A few weeks ago, we introduced you to the British manufacturer Raplas Technologies. The company has focused on resin additive manufacturing, and more specifically, stereolithography, to offer manufacturers reliable, repeatable, and precise solutions. This is exactly what it is continuing to do with the launch of its new machine, the PR 400i. However, it has made some changes to the basic resin technology by taking a closer look at the DLP process, which uses a projector instead of a laser to cure successive layers of resin. This new industrial 3D printer is equipped with a dual projector, combining the advantages of DLP with Raplas’ expertise in stereolithography. But why is the PR 400i so innovative? What are its strengths, and who is it aimed at? We asked Marko Aubel, the man behind this solution, a few questions.
3DN: Can you introduce yourself?
I finished my studies in 2015 and joined Raplas Technologies. It’s one of the first jobs I took. Back then, I was a development and service engineer.
3DN: You’ve created the new PR 400i machine: why did you develop this industrial 3D printer?
We’ve been looking at the market for some time now, listening to the needs and demands of our users. One trend we saw is that DLP or LCD machines are a holy grail, because they’re cheap and quick. But the problem is the materials are mainly made of acrylics, and they tend to warp and especially on these bottom-up systems where you use foils, you cannot go large. This is one of the issues.
The other challenge is, if you go top-down, then you have this cooling effect coming up which prevents you from building large parts.
Today, everybody thinks you can just expose an image to a layer, and it’s going to be fine. But you have to listen to the resin, understand its chemistry. That is what we are doing at Raplas.
We transformed the technology from our SLA systems, so the 700 and 450, to create an image-based system, which means we can do borders, in-skin, up-skin, waving effects, and so on. We can give the chemistry exactly what it needs. As such, we avoid a lot of obstacles like massive shrinkage effects. We can build good parts.
Example of 3D printed parts on the PR 400i
3DN: What is the difference between a classic DLP machine and the PR 400i?
A traditional DLP solution is using images, and more precisely one image per layer across all parts. With our machine, we have an image or multiple images for outer borders and inner borders, for the contours of the parts. We have all the images for the in-skins, up and down-skins of the part, unique to each part. Then, we assign profiles where we can define precisely different zones between the outer contours and the inner section. This is unique to each resin, and our engineers can understand them and set everything correctly.
3DN: So, how does it work in terms of materials?
We qualify every resin separately and add it to our library so that the user can count on a “Plug and Play” machine if they use a qualified material. However, our PR 400i is an open system, so you can choose your own resin. Two options are possible: you either count on our support, or you do it yourself.
3DN: What are the main specs of the printer?
First of all, the PR 400i has quite high power. It uses the latest set of projectors on the market. Our experts are also very good when it comes to managing the optics of the machine. We can run antialiasing not only on the software, but on the hardware itself.
We also have solid granite in our machine, a reliable set axis; we’re using industrial components. It’s always the state of the art. Every component in this machine is not unique to the machine. If something breaks, it can be easily replaced.
I would say that the PR 400i is very precise. We can run supports like an SLA machine with 50 to 250 micrometers thickness. The appearance after building is literally the same as on an SLA based system. And we can go fast or slow.
Finally, just to share some numbers, the PR 400i offers a generous building volume of 420x384x400 mm and is equipped with a dual projector of 405 nm.
3DN: Who is the perfect user for this machine?
Our machine is an industrial solution; it is not made for someone to play around at home. I would say it’s made for anyone who needs precision and large parts. We’re targeting the aerospace and defense sectors, as well as the automotive industry. Some universities and research institutes are also interested in the PR 400i.
3DN: Can your solution SmartBuild work to its full capacity on this machine?
Yes, since it’s an image-based system, it can reach full capacity without any issues. When you’re using SmartBuild, you can work in sections. That means that if you have parts that are growing straight and others that have curves or angles, then you can avoid precision zones on these straight sections. They do it every 200 micrometers, whereas on the part where you have angled sections, it’s every 100. It saves scan time and increases the build speed in a DLP-based system like this. It doesn’t matter if you skip those regions or not; the projection time always stays the same per layer, no matter how many regions there are.
3DN: Can you tell us more about the product development itself: how does it work and what is exciting about it?
When we start developing a machine, we isolate ourselves for a couple of days in a dark room. I’m with the Lead System Developer, James Freeman, and we just get started. We also travel a lot, visit customers, and try to understand what we could do better, what technology we could create that doesn’t exist. It’s very exciting! It’s also challenging sometimes because I’m away from my family, but I have a very supportive wife. I just have fun doing what I do!
3DN: Any last words for our readers?
Raplas focuses on resin SLA machines and no other type of 3D printing technology. That is what we do. We’ve gathered a lot of expertise in this field, and this is why we can push the current boundaries of the process and offer a repeatable, precise, and accurate solution today.
You want to know more about the PR 400i? Click HERE.
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*All Photo Credits: Raplas Technologies