Complete comparison of SLA, SLS & MJF design rules: general guidelines (holes, posts, details, clearance, threads, warping, tolerance) + material specs for Somos resins, SLS nylons, HP PA12, and MJF.
SLA- SLS- MJF- Printing- Rules
Hole. Hole size stands for minimum diameter that a machine can successfully print. To decide the diameter, please check 3D Printing services rules in the following part.
Figure 1
Escape Hole. Prepare at least one escape hole for hollow model so that excess material can escape during 3D Printing process. It is best to have multiple escape holes at different locations so that excess material near the hole can be removed.
Figure 2
Vertical Post Thickness. In the model, post is the protruding part where length exceeds 2 times the width (embossed detail is when length less than 2 times the width). Part that does not meet the guidelines might warp or detach from the model during printing. Please increase the thickness or select different materials.
Supported post is when both ends are connected to wall.
Figure 3
Unsupported post is when only end is connected to wall.
Figure 4
Embossed Details. Embossed details are feature raised on the model, for instance, text. Feature that does not meet guidelines of thickness and height might not be visible on your print. Please consider the effect of post-processing as well. Width and height of the feature may need to be increased or choose the suitable materials.
Figure 5
Engraved Details. Engraved details are feature imprinted or recessed below your model. Feature that does not meet guidelines of thickness and height might not be visible on your print. Please consider the effect of post-processing as well. Width and height of the feature may need to be increased or choose the suitable materials.
Figure 6
Clearance. Clearance is the distance needed between two connecting or mobile parts of a model. Support might not be removed if clearance less than the required distance.
Figure 7
Threads and Screws. To design and 3D print threads and screws that fit is a challenge. The recommended thread angle is 20°. Pitch diameter varies from different materials and the recommended value is larger than 0.6mm.
Figure 8
Warping. Warping occurs due to material shrinkage while 3D Printing as the temperature differences between layers are too big so that it creates tension within the model. When it gets to be too much, the lower layers start to drag or lift. It is a physical change when melted, sintered, scanned with a laser or solidified. Besides, flat surfaces are prone to be warping. The solution is to avoid large flat surface or added rounded corners to the 3D models.
i.e.:
Figure 9
Surface Resolution. To ensure a good quality print, the level of detail and choose the right resolution should be considered. The level of detail varies by different 3D Printing technologies and materials. Therefore, it is important to design the minimum level details of 3D model and choose 3D Printing services accordingly.
i.e.:
Figure 10
Tolerance. Tolerances describe how much deviation from a particular value is expected or acceptable. In 3D printing, machines have specific tolerances. This means that prints may slightly deviate from the actual dimensions. A tighter tolerance indicates consistently higher dimensional accuracy.
3. SLA Printing Rules
Printing Theory
SLA, as known as Stereolithography, is a 3D Printing technology that uses UV laser light to keep curing liquid resin layer by layer, and eventually create a solid object.
Design Rules
1. Supported Wall
2. Unsupported Wall
Materials
Wall Thickness
Somos® GP Plus 14122 C-UV 9400E Somos Tough Resin Somos® Taurus Somos® LEDO 6060
1mm
Somos® WaterShed XC 11122
1mm
3. Minimum Hole Diameter
Materials
Diameter
Somos® GP Plus 14122 C-UV 9400E Somos Tough Resin Somos® Taurus Somos® LEDO 6060
1.2mm
Somos® WaterShed XC 11122
0.8mm
4. Minimum Escape Hole Diameter
Recommendation: > 2.0 mm Diameter
5. Minimum Vertical Post Thickness
Materials
Supported Post
Unsupported Post
Somos® GP Plus 14122 C-UV 9400E Somos Tough Resin Somos® Taurus Somos® LEDO 6060
1.2mm
1.5mm
Somos® WaterShed XC 11122
0.5mm
0.5mm
6. Minimum Embossed Detail
Materials
Width & Height
Somos® GP Plus 14122 C-UV 9400E Somos® Taurus Somos® LEDO 6060
1.2mm
Somos Tough Resin
1.5mm
Somos® WaterShed XC 11122
0.5mm
7. Minimum Engraved Detail
Materials
Width & Height
Somos® GP Plus 14122 C-UV 9400E Somos® Taurus Somos® LEDO 6060
1.2mm
Somos Tough Resin
1.5mm
Somos® WaterShed XC 11122
0.5mm
8. Minimum Unsupported Overhang Angle
Recommendation: >20° from level
Materials
Width & Height
Somos® GP Plus 14122 C-UV 9400E Somos® Taurus Somos® LEDO 6060
1.2mm
Somos Tough Resin
1.5mm
Somos® WaterShed XC 11122
0.5mm
9. Minimum Clearance
Materials
Clearance Distance
Somos® GP Plus 14122 C-UV 9400E Somos Tough Resin Somos® Taurus Somos® LEDO 6060
2.0mm
Somos® WaterShed XC 11122
0.5mm
10. Threads and Screws Design Requirements
Materials
Pitch Diameter
Thread Angle
Somos® GP Plus 14122 C-UV 9400E Somos Tough Resin Somos® Taurus Somos® LEDO 6060
0.6mm
20°
Somos® WaterShed XC 11122
0.5mm
20°
11. Tolerance
200μm or 0.2%
4. SLS Printing Rules
Printing Theory
SLS, Selective Laser Sintering, uses a high-power laser to sinter powdered material, leading the laser automatically at points based on a 3D model, binding the material together to create a solid and stable structure.
Design Rules
1. Supported Wall
Materials
5*5mm
10*10mm
50*50mm
100*100mm
200*200mm
SLS White Nylon SLS Black Nylon SLS FS3400GF fiberglass PPGB
0.8mm
0.8mm
1mm
1mm
1.2mm
2. Unsupported Wall
Materials
Wall Thickness
SLS White Nylon SLS Black Nylon SLS FS3400GF fiberglass PPGB
0.8mm
3. Minimum Hole Diameter
Materials
Diameter
SLS White Nylon SLS Black Nylon SLS FS3400GF fiberglass PPGB
1.5mm
4. Minimum Escape Hole Diameter
Recommendation: > 2.0 mm Diameter
5. Minimum Vertical Post Thickness
Materials
Supported Post
Unsupported Post
SLS White Nylon SLS Black Nylon SLS FS3400GF fiberglass PPGB
1mm
1mm
6. Minimum Embossed Detail
Materials
Width & Height
SLS White Nylon SLS Black Nylon SLS FS3400GF fiberglass PPGB
1mm
7. Minimum Engraved Detail
Materials
Width & Height
SLS White Nylon SLS Black Nylon SLS FS3400GF fiberglass PPGB
1mm
Materials
Width & Height
SLS White Nylon SLS Black Nylon SLS FS3400GF fiberglass PPGB
1mm
Materials
Clearance Distance
SLS White Nylon SLS Black Nylon SLS FS3400GF fiberglass PPGB
1mm
Materials
Pitch Diameter
Thread Angle
SLS White Nylon SLS Black Nylon SLS FS3400GF fiberglass PPGB
