This is Koga from 3D Printing Corporation.
This time, I would like to compare 3D printed carbon material and conventional aluminum material to confirm the ability of 3D printed carbon.
This article is divided into the first and second halves, with 1 and 2 in the first half and 3 and 4 in the second half.
1. 3D printing vs home center
2. 3D printing vs conventional processing technology
3. Application development with 3D printing
In 1, we will compare the natural enemy of 3D printing, the simple parts sold at home centers, and the forbidden 3D printing. I will challenge my slogan for utilizing 3D printing, "Procure what is sold at home centers at home centers". The opponent is the strongest item of the home center, the aluminum pipe.
In 2, we will compare 3D printing with processing methods such as cutting and sheet metal, which are often compared to 3D printing. We will compare the difference between 3D printed carbon material and conventional aluminum material when making parts that are difficult to be strong or weak.
In 3, as an example of application development using 3D printed carbon materials, we will design and manufacture a carbon L-shaped joint by 3D printing. We will look at the merits of 3D printed carbon material while comparing it with the case of designing and manufacturing with conventional methods.
Here are the intended readers: If you got it right, please enjoy it until the end!
・Those who regularly use plastic 3D printers but feel that the strength is insufficient.
・Those who usually use aluminum materials and cutting, but feel the lack of production time and resources
・ Those who want to accelerate daily prototype development
・ Those who are dissatisfied with manufacturing outsourcing
In addition, we will take the form of summarizing and introducing specialized content in a column. It is structured so that it is OK to skip columns. If you are curious about the background and terminology, please read the column.
Column0. Drafting class nightmare and 3DCAD* training time
I will briefly explain the misunderstanding of 3DCAD proficiency difficulty that many people who do not eat 3DCAD do. Drafting requires a lot of memorization, and spatial recognition ability is required. 3DCAD does not require both. All you need is the training to "press the △△ button when doing ○○ work". Elementary school students in the United States are learning 3DCAD because specialized knowledge is no longer necessary. If you have studied drafting, you will definitely be able to use 3DCAD, and the training time to master it should be much shorter than that of drafting.
1. 3DCAD refers to digital data or editing software in which three-dimensional design drawings are written. 3DCAD data is required to operate a 3D printer. You can prepare 3D CAD data by designing it yourself using editing software or downloading it from an online site that provides 3D CAD.
1. 3DP vs home center
A forbidden comparison of 3D printing with simple parts sold at home centers, the natural enemy of 3D printing. The comparison partner is the strongest item of the home center, the aluminum pipe.
Aluminum pipe is one of the most familiar materials. It is lightweight, easy to process, and extremely strong compared to plastic. Blessed with the manufacturing technology of pultrusion, which is a wonderful combination, it is supplied at a low price. If you can use aluminum materials, it is an excellent material that will be the first candidate.
On the other hand, as the fate of standard products, there are bottlenecks in that designs that match standard products are required and it takes time and effort to process to the size you want.
Now, let's use a 3D printer and carbon materials to create a pipe material that has the same external dimensions, lightness, and resistance to deformation as an aluminum pipe. The object is an aluminum square pipe with a thickness of 1 mm and a side of 10 mm, and the 3D printer used is MarkTwo manufactured by MarkForged.
Now the calculation is over. Although the calculation process is omitted, if it is designed with the same lightness and resistance to deformation, the dimensions will be 2 mm thick and 10 mm on each side (100 mm long). It's a simple shape, so you can start 3DCAD right away! 3D printing starts immediately after raising 3DCAD.
An hour later, it's ready. Comparing the time, it takes an hour just to go to the home center and come back (compared to our company), so the 3D printer is faster. Also, in terms of human labor time, it is even shorter.
Comparing the cost, 3D printing seems expensive at 1176 yen, but whether you buy it at a home center or make it in-house, labor costs are high, so even if you calculate it at 1000 yen per hour The actual cost does not change much. However, if you look only at the actual cost, it is like a home center.
Comparing the performance aspects, the bending rigidity (difficulty deforming against bending) is 33.8 N / m2 for aluminum, and 30.9 N / m2 for 3D printed carbon is 8.4% lower than aluminum, but the weight is 5.13 g for aluminum. On the other hand, 3D printed carbon is 4.08g, which is 20.5% lighter, and the specific bending rigidity (bending strength per weight) is 15.0% higher than aluminum pipes, so it can be said that it has a higher potential for weight reduction than aluminum pipes. However, in environments such as high heat, carbon materials are inferior to aluminum because they are based on plastic.
Actually, when a weight of 7.7 kg was hung 5-10 mm from the tip, as shown in the figure, there was almost no apparent deflection of the part, which is reasonable even when compared with the calculated deflection amount (0.4 mm). good results were obtained. For the weight, we use stainless steel parts and a build plate molded by the metal 3D printer Meltio, which is currently on sale.
〇 Procurement and processing in a short time takes only a few minutes
〇 Cost is the same as aluminum pipe including labor cost
〇Performance similar to metal aluminum (3D printed carbon has higher weight reduction potential)
△Aluminum pipe is cheaper than actual cost
△ Characteristics such as heat resistance are inferior to metal
Column1.Comparison of rigidity and density of carbon materials, plastics, and metals
In general, there is a large gap between plastic and metal in terms of strength and resistance to deformation. Carbon material is a material made by adding a carbon-based material to plastic to strengthen it and acquire the strength and resistance to deformation of metal. The figure is called an ashby chart, a material map classified by material performance. The blue group in the center is classified as Plastics, the red group is Metals, and the carbon material is classified as CFRP in the purple group as Composites. The material is heavier toward the right of the figure, and less deformable toward the top. As you can see from this figure, carbon materials are as hard to deform as metals and as light as plastics.
2. 3DP vs conventional machining
Next, let's compare the familiar cutting process and 3D printing. We will compare the difference between 3D printed carbon material and conventional aluminum material when making parts that are difficult to be strong or weak.
This time, I will choose a shape that cannot be purchased at a home center and cannot be avoided by processing. A truss structure is adopted as a representative shape that forms the basis of structural design. This time, the object of comparison is a truss structure with a length of 170 mm, a height of 75 mm, a thickness of 10 mm, and a width of about 3 mm.
Next, create parts for each construction method with the same dimensions. Both 3D printed carbon truss and machined aluminum truss are very light at 21.7g and 45.9g. In 1, the carbon pipe was thicker than the aluminum pipe, but when comparing the same shape, the weight difference is noticeable. Carbon material seems to be advantageous when weight reduction is necessary in a limited space.
Build time is 04h24m for 3D printing. It takes more time than aluminum shaving, but it seems that it takes less time and effort than aluminum shaving, whether it is made in-house or outsourced. In terms of time, if you value time and effort, you may choose 3D printing. The cost of 3D printing is 2,964 yen per part, so if the total processing time is 2 hours or more, 3D printing is advantageous in terms of total cost, and aluminum is advantageous in terms of actual cost.
In order to compare the resistance to deformation, let's put a 10kg load on the top surface of each. Then, the carbon truss and the aluminum truss are deformed by 0.3mm and 0.1mm, respectively. Aluminum truss is about 1.5 times harder than carbon truss when comparing rigidity to weight ratio. In general plastic, the deformation is 6mm or more, which is obvious even visually, so you can see that 3D printed carbon overwhelms plastic and exhibits performance comparable to metal. .
This time, we compared the simplest shape as a truss structure. When actually designing and manufacturing, the final shape will be determined after repeated numerical analysis and experiments, and the design will be changed several times. At that time, 3D printers will show great value. For example, if there are three design changes, in the case of cutting, the time and effort that occurs in the process is several hours, such as designing the machining process, preparation, and processing. It takes time. On the other hand, if you use a 3D printer, the total processing time itself is about 20 minutes, so you can use your time outside of work. Considering the hassle of work, the minimum time limit is 2 business days. In addition to this time constraint, even if we were able to complete tasks such as design changes as quickly as possible, it would take a total of eight business days. On the other hand, with a 3D printer, the total turnaround time is 20 minutes, and even if the design change time is the same, it could be completed in about 5 business days.
This time, we are working with a very simple shape, so this difference is enough, but in the actual application where the design becomes more complicated, the effect will be even greater.
When the actual load is applied, there is almost no apparent deformation even with a weight of 7.7 kg, and it can be seen that the results are similar to the calculation results.
〇 3D printing takes only a few minutes
〇The cost is the same as aluminum cutting if labor costs are included.
〇Performance comparable to that of aluminum, greatly exceeding that of plastic
〇 Agile development cycle
△ Aluminum cutting is cheaper than actual cost
△ Characteristics such as heat resistance are inferior to metal
Column2. What is carbon material?
Technically speaking, there are several types of carbon materials. "Carbon material" in this article refers to a material called fiber reinforced plastic (FRP). FRP, as the Japanese name suggests, is a plastic-based composite material that has enhanced performance by incorporating tough fiber materials. Since most of the performance is dependent on the fiber inside, the performance changes depending on the condition of the fiber inside. Of particular importance is the orientation of the fibers. Before the advent of 3D printing, FRP was generally produced using a manufacturing method called prepreg lamination. When stacked so that the direction of the fibers is nested as shown in the figure, it becomes a material that is lighter and stronger than metal. In the case of 3D printing, the fibers can be arranged in a more complex manner. For example, in the carbon truss in 2, the fibers are arranged along the blue lines in the figure to achieve a strong truss structure.
The first half is over! What did you think?
For those who didn't know that carbon materials could be printed with 3D printing, it must have been an eye-opener. In this experiment, we found that a 3D printer with performance equivalent to that of aluminum is effective in terms of cost and labor. The manufacturing method of 3D printing is attracting attention as an advantageous method for reducing weight and material loss. In the second half, I will pay attention to these points and try to make a slightly more complicated shape. We would like you to know the appeal of 3D printed carbon materials through comparison with aluminum materials when developing prototypes using 3D printing and carbon materials. Next time we look forward to!