6 design tips to improve your 3D prints
When we are used to design for other manufacturing technologies it is very likely that we do not take into account certain aspects of the design that can make our 3D printed parts improve their finish and functionality.
That's why in this blog article we're going to collect 6 design tricks that will help you get the most out of your 3D printer.
6.-Design to avoid supports
Although every day slicing programs improve their algorithms to generate supports, it is a reality that perfect supports have not yet been achieved that leave the piece with a clean finish.
This for certain materials is not a problem, but for example in the case of flexible can be a very important aspect. Soon we will write an article explaining the best way to generate supports for flexible filaments such as eFil.
Returning to the theme of the article there are more reasons than the aesthetic to design avoiding supports.
The supports are usually made of the same material as the piece or others that are usually more expensive. Being usual that the pieces that require support need more material for this structure we find cases in which the support itself has turned out to be more expensive than the piece itself.
Adding support inevitably increases the printing time. In very extreme cases the fact of adding them can multiply by two the time necessary to print the piece. In addition, we must take into account the extra cleaning time of the piece to eliminate them and improve the finish of the piece.
When we add support these adding complexity to the 3D model which increases the probability of errors.
As we have mentioned before, however much the algorithms that generate the support of our piece improve. The parts that require support will always have a worse finish than the parts that do not require it.
Reducing supports in our design.
When designing we must apply the well-known 45º rule that guarantees that everything that does not exceed that angle will be printed without the need to add supports.
We can also see it as the YHT rule, a good way to remember the forms you will need or not support.
|The YHT rule|
And: Any piece that is printed with this form guarantees that you will not need support. This is due to the fact that the inclination increase will occur gradually, which guarantees that each layer can rest on the previous one avoiding descuelgues.
H: The forms in H suppose that we are going to have an intermediate form that will be on air with nothing to support it. By using a layer fan and a slow printing speed, we can achieve very good results without the need for support. Typical values that usually work in these designs are the following. The intermediate length must be less than 35mm to guarantee that it will hold without supports or with a minimum descuelgue.
This value may vary depending on the material and other parameters such as printing temperature or flow.
T: These forms guarantee 100% the need for support. We can try to reduce the length of the projections to minimize the effect, but it is certain that we will need supports. In this way the plastic has no surface on which to rest until it cools.
Other ways to reduce support in very complex models is to divide it into parts. We must look for divisions that guarantee that the angle of impression is less than 45º. Also the orientation of the pieces is very important to try to reduce the amount of support. Before launching a piece in 3D, it is important to try several orientations in our slicer and see in the previous simulation which will require a smaller amount of support.
5.- Take into account the tolerances
We must be aware of the limitations of our 3D printer when designing. Above all, if we design mechanical assemblies that must fit together and much more if they are going to move relative to another printed piece.
Normally manufacturers of filament 3D printers give a resolution of 0.05 mm layer, but in reality the best results are obtained with a resolution of 0.1mm
In general terms, our recommendations regarding tolerances are:
- 0.15 mm for parts that will fit together.
- 0.20 mm for parts that will rotate.
- 0.25 mm for parts that will slide between them.
|Rules for tolerances|
4-Sharp eddies or thin walls
Normally if we print very narrow parts in the upper layers we can have problems of overheating of the material, which will deform the pieces. We leave you a picture below so you can understand the problem. This is because being such small parts do not allow time for the material to cool before adding the next layer.
|Example of overheating-simplify 3D|
To solve this we can do two things.
Print several identical pieces in the same printing tray. This will allow time for the plastic to cool in the transfer of the extrusion head. We can also design a small structure that we will place near the piece to achieve the same effect. Using this second way we can save material since we do not have to print another piece of the same.
3.- The orientation is key for the resistance of the piece
If we want to avoid that our piece starts by subjecting it to some force, we must orient the piece so that the layers are perpendicular to the point at which the force will be applied.
The weakest parts of a piece printed in 3D are the points of union between the layers because each layer is printed when the upper one has cooled which makes the union is not perfect.
|Orients the piece according to the applied force|
2- Avoiding warping.
Warping is perhaps the most hated effect by any user of a 3D printer. It is a very remarkable effect in some materials such as ABS or Nylon. These materials have a high shrinkage on cooling which causes the corners of our models to rise from the printing surface during the process.
We will notice more the warping in pieces whose base is very big and flat. A good way to avoid it, besides using a warm bed and a system of adhesion to the printing surface, is to round the boards of the surfaces that we are going to print.
1.- Exporting the design
Once we have the design ready it is necessary to export it to prepare it for our 3D printer, the format that is used is the. STL. You can learn more about him in the article we wrote about it.
When exporting it, we must take into account the size of the file. The normal weight of a stl should be between 200KB and 10MB. The slicing programs usually have problems with files of a greater weight.
Do you have a trick you want to share with us? Tell us in the comments section
Greetings and see you printing
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