. There’s tons of stuff on YouTube but anybody can just make a five-minute video and put it on YouTube. This is a totally different kind of thing, where it’s 30-minute long, in-depth episodes. It should be out by November on Amazon. I need to go ahead and get an account. I use Netflix and I’ve got cable. I don’t know if I really need a third thing but if I got my own TV show then I’m in. I’m going to get it. That’s where the show is at.
You must not be much of an Amazon shopper then because if you are a Prime Amazon shopper, you get access to Amazon Instant Video for free.
I’ll just join Prime. I do shop a little on there but I prefer eBay. I think eBay is a little less expensive from my experiences so I’ve just always been more of an eBay shopper. If I’m going to get Amazon video, I might as well get Prime and then I can get stuff shipped to me faster.
Amazon Instant Video, I do have quite a good experience with it. We’ve got several Kindles in our household and especially with the younger kids. They stream videos from Amazon Instant Video all the time. There are a lot of new programs. In fact, my brother is actually in Hollywood and writes and produces films and has done some with Amazon. They actually have a production company producing their own content just like Netflix is doing with House of Cards and things like that. They’re becoming bigger in the space and we’ll probably all be using it before too long. I think it’s a great place actually to put your show.
My production team, Gina and Brett, they’ve already released four or five really well-received shows. They’re getting a lot of hours watched or however they record it. They’re ranking very high. They know how to make a show good. They know how to not lose people’s interest in the way that they’re going to have it done. After they recorded everything, I went home. I haven’t seen any previews yet, although I think I’m going to see one here soon. I’m really curious to see how it turned out. I know they’re going to make it to where it’s entertaining and people won’t get bored even if they’re on the fringe of 3D printing or not really into it. We wanted to get those people into the show. I’m pretty sure that they’re going to do a good job with that.
Eventually, if the show is really taking off and if there are two more seasons, explore the Netflix option. With the Netflix option, you got to pay them a pretty high upfront fee to get your show on there. It doesn’t really make business sense at the beginning to start there. Where Amazon, I don’t think there are any fees or if there are, they’re a lot less. It’s more a matter of you have to be able to produce a show to their standards and that’s where most people, unless you have professional video equipment, couldn’t do it because you can’t just use your cellphone, take a video and get a TV show done that way. You have to have all the real equipment.
I think Amazon is pretty smart not charging a whole lot to get a show listed there initially, especially when you’re new and up and coming in an area. Even though Amazon is now one of the biggest companies in the world, they’re new in that space. They understand how to really launch into a new space really well. Maybe they’ll charge in the future, but right now it’s about getting good content. I’m excited to watch your show as soon as it comes out. I’m sure many other listeners of our podcast will as well.
You can already go to Facebook and type in CADDesignHelp.com and there’s a Facebook page for it. There’s a trailer already on there for the show.
Scott, you’re one of those guys that’s very knowledgeable about many things 3D printing and you’re getting involved in getting exposure to so many different things. I thought it would be great to just talk about a few different subjects in and around 3D printing space that you’re seeing of interest lately. I’d like to start with one that actually relates back to one of the new episodes that we’ve done since we came back from our hiatus, which is about 3D scanning and scanned 3D models. You have some thoughts on 3D scanning and I’d like to hear about that.
I just listened to it in fact earlier today. I started the episode and I finished it. You’re talking about the Matter and Form scanner. It was only $400.
When I bought it on Amazon in fact, it was only $400. When I go to their website, they listed it over $500.
That is so inexpensive. I’ll take your word that you got good results. When I’ve seen what I would call inexpensive scanners, I just never seen really good results and the software to get like a file that you can use. Maybe that’s the difference. Let me fill in some experience that I have with scanning. I did a project probably eight months ago and lasted quite a while where there was a podiatrist who’s got an implant device that goes in the toe. What he did is he literally mailed me a human toe bone through the USPS. I have a service company near me that 3D scanned it but they’re using $10,000 Artec scanners and the results were good. What I need is a surface file or ideally a solid file that I can bring into SOLIDWORKS. I can’t work with polygons very much at all. It’s just very cumbersome. They do it in their software themselves with the Artec and maybe that’s why the price is so much higher. When I get something scanned, I need to be able to bring it in and then work with it, generally.
Like with that toe for example, we scanned the toe and he wanted to use the actual toe shape in geometry for the implant, which makes complete sense. I brought it in, I sliced it, took it a flat spot and then basically we worked on getting a stem made that comes off that flat spot. Literally, this thing will be 3D printed in titanium. I finished my phase of the project getting the CAD. We did plastic prints in SLA to get the detail because this thing was really small. In FDM, you would never get the detail you needed. They’re going to 3D print it on titanium and that thing is going to get literally hammered into somebody’s foot as the new joint essentially. That’s an example with 3D scanning that your scanner, I’m curious would it actually be able to get a surface file from it that you could bring into a program like SOLIDWORKS.
This is a great subject to talk about because we did discussed it a little bit in our episode review of that Matter and Form scanner but it’s a really important technical point. I felt like I really did get a good quality scan and I was somewhat surprised because I had a really precise thing I needed to do. I was making a part to go inside a machine.
I saw that part. It’s a really complex helix. It’s really small and it’s also hard to measure.
It was very hard to measure. The only reference points on it are the flat top and the flat bottom of the thing. It was a helix but it was also almost a cross between a spiral and a helix. It was so complicated. I tried creating that geometry just in CAD myself, and I’m pretty darn good at it and it was hard. I was like, “Forget it, I can’t do this and make it accurate.” In this case, I wasn’t just creating new geometry. If I was creating all new parts for this coffee grinder, I would have just started fresh, made a new geometry. Because I’m making one part that had to fit and mate with other parts that were in there, I really need to make sure what I had here was pretty accurate to the existing part. I was only changing some of the internal, the inside parts of it. I didn’t show because that’s proprietary to my client. The outside of the part is pretty common in coffee grinders. I needed to get the outside shell of this thing accurate. I think it did an excellent job. I had to scan at the finest possible resolution that this Matter and Form scanner could do, turning a quarter of a degree at a time and taking readings. You can imagine, 360 degrees times four, it had to take a lot of readings.
You can edit in their software to a degree, it’s pretty simple, but the native file it produces is still a surface mesh. I found that the software itself produces this mesh of polygons that are not one mesh. It’s like a whole, hundreds and thousands of different meshes. Then I use Netfabb. Netfabb is an amazing program because it really put it all together and made it one mesh, which solved a whole lot of problems for me. I didn’t really know until I 3D printed it in steel, because I had it printed in stainless steel in an outsource. Until I got that back, I didn’t really know how accurate this was. It was accurate enough I could put it in the coffee grinder and it worked perfectly. The surface detail I think, it wasn’t absolutely perfectly accurate to the surface of the part. There was some slight texture to it, but to me it’s the type of texture you’d see in something if you sand blasted a metal part where you have just this little stipple texture all over it. That was such a small texture and it’s such a fine tolerance if you will that it did not negatively affect the performance of the part, so it worked for me.
I agree with you, the Artec scanners, those are serious professional scanners. I got scanned by one at CES this year. That thing is fast. It’s using photogrammetry, at least the one at CES was, where it’s going 360 degrees around you, taking pictures and you’re creating a model that that’s the physical geometry and the color information. It had my clothes, my face as part of the file. That was impressive how fast it went and although that was producing a low quality model in general, it was still very impressive how fast it went. I’m certain that when they scan something, if they were to use their scanners to scan the same part, it would produce a much finer quality model that you could do more with. Here’s where it gets difficult for me, and I had to deal with this problem, and you alluded to it earlier about bringing it into SOLIDWORKS. At the end of the day, at least with this desktop scanner, the software is outputting an STL file, which is what I’ve referred to in the past as a dumb solid. You’re going to bring it in to SOLIDWORKS and there’s no information associated with it, no constraints and it’s not parametric at all. What do you with that file? How would you do it in SOLIDWORKS?
This is where I think the difference is. You use Rhino, correct?
It’s parametric like SOLIDWORKS in that sense, right?
It can be. There’s a certain plug-in that makes it parametric but in general, no. It’s a surface modeler and you’re not putting constraints on models. That’s why I like it. I can create much more organic geometry that is hard to in SOLIDWORKS.
I started exploring Blender. Is it similar to Blender in how it creates stuff or is it different than that?
I would say yes, it’s probably more similar to Blender.
Let’s get one thing clear first, is that an STL is different than a STEP. There’s a big difference. The big difference in STL is it’s a polygon mesh. It’s hard to work with it because there’s nothing actually curved in it as far as SOLIDWORKS is concerned. Everything is actually a flat surface. Even like a cylinder is literally just little triangles at a very, very small angles to each other that goes only around it. For example, if I’m going to update the inside, if I’m just going to cut a slot in it, it’s not a big deal to do that in STL but the file itself is not going to be really round. Although, if I cut the inside of the enclosed space of the surfaces, I guess that would theoretically be smooth or be round. The difference in a STEP file is literally smooth surfaces. It looks weird. It’s like little patches but they’re continuously curved. If I turn off edges, it’s like a smooth surface. This is a lot better because it’s just easier to work with. I can do a surface cut, I can offset things. If it’s an STL file, it doesn’t work really well at all and SOLIDWORKS pretty much crashes if you get beyond 75,000 polygons. I started to learn Blender lately and it helps a bunch because in Blender I can bring an STL in and do what’s called decimate which reduces the polygons. You’ll lose some detail but it gets it down to the point where you can work with it.
Going back to the whole point of it is that the nice thing about Artec or at least the software with it is the guys who did it, I told them I need a STEP file because while there’s no parametric features like step one, I cut extrudes, step two, I did a lofted feature or whatever. It’s still a continuously smooth model that is a lot easier to work with. When it’s the triangles, just the polygons, it’s really tough because there’s no smooth surfaces. It’s all just straight flat planes and the software just bogs down so much more. It runs so slowly. That’s the differences between the STEP and STL.
I agree with that 100%. I’ve had experience working with STEP files a lot myself. I actually like that file format. It is like proper geometry; a circle is a circle, a cylinder is a cylinder.
The technical term is it’s a NURBS surface, which is Non-Uniform Rational B-Splines. It’s incredibly complex Math formula essentially. That’s what in the background of these parametric programs that is defining everything. That’s the way it thinks. That’s why everything in that 3D space is essentially smooth or continuously curved.
I wish there was an easier way to convert an STL file from a scan or even an STL file that you would get even just by downloading some of these STL files that you wanted to modify to then make that into a STEP or some other kind of NURBS or other geometry because it would make working with it a lot harder. Here’s what I had to do with my part. Once I scanned in this part, it was a dumb solid and it had no holes through it. This part has a core to it and has geometry on the inside. I actually had to model that geometry in Rhino how I wanted it, then convert that to mesh it. This isn’t even saving STL file but within Rhino, you can convert any model to a mesh, which does what you’re talking about. It makes it in all those small triangular phases. That puts that model then in the same CAD language as the scan. Then I can do a Boolean operation to the mesh files so I made the positive of the negative space I want to do inside of the part, put it in the right place and subtracted it and end up still with an STL file though of what my final part is, which I was able to 3D print and use.
I don’t like this process. I think it is inherently difficult in scanning to go from scanning something, putting lasers and light on it and reading the geometry to then the geometry that is then created in a model from that information I think always starts as this triangular phase surface information. How that can get converted back? I don’t know. I’m sure the people at Artec and other similar companies probably know how to do it. I guarantee you, it’s not easy. It probably involves an interpretation of those triangular phases and then creating the geometry that it thinks it should be.
I’ve got a good story. I took over a project where it was an engine manifold. That’s essentially the air chamber of an engine. CAD guy number one just drew that from scratch. It’s an eight-port engine manifold. We 3D printed it and he used some local company that can make a big 3D print. I think it might have been done in multiple pieces. It was two feet by one foot by maybe eight inches tall. After that was 3D printed, the client himself took a putty or some kind of molding compound and started shaping these ports to be a certain curvature. He’s an expert in high engine performance. He worked for NASCAR for a long time. What they did was he went to CAD guy number two who had a really high end scanner and a program called Geomagic Design X. He scanned this thing but the software is so high-end. I think it’s $20,000 for it. It recognizes the surface from the triangles and say, “This surface is defined by this equation.” It’s basically what SOLIDWORKS is doing.
If you had to revolve a cylinder essentially with a diameter of 10 millimeters and a height of 20, it would recognize that that’s pretty much what that hole is and would make that an actual parametric STEP, like a feature in the tree. It would build the tree this way. It was incredible that just from a scan and then there’s a lot of manual work to find each surface, but it can be done. It models it in such a way that no human would ever model it this way. It was truly one of the craziest feature trees I’ve ever seen. There was a loft created by the automatic machine of this Design X program that used roughly eighteen different planes at different angles with curves and none of it was defined to make this loft that goes through. It was parametric but it was just impossible to work with. That was a tricky project because we were trying to make changes from it and it was just constantly having issues.
It actually brought to mind something that would be incredibly useful if a scanner could do. When you think about it, when you have a lot of geometry that you might scan, there may be some very unique parts to that file that need to be completely scanned because you can’t measure it and know what it is. There are other parts of geometry that if you could just take a reading of almost the edge in one theoretic plane of even one side of the part and get that line where the laser would be going on the outer surface of the part and then have that curve be generated by the scan and then be able to revolve it, and other similar functions like that. That would be incredibly useful I would think.
That’s basically what the software is doing after the fact. You’re going through it and you’re picking certain regions. Imagine that you have a box, real simple shape. If you went to one side of it, I watched the guy do it in Design X, where it would simply show one side and says, “We think this is a flat plane and this is the area that it goes in. Confirm or don’t confirm,” and you can change where essentially that is. It goes from triangles, from polygon to smooth sided NURBS surfaces. It builds that feature into the feature tree. It actually integrates with SOLIDWORKS. The guys that did SOLIDWORKS spun off and created this company after it, I think is the story. It’s incredible software. This guy is like, “You should get it.” I was like, “I can’t justify $20,000 just for one project,” but it’s really, really awesome, Design X. I may have totally been off base on some of the things in the way that it does it but in general, I think I’m right in how I described it.
Conceptually, I’m sure you are whether the detail level there are some differences, that’s probably not really critical for our purposes. That makes a lot of sense and I’m glad somebody has done that. I agree with you just for the amount of things that I scan and work with, which is very little, I had a specific need, it was worth it to me to buy this $400 scanner to do what I need to do with that part. $20,000 for that software, I couldn’t really justify that. I don’t have enough of that kind of work and really get the return off it.
The CAD guy number two that did the scanning, his real main business is NASCAR. He worked in it for a long time. What he does is he scans the drivers and then builds custom seats for their cars from the scan. In order to make the seat a smooth surface and everything, he has to scan their body essentially and then use a Boolean operation. He needs to create that into smooth surfaces in a sitting position and everything else and then go and create these chairs. He’s doing this all the time. Let’s be honest, NASCAR has a massive budget so it’s not too hard for him. He’s got more work than he can handle and he charges a lot per hour. He’s at a very niche industry. Like you, most of the stuff I do is not really necessary to have that. Although it would be cool to have, don’t get me wrong.
The other thing is if you’re not going to do it a lot, it’s going to take you a long time to even just to learn how to use the software. You got to factor not only the cost of software into it but the amount of time and training it’s going to take before you can actually make good use of the software. I’m sure if you have a good CAD experience you can accomplish some things but you wouldn’t be efficient at it at first. Lots to consider when it comes to the cost of that, but that’s very cool. To me, at the consumer level, you asked me, “Is that Matter and Form scanner really good quality?” I would call it good quality.
I might get one because I have enough stuff where I could definitely see the use in just getting the scan to have something, certainly for small parts. It’s not one of those handheld ones like the Artec where I can go around the big part and get it. For that price point, I think I may check that out or check out similar ones. I got one more example of something I’m actually still working on right now where we did some scanned 3D models. It’s a local company here in Charlotte that does drones. Not just air drones but those RC car drones and water drones. When people say drones, I think it’s more than just the ones that fly. This car drone this guy had, he was working on it in process. It’s a custom one off, it’s a big RC car. It’s two feet long by a foot wide. It’s a big strong car with two huge batteries that would drive it. He could do it himself, he’s a mechanical engineer but he’s just busy running the company. He hired me to create essentially little shells or lids.
He has the car body done. There’s a cage that rotates from the back and inside of it there are some very expensive electronics and then these two batteries. He’s like, “Can you create essentially trays that fit in there but fit over all the stuff in it?” We’ve already got an engine in there. We’ve got a capacitor and there was a couple of things in there that have to create a little platform that lift it up. It had legs around the edges, like a table almost. It had a bottom thing to hold up and in that upper platform, we put this stuff and then put another lid on top of that that got screwed in to keep all the water and stuff from splashing in there. I thought this is not too complicated but the problem is there’s just so much stuff going on the bed of this car. I’ve got this cage that clamps down on top and I’ve got to make sure that the lid tapers in at the top and is not too tall so that when the cage gets closed down and screwed down, it doesn’t collide.
I was like, “This is a really good use case for scanning.” First of all, once I get it scanned, I don’t need his car anymore if he’s going to work on it. Number two, it’s going to take forever to measure every little component and make sure that nothing’s interfering. I used that same company in Greenville, South Carolina. They’re called Digitize Designs. They scan the car, just the top of it because there is so much detail. You would not believe the size of this file. It was 300,000 kilobytes, that would be 3 gigabytes. That’s how big this file was. It’s crazy, but it was so much detail. I actually went and bought a new computer with 32 gigabytes of RAM because I realized that 8 gigabytes just wasn’t handling this well at all. I was able to see everything in there on the computer and create these platforms and lids and stuff. They did the cage as a separate scan so I can bring it as an assembly and actually have the cage open, make sure everything fit. Then also close it and make sure it still fits. That was a really good use case. My lesson learned is that if the scan data is that large, I’m on the fence. It was useful but even with my new computer, it still takes so much time to do stuff in there because it’s just so memory intensive. It was definitely useful but it’s just such a massive file. I couldn’t believe how big it was.
Doesn’t it always seem that no matter how more advanced our computers get and our processor speed increases and RAM has gotten so cheap, it’s all getting so fast. You have quicker processors, much more RAM, but no matter how much bigger and faster our drives and our memory storage gets, it seems they just keep making the programs create files that are bigger and bigger, almost as fast as they’re making the hardware bigger. I think it’s this great conspiracy.
I just know that when I bought this new, I had the approved graphic card for SOLIDWORKS. I had the best processor. I had the most RAM I could get, but even after all that, it still takes way longer than what I would call acceptable or normal when you’re just creating a file from scratch. The scanned data is just massive. There’s just so many surfaces on this car. They did only scanned half the car. They just scanned the top half. There are no wheels in it. There’s no underside information. They said even themselves, “We way underquoted this job because we didn’t think it would be this hard to scan it.” It was black surface like you were talking about, with the head against the powder.
It’s an imperfect situation. There’s this company I know of up in Santa Barbara, California that has been making some amazing software, not related to CAD whatsoever but it is related to imaging. They’ve also come up with this amazing process for hyper-accurate scanning but it’s very proprietary, very hush-hush and I’m not even really allowed to talk about it so I’m being vague about it. The point is that there’s a lot of development going on in very high resolution scanning that is going to continue to make advancements in this. This whole issue of file size has to be a big thing that people in this space are looking at. I know memory keeps getting cheaper and we can make bigger and faster computers but at some point there’s got to be a way to make these files with little less overhead so you don’t have to just take over every ounce of your computing power.
I think these guys at Digitize Designs, Andrew and Bo, they would be great guests for the show. I interviewed Andrew on my show but I don’t know if we touched as much on the scanning as we did. He was doing more 3D printing then, he’s doing more scanning now. I’d recommend them as guests. If you want to talk on scanned 3D models, they know as much as anybody in this space.
That would be great. It’s an area that we haven’t covered as much on this show but I think it’s an area that is important to cover especially as time goes on. We definitely want to do that. What else is new and exciting in your world? Any new projects?
I was talking about that toe project. I had actually used one of the guys, one of my resources, to do the 3D printing in SLA but since then I’ve got one myself. I think that if you start 3D printing and you wanted to make small parts with small details, you really need to have it. I think the Form 2 is the most popular, that’s what I bought. For the price, you really can’t beat it. It’s just amazing, the detail. If you ever had to make something with a feature size less than a millimeter, it’s really hard to get good quality out of an FDM print. It was so easy to use. I didn’t even have one failed print since I got it. It’s just all set up for you. That’s the new thing for me.
One of my friends, he has his own design firm too. We work together. If I got too much work, I’ll take on some to his and vice versa but he doesn’t have any printers. He invented this paint roller device that had these small clips, it was snap-fits. I tried printing an FDM and it kept breaking and it was just so rough. It needed to be a lot smoother. When you print an SLA with the flexible resin, it’s like injection molded. It’s literally that quality. Just getting that machine has really made some projects a lot easier because if it’s small parts, I just know I can do it. It does it almost as fast for a small part for about the same. It’s a little bit more expensive, but if it’s a small part, it’s not going to use really any more material than an FDM one.
I have a lot of respect for that printer and that company. I’ve seen them in person and seen the kind of detail that they can produce. An SLA printer produces quite a bit of detail. I’ve never thought that it’s a situation where one is better than another, the SLA versus FDM. I see them as being useful.
There’s plenty of stuff that I don’t bother even though it would fit on there because like a big, solid block, SLA cannot do infill. It’s 100%. I would never print that unless there were some details on the outside, the reason I’ve had to on an SLA, because it would be just so expensive. It would use a massive amount of resin because it can’t do 10% infill.
That’s one thing that I’m just learning right now. I did not realize an SLA printer cannot do infill.
Because it has to shoot each layer with the laser. You could do it, but what’s going to happen is you’re going to have liquid resin trapped in there. The stuff could spill out or if it cracks. You can design with a hole at the bottom for it the drain out.
I know it builds parts upside down, that every time it cures a layer, it lifts it up and I would think resin would be dripping out. I don’t know how much resin you would actually trap in there but it’s a good point. You certainly couldn’t bathe the part. Don’t you have to wash the part?
I can explain the process. It’s actually a lot more labor intensive in some ways. You don’t print it the same way as FDM at all. In fact, you print it the complete opposite way. If you had a cylinder or a block, in FDM, you just put it flat on the bed and print it, and you’re fine, no supports. On SLA, you almost have to have supports for everything. The reason is, the more surface area that touches the bed, it can actually just get stuck so tight you’ll never get it off. The PreForm Software that the Form 2 uses, I usually just use the one-click print where it automatically figures out the best way to do it. Sometimes I’ll orient the part because if you’ve got too much of an overhang of an area, and it’s weird because it’s an overhang upside down, that’s not being essentially scaffolded with the supports, it could fall off. It actually minimizes the surface area and prints what is equivalent to a raft in FDM printing. It basically makes a raft and then put supports and just holds the whole part up off of those. That’s the first thing.
After it’s done, what you do is you take it out and you got to pry it off the plate. It’s not too bad. You’ve got to keep the plate really clean. If there’s any leftover resin, it can actually cure from any ambient light and your build plate could be destroyed or just ruined. You don’t want to do that. You put it in alcohol, 90%, rubbing alcohol. You just move it around in there, just get the alcohol in everything, let it set for ten minutes. Then you move to a second tub and do the same thing.
It works most of the time but I had this part where it was a handle with a brush with a curved end, where the bristles are. That concave surface, I had to go through the process four more times. If it’s not on the alcohol enough or you don’t switch it around enough, it stays sticky like the outside surface is not cleaned off. I don’t know why, I got to call them about that. I have no idea why. It was just this one part with that concave shape. Most of the time it works. You get it out, you let it air dry. It’s a long process because you got twenty minutes usually in the two alcohol tubs. Then you let it air dry and that could take five to six hours, although there may be a way to speed it up. I usually just give my projects enough lead time that I can let it air dry. Then you can trim the supports and be done. If you really want to get the best in mechanical properties, since this stuff is cured essentially. The laser hits the liquid resin, turns it from a liquid to a solid at 405 nanometer light. I bought these lights off of eBay for $12. If you put it in a chamber, the tensile strength of it will triple.
Formlabs did a lot of research in science and stuff, testing this, and there’s these bars called IZOD rods. Essentially, there’s a standard test where you 3D print or produce in any measurement you have of these bars, and you can measure the force to break it in half. They did this with just your normal print plus alcohol, and then normal print, alcohol and then this UV chamber where you put the part in there. They did use different times but they graft the data and they said, “If we cure it in this UV chamber for three hours, it went from an impact test filling at 1 megapascal to filling at 3. It’s way stronger especially with the engineering and the flexible resins. The standard resins as well but to a more degree for the engineering and the flexible that you get this much higher strength of the part essentially. I built my own chamber. It’s really not that hard to do. They actually made their own chamber that’s probably better because it turns the part around and does some other things. It’s at a certain temperature they’ve studied that is ideal. I think it’s 60 Celsius. If it’s at that temperature, it also strengthens it more. Essentially, to do this post-processing, you get stronger parts. That’s the whole after you print part of the extra work you still have to do or should do.
Again, pros and cons, I respect the quality of parts they can make but I do not want to have to deal with all that post processing and that alcohol and how I dispose of that when it’s done. That’s very high maintenance on the back end but you’re getting a finer quality part on the front end. I’ve asked even manufacturers of resins or some of the people at some of these companies that make SLA machines about the final cured parts. They’ve all admitted that those parts that they make are not completely stable, that overtime they continue to change. Maybe you’re curing it an extra amount and this UV chamber would help, but eventually this material because it’s a thermoset resin, it’s making a chemical change. It’s not just changing state from liquid to solid. The resin continues to cure over time which what that means is that when you have a part that is something you want to last a long time, you’re going to 3D print it and it’s not just a prototype. You may be disappointed in the result in the performance of that resin that’s UV-cured over time, whereas with an FFF 3D printer with PLA or ABS or some other thermal plastic that’s just being heated, melted and cooled, the properties of that material are going to remain constant in comparison.
It does take a long time though. When I worked for Bosch Home Appliances, we had a very large SLA print. In about a year, it changed color and become a little more brittle. It took a year for that to start noticing it for it to become significant. I would say most 3D printing is for prototype’s, not end use. Once you’ve proven your concept and stuff, it’s not a big deal if it changes and it takes a year to happen. This new resin might be different. I haven’t had my printer long enough or my parts out in the sun enough to really know for sure, but the stuff that I have printed that’s been sitting on my desk hasn’t change at all. I’ve had the printer for a couple of months.
The way I see the market going, I think there will be more and more 3D printing of end use products. I’ve been doing a bunch of that myself. I know others in the industry that are interested in doing the same thing. Again, it’s just different machines for different purposes. They’re all good. Scott, I want to thank you so much for coming back on the show and sharing some very useful perspective and information.
I enjoyed the conversation. You guys’ show is probably the most relevant one that I found to what I do.
Thank you I appreciate that.
Working with Scanned 3D Models with Scott Tarcy – Final Thoughts
I hope you enjoyed the interview as much as I did. I actually really liked getting into the nitty-gritty details of scanned 3D models and the files and how they’re used or how you can use them and a lot of the different realities of 3D scanning and scanned 3D models. I definitely think it’s a process and an industry that is not very mature yet. We’ve had several different companies we’ve interviewed on the podcast who use 3D scanning as a part of their process. We had that company out of South Carolina that does those, “We’ll scan you and create figures and prints for you,” as well as others we’ve had in the past. It’s a specialized area. I think there’s a lot of opportunity and room for improvement in working with the CAD files and also in creating the scans in the first place.
I really appreciate Scott’s perspective and want to thank him for coming back on the show. I hope that was of interest to you as it was to me, so I really enjoyed it. Definitely, I recommend you go and check out 3D Print the Future TV Show on Amazon Instant Video. I’m going too as well. If you have a question or a comment about this episode or any other, please leave us a comment. You can reach out to us anywhere on 3D Start Point in social media, especially on Facebook. Thanks very much for listening. Tracy and I will both be back next week. This has been Tom on the WTFFF 3D Printing Podcast.
- CAD Design Help
- 3D Print The Future TV Show
- Jeremy Proffitt
- Geomagic Design X
- Digitize Designs
- Form 2
About Scott Tarcy
Scott is the president of CADdesignhelp.com. The company specializes in 2D/3D CAD work, product design, 3D prinng and prototyping. He has about 10 years of experience in product design. He got his undergraduate degree from Virginia Tech and his MBA from ECU. He worked for both United Pet Group (Blacksburg, VA) and Bosch Home Appliances (New Bern, NC) before moving to Charloe, NC and starng his own company. He is also involved in a 3D Print the Future the TV Show. There are already 4 filmed episodes of it.
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