Figure 4 Direct Digital Molding – Printing Time
In the previous part of this blog series, I spoke about the limited use of 3D printing in order to augment vacuum casting and injection molding. One of the limiting factors has been print time. I will talk about the other limiting factor, the materials, in the next part. But for now lets concentrate on printing time only.
I would like to spend some time discussing how per part cost relates to total quantity of parts required.
The red curve in the figure above explains how the cost to produce each part relates to the total quantity of parts required. If you need a small number of parts, the per part cost is very high since you apportion the high tooling cost over a smaller number of parts. But as the quantity increases, the per part cost drops significantly.
The blue line signifies the same thing for 3D printing. Although the time to print each part remains the same, the blue line slopes slightly due to the time benefits you get from scale. Note that these curves don’t say anything about the time to get the first part. In the case of injection molding it can take days or weeks before you see the first part and then subsequent parts are produced quite very quickly. But in the case of 3D printing, you start getting parts the same day. So if you need parts very urgently, then you may have no choice other than 3D printing.
The point where the two curves intersect is the point of inflection where the benefits of 3D printing start to go down and that of injection molding start to increase. It’s important to understand that this inflection point is dependent on each application or even each part. You can’t say that for a quantity of say 100 parts, 3D printing is better and after that injection molding is better. It depends on the part geometry, part size and a few other factors.
To solve the problem of printing time, 3D Systems has created a scalable solution based on our Figure 4 technology. We have the Figure 4 Standalone, the Figure 4 Modular and the Figure 4 Production. For the purposes of this conversation, I will talk only about the Figure 4 Modular.
This scalable 3D printing system is designed for low to mid-level production of parts that can fit in a build volume of 120 x 70 x 346 mm. It can print up to 100 mm per hour, which is amazing fast in the 3D printing world. This amounts to around 10,000 parts per month. The system is scalable in the sense that there is one controller which can control multiple print modules, up to a maximum of 24 print modules. Each print module can print using different materials, which means that you can run different production batches simultaneously. You can also start with one or two modules and add more modules as the need arises. Unlike the Figure 4 Standalone which is meant for prototyping or R&D, material handling in the Modular is automated which reduces the time and labor involved.
Since 3D printing is a process that build parts one layer at a time, you end up with visible build lines on the surface of the part. This isn’t desirable in an end use production part. Since Figure 4 uses a non-contact membrane technology, there are no visible build lines on the surface of parts printed using this system, giving them the look and feel of vacuum casted or injection molded parts. Here are some examples.
I have handed Figure 4 parts to people who live and breathe vacuum casting and injection molding. Some looked at the part and asked me, “How did you create a mold for this part?“. When I tell them that the part they are holding in their hand was 3D printed, their reaction is priceless. The level of detail that can be achieved with the Figure 4 non-contact membrane technology is insane.
In fact, the number one question that people have asked me is “Can’t you increase the size of the build platform?” They are already seeing this changing their production workflows. All I can say is this is just the start. There is a lot more goodness to come. Let’s first run out of parts that can be printed in a 120 x 70 x 346 mm build volume and then worry about printing larger parts.
In the next part of this series I will talk about the other limiting factor – the materials.
